Group Title: Lake Alfred AREC Research report
Title: Packinghouse newsletter
Full Citation
Permanent Link:
 Material Information
Title: Packinghouse newsletter
Series Title: Lake Alfred AREC Research report
Alternate Title: Citrus packinghouse newsletters
Packing house newsletter
Physical Description: v. : ill. ; 28 cm.
Language: English
Creator: Citrus Experiment Station (Lake Alfred, Fla.)
Citrus Experiment Station (Lake Alfred, Fla.)
Agricultural Research and Education Center (Lake Alfred, Fla.)
Citrus Research and Education Center (Lake Alfred, Fla.)
Indian River Research Education Center
Publisher: Citrus Experiment Station
Place of Publication: Lake Alfred Fla
Lake Alfred Fla
Publication Date: September 1971
Copyright Date: 1965
Frequency: irregular
completely irregular
Subject: Citrus fruits -- Harvesting -- Periodicals -- Florida   ( lcsh )
Citrus fruits -- Packing -- Periodicals -- Florida   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
periodical   ( marcgt )
Additional Physical Form: Also issued on the World Wide Web.
Dates or Sequential Designation: No.1 (Sept. 1, 1965)-
Issuing Body: Issued by the Citrus Experiment Station (no. 1-38); Lake Alfred (Fla.) Agricultural Research and Education Center (no. 39-136); Lake Alfred (Fla.) Citrus Research and Education Center (no. 137-189); and the Ft. Pierce (Fla.) Indian River Research and Education Center (no. 190- ).
General Note: Title from caption.
General Note: Latest issue consulted: No. 202 (Aug. 1, 2005)
 Record Information
Bibliographic ID: UF00095555
Volume ID: VID00028
Source Institution: University of Florida
Holding Location: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 02430250
lccn - 2006229390

Full Text

gs- 1-i7l/

ter No. 39 (*-,) .
AREC-LA-71-41 (71- 1
September 24, 1971
1000-lTFW-Lake Alfred, Florida

Editor: W. F. Wardowski
Harvesting and Handling Section
University of Florida
Agricultural Research and Education Centei
P. O. Box 1088
-I Lake Alfred, Florida 33850




*Anyone wishing to receive this newsletter
may send a dozen stamped, preaddressed
envelopes to the above address.

Newsletter No. 39 AREC-LA-71-41
September 24, 1971
1000-WFW-Lake Alfred, Florida

Harvesting and Handling Section



Even though a number of packinghouses were severely hampered by trash accu-
mulation in the last two seasons, the general attitude seems to be to ignore the
problem in the hope that it will go away. It won't. In the last several
months, we have gone over plans for several proposed new packinghouses or revi-
sions of old ones. None included what we consider adequate provision for prompt
removal of trash brought in with the fruit due to sloppy picking. We in the
Harvesting & Handling Section can do nothing about the pickers; we can, however,
help cope with the resulting trash.
Sloping Belt Trash Eliminator

The demonstration of the sloping belt trash eliminator at our recent Packing-
house Day caused so much interest that a brief description seems to be in order.
Figure 1 illustrates the principle for the removal of loose trash and sand. The
surface of the belt is arranged to engage with leaves, twigs, sand, etc. as it
moves sideways across the direction of fruit flow. The slope of the belt is
sufficient for fruit that is not encumbered by long stems and leaves to roll
across it. This is an old principle and familiar to anybody who has watched a
potato digger working.
Figure 2 illustrates what we believe to be a new principle. A pintle rubber
roller engages with the ridged surface of the belt so that the two just touch.
The peripheral speed of the roller should be approximately equal to the linear
speed of the belt. At the point of contact, the pintle rubber and the belt are
moving in the same direction. Long stems attached to fruit are engaged between
the pintle rubber and the belt and pulled through forcefully. A roller of.
approximately 2-1/2 inches diameter rotates in the opposite direction to the pintle
rubber roller thrusting the attached fruit away from the stem. Fruit that engage
this device tend to be picked cleanly from the long stems. All long stems and
trash are deposited in one place and can be accumulated in a pallet box or
conveyed to a disposal bin or waiting truck.
So far, this has only been operated on our small packinghouse line. It is
conceivable that on a large line, it might be necessary to have several belts
working in opposite directions with rollers on each side of the conveyor as
shown in Figure 3.
We are anxious to find a cooperator with a trash problem who is willing to
work with us to set up such a device in his packing line. We have to work under
quite anomalous conditions even to specially requesting loads with trash in them!
A short time in a commercial packinghouse line will do far more to "work the bugs
out" than a season in our little pilot plant.

September 24, 1971

Fig. 1. Principle of sloping belt Fig..2. Principle of the "in-house
trash eliminator, fruit picker."


belt trash remover in a high etc. from citrus fruit prior


Fig. 3. Possible multiple belt Fig. 4. Vacuum brusher for removal
arrangement for a sloping of dust, dirt, scale insects,
belt trash remover in a high etc. from citrus fruit prior
volume packinghouse line. to the washer.

Vacuum Brusher
This is not a new device. To the best of my knowledge, the first one was
built by Cecil Chapman's shop staff at Haines City Growers' Association at least
a dozen years ago. Its purpose then was to keep dust and light trash out of the
bulk bins. Another was installed at Adam's Fresh Fruit Division to keep trash
out of the pre-grade system. Figure 4 shows a diagrammatic representation of a
vacuum brusher. The fruit goes over a bed of soft (horsehair or horsehair-grade
synthetic) brushes turning slowly (not over 100 rpm). The area under the brushes
is completely enclosed with a large fan (about 5,000 cfm), pulling air down through
the brushes.
This is obviously an excellent device for reducing the proportion of organic
matter such as dust, scale insects, mold spores, leaf and twig fragments, etc.
before they have a chance to get into the wash water. Such trash contributes to
high B.O.D. levels unacceptable under the new Air & Water Pollution Control Act.
If anybody contemplates building or installing such equipment, we urge them
to contact us as we see several fairly obvious improvements which we would like to
have incorporated. In particular, we wish to minimize the blowing of particulate
matter into the air and also believe that it should be possible to design a vacuum
brusher in which removal of the accumulated trash is mechanized.

W. Grierson
Agricultural Research & Education Center
Lake Alfred

Newsletter No. 39

September 24, 1971


The degreening season is beginning, and a reminder of some points could
help you avoid an expensive problem. Degreening is necessary because the
edible portion of early season fruit usually matures before the peel attains
the characteristic varietal color. However, ethylene increases stem-end rot,
to degreening time should be as short as possible.
Temperature: 850F is recommended for degreening. Higher or lower tempera-
tures tend to slow degreening. Florida Department of Citrus regulations prohibit
exceeding'850F by the application of heat, except when the added heat comes from
steam released into the atmosphere to increase humidity."
Ethylene: One to 5 ppm gives adequate degreening. Concentration of ethylene
in degreening rooms can be easily measured by a portable ethylene analyzer which
every packinghouse should have. Ethylene should be accurately metered into the
room using the bubble system for smaller rooms (1 bubble for every 10 field-box-
capacity of the room) or a flowmeter with integral needle valve for large rooms.
See Table 1.
Humidity: 88 to 96% R.H. 'is recommended and can be maintained by steam
later in the season. When room temperatures tend to exceed 850F, pneumatic water
spray nozzles may be necessary. The next Newsletter will have more details on
this subject.
Ventilation: One air change per hour with fresh air will prevent an accumu-
lation of carbon dioxide which is given off by the fruit.
Air movement: This should be a minimum of 7.5 cubic feet per box per minute.
This is necessary to maintain uniform temperature, ethylene concentration, and
humidity and to move the air mixture past each fruit in the degreening room.

Some specific degreening problems are:
Stem-End Rind Breakdown (SERB) is the most common peel injury problem
encountered in the degreening season. SERB is caused by low humidity between
harvest and waxing, particularly in the degreening room. The fruit dries out
causing a dark area around the stem end. Decay, particularly green mold, enters
the fruit through this injured peel. Avoid delays between harvest and waxing,
and do not expose fruit to the sun or other drying conditions. Additional infor-
mation on SERB can be found in the Available Publications list in "Practical
Measures for Control of Stem-End Rind Breakdown of Oranges" by A. A. McCornack
and W. Grierson.
Oleocellosis (oil spotting) can be expected to be severe when wet fruit are
roughly handled. The oil cells are prominent on wet, turgid fruit and, hence,
easily broken. Not only does this cause the blemish known as oil spotting
(oleocellosis), but the broken oil cells are a common point for entry of green
mold and other decay organisms. In wet weather, every effort should be made to
enforce gentle handling by the pickers. Boxes should not be over-filled, and
handling wet fruit should be kept to a minimum. Degreening at lower than recommended
humidity makes oil spotting blemishes more prominent.
'Robinson' tangerines: A special word of warning is offered with regard to this
valuable fruit. It is very susceptible to several fungi, including anthracnose,
which does not usually cause fruit decay in other-varieties. 'Robinsons' should

Newsletter No. 39

September 24, 1971

never be held in the degreening room for longer than 36 hours. They should
not be picked until showing a definite orange color break. Samples should
be picked and degreened to make sure that large quantities are not picked
until 36-hour degreening is possible. After packing, they should be refrig-
erated promptly where possible. These comments also apply to other early season
mandarin fruits.
'Temples': 'Temples' are the only citrus fruit known to show a true
ethylene burn in serious amounts. A dark colored peel injury may appear any
time up to 2 weeks after degreening. When this occurs (all 'Temples' are not
susceptible), the amount of the damage is proportional to both time in the
degreening room and the amount of ethylene used. Degreening of 'Temples'
is not recommended. However, if they are being degreened, ethylene should be
kept to the minimum; and the degreening period should be as short as possible.

Zebra skin occurs when tangerines under drought stress receive a heavy rain
or irrigation and are then harvested within 2 to 4 days. The loss can be 100%,
but the susceptibility slowly declines after the combination of a drought broken
by heavy rain or irrigation. For more details on Zebra skin, request "Tangerine
Handling" by W. Grierson, A. A, McCornack, and F. W. Hayward from the Available
Publication list.

Table 1. Flow rates for ethylene to establish a degreening atmosphere
of 1 to 5 ppm ethylene and minimum CO2.a

Size of roomb Ethylene flow rate as
Field Pallet Bubbles/ cc or ml/ liters/ cu ft/
boxes boxes minc min hour hour
500 50 50 12.5 0.75 0.025
1,000 100 100 25 1.5 0.05
2,000 200 200 50 3.0 0.1
5,000 500 500 125 7.5 0.25
10,000 1,000 1,000 250 15.0 0.5

aTo be combined with continuous ventilation to keep CO2 below 0.1% in
the room atmosphere.
Ethylene delivery should be proportional to the size of the room but
not to the load in the room.
Bubbles from 1/4-inch line in a standard FMC trickle unit.

W. F. Wardowski
Lake Alfred

Available from Harvesting & Handling Section, Agricultural Research and Education
Center, P. O. Box 1088, Lake Alfred, Florida 33850.

"Program and Abstracts for Tenth Annual Packinghouse Day", Mimeo Report AREC-LA
71-32. September 8, 1971.

"Citrus Plant Modernization--A Leap Into the Present" by W. F. Wardowski, C. D.
Atkins, and R. D. Carter. Citrus World 8(2):10-12 & 17. July, 1971.

Newsletter No. 39

September 24, 1971

"Status of Postharvest Fungicides for Citrus Fruit," by A. A. McCornack. Proc.
Fla. State Hort. Soc. 83:229-232. 1970.

"Peel Injury of Florida Navel Oranges," by A. A. McCornack. Proc. Fla. State
Hort. Soc. 83:267-270. 1970.

"A Method of Determining Machinery Operating Costs and Costs of Production
Practices in Producing Florida Citrus," by C. L. Anderson and D. L. Deason.
Ag. Econ. Report 27, July, 1971. 22 pages.

"Tangerine Handling," by W. Grierson, A. A. McCornack, and F. W. Hayward.
Extension Circular 285. May, 1965.

"Practical Measures for Control of Rind Breakdown of Oranges," by A. A. McCornack
and W. Grierson. Circular 286. May, 1965.

"A Step Toward Development of a Better Export Citrus Box," talk by Philip W.
Hale and R. H. Hinds at Tenth Annual Packinghouse Day, September 8, 1971.

Application for Permit to Operate Air Pollution Sources. 1-D -- 8-D.
Department of Air and Water Pollution Control.

Application for Permit to Operate Water Pollution Sources. 1-B --12-B.
Department of Air and Water Pollution Control.

Available from CRD, ARS, USDA, 2120 Camden Road, Orlando, Florida 32804.

"Abscission Chemicals in Relation to Citrus Fruit Harvest," by W. C. Cooper and
W. H. Henry. J. Agr. and Food Chemistry 19(3):559-563. May/June, 1971.

"Relation of Ethanol Content of Citrus Fruits to Maturity and to Storage Conditions,"
by Paul L. Davis. Proc. Fla. State Hort. Soc. 83:294-298. 1970.

"Decay Control of Florida Citrus Fruits with Packinghouse Applications of Thia-
bendazole," by J. J. Smoot and C. F. Melvin. Proc. Fla. State Hort. Soc.
83:225-228. 1970.

"Effects of Washing Sequence on the Degreening Response and Decay of Some Citrus
Fruits," by 0. L. Jahn, R. H. Cubbedge, and J. J. Smoot. Proc. Fla. State Hort.
Soc. 83:217-221. 1970.

Available from Superintendent of Documents, U. S. Government Printing Office,
Washington, D. C. 20402 Price: 10 cents.

"Biphenyl Absorption of Citrus Fruits: The Effect of Variety, Color Class,
and Injury by Freezing, Peeling, and Lack of Oxygen," by Shirley Norman, C. C.
Craft, and D. C. Fouse. ARS, USDA, MRR No. 896. March, 1971.

Newsletter No. 39

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