• TABLE OF CONTENTS
HIDE
 Front Cover
 Front Matter
 Summary
 Introduction
 Materials and methods
 Results
 Literature cited
 Table 3. The ascorbic acid content...














Group Title: Bulletin - University of Florida. Agricultural Experiment Station ; no. 414
Title: Ascorbic acid content of some Florida-grown guavas
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Full Citation
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Permanent Link: http://ufdc.ufl.edu/UF00015126/00001
 Material Information
Title: Ascorbic acid content of some Florida-grown guavas
Series Title: Bulletin University of Florida. Agricultural Experiment Station
Physical Description: 12, 2 p. : ill. ; 23 cm.
Language: English
Creator: Mustard, Margaret J
Publisher: University of Florida Agricultural Experiment Station
Place of Publication: Gainesville Fla
Publication Date: 1945
 Subjects
Subject: Vitamin C   ( lcsh )
Guava -- Composition   ( lcsh )
Guava -- Florida   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
bibliography   ( marcgt )
non-fiction   ( marcgt )
 Notes
Bibliography: Bibliography: p. 12.
Statement of Responsibility: by Margaret J. Mustard.
General Note: Cover title.
General Note: "A contribution from the Sub-Tropical Station"--T.p.
Funding: Bulletin (University of Florida. Agricultural Experiment Station)
 Record Information
Bibliographic ID: UF00015126
Volume ID: VID00001
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: aleph - 000925224
oclc - 18237203
notis - AEN5872

Table of Contents
    Front Cover
        Page 1
    Front Matter
        Page 2
        Page 3
    Summary
        Page 4
    Introduction
        Page 5
    Materials and methods
        Page 5
        Page 6
        Page 7
        Page 8
    Results
        Page 9
        Page 10
        Page 11
    Literature cited
        Page 12
    Table 3. The ascorbic acid content of some Florida grown guavas
        Page 13
        Page 14
Full Text



August, 1945


UNIVERSITY OF FLORIDA
AGRICULTURAL EXPERIMENT STATION
HAROLD MOWRY, Director
GAINESVILLE, FLORIDA
(A contribution from the Sub-Tropical Station)







ASCORBIC ACID CONTENT

OF SOME FLORIDA-GROWN GUAVAS



By MARGARET J. MUSTARD

















Fig. 1.-Indian guava.


Single copies free to Florida residents upon request to
AGRICULTURAL EXPERIMENT STATION
GAINESVILLE, FLORIDA


Bulletin 414










BOARD OF CONTROL


N. B. Jordan, Acting Chairman, Quincy
Thos. W. Bryant, Lakeland
M. L. Mershon, Miami
J. Henson Markham, Jacksonville
J. Thos. Gurney, Orlando
J. T. Diamond, Secretary, Tallahassee



EXECUTIVE STAFF

John J. Tigert, M.A., LL.D., President of the
University3
H. Harold Hume, D.Sc., Provost for Agricul-
ture
Harold Mowry, M.S.A., Director
L. O. Gratz, Ph.D., Asst. Dir., Research
W. M. Fifield, M.S., Asst. Dir., Admin.'
J. Francis Cooper, M.S.A., Editor3
Clyde Beale, A.B.J., Associate Editors
Jefferson Thomas, Assistant Editor3
Ida Keeling Cresap, Librarian
Ruby Newhall, Administrative Managers
K. H. Graham, LL.D., Business Managers
Claranelle Alderman, Accountants



MAIN STATION, GAINESVILLE

AGRONOMY

W. E. Stokes, M.S., Agronomist'
Fred H. Hull, Ph.D., Agronomist
G. E. Ritchey, M.S., Agronomist2
G. B. Killinger, Ph.D., Agronomist
W. A. Carver, Ph.D., Associate
Roy E. Blaser, M.S., Associate
H. C. Harris, Ph.D., Associate
R. W. Bledsoe, Ph.D., Agronomist
Fred A. Clark, B.S., Assistant

ANIMAL INDUSTRY
A. L. Shealy, D.V.M., An. Industrialist' s
R. B. Becker, Ph.D., Dairy Husbandmans
E. L. Fouts, Ph.D., Dairy Technologists
D. A. Sanders, D.V.M., Veterinarian
M. W. Emmel, D.V.M., Veterinarian3
L. E. Swanson, D.V.M., Parasitologist'
N. R. Mehrhof, M.Agr., Poultry Husb.3
G. K. Davis, Ph.D., Animal Nutritionist
T. R. Freeman, Ph.D., Asso. in Dairy Mfg.
R. S. Glasscock, Ph.D., An. Husbandman
D. J. Smith, B.S.A., Asst. An. Husb.'
P. T. Dix Arnold. M.S.A., Asst. Dairy Husb."
C. L. Comar, Ph.D.. Asso. Biochemist
L. E. Mull, M.S., Asst. in Dairy Tech.4
J. E. Pace, B.S., Asst. An. Husbandman'
S. P. Marshall, M.S., Asst. in An. Nutrition4
Ruth Taylor, A.B., Asst. Biochem.
Katherine Boney, B.S., Asst. Chem.
Peggy R. Lockwood, B.S., Asst. in Dairy Mfs.


ECONOMICS, AGRICULTURAL

C. V. Noble, Ph.D., Agr. Economist1 s
Zach Savage, M.S.A., Associate3
A. H. Spurlock, M.S.A., Associate
Max E. Brunk, M.S., Associate


ECONOMICS, HOME

Ouida D. Abbott, Ph.D., Home Econ.1
R. B. French, Ph.D., Biochemist


ENTOMOLOGY

J. R. Watson, A.M., Entomologist1
A. N. Tissot, Ph.D., Associate3
H. E. Bratley, M.S.A., Assistant


HORTICULTURE

G. H. Blackmon, M.S.A., Horticulturist'
A. L. Stahl, Ph.D., Asso. Horticulturist
F. S. Jamison, Ph.D., Truck Hort.
R. J. Wilmot, M.S.A., Asst. Hert.
R. D. Dickey, M.S.A., Asst. Hort.
J. Carlton Cain, B.S.A., Asst. Hort.4
Victor F. Nettles, M.S.A., Asst. Hort.'
Byron E. Janes, Ph.D., Asst. Hort.
F. S. Lagasse, Ph.D., Asso. Hort.2



PLANT PATHOLOGY

W. B. Tisdale, Ph.D., Plant Pathologist'
Phares Decker, Ph.D., Asso. Plant Path.
Erdman West, M.S., Mycologist
Lillian E. Arnold, M.S., Asst. Botanist


SOILS

F. B. Smith, Ph.D., Microbiologist' 8
Gaylord M. Volk, M.S., Chemist6
J. R. Henderson, M.S.A., Soil Technologist
J. R. Neller, Ph.D.. Soils Chemist
C. E. Bell, Ph.D., Associate Chemist
L. H. Rogers, Ph.D., Associate Biochemist'
R. A. Carrigan, B.S., Asso. Biochemist
G. T. Sims, M.S.A., Associate Chemist
T. C. Erwin, Assistant Chemist
H. W. Winsor, B.S.A., Assistant Chemist
Geo. D. Thornton, M.S., Asst. Microbiologist5
R. E. Caldwell, M.S.A., Asst. Soil Surveyor'
Olaf C. Olson, B.S., Asst. Soil Surveyor4




1 Head of Department.
2 In cooperation with U. S.
3 Cooperative, other divisions, U. of F.
4 In Military Service.
5 On leave.











BRANCH STATIONS

NORTH FLORIDA STATION, QUINCY

J. D. Warner, M.S., Vice-Director in Charge
R. R. Kincaid, Ph.D., Plant Pathologist
V. E. Whitehurst, Jr., B.S.A., Asst. An.
Husb.4
Jesse Reeves, Asst. Agron., Tobacco
W. H. Chapman, M.S., Asst. Agron.'
R. C. Bond, M.S.A., Asst. Agronomist



Mobile Unit, Monticello

R. W. Wallace, B.S., Associate Agronomist


Mobile Unit, Milton

Ralph L. Smith, M.S., Associate Agronomist


Mobile Unit, Marianna

R. W. Lipscomb, M.S., Associate Agronomis


Mobile Unit, Wewahitchka

J. B. White, B.S.A., Asso. Agronomist



CITRUS STATION, LAKE ALFRED

A. F. Camp, Ph.D., Vice-Director in Charge
V. C. Jamison, Ph.D., Soils Chemist
B. R. Fudge, Ph.D., Associate Chemist
W. L. Thompson, B.S., Entomologist
W. W. Lawless, B.S., Asst. Horticulturist
C. R. Stearns, Jr., B.S.A., Asso. Chemist
H. O. Sterling, B.S., Asst. Horticulturist
T. W. Young, Ph.D., Asso. Horticulturist
J. W. Sites, M.S.A., Asso. Horticulturists
J. B. Redd, Ph.D., Insecticide Chemist



EVERGLADES STA., BELLE GLADE

R. V. Allison, Ph.D., Vice-Director in Charge
J. W. Wilson, Sc.D., Entomologist4
F. D. Stevens, B.S., Sugarcane Agron.
Thomas Bregger, Ph.D., Sugarcane
Physiologist
G. R. Townsend, Ph.D., Plant Pathologist
R. W. Kidder, M.S., Asst. An. Hush.
W. T. Forsee, Jr., Ph.D., Asso. Chemist
B. S. Clayton, B.S.C.E., Drainage Eng.2
F. S. Andrews, Ph.D., Asso. Truck Hort.4
R. A. Bair, Ph.D., Asst. Agronomist
E. L. Felix, B.S.A., Asst. Plant Path.


SUB-TROPICAL STA., HOMESTEAD

Geo. D. Ruehle, Ph.D., Vice-Director in
Charge
P. J. Westgate, Ph.D., Asso. Horticulturist
H. I. Borders, M.S., Asso. Plant Path.

W. CENT. FLA. STA., BROOKSVILLE

Clement D. Gordon, Ph.D., Asso. Poultry
Geneticist in Charge2

RANGE CATTLE STA., ONA

W. G. Kirk, Ph.D., Vice-Director in Charge
E. M. Hodges, Ph.D., Asso. Agron.
Gilbert A. Tucker, B.S.A., Asst. An. Hush.'


FIELD STATIONS

Leesburg

G. K. Parris, Ph.D., Plant Path. in Charge

Plant City

A. N. Brooks, Ph.D., Plant Pathologist

Hastings

A. H. Eddins, Ph.D., Plant Pathologist
E. N. McCubbin, Ph.D., Truck Horticulturist

Monticello

S. O. Hill, B.S., Asst. Entomologist2 *
A. M. Phillips, B.S., Asst. Entomologist2

Bradenton

J. R. Beckenbach, Ph.D., Horticulturist in
Charge
E. G. Kelsheimer, Ph.D., Entomologist
A. L. Harrison, Ph.D., Plant Pathologist
David G. Kelbert, Asst. Plant Pathologist
E. L. Spencer, Ph.D., Soils Chemist

Sanford

R. W. Ruprecht, Ph.D., Chemist in Charge
J. C. Russell, M.S., Asst. Entomologist5

Lakeland

E. S. Ellison, Meteorologist 2
Warren 0. Johnson, Meteorologist2


SHead of Department.
2 In cooperation with U. S.
S Cooperative, other divisions, U. of F.
In Military Service.
5 On leave.















SUMMARY


Ascorbic acid determinations were made upon representative
fruits of various species, seedlings and seedling races of guavas.
All of these guavas were subject to similar environmental
factors, since all of the fruits were collected from a single block
of trees growing at the Sub-Tropical Experiment Station at
Homestead, Florida.
The ascorbic acid content of the skin, outer flesh and central
portion of 1 group of seedlings was determined. Statistical
analyses of these data showed that significantly more ascorbic
acid is found in the outer portions than in the inner portions
of the fruit.
The analyses of guavas picked at different stages of maturity
and not allowed to ripen before testing showed that small green
and overripe fruits contain the most ascorbic acid while large
green and firm ripe fruits contain slightly less ascorbic acid.
The majority of the guavas classified as Psidium guajava L.
were found to contain considerably more ascorbic acid than
did those of the other species of guavas tested.
No correlation between flesh color and ascorbic acid content
was apparent among the fruit tested.









ASCORBIC ACID CONTENT
OF SOME FLORIDA-GROWN GUAVAS

MARGARET J. MUSTARD
Formerly Laboratory Assistant, Sub-Tropical Station

INTRODUCTION
The recent increased interest in the vitamin content of fruits
and vegetables can be attributed to several factors. Foremost
among these are the development of accurate methods of an-
alyses and the endeavor on the part of food specialists to find
new sources of vitamins to supplement both civilian and military
needs.
Guavas are among the tropical and subtropical fruits that
have recently been recognized as valuable sources of ascorbic
acid. These fruits should be utilized more extensively, since
they mature at a season when the supply of other fruits con-
taining ascorbic acid is limited.
The guava, a native of tropical America, has been distributed
throughout most of the tropical and subtropical regions of the
world (6).1 Its wide distribution is due in part to the ease
with which it propagates itself by seed. Seedling guavas are
frequently found growing wild along roadsides and on unculti-
vated land in Florida. Although the guava is utilized in numer-
ous ways by those fortunate enough to live in guava-producing
areas, its chief commercial use at present is in the production
of jelly.
The purpose of the present investigation is to obtain addi-
tional information concerning the ascorbic acid content of vari-
ous species, seedlings and seedling races of the guava.

MATERIALS AND METHODS
The guavas used in this study were collected from a single
block of trees growing on the Rockdale series soil of south Dade
County. Since the soil, climate and other environmental factors
were as nearly the same as possible, any differences which were
found can be considered inherent. Most of the fruits, unless
otherwise designated, were picked when they were firm-ripe
and sampled within the next 2 days. A few which were picked

1 Italic figures in parentheses refer to "Literature Cited" in the back
of this bulletin.









ASCORBIC ACID CONTENT
OF SOME FLORIDA-GROWN GUAVAS

MARGARET J. MUSTARD
Formerly Laboratory Assistant, Sub-Tropical Station

INTRODUCTION
The recent increased interest in the vitamin content of fruits
and vegetables can be attributed to several factors. Foremost
among these are the development of accurate methods of an-
alyses and the endeavor on the part of food specialists to find
new sources of vitamins to supplement both civilian and military
needs.
Guavas are among the tropical and subtropical fruits that
have recently been recognized as valuable sources of ascorbic
acid. These fruits should be utilized more extensively, since
they mature at a season when the supply of other fruits con-
taining ascorbic acid is limited.
The guava, a native of tropical America, has been distributed
throughout most of the tropical and subtropical regions of the
world (6).1 Its wide distribution is due in part to the ease
with which it propagates itself by seed. Seedling guavas are
frequently found growing wild along roadsides and on unculti-
vated land in Florida. Although the guava is utilized in numer-
ous ways by those fortunate enough to live in guava-producing
areas, its chief commercial use at present is in the production
of jelly.
The purpose of the present investigation is to obtain addi-
tional information concerning the ascorbic acid content of vari-
ous species, seedlings and seedling races of the guava.

MATERIALS AND METHODS
The guavas used in this study were collected from a single
block of trees growing on the Rockdale series soil of south Dade
County. Since the soil, climate and other environmental factors
were as nearly the same as possible, any differences which were
found can be considered inherent. Most of the fruits, unless
otherwise designated, were picked when they were firm-ripe
and sampled within the next 2 days. A few which were picked

1 Italic figures in parentheses refer to "Literature Cited" in the back
of this bulletin.







Florida Agricultural Experiment Station


when slightly greener were allowed to reach the firm-ripe stage
of maturity before being sampled.
It seems advisable before presenting the analytical data to
give a very brief description of some of these species, their
seedlings and seedling races.



















Fig. 2.-Riverside guava.

The majority of the guavas belong to the species Psidium
guajava L. Since these common guavas may not come true from
seed there occur within this species many variations. Very
few true horticultural varieties exist; however, several more
or less well-defined seedling races are frequently erroneously
referred to as varieties (6). The Indian guavas (Fig. 1) which
were here analyzed for ascorbic acid are all similar in external
appearance, being roeind, yellow-skinned fruit of varying size
averaging approximately 21/2 inches in diameter. The flesh of
these different Indian guavas is variously colored, as is indi-
cated in Table 3. Eloina and Riverside (Fig. 2) are 2 of several
varieties of California guavas grafted from scions sent to this
Station by H. J. Webber, California Citrus Experiment Station,
in 1943. These scions were grafted on stumps of common guava
seedlings and have this year borne exceptionally large fruit.
The Redland variety of guava (Fig. 3) was described in detail
by Lynch and Wolfe (3). This pear-shaped guava is consider-







Ascorbic Acid Content of Gzatvas


ably larger than common guavas and lacks much of the odor
which is characteristic of this latter group. In the following
analytical results various other grafted guavas are referred to
as Stone, Supreme (Fig. 4), Fuchs, Lenz, Donaldson, and so
forth. All of the trees from which this graftwood was obtained
originated as seedlings of Psidium guajava and have been
grafted onto Psidium guajava rootstock at this Station. For
the most part, these trees bear the name of the grower from
whom the graftwood was obtained. No detailed description of
these fruits will be attempted here. In Table 3 they are grouped
according to the color of their flesh.


b


Fig. 3.-Redland guava.

Psidium araca Raddi and Psidium guineense Sw. both bear
small, round, yellow fruits. Psidium cujavillus Burm. f. bears
small, yellow fruits which in size and color resemble those of
Psidium araca but have dry calyx segments (5). P. coriaceum
Mart. referred to in this paper is described by the Bureau of
Plant Industry (5) as bearing "dark-purple fleshy fruits the
size of plums." The fruits which were analyzed here for ascorbic





Florida Agricultural Experiment Station


acid came from shrubs bearing this plant introduction number
but, since they bore small yellow-skinned fruits with yellow-
white flesh, the identity of this group is questionable.
P. littorale Raddi, more commonly referred to as the straw-
berry guava or Red Cattley, is popularly used by housewives
in making jelly. The purple-red color of its skin makes it a
very attractive fruit. As yet no horticultural varieties of the
Red Cattley have been established. However, the Chinese or
Yellow Cattley has been established as a seedling race or botani-
cal variety and given the name P. littorale lucidum Hort. (6).




























Fig. 4.-Supreme guava.

The ascorbic acid determinations were made by a method
which is essentially the same as that described by Heinze (2).
Each sample consisted of a thin slice extending from stem to
blossom-end of the fruit and included the skin, outer flesh and






Ascorbic Acid Content of Guavas


central portion with seeds. Due to the wide variation in the
ascorbic acid content, it was necessary to use various sized
samples ranging from 5 to 25 grams. After the samples had
been extracted with 200 ml. of 1 percent metaphosphoric acid
for from 2 to 5 minutes in a Waring blendor, a portion of the
extract was centrifuged for 5 minutes at 2,000 r.p.m. In most
cases a 0.5 ml. aliquot of this extract was found to contain a
small enough amount of ascorbic acid to be measured by this
method; however, occasionally an extract was found which con-
tained so much ascorbic acid that the addition of a 0.5 ml. aliquot
would almost completely decolorize the dye to which it was
added. In the latter case, a smaller aliquot was used and the
difference in the volume compensated for by the addition of
enough 1 percent metaphosphoric acid to make the total volume
of solution equal to that of the larger aliquot. The aliquot was
added to an absorption cell containing 9 ml. of sodium 2,6-
dichlorobenzenoneindophenol, mixed, and a reading taken in a
Cenco Photelometer within 30 seconds. A small crystal of
ascorbic acid was added to complete the reduction of the dye
and a second reading taken. The blanks, which were run daily
or more often if fresh solutions were mixed during the day,
consisted of 0.5 ml. of metaphosphoric acid and 9 ml. of the
dye. Corrected readings were obtained by adding the reading
for the blank to the difference between the first reading with
the sample and a second reading after the addition of the crystal
of ascorbic acid. The corrected readings were converted into
milligrams per 100 grams of fresh fruit by reference to a cali-
bration curve.
Waddington and Cist (7) have demonstrated the accuracy
of other methods based upon the oxidation of ascorbic acid to
dehydroascorbic acid in the guava. Although these authors did
not include the above colorimetric procedure in their study, it
seems reasonable to assume that this procedure which is also
based upon the oxidation of ascorbic acid would likewise be
reliable for the analysis of this fruit.

RESULTS
Effect of Part Sampled.-It has been repeatedly demonstrated
in the past that ascorbic acid is not uniformly distributed
throughout individual fruits and vegetables. It is, therefore,
important in running any series of analyses to choose a method







Florida Agricultural Experiment Station


of sampling which will most nearly represent the food as it is
eaten.
To determine the manner of distribution of ascorbic acid in
the guava, 5 firm-ripe fruits were collected from a single tree.
Three samples were taken for analysis from each of these fruits:
skin, outer flesh and inner flesh with seeds. Results of these
analyses are given in Table 1.

TABLE 1.-DISTRIBUTION OF ASCORBIC ACID IN THE FRUIT OF A
COMMON GUAVA.

Section of Fruit Analyzed No. of Analyses Mean S.E.
_Mg./100 gm.

Skin ............... --------------- --------- 5 1,092.0 129.28
Outer flesh .....-- .............--- ....- ---------.. .... 5 588.8 51.21
Inner flesh and seeds ......-- ...................... 5 405.1 54.68

Differences in ascorbic acid content of the 3 portions of the
fruit were found to be significant at odds of 19:1, since the
difference between any 2 means is greater than twice their
standard error of difference. Due both to this unequal distribu-
tion of ascorbic acid and to the diversified uses of the guava,
it was decided to select samples which were representative of
the whole fruit as it is picked from the tree. To obtain such
a sample, a longitudinal slice extending from stem to blossom-
end and including the skin, outer flesh and central portion with
seeds was removed from each fruit for analysis.
Effect of Maturity.-Various workers have studied the cor-
relation between stage of development of different fruits and
vegetables and their ascorbic acid content. Some fruits and
vegetables show a decrease in ascorbic acid as they mature,
while others show an increase. Waddington and Cist (7) found
that over-ripe and hard green guavas contained less ascorbic
acid than did the firm but somewhat underripe fruits. These
same authors also found that the nearly ripe fruit contained al-
most as much ascorbic acid as did the mature fruit. Hawaiian-
grown guavas tested when green, half-ripe and ripe were found
by Miller and her associates (4) to contain most ascorbic acid
when half ripe and least when ripe.
The present investigation was undertaken to determine what
relationship if any could be found between the stages of ma-
turity and ascorbic acid content in 2 guavas of South Florida,
the Redland and Stone. It was originally planned that 2 groups







Ascorbic Acid Content of Guavas


of fruit representing each stage of maturity would be picked
from each of the trees. One group was to be tested immediately
after picking; the other group was to be allowed to ripen at
room temperature before being sampled. It was found, however,
that these fruit when ripened off the tree were very prone to
spotting and decay. The only groups which ripened successfully
were those fruit which were picked when they had reached their
full size. The results of these analyses as given in Table 2.

TABLE 2.-ASCORBIC ACID CONTENT OF SOME GUAVAS PICKED AND TESTED
AT DIFFERENT STAGES OF MATURITY.

Stage of Maturity When Picked No. of Analyses Mean S.E.
and Tested I ______ Mg./100 gm.
Redland:
Small green, tested at this stage.... 5 33.3 1.01
Large green, tested at this stage.... 5 20.6 0.56
Large green, allowed to ripen........ 3 18.7 2.04
Firm ripe, tested at this stage........ 5 24.7 0.67
Overripe, tested at this stage.......... 5 27.0 2.33
Stone 13%-10:
Small green, tested at this stage.... 5 147.2 9.36
Large green, tested at this stage.... 5 142.1 5.81
Large green, allowed to ripen ........3 172.8 16.74
Firm ripe, tested at this stage........ 5 143.0 7.96
Overripe, tested at this stage.......... 5 152.2 3.53

Significantly more ascorbic acid was found in small green
Redland guavas'than in those picked at any other stage of ma-
turity. The overripe fruits of this variety were likewise found
to contain significantly more ascorbic acid than did any of the
large green fruits. No significant differences were found, how-
ever, between the 2 groups of large green fruit nor between
the overripe and firm-ripe Redland guavas. No differences
among the Stone guavas were found to be significant. It is inter-
esting to note, however, that the figures for the fruit tested im-
mediately after picking followed the same general trend in each
variety; that is, the small green and overripe fruits contained
more ascorbic acid than did the large green and firm ripe fruits
of the same variety. Since these results are not entirely in
agreement with the results of the above-mentioned workers,
a more extensive investigation including a larger number of
seedlings must be made before a definite conclusion can be
reached. In view of the above-mentioned experience with refer-
ence to spotting and decay, this hardly seems practical unless







Florida Agricultural Experiment Station


some means of utilizing these fruit in their immature stages
can be found.
Ascorbic Acid Content of Some Species, Seedlings and Seed-
ling Races of Guavas.-The ascorbic acid content of a number
of guavas representing various species, seedlings, and seedling
races is listed in Table 3.
These results are in agreement with those reported by such
workers as Miller and her associates in Hawaii (4), Ranganathan
in India (1) and Hill in Australia (1), all of whom likewise
found the guavas to be an excellent source of ascorbic acid.
It is evident from results in Table 3 that the ascorbic acid
content of P. guajava covers a wide range. Among the higher
results obtained for this group were 486.0 mg. per 100 gm. for
Seedling 15-11 and 481.3 for Seedling 16-11; among the lower
values obtained were 23.1 for a grafted Redland and 26.2 for
Eloina. The other species of guava tested were found to contain
less ascorbic acid than did the majority of the P. guajava.
Results in Table 3 indicate that among these guavas there was
no apparent correlation between color of flesh and ascorbic acid
content. Since no attempt was made to select a representative
number having each of the flesh colors, these results cannot be
considered conclusive in this respect.

LITERATURE CITED
1. BOOKER, LELA E., et al. A compilation of the vitamin values of foods
in relation to processing and other variants. U.S.D.A. Cir. 638, p.
100. 1942.
2. HEINZE, P. H., et al. Ascorbic acid content of 39 varieties of snap
beans. Food Research 9 (1): 19-26. 1944.
3. LYNCH, S. J., and H. S. WOLFE. The Redland guava. Fla. Agr. Exp.
Sta. Press Bull. 562. 1941.
4. MILLER, CAREY D., et al. Vitamin values of Hawaiian grown fruits
and vegetables. Hawaii Agri. Exp. Sta. Progress Notes 36, revised
1944.
5. Plant Material Introduced by the Division of Foreign Plant Introduction,
Bureau of Plant Industry, Oct. 1 to Dec. 31, 1932. U.S.D.A. Inven-
tory 113, p. 18. 1934.
6. POPENOE, WILSON. Manual of tropical and subtropical fruits, pp. 272-286.
The Macmillan Company. 1919.
7. WADDINGTON, GUY, and FRANKLIN M. CIST. The vitamin content of
Psidium guajava. Florida State Hort. Soc. Proc. 56: 110-112. 1942.






TABLE 3.-THE ASCORBIC ACID CONTENT OF SOME FLORIDA GROWN GUAVAS.


Color of Flesh
Tree Designation


Psidium guajava L.
Indian
Red Indian 22-11* ..................................
White Indian 24-10 ................................
Pink Indian 23%-10 ..............................
Indian 21Y2-10 ......... ..............................
Indian 23-11 .........................................
Indian 22-10 ...........................................
Indian grafted 14-10 .........................
Indian grafted 131/2-10 ......................
California Varieties
Eloina 161/2-11 ......................................
Riverside 15 -10 ......................................
Redland
Original seedlings .................................
Grafted 13 -11 ......................................
Grafted 142-11 ....................................
Undescribed Seedlings and Grafted Trees
Seedling 10-28 ...................................
Choice grafted 18-11 ..............................
Stone grafted 13/2-10 .......................
Stone grafted 17'/2-101/2 ..................
Stone grafted 17 -10 ............................
Seedling 16-10 ....... .............................
Seedling 15-112 ........... ...............
Fuchs grafted (s.)** 17-112 ....
Seedling 16-11 ..........................................
Seedling 21-10 ............................................
*Numbers indicate tree and row in grove plot.
**Letters (s.) and (1.) are used to indicate two separate grafts on one tree.


Ruby red to carmine ....
White ........... .....
Red .................................
Light yellow ..................
Yellow-white ...........-
Yellow-white .. .......
Deep red .....................
Deep red ....................

Yellow-white ..................
W hite ................... .....

White to light pink .......
White ...........................
White ......................

Red ......................... ........
Ruby red .....................
Deep pink ................--
Deep pink ........................
Deep pink ......................
Salmon pink ....................
Pink and yellow mottled
Pink and yellow mottled
Pink and yellow mottled
Pink and yellow mottled


No. of Ascorbic Acid Content
Analyses (mg./100 gm.)
Average Range


195.7
111.0
177.6
142.4
129.5
100.2
127.0
120.1

26.2
104.0

24.7
24.6
23.1

119.2
100.3
143.0
229.5
252.4
281.3
338.3
161.2
481.3
217.6





Min.

170.0
77.6
157.6
142.4
89.0
88.0
101.2
107.4

16.2
95.4

22.5
24.6
23.1

95.0
87.4
124.2
187.0
252.4
259.3
279.0
152.4
436.6
167.4


--


Max.

212.4
147.4
195.6
142.4
153.6
115.2
152.0
130.0

40.0
110.4

26.0
24.6
23.1

147.4
112.4
167.2
255.0
252.4
320.7
387.3
170.0
531.3
280.0









TABLE 3.-THE ASCORBIC ACID CONTENT OF SOME FLORIDA GROWN GUAVAS.-(Concluded.)


Psidium araca Raddi

Psidium guineense Sw.

Psidium coriaceum Mart.

Psidium cujavillus Burm. f.

Psidium littorale Raddi


Tree Designation


Seedling 17-12* ..........................................
Seedling 13-11% ....................... ...........
Fuchs grafted (1.)** 172-111/ ............
Fuchs grafted 18-11/ ............................
Seedling 15-11 .........................................
Seedling 17-11 ............................................
Seedling 13-101/2 .....................................
Lenz grafted 17-102 ..............................
Hybrid 21-12 ..............................................
Donaldson grafted or a root sprout
24-11 ............................................ ............
Supreme grafted 131/-12 ........................
Seedling 13-11 .........................................

Tree 8 2-12 .........................................

Tree 24-111/ ................................................
Tree 23-11/2 ...........................................

Composite sample from several trees....

Tree 12-10 ...........................................

Red Cattley 261/2-11 ............................
Composite sample from several trees
of Yellow Cattley ..............................


Color of Flesh


Yellow-white ..............
Yellow-white .............
Yellow-white .............
Yellow-white ................
Yellow-white ..............
Yellow-white ..............
Yellow-white .............
Yellow-white ..............
Yellow-white ................

Yellow-white ................
White .......... ................
White ........... ...........

Yellow-white ..............

Yellow-white ...............
Yellow-white ................

Yellow-white ..............

Yellow-white ................

Yellow-white ..............

Light yellow ...... ..........


No. of
Analyses


5
2

5

1

5

5


Ascorbic Acid Content
(mg./100 gm.)
Average | Range


52.7
107.0
41.5
88.0
486.0
35.0
93.4
29.4
305.7

31.8
246.9
334.2

37.2

27.3
40.5

35.1

32.4

29.1

39.2


Min.

44.2
94.4
25.0
88.0
408.3
26.0
73.8
20.0
253.2

25.2
181.6
295.7

30.0

15.0
37.4

33.8

32.4

25.1

35.0


Max.

62.4
125.4
73.8
88.0
525.0
47.4
125.2
44.0
359.2

37.4
284.6
375.0

45.2

37.4
43.6

37.7

32.4

31.6

43.4


*Numbers indicate tree and row in grove plot.
**Letters (s.) and (1.) are used to indicate two separate grafts on one tree.




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