Group Title: development of microbial decontamination and moisture loss control procedures for beef, pork and lamb carcasses /
Title: The development of microbial decontamination and moisture loss control procedures for beef, pork and lamb carcasses /
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Title: The development of microbial decontamination and moisture loss control procedures for beef, pork and lamb carcasses /
Physical Description: x, 63 leaves : ill. ; 28 cm.
Language: English
Creator: Lazarus, Charles Raphael, 1940-
Publication Date: 1976
Copyright Date: 1976
 Subjects
Subject: Meat -- Microbiology   ( lcsh )
Meat industry and trade   ( lcsh )
Animal Science thesis Ph. D
Dissertations, Academic -- UF -- Animal Science
Genre: bibliography   ( marcgt )
non-fiction   ( marcgt )
 Notes
Thesis: Thesis--University of Florida.
Bibliography: Bibliography: leaves 58-62.
Statement of Responsibility: by Charles Raphael Lazarus.
General Note: Typescript.
General Note: Vita.
 Record Information
Bibliographic ID: UF00099397
Volume ID: VID00001
Source Institution: University of Florida
Holding Location: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: alephbibnum - 000009128
oclc - 02526908
notis - AAB1003

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THE DEVELOPMENT OF MICROBIAL DECONTAMINATION AND MOISTURE LOSS
CONTROL PROCEDURES FOR BEEF, PORK AND LAMB CARCASSES









By

CHARLES RAPHAEL LAZARUS


A DISSERTATION PRESENTED TO THE GRADUATE COUNCIL OF
THE UNIVERSITY OF FLORIDA
IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE
DEGREE OF DOCTOR Of PHILOSOPHY
















UNIVERSITY OF FLORIDA










































For Amy

















ACKNOWLEDGMENTS


I wish to express my thanks to Dr. A.Z. Palmer for his advice and

guidance throughout this doctoral program. Sincere appreciation is

expressed to Dr. R.L. West for his instruction and assistance in all

phases of this study. Appreciation is extended to Dr. C.B. Ammerman,

Dr. J.L. Oblinger and Dr. J.C. Deng for their counsel and advice in

addition to serving on my examining committee.

The efforts of Miss Janet Eastridge in the collection of data is

acknowledged with sincere appreciation. Thanks are also extended to the

following meat laboratory managers: Mr. Jerry Scott, Larry Eubanks and

Hal Clifton who,with their supporting help,provided me with the necessary

carcasses for study.















TABLE OF CONTENTS



Page

ACKNOWLEDGEMENTS . . . . . . . . . ... iii

LIST OF TABLES . . . . .. . . . . . . . i

LIST OF FIGURES. ...... . . . . . .... . viii

ABSTRACT. . ................ . . . . . ix

INTRODUCTION . . . . . .. .. ..... . . . 1

LITERATURE REVIEW. . .. ........... . . ... 3

Carcass Chilling. . ........ .. .. .... 3
Beef Carcass Shrinkage. ....... . . . . .... 4
Lamb Carcass Shrinkage .... . ..... . . . .. 5
Pork Carcass Shrinkage. . ........ ... . . 6
Edible and Non-Edible Coatings. . ... . .. . .. 7
Microbial Aspects of Meat Carcasses . .. . . ... 8
Beef Surface Microbial Flora . .. ... ..... . 9
Lamb Surface Microbial Flora. . .... . . . 10
Pork Surface Microbial Flora. . . . ... . . . . 10
Control of Carcass Microorganisms . . . .. . . 11
Atmospheric Changes. .. ...... .. ... .. 12
Antibiotics and Radiation. . ... . ....... .. 13
Organic Acids. . .... . . . . .. . . . 13
Chlorine Compounds .. .. ... ..... . 14

MATERIALS AND METHODS. ... ......... .. . . 17

Processing of Carcasses .. ....... . . . .. . 17
Lamb . . . . . . . . ... 17
Beef .. . .. . . . . . . . . .. . 18
Pork . . . . . . . . .. . . . 19
Decontamination of Carcass Surfaces . ... . . . . 19
Microbial Determinations. ............... . 20
Analytical Procedures .... ..... . . . . 20
Statistical Analysis. .. ... . ...... 21

RESULTS AND DISCUSSION . .. .. . .. .. . . . 23

Lamb Carcass Shrinkage Experiment . . . . . . 23
Beef Carcass Shrinkage Experiments. .. . . . . 26
Pork Carcass Shrinkage Experiments. . . . . . . 29
Properties of Ca-alginate Films Relating to Shrinkage . . 33










TABLE il' CONTENTS
(C, nlLinued)


Page

Oxygen Permeability of Ca-alginate and Plastic Wrap Films. 35
Decontamination of Meat Carcass Surfaces .... . . 39
Lamb. .. . .. .. ...... . . . . . 39
Beef . ... . . ... . . . . . . 40
Pork . . . . . . . . . . . . 51

SUMMARY . . . . . . . . . . . . 56

LITERATURE CITED. .... . . . . . . . . ... . 58

BIOGRAPHICAL SKETCH ........ .... ... . . 63
















LIST OF TABLES


Table Page

1. Mean values for postmortem shrinkage (%) and internal
leg temperature ( C) of lamb carcasses by shrinkage
treatment and day of slaughter. . . . ... . . . 24

2. Mean values for postmortem shrinkage (%) of beef carcasses
as affected by shroud cloth .. .... .. .. .. . 27

3. Mean values for postmortem shrinkage (%) of beef carcasses
following shrinkage treatment . . .. ... . 28

4. Mean values for postmortem shrinkage (%) of beef carcasses
with different concentrations of alginate-maltodextran. . 30

5. Mean values for postmortem shrinkage (%) of pork carcasses
with Ca-alginate film .... . .. .. .. .... ... 31

6. Mean values for postmortem shrinkage (%) of naked vs Ca-
alginate coated pork carcasses . . ........ 32

7. Mean values for postmortem shrinkage (%) of pork carcasses
with different concentrations of alginate-maltodextran. 34

8. Percent water held in various concentrations of sodium
alginate-maltodextran and calcium chloride gels . . .. 36

9. Mean log10 values for total microbial count/6.46 cm from
sirloin and belly areas of control and treated lamb
carcasses ... . ........ . . . . 41

10. Beef carcass surface microbial flora and their relative
percentages at various time periods post-slaughter. ... . 42

11. Mean logl0 values for total microbial count/6.46 cm2 from
the neck area of control and acetate buffer-HC10 treated
beef carcasses. . . . . .. . .. . . . 45

12. Mean logl0 values for total microbial count/6.46 cm2 from
the neck area of control and created beef carcasses .. 47
2
13. Mean logl0 values for total microbial count/6.46 cm from
the neck area of control and acetate buffer-HCIO treated
beef carcasses ... . ... . . . . . . 48









LIST OF TABLES
(Continued)


Table Page

14. Mean logl0 values for total microbial count/6.46 cm2
from the neck area of control and treated beef carcasses 50

15. Mean log10 values for total microbial count/6.46 cm2 from
the shoulder area of control and treated pork carcasses. . 52

16. Pork carcass surface microbial flora and their relative
percentages following treatment with a Ca-aglinate coating 54
















LIST OF FIGURES


Figure Page

1. Apparatus for measuring oxygen permeability of Ca-
alginate and plastic wrapping flims. .. . . ... . 22

2. Release of moisture from Flavor-Tex alginate film at
2 and 83 C . .. .. . . . . .. . .. . 37

3. Oxygen permeability of Ca-alginate films and plastic
wraps ..... .. .. . .. .. . . . 38
















Abstract of Dissertation Presented to the Graduate Council
of the University of Florida in Partial Fulfillment of the Requirements
for the Degree of Doctor of Philosophy



THE DEVELOPMENT OF MICROBIAL DECONTAMINATION AND MOISTURE LOSS
CONTROL PROCEDURES FOR BEEF, PORK AND LAMB CARCASSES

By

Charles Raphael Lazarus

August, 1976

Chairman: Arno Zane Palmer
Major Department: Animal Science


Surface microbial decontamination and moisture loss control pro-

cedures were evaluated on lamb, beef and pork carcasses.

Decontamination of beef carcasses, resulting in a significant

decrease in surface microbial flora at 24 and 96 hr postmortem was

accomplished by combining hypochlorous acid with an acetate-acetic

buffer. This antimicrobial activity was observed with concentrations

between 25 and 200 ppm available chlorine when suspended in 0.01 M,

pH 4.5 acetate buffer. Significant reduction in surface microbial flora

was observed within 12 hr post-treatment but was non-significant at

1 hr post-treatment. When hypochlorous acid was combined with a sodium

alginate solution (Flavor-Tex") and sprayed onto pork carcasses, no

significant reduction in surface microbial flora occurred. However,

lamb carcass surface microbial flora was significantly reduced by the

Flavor-Tex film.

Application of the edible alginate film coating as a moisture loss










control procedure to freshly slaughtered carcasses significantly reduced

chill cooler shrinkage, and maintained this superiority through 72 hours

postmortem.

At low alginate concentrations, loosely held water within the gel

allowed for a greater reduction in shrinkage loss than when high concen-

trations of the alginate were sprayed onto beef carcasses. This trapped

water permitted the gel to act as the moisture sacrificing agent on the

carcass during chill cooler storage, with maximum shrinkage control

being obtained within the initial 72 hr period. Oxygen permeability of

the Ca-alginate films was not impeded; increasing as moisture content of

the film decreased.

Application of either or both control procedures could effectively

reduce shrinkage and surface microbial flora on lamb, beef and pork

carcasses.

















INTRODUCTION


The loss of moisture associated with beef, lamb and pork carcasses

during the post-slaughter chill and distribution periods is of major

concern to the meat packing industry. Following an initial 1.0-1.5%

moisture loss, an estimated 0.5% daily reduction in weight occurs. Con-

tinued moisture loss results in discoloration of lean, desiccation of

surfaces, increased trim losses and ultimately decreased shelf-life and

consumer acceptability.

Control of the heat and mass transfer during cooling can be main-

tained by increasing the relative humidity in the chill cooler and/or

reducing air circulation to a minimum. However, elevated relative

humidity in the chill cooler increases the water activity (a ) on the

carcass surface. This increased a promotes surface microbial growth

even though good processing and sanitation procedures are observed.

Techniques commonly used to reduce the initial moisture loss from beef

carcasses involve the moist cotton shroud which is tightly wrapped

around the carcass. Pork and lamb carcasses remain unprotected through-

out the initial chill and storage period.

Reduction of the surface microbial flora remains a difficult pro-

cedure for the meat processor. Techniques employing elevated CO2

atmospheres, high pressure hot, warm and cold waters, drying of the

carcasses, ultra-violet light, spraying of antibiotics, use of organic

sprays and bactericidal agents have at one time or another been used

to reduce this flora.







-2-



Development of procedures ,' ich effectively reduce and maintain

negligible surface microbial levels could be beneficial to meat when it

is aged to enhance tenderness. The use of moderate chill temperatures

of 14-19 C have been shown to enhance tenderness, however processors are

hesitant to use this procedure due to increased surface microbial

growth.

From these observations, the objectives of this study were

(1) To develop procedures to effectively reduce and maintain

low levels of microbial growth on the surface of these

carcasses.

(2) To evaluate various moisture loss control procedures on

beef, lamb and pork carcasses.
















LITERATURE REVIEW


Carcass Chilling


The movement of heat from carcass tissues to the surrounding cold

air results in a rapid decrease in carcass temperature. This chilling

process, according to Locker et al. (1975) can be separated into two

phases: (1) cooling and (2) storage. During the cooling phase the

carcass surface heat (38-40 C) initially interacts with the chill cooler

air (1-3 C). The rate of heat transfer from the hot carcass to the air

will be proportional to the air velocity in the chill cooler. Except

when there is little air velocity, the resulting high vapor pressure

between the hot carcass surface and surrounding air produces a rapid

flow of heat and moisture from the carcass. It is in this phase of the

cooling process that the greatest shrinkage, or moisture loss, occurs.

In the storage phase, the vapor pressure between the carcass sur-

face and surrounding air has decreased, therefore the regulation of the

relative humidity in the chill cooler becomes critical for the control

of shrinkage and microbial growth. When the convectional heat has been

removed from the carcass, the air and carcass temperature become equili-

brated and the vapor pressure difference between the carcass surface and

the surrounding air is reduced. At this point, increases in the rela-

tive humidity reduces the drying power of the air. This increased

relative humidity can be employed effectively to reduce further moisture

loss. However, elevation of the relative humidity increases the water










activity (a ) on the carcass surin:e and may result in enhanced micro-

bial growth. Because moisture loss from the carcass is relatively

slight in the storage phase, a reduced relative humidity is generally

employed so that increased microbial growth can be prevented.

Development of an alternative chill cooling procedure to reduce

beef carcass shrinkage has been reported by Watt and Herring (1974).

Their study indicated that chilling beef carcasses in an ammonia-

mechanical blast cooler at -29 C for four hours followed by a 14 hr

equilibration period at 2 C significantly reduced shrinkage; however

cold shortening, which results in a toughening of the muscle tissue,

developed. This toughening of the muscle tissue is an important factor

which must be considered when attempting to chill carcasses rapidly.

In addition to refrigeration and environmental factors, physio-

logical characteristics of the animal may influence the degree of

shrinkage. Some of the more important physiological factors are as

follows: ante-mortem stress of the animal (Davidson et al., 1968),

subcutaneous fat thickness of the carcass (Smith and Carpenter, 1973),

and carcass weight and sex of animal (Fredeen et al., 1971).



Beef Carcass Shrinkage


A standard procedure used for the control of beef carcass shrinkage

during the initial chill period is the shrouding of hot carcasses in a

cotton shroud. The wet cloth, which is soaked in hot salt water prior

to being tightly wrapped around the carcass, reduces carcass moisture

loss during the cooling phase. The removal of the moisture from the

shroud instead of the carcass during the transfer of heat to the sur-

rounding air allows the wet cloth to act as a moisture sacrificing agent.










Following a 18-24 hr chill, the i!,roud is removed from the carcass.

Data collected by Fredeen et al. (1971) relating bovine animal and

carcass characteristics to carcass shrinkage, revealed that moisture

loss was inversely related to carcass weight and that the animal's sex

influenced shrinkage with heifers having the lowest loss (0.4%) and bull

carcasses the greatest (0.91%). Overall fat thickness, which is in-

versely related to carcass shrinkage (Smith and Carpenter, 1973) was

greater in the heifer carcasses than bull carcasses.

Control and reduction of shrinkage for beef carcasses and wholesale

cuts during shipment to central distribution centers or retail outlets

is important to the meat industry. In a study by Rea et al. (1972),

beef wholesale cuts were wrapped in paper, polyethylene bags or poly-

vinyl chloride films prior to long distance shipment. Essentially all

treatments had significantly lower intransit shrinkage when compared

with the unprotected cut. Muscle color scores for the individual treat-

ments were similar, however subcutaneous fat color was significantly

fresher looking in appearance (whiter) when the cuts were packaged in

polyethylene bag containers.



Lamb Carcass Shrinkage


Control of lamb carcass shrinkage has centered around the inter-

relationship of temperature and relative humidity to control surface

desiccation (Fleming and Earle, 1968; Smith and Carpenter, 1973).

Because no artificial covering is placed about the carcass, the fell

membrane, a connective tissue lying on the surface, can provide only

limited protection from moisture loss. Smith and Carpenter (1973)

reported that 92% of the 72 hr weight loss in lamb carcasses occurred










during the first 36 hr period. Subcutaneous fat thickness and carcass

weight significantly affected shrinkage loss with reduced losses being

attributed to either decreases in total surface area per unit weight

and/or increased fat covering. Fat thickness between 2.5 and 9.1 mm

was associated with decreased weight loss over the time periods examined.

Lamb carcass shrinkage, as affected by relative humidity, was shown by

Fleming and Earle (1968) to be lowest at 90-97% relative humidity and

highest at 51-57%. Actual and estimated weight losses indicated that

by 6 hr post-slaughter, a 25 kg ewe had an accumulated weight loss of

1.8%. Nottingham (1971) reported that when lamb carcasses were stored

at 100% relative humidity and little air velocity, shrinkage amounted

to 0.6% while at 85% relative humidity and 0.1 m/sec air velocity,

shrinkage amounted to 2.3%. Carpenter et al. (1975) reported that

shrinkage losses for lamb carcasses wrapped in PVC film were substan-

tially reduced and external fat covering was more attractive than when

carcasses were left uncovered. Recently, Smith et al. (1976) reported

that high velocity air drying increased lamb carcass shrinkage signi-

ficantly while polyvinyl chloride film wrap decreased moisture loss

significantly, especially when placed about the carcass in a mummy-type

manner.



Pork Carcass Shrinkage


Very little published information is available concerning pork

carcass shrinkage. In a study by Davidson et al. (1968), the effects of

ante-mortem stress induced by fasting littermate pigs for 68-70 hr were

evaluated for slaughter and carcass characteristics. Following a 24 hr

chill, shrinkage was 2.42 and 2.83% for the fed and fasted groups,










respectively. With swine carcasses being fabricated into wholesale

cuts, wrapped, boxed and shipped within 24 hr after slaughter, the need

to reduce this large amount of shrinkage during the cooling phase be-

comes economically important.



Edible and Non-Edible Coatings


Early research by Pearce and Lavers (1949) indicated that poultry

carcasses dipped in a melted (65.5 C) solution of carrageenin (a gelat-

inous polysaccharide extracted from Irish moss) and sodium chloride

prior to freezing delayed off-odors on eviscerated surfaces of defrosted

carcasses. Meyer et al. (1959), in evaluating an agar and carrageenin

gel on poultry parts, observed little improvement in retarding microbial

spoilage when coated samples were stored at 24 or 13 C. Shelf-life

improved slightly when the coated poultry was stored at 2 C. Use of

these gels as a carrier for water soluble antibiotics proved successful

in inhibiting microbial growth. Ayres (1959) found that when a hot melt

(65.5 C) diacetin fat agar solution with plasticizer was coated onto

fresh meats, microbial growth was retarded and desiccation prevented;

however, these coated meats had an undesireable color. Zabik and Dawson

(1963) reported off-flavors but increased percent press fluids and less

cooking losses than controls when poultry pieces were coated with an

edible acetylated mono-glyceride solution (Myvacet 7-00, Myvacet 7-15)

and stored for 1 and 2 weeks at 4 C. Ayres (1964), using an inedible

hot melt coating material (Lepak), observed that pork chops stored for

5 months at -30 C in an air-blast freezer had a 2% moisture loss, while

controls had 2.4% loss. Off-flavors in the coated samples were observed

prior to cooking and may have been due to the high temperature (180-220 C)










of the hot melt solution.

Naturally occurring film components were evaluated by Allen et al.

(1963). These films, consisting of either sodium alginate or alginate-

cornstarch solutions, were heated to 87.7 C with beef steaks, pork chops

and poultry pieces being dipped into them. After dipping, the sample

was dipped into 5 M CaCI2 to form a semisolid film. In general the

alginate-cornstarch mixture retarded moisture loss more than the plain

alginate, while both coating solutions effectively reduced moisture loss

when compared to untreated controls. Earle (1968a)described a calcium

alginate gel coating not requiring elevated temperatures for solubility,

to be used for the protection of raw fish, meat and poultry. This

edible coating, known commercially as Flavor-Tex involves the forma-

tion of a film around the food product by gelling the maltodextran

sodium alginate coating with a calcium chloride-carboxymethylcellulose

solution. Earle (1968b) reported that Flavor-Tex treated samples had

less moisture loss than untreated controls and exhibited no bitter off-

flavors as had been reported by Allen et al. (1963).



Microbial Aspects of Meat Carcasses


Microbial growth and spoilage of meat present many problems to the

meat industry. Dockerty et al. (1970) indicated three general factors

that can influence ultimate spoilage of fresh meat: (1) dressing;

(2) wholesale cutting and shipping; and (3) retail cutting and storage

shelf-life. The sources from which spoilage organisms originate are

numerous; hides, equipment, water and man are the primary sources (Empey

and Scott, 1939; Ayres, 1955; Patterson, 1967, 1968). The bacterial

flora on the surface of carcasses prior to entering the chill cooler









and their subsequent growth becLo.,s a source for cross-contamination

and distribution onto cut surfaces.

Besides physical conditions which contribute to the surface micro-

bial flora, environmental conditions determine the eventual growth of

these microorganisms (Locker et al., 1975). Rapid chilling is one

effective means of controlling microbial growth; but the effects of

cold shortening as mentioned earlier must be considered so that a

balance is established between palatability and sanitation.

Normal chill room temperatures exert a lethal effect on bacteria,

particularly when combined with decreased water activity and nutrient

availability (Locker et al., 1975). Although the a for most bacteria

is in the range of 0.90-0.99 (Lamana and Mallette, 1965), psychrotrophic

bacteria become the predominant flora following the initial 24-48 hr

chill (Thatcher and Clark, 1968). These surviving bacteria, and the

presence of yeasts and filamentous fungi which survive low a 's, con-

tribute to the eventual spoilage of meat tissue (Lawrie, 1974).

Reducing the relative humidity in the chill cooler, although

effective in inhibiting bacterial growth, exerts a negative effect on

carcasses by increasing shrinkage, desiccation, and, when frozen,

freezer burn, which reduces the quality of the meat. These effects are

especially important for the lamb carcass which has a large surface

area to volume ratio (Locker et al., 1975).



Beef Surface Microbial Flora


Beef slaughtering is a highly industrialized process involving

modern machinery to remove the hide and shanks automatically. This

mechanization eliminates a large source of microbial contaminants by









reducing the direct contact of ii carcass with those less clean parts.

Use of wash-water tunnels with optimum pressure nozzles for washing

carcass surfaces has helped to further remove many contaminating mate-

rials (bone, hair, fecal matter). Following washing procedures, no

further treatments are normally performed to reduce the remaining micro-

bial flora. An exception to this is the Clor-Chil process, implemented

by Swift & Company (Heitter, 1975). In this process, carcasses are

intermittently sprayed in the chill cooler with a mild chlorine solution

to reduce surface microflora and moisture loss.



Lamb Surface Microbial Flora


The lamb slaughter process involves extensive human contact with

the carcass surface. The removal of the pelt by the fisting technique

and the presence of soiled fleece increases the level of surface micro-

bial flora. Washing thoroughly helps to reduce the surface flora,

however ample microbial growth has been demonstrated on the carcass

(Patterson, 1968). An attempt to control microbial growth on lamb

carcasses was conducted by Carpenter et al. (1975). Treatment of car-

casses with 200 ppm available chlorine reduced bacterial counts sub-

stantially without impairing subsequent meat flavor. It was also

observed that decontaminating agents were most effective in reducing

bacterial growth when applied to carcasses immediately post-slaughter.

Treatment of carcasses with chlorine after 7 days storage also resulted

in a substantial reduction in microbial growth.



Pork Surface Microbial Flora


The manner in which swine are slaughtered presents many opportunities










for cross-contamination as well reduction of the microbial flora.

The scalding of hogs at 58-62 C in a common vat following exsanguination

provides a medium for the dispersal of pathogenic and saprophytic

bacteria from one carcass to another. However, in the singeing and

surface cleaning process, reduction of the microbial load has been

observed (Dockerty et al., 1970).



Control of Carcass Microorganisms


To effectively control carcass surface microorganisms, the kinds of

bacteria, yeasts and filamentous fungi normally present must be identi-

fied. Early investigations (Empey and Scott, 1939; Haines, 1933) re-

vealed the presence of Achromobacter species. Taxonomic revisions now

include this genus in the genus Pseudomonas which was then commonly

reported to be present most frequently. Stringer et al. (1969) indicated

that in addition to Psezdomonas, Viicroocccus and Bacillus constituted

the majority of carcass surface microorganisms. More recently, Locker

et al. (1975) reported that the initial microflora on the surface of

beef carcasses consisted of N!icrococcG (43%), Staphylococcus (27%) and

smaller amounts of Acinetobacter, Pseudomonas, Corynebacteria and bac-

teria of the Enterobacteriaceae family.

The combination of chill cooler temperature and reduced a can
w
selectively inhibit some bacteria (e.g. Enterobacteroaceae) and enhance

the growth of others (Microoccus, Staphy lococcu., Poeudomoius) (Ingram,

1951). These selected bacteria then, become the important microflora to

inhibit or reduce.

A review of the literature reveals that four basic processes have

been investigated as possible means for controlling and reducing meat










surface microorganisms: (I) Al] r.ition of the atmosphere in which the

carcasses are stored; (2) antibiotics; (3) chlorine; and (4) organic

acid sprays. Besides these four chemical treatments, Patterson (1972)

indicated that the most commonly practiced method of reducing initial

microbial flora is a final wash with either cold or warm water under

pressure. When different water pressures were evaluated, he observed

that water at 68 kg/6.45 cm2 of pressure was significantly more effective

2
in reducing surface microflora than either 113 or 159 kg/cm Increased

pressures were thought to drive the bacteria into the tissues, however

the effects of water temperature (4-18 C), and chill cooler variation

(3-10 C), could also have influenced this response.

Atmospheric Changes. As reported by Lugg and Woodruff(1973), Kolbe,

in 1882, stored meat in an elevated carbon dioxide environment for 4-5

weeks without deteriorative changes. Killefer (1930), in comparing

carbon dioxide, nitrogen and air atmospheres for the storage of pork

and lamb carcasses, observed that carbon dioxide was superior to air or

nitrogen after 10 days of storage while Brooks (1933) found that carbon

dioxide atmospheres greater than 20% resulted in loss of acceptable beef

muscle color. Recently, Marriott et al. (1976a)reported that trans-

oceanic shipment of beef quarters and subprimal cuts, shipped in either

air or modified atmosphere (60% CO2, 25% 02 and 15% N2) vans resulted

in no significant differences in weight loss, appearance or microbial

flora following 20-21 days shipment. In a similar study, Marriott et al.

(1976b), using similar air and modified atmosphere vans as before, noted

that beef quarters had significantly less microbial flora from the

modified van transport than the normal atmosphere van following 7-11

days of intransit storage.










Antibiotics and Radiation. Permission to use certain antibiotics

chlortetracyclinee, oxytetracycline) to control the microbial flora on

raw poultry was granted by the Food and Drug Administration in November,

1955. By 1959, chlortetracycline was permitted in or on uncooked

vertebrate fish; permission was not granted for red meats (Firman et al.,

1959). Further studies on residual antibiotic compounds, development

of resistant bacteria and the concept of additives to natural foods,

ultimately forced all antibiotics to be prohibited in fish and red meat

products (Desrosier, 1970).

Experiments in the application of beta or gamma radiation to fresh

meat suggest this procedure results in a sterilization of the surface

tissue (Phillips et al., 1961). This sterilization, however requires

2-4 megarads and can result in undesireable off-flavors. To prevent

off-odors, which develop more rapidly in beef than pork (Kirn et al.,

1956), lower radiation dosages (45,500 rads) in combination with the

infusion of 30-50 ppm oxytetracycline into the meat tissues have been

successfully used (Wilson et al., 1960).

Organic Acids. The initial use of organic acids on surface micro-

bial flora centered on the treatment of chicken carcasses and sought to

reduce or destroy salmonellae. Because chicken carcasses share a common

chill water bath, the reduction of salmonella as well as saprophytic

bacteria would reduce cross-contamination. Data reported by Mountney

and O'Malley (1965) indicated that acetic, adipic and succinic acids at

6.0, 3.5 and 1.0% concentration (all at pli 2.5) respectively, were more

effective in reducing microbial numbers than were citric, fumaric,

malonic, sorbic, hydrochloric, phosphoric and lactic acids. Thomson

et al. (1967) reported that citric (0.3%) and succinic (1.0%) acids










reduced the growth of Salmonella ,.beribidis on inoculated fryer

chickens. For the control of lamb carcass microflora, Ockerman et al.

(1974) indicated that acetic acid at a concentration of 18% was signi-

ficantly more effective than 6 or 12%, but that a bleaching effect

occurred at 12%. Use of lactic acid, varying between 12 and 18% con-

centration over the 12 day storage period, was not as effective and

a bleaching effect was again observed at 18%. Varnadore (1972) reported

that propionic acid (4%) was more effective in reducing the microbial

flora on lamb carcasses stored at 16 C for the first 24 hr postmortem

and then moved to a 0 C cooler, than it was for carcasses stored at 0 C

initially. However, carcasses treated with the propionic acid were dry

on the surface and the subcutaneous fat was tannish-yellow in color.

For reduction of the microbial flora on pork carcasses, Biemuller

et al. (1973) noted that, regardless of a 30 or 60 second spraying time,

pH 2.0 acetic acid (0.1 N) significantly reduced surface flora but

caused some surface discoloration. Five percent hydrogen peroxide,

although effective in antibacterial activity, also caused a marked skin

discoloration. Stannous chloride (5%), a reducing agent, caused the

least amount of surface discoloration and significantly reduced surface

microflora.

Chlorine Compounds. The first use of hypochlorites as a disin-

fectant occurred in the 1780's, followed by development of calcium

hypochlorite as a sewage deodorant in England in the 1850's (Rudolph

and Levine, 1941). As reported by Charlton and Levine (1937) the bac-

tericidal activity of hypochlorites was first reported in 1881 by Koch,

but it was not until World War I that chlorine compounds (chloramine,

chloramine T, azochloramide) were widely used as tissue disinfectants.









The use of hypochlorites in water systems was first described by

Johnson (1911), who reported that as little as 0.2 ppm might render

water safe.

As early as 1904, the germicidal action of hypochlorites and chlori-

nated waters was thought to be due to the same substance; namely hypo-

chlorous acid (HC10) (Charlton and Levine, 1937). Both the reaction of

gaseous chlorine in the chlorination of water (C12 + H20 HC1 + IIC10)

and the reaction of calcium hypochlorite (Ca(OC1)2 + HC1 Ca(OH)2 + HC10)

were shown to be greatly increased in the presence of various acids

(Charlton and Levine, 1937). This pH dependence coincided with the

oxidative nature of hypochlorous acid, wherein the 'nascent oxygen'

oxidizes proteins following contact. The bactericidal property of

hypochlorite has been shown to be proportional to the ratio of hypo-

chlorous acid/hypochlorite ion in solution. At pH 7.5, half of the

available chlorine is present as hypochlorous acid and half as hypo-

chlroite ion. At pH 10, only 0.3% of the available chlorine is present

as hypochlorous acid (Anonymous, 1964). To maximize bactericidal activ-

ity, the pH can be lowered (4.0-6.0), however the acid becomes less

stable and inactivity develops. Other factors which contribute to

deterioration of HC10 are temperature and amount of organic matter

present. High concentrations of proteinaceous materials are acted upon

by the hypochlorous acid, while carbohydrates are relatively inert to

oxidation.

Besides the treatment of municipal water systems with hypochlorous

acid via C12 gas, considerable data have been collected on the spraying

and dipping of poultry and meat carcasses with an available chlorine

compound to reduce Salmonella, other pathogens and saprophytic bacteria.









Dixon and Pooley (1961) reported that treatment of chicken carcasses

with 200 ppm of chlorine solution for 10 min effectively reduced the

presence of salmonella when the carcasses had less than 1 x 10 total

organisms. Thomson et al. (1967) indicated that if chicken carcasses

were sprayed with water or with chlorine, Saimoneue a typhimurwn counts

were lower than unsprayed controls and that chlorine treatments resulted

in significantly lower S. typhimurium counts than did water washing.

However, no significant differences occurred between 100 and 200 ppm

chlorine treatments.

For the control of surface microbial flora on lamb carcasses,

Patterson (1968) recommended the use of 20 ppm free residual chlorine in

the spray wash. Kotula et al. (1974) reported that a high pressure

24.6 kg/cm2 washwater containing 200 ppm available chlorine was more

effective than a 4.2 kg/cm2 pressure and that the chlorine wash water

at 51 C resulted in a larger decrease in viable bacteria than chlorine

water at 18 C. Heitter (1975) reported that the Clor-Chil process,

which involves intermittent spraying of carcasses with chlorine solutions

during the initial chill phase, reduced viable bacterial counts on pork

carcasses by 97-99%, on beef by 94-98% and by 94-99% on lamb carcasses.

Marriott et al. (1976a,1976b) however, indicated that the use of 200 ppm

sodium hypochlorite on shipments of beef quarters and subprimals re-

sulted in no significant change in the microbial flora.

















MATERIALS AND METHODS


Experiments were designed on an animal group and number available

basis as they were received at the Meats Laboratory for slaughter. Due

to availability, all groups of animals could not be evaluated for the

same specific treatment. This was especially true for lamb carcasses

which consisted of one experiment involving 90 animals. Beef carcasses

were more readily available and were the most frequent species evaluated.



Processing of Carcasses


Lamb. A total of 90 lambs were slaughtered on three consecutive

days (30/day). Each lamb was randomly assigned to a day of slaughter

and to one of three shrinkage treatments: calcium alginate edible film

coating, plastic wrap or control (no covering). The edible Ca-alginate

film coating, Flavor-TexR (U.S. patent No. 3,395,024, Food Research

Inc., Tampa, Fla.) consists of two solutions: (1) sodium alginate-

maltodextran, (142 g/liter water); and (2) CaC12-carboxymethylcellulose.

Solution 1 was sprayed directly onto all surfaces of the carcass,

followed immediately by the spraying of solution 2 over solution 1.

Interaction of these two solutions by cooperative association (Morris,

1973) causes formation of a clear homogeneous film over the entire

carcass. Both solutions were applied using a Binks Model 33-112 com-

pressed air system fitted with dual spray guns (Binks Mfg. Co., Chicago,

Ill.)



-17-










Carcasses which received tl, plastic wrap (Borden Resinite-90, a

low moisture, high oxygen transfer wrap) were wrapped while hanging

from the overhead rail. At the end of 24 hr, the plastic wrap was re-

moved.

Control carcasses received no external covering. Immediately

following slaughter and washing, all carcasses were moved by overhead

rail into an adjacent room (10 C) where an initial microbial count,

internal temperature from the thick area of the legs, hot carcass weight

and shrinkage treatment were conducted. All carcasses were placed in a

2 C cooler with a relative humidity of 80% and a wind velocity of approx-

imately 24 km/hr.

Carcass weights were determined at 0, 1, 2, 3, 5 and 7 days post-

mortem using a Toledo Model 2071 scale with 0.1 lb gradations. Shrinkage

at each day postmortem was based on the initial hot carcass weight taken

after washing the carcass.

Carcass temperature was determined by averaging the internal

temperatures from both hind legs. Temperatures were collected at 0, 6,

24 and 48 hr postmortem using a pyrometer equipped with a 7.6 cm probe

(PYRO Surface Pyrometer, Pyrometer Instrument Co.).

Beef. Eight experiments involving 172 beef carcasses were evalu-

ated for moisture loss control procedures and/or surface microbial

decontamination. For shrinkage treatments, following slaughter and

washing, one side was randomly assigned to either the control (shroud),

treatment (Flavor-Tex) or naked (no shroud) group. Flavor-Tex treated

sides were sprayed with various concentrations of the sodium alginate-

maltodextran solution. At the end of 24 hr the shroud cloth was removed

from the control side.










Carcass weights were determined at 24 hr intervals using an on

the rail scale with 0.5 Ib gradations. Percent shrinkage at each day

postmortem was calculated using the initial hot carcass weight after

washing.

Pork. Following slaughter and washing, carcasses were sprayed with

various concentrations of sodium alginate-maltodextran. Percent shrink-

age at each day postmortem was calculated using the initial hot carcass

weight after washing.



Decontamination of Carcass Surfaces


Carcass surface areas were sprayed with antimicrobial agents using

a Binks Model 33-112 compressed air system fitted with dual spray guns.

Application pressure was maintained at 1.0 kg/cm2

The primary antimicrobial agent employed in this study consisted

of hypochlorousacid. From a filtered stock solution of calcium hypo-

chlorite (1%), working concentrations up to and including 200 ppm were

prepared (Anonymous, 1968). Final concentration of available chlorine

was determined using a Hach High Range Chlorine Test Kit Model CN 21-P

(Hach Chemical Co., Ames, Iowa).

The effectiveness of hypochlorous acid, as produced by electrolysis

of chloride ions was evaluated by spraying concentrations up to 200 ppm

available chlorine prepared by a Morton Biocidal Flow-Thru Design Unit,

Model 110-415 ID (Morton Salt Co., Chicago, Ill.).

Organic buffer systems were prepared at various concentrations and

pH using the Henderson-Hasselbach equation. Following buffer prepara-

tion, a given amount of stock calcium hypochlorite solution was added

to the buffer system. This solution was then sprayed onto the carcasses.










Microbial Determinations


Lamb surface microbial samples were collected from the sirloin

and belly (flank-plate juncture) areas of the carcass. A 6.46 cm area

was swabbed using the standard moist-swab technique (APHA, 1972).

Serial dilutions were prepared using Butterfield's phosphate diluent

and plates were poured with Standard Plate Count Agar (Difco) for aerobic

counts. Incubation of the plates were for 5 days at 20 C. Samples were

collected at 0, 2, 5 and 7 days postmortem.

Preliminary research by Lazarus and West (1975), as well as the

work of Stringer (1975), using beef carcasses, indicated that the neck

area, as opposed to the flank, outside round, inside round or rib re-

gion provided the highest concentration of microbial flora. This area

has both lean and fat surfaces, is conveniently accessible, is not

easily cross-contaminated and can be readily treated by decontaminating

solutions. Swab samples were collected, serially diluted, plated and

incubated as previously outlined. Surface microbial flora were identi-

fied according to the procedures of Vanderzant and Nickelson (1969) and

Breed et al. (1975).

Pork surface microbial flora was monitored by swabbing the shoulder

area of the split carcass at various time periods. Serial dilutions,

agar medium and incubation of plates were similar to procedures pre-

viously outlined.



Analytical Procedures


Oxygen permeability of the Ca-alginate, Borden Resinite-90 and a

high oxygen low moisture transmission film (Goodyear Prime Wrap) was










determined using a Model 777 Be, :in Oxygen Analyzer. Figure 1 illus-

trates the apparatus constructed to determine the permeability of the

films. Analyses were conducted at 2 C to simulate carcass storage

conditions. Following removal of oxygen from the T-chamber by perfusion

with nitrogen, the outlet tube was clamped (in addition to remaining in

water). Oxygen in normal atmospheric air which entered through the film

was monitored until saturation (160 mm 02) of the chamber was obtained.

Calcium alginate gel properties, employing various concentrations

of sodium alginate-maltodextran and calcium chloride were determined by

reacting known weights and volumes of the two components in tared

beakers. The resultant gel material as well as remaining liquid was

weighed on a wet and dry basis (83 C, 24 hr) using a Mettler H10 balance

(Mettler Instrument Corp., Princeton, N.J.). Percentage liquid and

solid was determined from the total weights of the two solutions.

Loss of moisture from the Ca-alginate film was determined by

reacting the two solutions on tared glass plates. The coated plates

were stored at 2 and 83 C for a total of 72 hr with weights being col-

lected at various time periods on a Mettler H10 balance. Percentage

gel remaining was determined using the initial weight of the film.



Statistical Analysis


Data were analyzed using the Statistical Analysis System (SAS)

designed and implemented by Barr and Goodnight (1972), analysis of

variance (Snedecor and Cochran, 1967) and the mean separation technique

of Duncan (1955).





































NITROGEN


FILM





ELECTRODE



- T-CHAMBER (STEEL)


OXYGEN
ANALYZER


Fig. 1. Apparatus for measuring oxygen permeability of Ca-alginate and
plastic wrapping films.


OUTLET


CLAMP
















RESULTS AND DISCUSSION


Lamb Carcass Shrinkage Experiment


Overall, lamb carcass weights (n = 90) were from 17.8 28.8 kg

with fat thickness measurements at the 13th rib ranging between 3.8 and

8.9 mm. This variation in level of fatness should not influence carcass

shrinkage because it is within the 2.5 to 9.1 mm range described by

Smith and Carpenter (1973) as being non-significant with respect to

moisture loss.

Mean values for postmortem shrinkage of lamb carcasses analyzed by

shrinkage treatment and by day of slaughter are presented in Table 1.

At all time periods postmortem, the carcasses coated with Ca-alginate

(142 g/1) or wrapped in plastic film had significantly (P < 0.05) lower

shrinkage values than the control carcasses. In addition, the plastic

wrapped carcasses had significantly less shrinkage than the Ca-alginate

treated carcasses.

Smith and Carpenter (1973) reported that 75% of the 72 hr weight

loss of lamb carcasses was incurred during the initial 24 hr post-

slaughter chill period. These workers attributed this large initial

shrinkage to loss of water added during the washing procedure. Sub-

sequent weight loss was attributed to moisture loss, in the form of

evaporation from the carcass tissue.

In this experiment, the plastic wrap impeded both evaporation of

moisture and heat transfer (Table 1) from the carcass during the first






-24-


Table 1. Mean valuesa for positmrtem shrinkage (%) and internal leg
temperature (C ) of lamb carcasses by shrinkage treatment and
day of slaughter.



Shrinkage treatment Day of slaughter

Day
postmortem Control Ca-alginate Plastic wrap 1 2 3


Shrinkage loss (%)

1 2.77a 1.55b 1.20c 2.22a 1.59b 1.67b

2 3.25a 2.22b 1.88c 2.93a 2.04b 2.35b

3 3.80a 2.96b 2.49c 3.49a 2.68b 3.05b

5 4.71a 4.01b 3.43c 4.72a 3.64b 3.75b

7 5.36a 4.81b 4.19c 5.59a 4.34b 4.40b

Hour
postmortem Internal temperature (C)

0 38.7a 38.2a 38.4a 36.4a 39.3b 39.8b

6 10.3a 10.0a 14.3b 10.3a 11.5ab 12.7b

24 4.la 4.4a 5.0a 3.3a 4.7b 5.4b

48 5.3a 5.4a 5.4a 4.7a 6.0b 5.5b


Means on the same horizontal line bearing different letters differ
significantly (P < 0.05)
b
n = 30 carcasses/treatment










24 hr. The 1.20% shrinkage recorded for this treatment group should

primarily reflect loss of accumulated wash water. Accumulated moisture

on the inside portion of the wrap and very moist carcass surfaces were

noted for this group. These conditions would be expected to influence

both microbial growth and initial chill rate.

In order to measure the effect of shrinkage treatment on chill

rate, internal leg temperatures were collected (Table i). At 6 hr

postmortem, the plastic wrap had prevented the dissipation (P < 0.05)

of carcass heat, but after 24 hr, no difference was observed. Addition

of 30 hot carcasses/day to the cooler reduced (P < 0.05) (Table 1) the

chilling rate of the carcasses; however no interaction between shrinkage

treatment and day slaughtered occurred, indicating the loss of carcass

heat was uniform across the treatments regardless of the effects of day

slaughtered.

Visual evaluation of carcass appearance revealed treatment dif-

ferences. Those carcasses receiving the plastic wrap treatment had

moist surfaces and a softer, whiter subcutaneous fat covering than did

the other carcasses. Smith et al. (1976) reported that carcasses stored

in polyvinyl chloride film wrap throughout a 5 day storage period had

an accumulation of moisture on the surfaces and exhibited an extremely

attractive white fat. The alginate coated carcasses had a glossy pseudo-

moist appearance and the surface fat was slightly darker than the fat

on the control carcasses. Little variation in lean color was observed

between the treatment groups.

The carcasses from the first day's slaughter group had greater

(P < 0.05) shrinkage values on all subsequent days than did those car-

casses slaughtered on following days (Table 1). The addition of 30 hot










carcasses/day to the chill coolcr reduced the efficiency of the cooler,

however a significant interaction between shrinkage treatment and day

of slaughter was not observed.



Beef Carcass Shrinkage Experiments


Because the cotton shroud is commonly used in the meat industry to

retard moisture loss, smooth and whiten subcutaneous fat, and improve

carcass conformation, an experiment was conducted to determine what

influence the shroud cloth had on moisture loss. As can be seen in

Table 2, there were no differences (P > 0.05), using paired sides,

between the two treatments. The overall small percentage moisture loss

for these carcasses, regardless of the treatment, probably contributed

to this response.

There is a need for an alternative process to replace the shroud

cloth, which must be placed about the carcass manually, has a limited

longevity and is costly both in terms of energy required for laundry

and handling. With the beef carcass side being quite large, use of a

polyvinyl chloride wrap becomes impractical. A reasonable alternative

to the shroud is an edible film which could be sprayed on automatically,

reducing labor costs while at the same time achieving improved moisture-

control in the beef carcass.

Initial experiments in this study employed Flavor-Tex at a concen-

tration of 127.5 g/l (sodium alginate-maltodextran, Solution 1). When

this treatment concentration was compared with the shroud cloth to

evaluate moisture loss control, the alginate coated carcasses had a

lower (P < 0.05) moisture loss through 96 hr storage (Table 3) when

compared with 24 hr shroud covered controls. However, in a later







-27-





Table 2. Mean valuesa for postmortem shrinkageb (%) of beef carcasses
as affected by shroud cloth.



Hour postmortem

Treatments 24 48 72


No shroud 1.31 1.38 1.48

Shrouded 1.23 1.35 1.39


aNo significant differences (P > 0.05) between treatments

Based on pre-washed hot carcass weight; paired sides

cn = 15 carcass sides/treatment

Removed 24 hours postmortem











Table 3. Mean valuesa for postmortem shrinkage (%) of beef carcasses
following shrinkage treatment.



Shrinkage treatment

Hour postmortem Control Ca-alginatec


24 1.99a 1.51b

48 2.32a 1.81b

72 2.65a 2.04b

96 3.17a 2-67b


Means on the same horizontal line bearing different letters differ
significantly (P < 0.05)
b
n = 12 carcass sides/treatment

127.5 grams sodium alginate-maltodextran/liter water









experiment, employing three sodium alginate-maltodextran concentrations

(Table 4), no differences (P > 0.05) were observed between the alginate

coated carcasses and the paired side controls. The reason for the lack

of agreement is probably due to the total number of carcasses being

placed in the cooler. Where significance occurred (Table 3), only 12

carcasses were placed in the chill cooler. With the low number of

carcasses in the cooler, low humidity (80% R.H.) and high vapor pressure

between the carcass and cooler air resulted in a clear distinction

between the two treatments. In the second experiment (Table 4), 78 hot

carcasses were introduced into the chill cooler (60 were used in the

experiment). This would increase the humidity, reduce the vapor pressure

differential and tend to equalize all treatments being evaluated. This

effect can be seen in the differences between the shrinkage control

carcasses in the two experiments (1.99% for the 12 carcass experiment

and 1.51% for the 60 carcass experiment).



Pork Carcass Shrinkage Experiments


Since pork carcasses are cut and fabricated following a 24 hr chill,

the reduction of moisture loss from the carcass could be economically

important to the processor. With an increased carcass surface area to

volume ratio, considerable moisture is removed during the initial chill

period. Data presented in Table 5 summarizes the affect of Ca-alginate

(131 g/1) on controlling the initial shrinkage. Although only 24 hr

weights could be collected, a reduction (P < 0.01) in shrinkage occurred.

When carcasses became available, so that weights could be collected up

to 72 hr postmortem, a similar response using 98 g/1 sodium alginate-

maltodextran was observed (Table 6). Similarly, when various concentra-







-30-




Table 4. Mean valuesa for postmortem shrinkage (%) of beef carcasses
with different concentrations of alginate-maltodextran.



Alginate-maltodextran (g/l)


Control 98 Control


120 Control 142


1.45 1.46 1.64 1.50 1.48 1.44


1.75 1.91


1.81 1.67


72 2.07 N.D. 2.24 N.D. 2.04 N

aNo significant (P > 0.05) differences between alginate concentrations
and their respective controls or between alginate treatments

b
n = 10 carcass sides/treatment

N.D. = not determined


Hour
postmortem


1.70






-31-




Table 5. Mean valuesa for postmortem shrinkage (%) of pork carcasses
with Ca-alginate film.



Shrinkage treatment
Hour
postmortem Control Ca-alginatec



24 2.02a 1.53b





aMeans bearing different letters differ significantly (P < 0.01)

b
n = 10 carcasses (control), 15 carcasses (treatment)

131 grams sodium alginate-maltodextran/liter water







-32-




Table 6. Mean values for postmortem shrinkage (%) of naked vs
Ca-alginate coated pork carcasses.



Shrinkage treatment
Hour
postmortem Control Ca-alginatec


24 2.76a 2.17b

48 3.40a 2.83b

72 3.58a 2.95b

a
Means on the same horizontal line with different letters differ
significantly (P < 0.05)

b
n = 5 carcasses/treatment

c98 grams sodium alginate-maltodextran/liter water










tions of alginate-maltodextran c, e evaluated simultaneously (Table 7),

no differences (P > 0.01) between the three concentrations were observed

in the initial 24 hr chill; however all showed significantly

(P < 0.01) less moisture loss than the control group.

Data from the beef carcass shrinkage experiments indicated that

the 98 g/l alginate-maltodextran allowed the lowest numerical percent

shrinkage, however this was not true for pork carcasses. One possible

reason was that these carcasses appeared to be exceptionally prone to

increased shrinkage, with nearly 4% being lost within 24 hours.



Properties of Ca-alginate Films Relating to Shrinkage


Commercial alginates are largely copolymers of polymannuronic and/or

polyguluronic acid (Anonymous, 1973). Recent studies by Morris (1973)

using computer model building and X-ray diffraction of alginate fibers

revealed that polyguluronic acid chains can adopt a 'zig-zag' shape with

hydrophilic 'nests' which accommodate a calcium ion. These nests combine

with other chains to form a 'microcrystalline bundle'. Overall, the

calcium polyguronate becomes linked by segments of polymannuronate and

heteropolymeric acids in normal random solution conformation holding

approximately a hundred times its own weight of water.

For the effect of alginate concentration on controlling moisture

loss in beef and pork carcasses, there appears to be some differences

between the three concentrations with respect to reducing moisture loss,

although not always significant. From initial observations, it appeared

that the 142 g/l alginate would have provided a better reduction of

moisture loss from the carcass. However, the amount of water held in

the gel influences the total moisture lost from the carcass.












Table 7. Mean values for postmortem shrinkage (%) of pork carcasses
with different concentrations of alginate-maltodextran



Shrinkage treatment

Alginate-maltodextranc
Hour
postmortem Control 98 120 142


24 3.87a 3.20b 3.15b 2.93b

48 3.93a 3.36b 3.19bc 2.93c


aMeans on the same horizontal line with different letters differ
significantly (P < 0.01)
b
n = 8 carcasses/treatment

Grams sodium alginate-maltodextran/liter water










Laboratory experiments evaluating the gelling characteristics of

these concentrations are presented in Table 8. Data indicate that

more water was held within the gel when the alginate concentration

was 98 g/l than when it was 142 g/l. The trapping of water in the gel,

especially at low calcium chloride concentrations, permits the gel to

act as the sacrificing agent instead of the carcass tissue.

The manner in which Ca-alginate gel may act as the moisture sacri-

ficing agent on the carcass, especially during the initial chilling

phase, can be seen in Figure 2. Using glass plates coated with Ca-alginate

(142g/1), stored at 2 C in the chill cooler, trapped water was rapidly

released from the gel during the first 24 hr (55%). This rapid release

of moisture from the gel accounts for the significant decrease in

moisture loss which occurred in the lamb, beef and pork carcasses when

they were coated with the Flavor-Tex film. Continued release of mois-

ture through 72 hr storage results in essentially moisture-free Ca-

alginate.



Oxygen Permeability of Ca-alginate and Plastic Wrap Films


Using the apparatus (Figure 1) constructed for measuring oxygen

permeability through the Ca-alginate and plastic wrap films, data pre-

sented in Figure 3 indicate that the permeability of the Ca-alginate gel

to oxygen was greatest at the lower (98 g/1) concentration and decreased

with increasing alginate-maltodextran (142 g/1). The alginates, in

general, were more permeable to oxygen than the plastic Borden Resinite-

90 and Goodyear Prime-Wrap films, both high oxygen low moisture transfer

wraps.







-36-




Table 8. Percent water held in various concentrations of sodium
alginate-maltodextran and calcium chloride gels.



Calcium chloride (M)

Alginatea 0.1 0.3 0.5 0.8


98 92.33b 91.01 90.58 86.43

120 91.87 90.44 89.18 84.79

142 88.70 87.66 86.37 84.34


aGrams sodium alginate-maltodextran/liter water

Based on gel weight less dry gel weight/gel weight x 100















45.0-
S-2C

O- 83 c

40.0




35.0





30.0




25.0




20.0




15. 0




10.0 0-





5.0






24 48 72
TIME (Hr)


Fig. 2. Release of moisture from Flavor-Tex alginate film at 2 and 83 C.


















Borden Resinite-90
55
O Goodyear Prime-Wrap
98 g/l alginate U
50 120 g/l alginate



45 0



40



35



S30



25 0
25


20 ^





210
10


5




3 6 9 12 15 18 21 24
HOUR


Fig. 3. Oxygen permeability of Ca-alginate films and plastic wraps at 2 C.










The increasing permeability of the Ca-alginate films can be attri-

buted to the release of moisture from the film, thereby permitting the

oxygen to pass through more readily. This increased permeability

reduces the concern that lean tissue would appear too dark in color due

to the reduced state of myoglobin or that anaerobic bacteria could grow

if provided additional favorable conditions of increased temperatures.



Decontamination of Meat Carcass Surfaces


In addition to the control and reduction of carcass shrinkage, the

meat processor and consumer have become more aware of the presence of

undesireable bacteria which can cause a rapid alteration of the accept-

able quality of the meat.

In order to reduce and control surface microbial flora, treatment

of carcasses with antimicrobial agents in conjunction with good pro-

cessing procedures should be used as the initial step toward reducing

this surface flora.

As presented earlier, the Flavor-Tex alginate coating was effective

in reducing shrinkage losses from lamb, beef and pork carcasses. Addi-

tionally, Flavor-Tex as well as true antimicrobial agents were evaluated

for their ability to reduce and maintain low surface microbial flora.

Lamb. Flavor-Tex and plastic wrap shrinkage treatment effects on

lamb surface microbial growth were monitored by swabbing the sirloin

and belly (flank-plate juncture) areas of each carcass at 0, 2, 5 and 7

days postmortem. These areas were selected to represent areas which

are covered predominantly with fat (sirloin) or with lean (belly). Mean

values for total microbial count/6.46 cm2 from both sampling areas are










presented in Table 9. In the si loin area, no significant differences

were observed between treatment groups immediately postmortem. At 2

days postmortem, those carcasses which had been wrapped with the plastic

wrap had higher (P < 0.05) microbial counts (log10 = 3.65) than did the

control (log10 = 3.04) or alginate treated (log10 = 2.87) carcasses.

This difference was maintained through day 5 and day 7 with the plastic

wrapped carcasses at day 5 having a higher (P < 0.05) microbial count

than either control or alginate-treated carcasses. Elevated microbial

counts from the plastic wrapped carcasses probably were due to the

reduction in surface evaporation thereby maintaining a more favorable

water activity (a ) for growth. The calcium alginate-coated carcasses

tended to have lower surface microbial counts from the sirloin area at

all time periods, although not always significant. Inhibition of

microbial growth by the Flavor-Tex coating may be due partially to the

ionic effect of CaCI2 (0.8 M) which was used for the gelling of the

alginate on the carcass surface.

Microbial counts from the belly area were not significantly dif-

ferent among treatments at all intervals evaluated (Table 9). The high

counts and lack of significant differences were probably due to cross-

contamination that occurred during the weighing of the carcasses.

Beef. Although there is wide variation in the bovine animal with

respect to type of feed consumed, geographical region in which it is

raised and the slaughter processing technique employed, the initial

surface microbial flora and chill cooler flora appear to be rather con-

stant. Data presented in Table 10 confirm the report by Locker et al.

(1975) that the predominant genera of bacteria on the beef carcass after

washing are Micrococcus, Flaoobacteriwn and Acinetobacter. The presence












Table 9. Mean logl0 valuesa for total microbial count/6.46 cm2 from sirloin
and belly areas of control and treated lamb carcasses.


Postmortem Control


3.64a

3.04a

3.47a

3.45ab



3.90a

3.84a

4.24a

4.47a


Shrinkage treatment

Ca-alginatec


Sirloin area

3.75a

2.87a

2.80b

3.11b

Belly area

3.90a

3.99a

4.34a

4.46a


Means on the same horizontal line bearing different letters differ
significantly (P < 0.05)
b
n = 30 carcasses/treatment

c142 g sodium alginate-maltodextran/liter water


Plastic wrap


3.86a

3.64b

3.82c

4.14a



4.03a

4.09a

4.31a

4.01a












Table 10. Beef carcass surface microbial flora and their relative
percentages at various time periods post-slaughter.


Hour postmortem

0 %a 24 %


MicroocOcus 35.] Micrococcus 33.

Flavobacteriu 18.9 Acinetobacter 22.

Acinetobacter 10.8 Staphylococcus 22.

Staphy locccus 5.4 Faavobacteriun 11.

Pseudomonas 5.4 Enterobacteriaceae 11.

Lactobacillus 5.4

Streptococcus 5.4

Enterobacteriaceae 2.7

Yeasts 10.8


aPercent of total microorganisms identified


96 %


Micrococcus 83.3

Acinetobacter 8.3

Yeasts 8.3


~~


3

2

2

1

2









of yeasts, which may vary with -hii type of diet, constituted 11% of the

total initial microbial flora. Following a 24 hr chill, little change

occurred with respect to the relative percentages of bacteria present.

However, after 96 hr postmortem, Micrococcus was most prevalent with

Acinetobacter and yeasts being the only other organisms isolated. The

yeasts present were visually and morphologically similar to the genera

Rhodotorula and Candida.

The control and reduction of these microorganisms which have been

enhanced by the reduction of a and temperature environments becomes one
w
of the important criteria in the overall decontamination of beef carcass

surfaces. In order to effectively apply decontamination processes which

would be acceptable to governmental agencies and the meat industry the

process must meet basic criteria. Some of these criteria are: nontoxic

to humans, no affect on taste of meat, inexpensive, easy to apply, stable

and effective in reducing and maintaining low surface microbial levels.

A review of the literature revealed that one of the most practical

and inexpensive antimicrobial agents was hypochlorous acid (HC10).

Enhanced antimicrobial activity from low levels (5-200 ppm) of hypo-

chlorous acid can be obtained when the pH of the solution is maintained

between 4-6 (Charlton and Levine, 1937). However, the stability of the

acid decreases rapidly, resulting in a reduction of antimicrobial

activity, as the hydrogen ion concentration increases.

The development of an effective decontamination process for meat

carcasses which can be applied in the meat industry is described in this

series of experiments. The basic process to be presented involves the

buffering of hypochlorous acid in an organic solution so that stability

of the active component (HC10) can be maintained, thereby permitting it

to react effectively with, and reduce, the surface microbial flora.










The buffer system found to be most effective in maintaining HC10

stability was acetate-acetic. Other buffers evaluated were Citric-

Citrate, Sorbic-Sorbate and Tris(Hydroxymethyl-aminomethane). Data

presented in Table 11 indicate that 0.01 M, pH 4.5 acetate-acetic acid

buffer in conjunction with 150 ppm available chlorine as HC10 (Treat-

ment 1) reduced (P < 0.01) and maintained low surface microbial flora

through 96 hr postmortem. Addition of 0.001% Tween-80 (polyoxyethylene

sorbitan monooleate) (Treatment 2), a surface tension reducer, did not

increase the overall antimicrobial activity, however, the mean microbial

count at 96 hr for this treatment was lower than the 24 hr count,

whereas all other treatments had increased microbial counts at this

time period. Spraying of the buffer-HC10 solution through the shroud

cloth (Treatment 3) appears to have impeded the solution from reaching

the carcass surface even though the solution was applied at a pressure

of 1 kg/cm2. When 24 hr microbial counts from all treatments were

analyzed for significance (column), the control, Tween-80 and shroud

cloth treatments were higher (P < 0.01) than the acetate buffer-HCO1

treatment (2), indicating that even though the effects of chill tem-

perature and water activity reduced the total surface flora, treatment

with acetate buffer-HClO further reduced the number of viable organisms.

Because the addition of Tween-80 reduced the flora at 96 hr, the

treatment was repeated and incorporated into a second experiment de-

signed to determine whether increased molarity of the acetate-acetic

buffer could influence the surface microbial flora. Additionally,

sorbate-sorbic acid at 0.1 M, pH 5.5, was evaluated for its effective-

ness in reducing yeast microbial flora which was observed to be

frequently present following hypocllorous acid treatment. The results












Table 11. Mean logl0 valuesa for total microbial count/6.46 cm2 from
the neck area of control and acetate buffer-HCO1 treated
beef carcasses.


Hour postmortem

Ob 24 96


Treatmentcd


Control 3.30a 2.80b 3.14ab

1 2.09b 2.89c

2 2.96ab 2.72b

3 2.53b 2.98a


Means on the same horizontal line with different letters differ
significantly (P < 0.01)

bpooled response; collected prior to treatment application

Treatments denoted as:
Control = untreated
1 = 0.01 M acetate-acetic, pH 4.5 + 150 ppm available
chlorine
2 = same as treatment 1 + 0.001% Tween-80
3 = same as treatment 1 except sprayed through the shrouded
carcass
d
n = 20 carcass sides/treatment










from this experiment are presented in Table 12. The presence of the

surfactant (Tween-80) in the acetate buffer-HC10 solution reduced

(P < 0.01) the surface microbial flora again but was not found to be

superior to other treatments at the 96 hr storage period. Use of 0.1 M

acetate-acetic-HCIO did not result in greater surface microbial flora

reduction than 0.01 M acetate-acetic-HCIO nor did the sorbate-sorbic

buffer provide an improved response. Evaluation of microbial colonies

from the agar plates indicated no noticeable reduction in the number of

yeasts. In addition to its apparent failure to reduce the yeast flora,

the sorbate-sorbic buffer had a precipitate due to insolubility of sorbic

acid at this pH. Consequently, when sprayed onto the carcasses, flecks

of the chemical could be seen on the surface. Analysis of the mean

values from each treatment at 24 hr postmortem (column) indicated that

the 0.01 M acetate buffer-lHClO-Tween-80 treatment and the 0.1 M acetate

buffer-HCIO treatment were lower (P < 0.01) in total surface microbial

flora than the control or sorbate-sorbic buffer treated carcasses.

Although effective, the 0.1 M acetate-acetic buffer treatment does not

appear to be superior to the 0.01 M acetate-acetic buffer. At this

concentration, the buffer had a pungent odor which persisted on the

carcass for 4-6 hours.

Interim USDA guidelines suggest the use of hypochlorous acid, with

a maximum of 200 ppm available chlorine, as a surface rinse or spray;

thus an experiment was conducted to evaluate various concentrations of

hypochlorous acid. The buffer system to which the hypochlorite solution

was added was 0.01 M acetate-acetic, pH 4.5. Results presented in

Table 13 indicate that a reduction (P < 0.01) in surface microbial

flora occurred equally between 25 and 200 ppm available chlorine at

both 24 and 96 hr postmortem.












Table 12. Mean logl0 values for total microbial count/6.46 cm2 from
the neck area of control and treated beef carcasses.


Hour postmortem

0b 24 96


3.52a 2.57b 3.10ab

1.70b 1.80b

1.85b 1.55b

2.22b 1.90b


Means on the same horizontal line with different letters differ
significantly (P < 0.01)

Pooled response; collected prior to treatment application

Treatments denoted as:
Control = untreated
1 = 0.01 M acetate-acetic, pll 4.5 + 150 ppm available
chlorine + 0.001% Tween-80
2 = 0.1 M acetate-acetic, pH 4.5 + 150 ppm available
chlorine
3 = 0.1 M sorbate-sorbic, pH 5.5
d
n = 15 carcass sides/treatment


Treatment
Treatment


Control

1

2

3






-48-


Table 13. Mean loglo valuesa for total microbial count/6.46 cm2 from
the neck area of control and acetate buffer-HCIO treated
beef carcasses.b



Available chlorine
Hour
postmortem Control 25 100 200


Oc 3.73

24 3.13a 2.62b 2.31b 2.21b

96 3.53a 2.72b 2.33b 2.52b


Means on the same horizontal line with different letters differ
significantly (P < 0.01)

b
n = 15 carcass sides/treatment

cPooled response; collected prior to treatment application

departs per million available chlorine suspended in 0.01 M acetate-acetic
buffer, pH 4.5









The reaction of hypochlorous acid with microorganisms involves the

oxidation of proteinaceous material (Anonymous, 1964). Experiments

conducted by Johns (1934) revealed that bacteria (Svaphylococous aureus,

1 x 106 cells/ml) were destroyed within 5 minutes by 10 ppm available

chlorine in nutrient broth. With adequate washing of the beef carcass

surface, the remaining microbial flora should be effectively inhibited

by small concentrations of the highly active HC10. Therefore, the con-

centration which should be applied to carcass surfaces will depend

partially upon the thoroughness of the final wash water treatment. Use

of any antimicrobial agent is not meant to replace sanitation and hygiene

treatments of the carcass, but rather to aid in reducing the remaining

surface flora so that ultimately an increased shelf-life of the fresh

meat can be obtained. The use of the lowest effective concentration

will help to ensure that adequate wash water treatment will be conducted

and that the chance for secondary HC10 reactions involving the oxidation

of organic matter, which may ultimately be consumed, will be essentially

non-existent.

As a comparison to the calcium hypochlorite method of forming

hypochlorous acid, the Morton Biocidal System (Model 110-415 ID) using

chloride ion electrolysis to form chlorine (C12), followed by reaction

in acidic water to form hypochlorous acid was evaluated. Additionally,

the relative time required to observe a significant decrease in the

surface microbial count was determined. These data are presented in

Table 14. At 1 hr post-treatment, no differences (P > 0.05) were ob-

served between the control and treated carcasses. However, by 12 hr

post-treatment, the 50 ppm available chlorine treatment carcasses had

lower (P < 0.05) microbial counts than the control carcasses. The 170












Table 14. Mean log10 values for total microbial count/6.46 cm from
the neck area of control and treatedb beef carcasses.c



Available chlorine (ppm)
Hour
post-treatment Control 50 170


0d 3.05

1 2.82a 2.26a 2.39a

12 2.38a 1.69b 2.07ab


Means on the same horizontal line with different letters differ
significantly (P < 0.05)
b
Morton Biocidal Flow-Thru Design Unit Model 110-415 ID

c
n = 10 carcass sides/treatment

Pooled response; collected prior to treatment application






-51-


ppm available chlorine treatment ircass counts were similar to the

control and 50 ppm treatment carcasses. Ram Ayar (1930) observed that

a concentration of 20 ppm available chlorine was more effective than

100 or 200 ppm against spores of Bacillus su .ilis. Johns (1934) also

observed increased efficiency on dilution of sodium hypochlorite solu-

tions and attributed the results to the increase in hydrogen ion con-

centration. Kotula (1975) reported that 30 ppm chlorinated water was

equally as effective in reducing surface microbial flora on beef

carcasses as was 95 ppm.

Pork. One experiment was conducted on the decontamination of pork

carcasses. This experiment involved the addition of hypochlorous acid

directly to the alginate-maltodextran or calcium chloride solution.

Early interests were to mix the hypochlorous acid and alginate together

so that they could be sprayed simultaneously, however a basic problem

due to the pH of the two components existed. Because alginate had a

pH of 7.1 and calcium chloride a pH of 6.7, addition of the hypochlorite

ion would not permit the active hypochlorous acid to completely form.

When the alginate pH was decreased with organic or inorganic acids, a

gel formed. However, by adjusting the water and hypochlorite to pH

6.1-6.3 with acetic acid, followed by the addition of the alginate, a

relatively soluble mixture could be obtained. No difficulties were

encountered with the acidification of the calcium chloride solution.

When these treatment preparations were sprayed onto pork carcasses

and analyzed for surface microbial reduction (Table 15), no differences

(P > 0.05) among the five treatments occurred. The lack of a significant

decrease in microbial counts may have been due to the initial low

numbers of surface flora. Also, there was no significant increase in











Table 15. Mean log10 values for total microbial count/6.46 cm from
the shoulder area of control and treated pork carcasses.


Hour postmortem

Treatmentbc 0d 24 48


Control 2.82 2.39 2.64

1 2.36 2.52

2 2.76 2.61


96


2.87

2.49

2.55


2.


39


4 2.76 2.32


Means on the same horizontal line are not significantly (
different

Treatments denoted as:
Control = untreated
I = 50 ppm available chlorine rinse, plH 6.3
2 = 0 ppm alginate film coating
3 = 50 ppm available chlorine suspended in sod
(Solution 1)
4 = 50 ppm available chlorine suspended in cal
(Solution 2)

Cn = 5 carcasses/treatment

Pooled response; collected prior to treatment application


2.39

2.57


P > 0.05)







ium alginate

cium chloride












the flora after 96 hr postmortem as was observed in all previous ex-

periments. With pork carcass skin surfaces being dry, smooth, firm

and rather free of available nutrients, the opportunities for increasing

surface microbial growth appear remote, especially at chill cooler tem-

peratures.

The surface microbial flora, which was identified from the control

(0 hr) and Ca-alginate (48 hr) treated carcasses is presented in Table

16. The flora was essentially the same as the beef carcass (Table 10)

at similar time periods. The somewhat increased staphylococci per-

centage may be an indication of the greater human handling and manual

processing that occurs for these carcasses during the slaughter process.

Reduction of lamb surface microbial flora has been demonstrated

through application of the Flavor-Tex alginate coating. The application

of this film coating in addition Lo reducing carcass moisture loss can

provide some antimicrobial activity. This reduction in surface flora

is thought to be due to the ionic effect of calcium chloride. Use of

a plastic wrap allowed for an increase in surface flora by retaining

moisture and heat from the carcass. These changes resulted in an in-

crease in the surface microbial flora through 7 days postmortem.

The data presented in the beef carcass decontamination experiments

demonstrate that a practical process employing low concentrations of

available chlorine (25-100 ppm) in combination with 0.01 M, pH 4.5

acetate-acetic acid buffer can effectively reduce and maintain low

levels of surface microbial flora. This process incorporates the fun-

damental criteria outlined previously concerning the requirements for

an antimicrobial agent that can be acceptable to governmental agencies

and the meat industry. Application of this process not only to the












Table 16. Pork carcass surface microbial flora and their relative
percentages following treatment with a Ca-alginate coating.



Hour postmortem

0 48

Control %a Ca-alginate %a


Micrococcus 20 Staphylococcus 38

Staphy lococus 15 Flavobacteriwn 23

AMoraxe Z a 10 Pseudomonas 23

Acinetobacter 10 Micr.ooccus 8

FZavobacteriwn 10 Yeasts 8

Enterobacteraceae 10

Pseudomonos 5

Streptococcus 5

Yeasts 15


Percent of total microorganisms identified






-55-


carcass immediately post-slauglh but to wholesale and retail cuts

could help to increase the shelf-life and overall acceptance of the

particular meat product.

Addition of hypochlorous acid to the alginate film solutions prior

to spraying onto pork carcasses did not reduce surface microbial flora;

nor did it influence the type of flora remaining on the carcass when

compared with untreated controls. Although carbohydrates normally do

not interact with hypochlorous acid, the use of 50 ppm HC10 may have

interacted with the alginate sufficiently to become inactive.

The application of low concentrations of hypochlorous acid, sus-

pended in the acetate-acetic acid buffer, followed by the application of

an alginate film at a concentration of approximately 100 g/l could

result in a significant reduction in both surface microbial flora and

moisture loss from the meat carcass.

















SUMMARY


Lamb, beef and pork carcasses were evaluated for moisture loss

(shrinkage) procedures by employing Ca-alginate (Flavor-Tex) edible

films and/or plastic wrap (Borden Resinite-90). For lamb carcasses,

shrinkage was best controlled by wrapping the carcass in plastic wrap,

however increased microbial growth was observed through 7 days post-

mortem. The Ca-alginate film significantly reduced shrinkage and

surface microbial flora through 5 days postmortem.

Beef carcass shrinkage, using the cotton shroud cloth, was not

significantly reduced when compared with naked carcasses, however the

shroud provided the carcass with a smooth and more uniform appearing

surface.

Use of Ca-alginate films significantly reduced beef carcass shrink-

age through 96 hr storage when compared with shrouded control carcasses.

Application of various concentrations of the sodium alginate-maltodextran

solution resulted in a similar response in the reduction of beef carcass

shrinkage. Data indicated that when low concentrations of the alginate

solution were employed, water molecules were more easily held within

the Ca-alginate gel than when higher concentrations were used. The

trapping of water within the gel allows the alginate film to act as the

moisture sacrificing agent during the initial 72 hr chill cooler storage

period.

Oxygen permeability studies of the Ca-alginate and plastic wrap


-56-










films indicate that the Ca-algini.te film impeded the flow of oxygen

through the film less than the plastic wrap, Resinite-90.

Pork carcass shrinkage, which approached 4% within 24 hr portmortem,

was significantly reduced through 72 hr storage by application of the

Ca-alginate film. Use of various concentrations of sodium alginate-

maltodextran resulted in no significant differences between treatments,

but all concentrations significantly reduced moisture loss when compared

with untreated controls.

Surface microbial flora on beef carcasses was significantly reduced

through 96 hr chill cooler storage by the application of low concentra-

tions (25 ppm) of chlorine as hypochlorous acid. The optimum buffer

system in which to suspend the hypochlorous acid was observed to be

0.01 M, pH 4.5 acetate-acetic acid. No significant differences in sur-

face microbial growth were observed between the 25 and 200 ppm available

chlorine treatments.

The addition of 50 ppm available chlorine to either Flavor-Tex

solutions resulted in no significant reduction of pork carcass surface

microbial flora nor did the alginate influence the selection of micro-

organisms on the carcass after 48 hr postmortem storage.

The application of low (25-100 ppm available chlorine) concentra-

tions of hypochlorous acid, suspended in a weak acetate-acetic acid

buffer can significantly reduce and maintain low surface microbial

growth. The application of this decontamination process followed by

the application of an alginate film at a concentration of approximately

100 g/1 and 0.3 M calcium chloride could result in a significant reduc-

tion in both surface microbial flora and moisture loss from the meat

carcass.
















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BIOGRAPHICAL SKETCH


Charles Raphael Lazarus was born in Elkins, West Virginia on

January 28, 1940, son of Maurice J. and Jeanette A. Lazarus. He

received his primary education from Kruger Street and Bridge Street

School, and graduated from Triadelphia High School, Wheeling, West

Virginia in May 1957. He entered the United States Air Force in March

1960, and trained as a Medical Laboratory Technician. He was honorably

discharged in January 1964. He entered West Virginia University in

January 1964, and received his Bachelor of Arts degree in Biology in

June 1966. In September 1966 he began studying for the Master of

Science degree in Bacteriology at the same university and obtained this

degree in May 1969. Following employment as a microbiologist, he

entered the University of Florida Graduate School in June 1974 and

is a candidate for the degree of Doctor of Philosophy.

The author is a member of Alpha Zeta, Sigma Nu, American Society

for Microbiology, American Society of Animal Science, Institute of Food

Technologists, American Association for the Advancement of Science and

American Meat Science Association. He has a daughter Amy by a previous

marriage.












I certify that I have read this study and that in my opinion it
conforms to acceptable standards of scholarly presentation and is fully
adequate, in scope and quality, as a dissertation for the degree of
Doctor of Philosophy.






A.Z. Palmer, Chairman
Professor of Animal Science






I certify that I have read this study and that in my opinion it
conforms to acceptable standards of scholarly presentation and is fully
adequate, in scope and quality, as a dissertation for the degree of
Doctor of Philosophy.






C.B. Ammerman
Professor of Animal Science






I certify that I have read this study and that in my opinion it
conforms to acceptable standards of scholarly presentation and is fully
adequate, in scope and quality, as a dissertation for the degree of
Doctor of Philosophy.






R.L. West
Assistant Professor of Animal Science











I certify that I have read this study and that in my opinion it
conforms to acceptable standards of scholarly presentation and is fully
adequate, in scope and quality, as a dissertation for the degree of
Doctor of Philosophy.





J. Ob singer
Assistant Professor of Food Science






I certify that I have read this study and that in my opinion it
conforms to acceptable standards of scholarly presentation and is fully
adequate, in scope and quality, as a dissertation for the degree of
Doctor of Philosophy.





J.C/ Deng
Assistant Professor of Foo science






This dissertation was submitted to the Dean of the College of Agriculture
and to the Graduate Council, and was accepted as partial fulfillment
of the requirements for the degree of Doctor of Philosophy.

August, 1976

Dean, /College of Agriculture
/ /i



Dean, Graduate School





























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