THE EFFECT OF AUTIOXIDAHT ASCORBIC ACID UPON THE

ASCORBIC ACID COBT1HT OF CERTAIN FROZEH FRUITS

APPROVEDj

feajop fmt%amv

, .„ u. • V M $dfe*58<BSI rtrTV^. Minor Professor

Dean of th« School of Home Eeonoaios

aduat©'School «n of

THE EFFECT OF AHTIOXIDABT ASCORBIC ACID UPOIf THE

ASCORBIC ACID CONTENT OF CERTAIN FEOZEW FRUITS

THESIS

Presented to the Graduate Counoil of the

Horth Texas State College in Partial

Fulfillment of the Requirements

For the Degree of

MASTER OF SCIBHCB

By

223514 Luey Stuart Crow, B* 8»

Denton* Texas

August, 1953

223514

TABLE OF CONTENTS

Pag#

US* OF TABLES. . , , . . * . . iv

LIST OF ILLUSTRATIONS . V

INTRODUCTION. 1

PROCEDURES • . 4

DISCUSSION OF RESULTS IS

* • M

APPENDIX. . » 28

BIBLIOGRAPHY. • • . . 89

ill

LIST OF TABLES

Table Pag®

1, The Reduced, Dehydro, and Total Ascorbic Acid of Fresh and Frozen Peaches During a Five-Month Storage Period. . . . . . . . . 11

2* The Reduced, Dehydro, and Total Ascorbic Acid of Freah and Fro sen Apricots sad Cantaloupes During a Five-Month Storage Period . . . . . . . . . . . . . . . . . . . 20

5. Percentage of the Total Ascorbic Acid and the Percentage of Dehydro and Reduced Ascorbic Acid Retained in Peaches, Apricots, and Cantaloupe During a Five-Month Storage Period . . , , . 22

4, The Reduced, Dehydro, and Total Ascorbic Acid Content of Pies Made•from Home Frozen and Coraiaerelally Froaen Fruit • . . • 24

8. Basic Chemical Data of Reduced Ascorbic Acid Content of Fresh and Frozen Fruits. , . 30

6. Basic Chemical Data of Reduced Ascorbic Acid Content of Pies Made from Home Frozen and Commercially Frown. Fruit „ . • • SB

7. Basic Chemical Data of Dehydroaacorbic Acid Content of Fresh and Frozen Fruits# . . $4

8. Basic Ohemleal Data of Dehydroascorbic Acid Content of Pies Made from. Home Frozen and Commercially Frozen Fruit . . • . 36

9. Names of Brands of Frozen Peaches Analyzed in the fre»@nt Study » . * * « * * • * * « » SS

iv

LIST Of XLLTJSSRATIQHS

Figure Page 1* Calibration Curve for ftodueed Aaeorbie

Acid, * • «»,*» 10 0, Calibration Sam for Dehydroaseorbie

M14* W

IITRODUCTIOH

The effectiveness of ascorbic acid in inhibiting the

browning of fruit has been studied by a number of investl-

gators. Tressler and DuBois (1944)* reported ascorbic acid

to be the moat effective in preventing thla discoloration

and in retaining the natural, fresh flavor of the fruit.

In comparing ascorbic aold with eltrle aeld and counaerelal

mixtures used as antioxidants, Stracbsn and Moyls (1949)2

found ascorbic aeld to be the most satisfactory antioxidant.

Furthermore, Dawson, Kirkpatrick, and Toepfer (1952)3 report

that larger quantities of aseorble aold are needed to pre-

serve the quality of Elberta peaehes during storage in a dry

sugar paek than in a syrup pack. The amounts required are

225 milligrams per pint for the dry sugar pack and 86 milli-

grams per pint for the syrup paek.

Chin, Elliott, and Sohuck (1948)* have pointed out the

need to analyse stored fruits for both reduced and

•4). K. Tressler and C. DuBois, "Ho Browning of Cut Fruit by lew Process,* good Industry. XVI (1944), 75, 157-138.

% * C. Straohan and A, V. Moyls, "Ascorbio, Citric, and Dlhydroxymaleie Acids As Antioxidants in Frozen Packed fruits,* Food technology. III (1949), 328-332.

SKlsle H. Dawson, Mary E. Klrkpatrick, and Edward W. Toepfer, "Amount of Ascorbic Acid Required for Home Freesing of Elberta Peaehes,* Food Research, XVII (1952), 433-437.

4shlh Dyung Chen, K. Elliott, and Cecilia Schuck, Total, Dehvdro. and Reduced Ascorbic Acid in Cantaloupe. * Journal of the American Dietetic Association. XXIV (1948), 863-BBB.

2

dehydroascorbic aeld* Twenty per cent of the total amount

of ascorbic aeid present In cantaloupe at the beginning of

storage at refrigerator temperature was in the form of de-

hydroascorble aeld* This n o w l was increased to 39 per

cent during a twenty-four-hour storage period* With this

increase in dehydroasoorbie aeld, there was a decrease in

reduced ascorbic acid, thus indicating that the decrease of

reduced ascorbio aeid may be attributed to the increase in

dehydroasoorbie aeid only if both the reduced and dehydro-

asoorbic acid are determined*

Few studies have been made to determine the amount of

ascorbio acid retained following the storage of the frosen

fruit, Eighty per cent of the added ascorbic acid as an

antioxidant was retained after eight to sixteen months of

froses storage when the amounts of 160 to 200 milligrams

per fifteen ounces of fruit and syrup were used, according

to Straehan and Moyls (1949)*5 Eighteen to 36 per cent of

the total ascorbic acid retained was in the form of dehydro-

ascorbic acid# The latter was found to double in amount dur-

ing a two-hour standing period after the fruit was thawed*

Cooper* Sard* and Bedford C1949)® made a study ©f cow-

meroially frosen peaches and boyaenberrles which were

5Strachan and Hoyls« op* cit»» p* SSI,

%ladys 2, Cooper, Margaret M. Hard, and 0. L, Bedford, "The Ascorbic Aeld and Carotene Content of Frozen Peaches and Boyaenberrles Defrosted with Dielectric Heat," Food Technol-ogy. Ill C1949), 408-410*

prepared with added ascorbic aeid* The peach©® contained

from 17.0 to 82,0 milligrams ©f reduced asoorbic acid and

from 14,7 to 18*5 milligram® of dehydroascorbie aoid per

100 gram® of fruit and syrup* the boyaenberriea contained

from 10*2 to 20,2 milligrams of reduced ascorbic acid & M

from S*6 to 11*2 milligrams of dehydroascorbic aeid per

100 grams of fruit and syrup*

It was suggested by Tressler and DuBois (1944)7 that

ascorbic aeid used as an antioxidant in the freezing of

fruits could increase the ascorbic acid value of the fruit

in the diet. However, with the exception of the previously-

mentioned study Mi© fruits were not analysed prior to and

following frozen storage to determine the amount of ascorbic

acid present*

The purpose of the present study is to determine the

redueed and dehydroascorb ie acid of certain frozen fruits

prepared with and without ascorbic acid as an antioxidant*

7Tressler and DuBois, 0£* clt*. p. 138*

PR0C1DUHE

Three lots of peaches ant on© lot each of apricots and

cantaloups were purchased on the local market and Immedi-

ately f»os«&* The peaches available were over-ripe, mixed

varieties and were not of the best quality, but they were

representative of those la the local stores at the tine

this study was made* The aprloots and cantaloupe were of

fair quality* Procedures for the hone freesing of fruits

recommended by the United States Department of Agriculture

Bulletin Mwtoer 175 were followed except that corn syrup*

was used In place of a sugar syrup.

The peaches were washed, peeled, pitted, and sliced

Into one-eighth Inch slices• fhe apricots were washed#

peeled, and haired* The cantaloupe was washed, halved and

seeded, and made into melon halls three-fourths inch in di-

ameter* As prepared, the fruit was immediately placed In

a E per cent citric acid solution* The citric acid served

as an antioxidant while the entire purchase lot was being

prepared* The prepared fruit was then thoroughly mixed, and

a fifty-gram sample of each fruit was weighed into twenty

parts of 5 per cent metaphossborlo aold solution for the de-

termination of dehydroascorbie acid in the fresh fruits. A

•Sweetose*

second flfty-grs» sample of each fruit was weighed into

seven parts of 1 per cent motaphosphorie acid for the de-

tenaination of reduced ascorbic acid.

She fraits were all frosen in pint freeser jars* Three

hundred twenty greas of each lot of peaches and of the apri-

cots and 260 graaas of cantaloupe were weighed directly into

welched freezer jars and covered with 180 grass of corn

syrup to which 125 mllllgraaia of ascorbic acid were added

and thoroughly blended# the ascorbic aeid was used as an

antioxidant during freezing and atoraga of the fruits. It

has been shown by Dawson, Klrkpatrick, and Toepfer (1952)8

that §§ milligrams of ascorbic acid per pint used as an

antioxidant will preserve the quality of peaches during

frozen storage when a syrup pack la used* In the present

study 125 milligrams of ascorbic a©Id were used, which Is

59 milligrams above the amount needed as an antioxidant.

Consequently, the asoorble sold retention of the fruits used

In this study should be higher. One-half inoh of space was

left at the top of eaeh jar to allow for expansion, and

cruaapled looker paper was plaeed on top of the fruit to keep

it submerged in the syrup. The controls were prepared in

the seme manner except that the ascorbic aold was omitted

from the syrup. A total of nine pint jars of fruit were

prepared fro® each purchase lot of peaches and of apricots*

&Dawson, Klrkpatrlek, and Toepfer, ojj. clt.. p. 437.

Two of the nine Jars in each lot were used as controls •

Six pint jars of cantaloupe weim prepared, vlth only cm® jar

being used as a control, because no plea were to be made

from the cantaloupe*

The Jars were sealed and placed. In the bottom of the

deep freese and frosen at -29° C. for twelve hours. They

were then moved to a basket at a higher level in the deep

freese and stored at -20° G.

A pint Jar from each lot of fruit was removed from

storage at the end of four, eight, twelve* sixteen, and

twenty weeks of storage* The fruit was completely thawed

at refrigerator temperature (10° C.)« Sight and one-half

hours were required for complete thawing of the fruit* Two

controls from each lot of the peaches and the one lot of

aprloots were removed at the end of twenty weeks of storage#

One control was used to determine the amount of dehydro-

ascorbic acid and of reduced ascorbic acid remaining in the

thawed, raw fruit* The other control was used to determine

the amount of ascorbic acid remaining after the fruit had

been cooked in a pie. The cantaloupe control sample was re-

moved and analysed for dehydroascorblc acid and reduced as-

corbic acid at the end of twenty weeks of storage*

After each pint of the fruit was completely thawed, It

was divided in half by weight* One-half of the fruit and

syrup mixture was placed in an equal amount of 5 per cent

metaphosphor 1o acid. The other half of the fruit and syrup

was placed in an equal mount of 1 per cent metaphosphoric

acid* All samples were blended In the Waring Blendor be-

fore aliquots were taken for analysis*

Duplicate 20-milllliter sespies of the fruit and 5

per cent metaphoaphorlc aeid mixture were pipeted into dup-

licate 19G-milliliter portions of 5 per cent metapihosphorle

aeid for the deteiwination of dehydroascorbic aeid. Dupli-

cate 20-milllliter samples of the fruit and 1 per cent meta-

phosphoric acid mixture were pipeted into duplicate 60-

milliliter portions of 1 per cent metaphosphoric acid for

the determination of reduced ascorbic acid.

Pies were mad© at the end of twenty weeks of storage

with one pint of fruit from each of the three lots of peaches,

the one lot of apricots, and from one control of each lot of

fruit so that the amount of ascorbic acid remaining after

the fruit had been eooked could be determined*

The pies were cut into fourths, and one-fourth of each

pie was weighed and put into an equal part of 6 per eent

metaphoaphoric acid* Another fourth was weighed and put into

an equal part of 1 per eent metaphosphoric acid* Aliquots

for the determination of dehydroascorbie acid and reduced

ascorbic acid in the pies were obtained In the same manner

as in the frosen fruit*

Pies were also made from two different brands of eom-

merclally-frosen peaches during the first month of the study

and from four different brands during the last month of the

8

study. Dohyd.ro and reduced ascorbic aeld were determined

for these plea aiad compared with those values obtained In

pies made from the home-frozen peaches.

fhe method of Loeffler and Pontlng (1942)® was u>«d

for the determination of reduced ascorbic acid. The ex-

tracted sample was filtered and 1,8 mi H i lite re of the fil-

trate measured into a cylindrical tube from a pipet. Fire

milliliters of indophenol dye* previously standardised to

read 18, were added from a rapid delivery pipet and a read-

lng taken in the photelometer* which had been set on 100

with § milliliters of distilled water in a cylindrical tube.

Blue filter lumber 515 was used, fhe reading obtained la

the photelometer was then read on a standard curve*

Solutions of ascorbic acid containing from 0.001 to

0.04 milligrams per milliliter were prepared for establish-

ing the standard curve. The photelometer was set for 100,

using 5 milliliters of distilled water In a cylindrical cell*

fhe dye was then standardized by adding a few crystals of

the dye until the solution gave a reading of 18 with 1.8

milliliters of 1 per cent metaphosphorle acid. Five milli-

liters of the dye were added from a calibrated plpet to 1.8

milliliters of the ascorbic aeld solution in a cylindrical

cell. Headings were taken fifteen seconds after the addition

% . J. Loeffler and J. D. Pontlng, "Rapid Be termination in Fresh, Frozen, and Dehydrated Fruits and Vegetables** In-dustrial and Engineering Chemistry. XIV (1942)* 846-849.

of Mi© dye, using blue filter lumber SIS# 1®suits were

then plotted on semi-logarithmic paper, Figure 1.

Fruit samples were run in duplicate and a recovery made

for e&eh sample. For the recovery, a solution of 25 ml111-

grams ascorbic sold in 25 milliliters ©f 1 per cent metaphos-

phorio aoid was used. One milliliter of this solution was

diluted to 100 milliliters with 1 per cent metaphosphoric

acid and read In the photelometer to ©heck with the standard.

Five milliliters of this dilution were added to 20 milli-

liters of the fruit mixture, diluted to 80 milliliters, and

filtered* The solution was then read in the photelometer

and the reading read on the standard curve. For each recov-

ery 0.05 milligrams of ascorbic acid were added to the fruit

sample. Recoveries ranged from 96 to 110 per cent.

The determination of dehydroaseorbic acid was made by

the method of Roe and Osterling (1944)10 with the modifica-

tion of Baloney and Kremmerer (1946)^ being used to elimi-

nate the ice bath. The extracted sample was filtered and

4 milliliters of the extract measured into each of three

matched test tubes from a pipet. One tube was kept for a

blank. To each of the other tubes 1 milliliter of a 2 per

1 0 H . Roe and Jane ©sterling* "Determination of Dehy-droascorhic Acid in Plant Tissue by 2 - 4 - Dinitrophenyl-hydraslne Method," Journal of Biological Chemistry. CLII (1944), 511-517.

11R. H. Balomey and A* R. Kremmerer, ®De termination of Ascorbic Acid, A Simplification of the Roe Method," Journal of Biological Chemistry. CLXV (1946), 577-578.

10

_ /f> lf» IV.

O O O o O O O o

ol. - w - ^ <i 4Hf n8 m m ^ ~ o Millltsranis oo o o o o O o o o ° o o o o o

"Zfl

XX

cent 2 - 4 - dialtrophenyXhydraslne In approximately 9 1

suXfurie acid solution was added* The two tube® were held

at 37© 0, for three hours. To each of these tubes and to

the blank, S milliliters of concentrated acetic acid were

added from & burette, a drop at a time, during not leas than

one minute* The acetic aoid was used to eliminate the use

of the ioe bath* Finally X milliliter of the 2 per oent

2 - 4 » dlnitrophenylhydraslne solution was measured Into

the bXank tube fro® a pi pet • The tubes were aXX shaken

thoroughly.

Thirty minutes after the addition of the acetic acid*

5 milliliters were measured fro® each of the sample tubes

into matohed cyXindrloaX tubes. The photeXoaeter was set

at XOO, using 8 mlXXlllters of the blank soXutlon in a cyXln-

drlcal tube* A reading of the sample solutions was then

taken• Green filter Humber §80 was used. The reading ob-

tained in the pfaotelometer was read on a standard curre*

For the standard curve a solution of 26 milligrams of

ascorbic aoid In 25 milliliters of 5 per cent metaphosphorlo

aeid was treated with two drops of branlne, shaken until

yellow, decanted from the exeess of bromine into a large test

tube, and aerated until colorless* Standard solutions of de«

hydroascorble aeid In concentrations from 0.25 to 15 micro-

grams per milliliter were made by diluting the above solu-

tion with 5 per oent metaphosphorlo aeid and 1 per cent

thiourea. One milliliter of 2 - 4 - dlnltrophenylhydrasine

12

was added to 4 milliliters of each of the dehydroaseorbie

acid solutions and the solutions incubated three hours at

57° G* Five Milliliters of acetic acid were added to each

of the standard solutions and readings taken in the photelo-

aeter thirty minutes after the aaeti© aoid had been added*

The photelometer was set for 100 with the blank which eon-

taiaed 4 Milliliter® of 5 per eent metapfeoaphori© acid

treated as the standard solutions except that the incuba-

tion period was omitted* Green filter lumber 550 was used*

Results were then plotted on semi-logarithmic paper# Figure 2*

Samples were run in duplicate and a recovery made for

each sample. For the recovery a solution of 25 milligrams

ascorbic aeid in 25 milliliters ©f 6 per cent metaphosphorie

aoid was treated with two drops of bromine# shaken until

yellow# decanted# and aerated until colorless* One milli-

liter of this solution was-diluted up to 1000 with © per

cent metaphosphorie aeid and 1 per cent thiourea and read

in the photelometer to check with the standard* Twenty

milliliters.of the original solution were diluted to 100 with

S per cent metaphosphorie aoid and 1 per cent thiourea. Two

milliliters of this dilution were added to a B0*milliliter

sample of the food mixture, diluted to 210 milliliters, and

filtered* The solution was then incubated as the food

sample and read in the photelometer. This reading was read

on the standard curve* For the recovery# o»2 milligrams of

1 3

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14

dehydroascorbic acid were added to each fruit sample, R®-

eoT®ri©s rang@d from $4 to 1GS p©r o«nt*

DX3CUSSI0H OF RESULTS

fhe ascorble a©Id content of cantaloup© was studied by

Chin, Elliott, anfi S chuck (1948)^ before and after storage

at refrigerator temperature. fh® amount of dehydroaseorbic

aeid present increased from 20 to 39 par cent during the

storage period* With the increase in dehydroaseorbic acid,

there was also a decrease in reduced ascorbic acid. Straefaan

and Moyls (194fl)^3 report that 80 per oent of the ascorbic

aeid which was added as an antioxidant to frozen fruit was

retained. Of this amount retained, a large per oent was in

the form of dehydroaseorbic aeid. These studies indicate

the need to determine both the reduced and the dehydro-

aseorbic aeid of frosen fruits prior to and following stor-

age* especially when ascorbic aeid is used as an antioxi-

dant.

In the present study three lots of peaches and on® lot

each of apricots and of eantaloupe are analyzed for reduced

and dehydroasoorbis aeld prior to and following froaen stor-

age# For the determination of reduced ascorbic aeid, the

method of Loeffler and Ponting (1040)^ la used* while the

*8ehin, Klliott, and Sehuck, oj>. pit.

ISstraehan and Moyls, 0£. alt.

l^Loeffler and Ponting, 0£. clt.

1®

16

Baloney and Kreiamerer {1946)18 modification of the Ho# and

©sterling (1944) ® method 1» used to determine the dehydro*

asscorbic acid. Recoveries ranged frosa 96 to 110 per cent

for the former arid from 04 to 105 per eent for the latter#

The reduced and dehydroa s c orb i c acid values are added to

obtain the total aseorbie acid reported 1b this study. One

hundred gram portions of the fresh and frozen fruit® are

the basis for the calculations of the ascorbic acid content,

100 grams being the equivalent of one serving of fruit# One

hundred gram portions of fruit are also used in calculating

the asoorbic aeid in a serving of pie, These servings are

equivalent to one-fifth of an eight inch pie made from home

fro sen fruit and one-fourth of a six Inch pie made from ©on-

merclally frosen fruit# (Only twelve-ounce packages of com*

merclally frozen fruit are available* which accounts for the

difference in the size of the pies,)

The three lots of fresh peaches vary from 2.8 milli-

grams in Lot 1 to §.4 and S«? Milligrams reduced ascorbic

acid in Lots 2 and 5» respectively, Table 1, Lot 1 contains

twice as much dehydroascorbie acid as Lot 2, whereas Lots 2

and 5 differ only slightly in their values, Even less vari-

ation is evident for the total ascorbic acid values, 4.9,

®#§, and 7.4 milligrams for the respective Lots 1, 2, and 3.

The ascorbic- acid loss of peaches frozen without added

l^Balomey and Kremmerer, ojd. pit.

l%oe and ©sterling, oj>. oit.

17

TABLE 1

3SB KEDUCI©, DBHTD1Q, AID TOTAL ASCORBIC ACID OF PKESH A ® FROZSH PEACHES M R I M A FIVE-MONTH

STORAGE PERIOD

Ascorbic Acid in 100 Grams

Time le&ucefi Dehydro Total Time

tot 1 Lot 8 Lot 3 Lot 1 Lot 2 Lot 3 Lot 1 Lot 2 Lot 3

mg« ®g. ag* fflg. rig. Kg. ag. rag.

9yeib

0 mo. 8.8 5.4 5.7 2*1 1.1 1.7 4.9 6.3 7.4

5 mo. 2.3 3.4 3*4 1*4 1.0 1.6 3.7 4.4 4.9

Frozen#

1 BIO, 24.1 24*9 25.0 12.6 12.6 13.8 36.7 37.5 4*£| O oo#o 2 mo* 28*9 24*0 24*3 12.6 13.5 13.7 36.3 37.5 38.5

3 mo# 23.0 as.® 23*9 13.6 13.5 14.3 36.5 37.3 38.2 4 mo* 81,6 21.7 22*7 14.3 14# 4 14*3 56*9 36.1 37.0

5 mo* 21*6 21,7 21.6 14.3 14.6 14.3 36.9 36.3 35.9

Ave* oo A «€J 23.2 23*6 13*6 13.7 14.1 36.3 36.9 37.7

«A11 samples not indicated aa freeh have 12© mg, of aacorbie acid tuied m Antioxidant per pint of peaches*

18

ascorbic acid as the antioxidant is mainly of the reduced

forst Although there is also a small loss of dehydroaicorM®

acid# The total ascorbic acid mimes of these same lot#

after five months storage are from 1 to 2 milligrams less,

namely, 3.7, 4*4* and 4*9 milligrams for Lots 1, 2, and 3,

respectively* fhe reduced ascorbic a®Id Is changed more

during th# five months of storage of th© frozen peaches

than is the dehydroascorbic acid,

Th® reduced ascorbic acid of th® peaches frozen with

added ascorbic acid is decreased fro® 24*1 at the end of

the first month to 21,6 milligrams at the end of the fifth

month in Lot 1, from 24,9 to 01*? la Lot 2, and free 26.0

to 21.6 milligrams in Lot 3. With this decrease in the re»

dweed ascorbic acid there is an increase in the dehydro*

ascorbic acid from 1S*6 at th© #nd of th# first month of

storage to 14.8 milligrams at the end of the fifth month

in Lot 1, from 1B.6 to 14.0 in Lot 8» and fro® 13.8 to 14,3

milligrams in Lot 3. The total ascorbic acid values for

these lots are 36.7 at the end of the first month of a tor*

age and 35.© milligrams at the end of the fifth month in

Lot 1, with 37,5 and 36.3 In Lot 2, and with 38,8 and 36.9

milligrams in Lot 3« These totals fall within the range of

32*0 to 38*0 milligrams of total ascorbic acid per 100 grams

of fruit reported by Cooper, Hard, and Bedford (1949)17 for

l*7cooper, Hard, and Bedford, oj». pit.

li

commercial packs of frozen peaches, although the amount of

aaootfble acid added before freezing and the length of frozen

storage are not given.

In th# present study lis Milligrams of ascorbic acid

per pint of fruit art used, which Is 59 milligrams above the

66 milligrams per plat reported toy Dawson, Kirkpatrick, and

Toepfer <1952)18 to ha sufficient for pre string the quality

of peaches during frosen storage when a syrup pack It used.

However, the results of the present study show that the us©

of the larger amount gives a lOO^gram serving of frozen

peaches an ascorbic acid value equal to that of a 100-gram

serving of grapefruit,

fhe reduced, dehydro, and total ascorbic acid values

for apricota and cantaloup® prior to freezing and during a

five-months storage period are shown In Table 2, The fresh

apricots contain 5*5 milligram! of reduced ascorbic acid,

2.1 milligrams of dehydroaseorbie acid* end 7,6 milligrams

of total ascorbic acid* At the end of five months of frosen

storage, these values are 3.9, 8,9» and 6.2 Milligram#, re*

gpeotively. These changes are similar to those obtained with

peaches prepared without ascorbic acid as an antioxidant.

When ascorbie acid is used as an antioxidant, the apricot#

contain 25.0 milligrams of reduced, 13.1 milligrams of de-

hydro, and 36.1 milligrams total ascorbic acid at the end

3%awsonp Klrkpatrick, and Toepfer, 0£« git.

20

f kMM 2

fBB RSDOCEB, DEHYDRO, AMD TOTAL ASCORBIC ACID OF FRISB AM) FROZE! APBICOTS AH) CASTAtOTJFES

DUBIHG A PIVE-MOHf l STORAGE PERIOD

Aaoorble Ac id in 100 @r«s

§ 1 » Redueed Befaydro Total

Canta- C a n t a - Canta-Aprieota loupes Aprieota loupes Aprieota loup#®

mg . mg. mg. mg. ag» Rig*

Fresh

0 mo. 5 * 8 25.6 2.1 8.8 7.6 32*1

5 mo. 3*9 16.0 2 * 3 6*4 8*3 2 2 * 4

Pr®«®n#

1 mo# 25.0 45.1 13.1 18.0 3 6 * 1 @3*1

2 mo. 88*8 4 8 * 0 1 * » J*## f

17*7 37*5 62.7

3 mo* 23.6 43*0 13.7 18*8 37.3 61*8

4 mo. 0 1 , 6 42. 4 ^ i* 14*# s 19*1 38*9 81*8

5 mo* 21.4 41,8 1 4 * 3 19*4 38.7 6 1 , 2

A f « . 2 3 * 1 4 3 . 6 13.8 18*6 58*8 62*0

• A l l samples not I n d i c a t e d a® f r e s h have 125 mg. of aaoorble acid uaed as antioxidant per pint of fruit#

21

of on®' month of storage# At the end of five months of stor-

age the reduced ascorbic acid la decreased, t© 21«4 ®illl->

grama» and the dehydro is increased to 14,3 milligrams* giv-

ing a total of 38*7 milligram* of ascorbic acid, Again

these changes are similar to those observed with th# peaches,

fhe fresh cantaloupe contains 25,6 milligrams of re*

duced and 6.5 miHigrams of dehydro, giving 32.1 mi111grams .

of total ascorbic acid, Although all these values are low*

©red after five months of storage, the cantaloupe Is still

a good source of ascorbic acid, furnishing 16.0 milligrams

reduced, ©#4 dehydro, and a total ascorbic acid value of

22*4 milligrams. With the addition of ascorbic acid, the

reduced ascorbic acid values at th© end of on© month and

five months of storage ar# 45,1 and 41,8 milligrams, re-

spectively, The dehydroascorbio acid increased from 18,0

to 19.4, whereas the total ascorbic acid decreased from

63*1 to 61.2 milligrams, These values indicate that froaem

cantaloupe with added ascorbic acid is an excellent somrce

of ascorbic acid* When ascorbic acid is used m an *nti*

oxidant, there i® less loss in reduced and total ascorbic

acid during frozen storage.

The percentage of ascorbic add retained in the fruits

during the five-months storage period is shown in Table 3,

When ascorbic- acid is used as ®n antioxidant for the fruits*

the percentage is based on the amount of ascorbic acid. In

the fresh fruit plus the amount added as an antioxidant.

22

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There is less change in the dehydroascorbic a©Id and total

ascorbic acid when ascorbic acid is used as an antioxidant.

With tli® exception of apricots# the percentage of total

ascorbie aeid retained by the fresh fruit is lower than that

retained by the fresh fruit to which ascorbic acid is added .

as an antioxidant* Although the percentage of total as-

corbic acid,retained in the fresh apricots at the end of

the five-months storage period is slightly higher than that

of the apricots with added ascorbic acid, the milligram

value is only one-sixth that of the latter# In all the

fruits with added ascorbic acid the parcentage of dehydro-

ascorbie aeid increased slightly during the fife-month storage

period, whereas in the fresh fruit it decreased with the ex*

ception of peaches* Lot 2, and the apricots, both of whieh

Increased slightly# The dehy dro a s e orb i c acid value of fresh

cantaloupe remained unchanged*

from Table 4 it is evident that frozen peaches made into

pies contain lets reduced ascorbic aeid than dehydroascorbio

acid* fhe reduced ascorbic aeid value of the controls, whleh

have no added ascorbic acid prior to freezing, is 0#d, 0.4,

and 0.6 milligrams for Lots 1, 2, and 3 of peaches and 0.6

tot apricots, with 1.1, 1*1$ 1*0# and 1*1 milligrams of de»

hydroascorbic acid for these same pies. When 125 milligrams

of ascorbic acid are added to these peaches prior to freezing,

the pies contain 1.6, 1.4, and 1.5 mlHigrams of reduced as-

corbic acid, and there is 4#2# 5*3, and 5*0 milligrams of

24

TABLE 4

REDUCED,, BBHXDRO, AND TOTAL ASCORBIC ACID COWlSf OF PIBS MADE FROH SOUS WROZM

A W COMMERCIALLY moms wmm

Aaoorbic Aeid in 100 Oraaui Frait

Raduead Dehyflro fotal

ag. lag* Kg.

Home Frozen Fruit

Pe&ehe* Lot 1 Control* 0,6 3* . 1.7 Exp. 1,6 4.2 5.8 Lot 2 Control* 0*4 1.7 2.1 Exp. 1«4 §.3 6.7 Lot 5 Control# 0*@ 1.6 2.2 Exp, 1.5 5.9 7.4

Aprleofcs Control* 0*® 1.1 1.7 lxp« 2.0 ft.3 8.3

Commercially Frozen Pruit

Peaches A Sample 1 1.1 tt 0

0*0 4.9

Sample 2 0.8 9*6 4.4 B Sample 1 0.8 4.3 5.1 Sample 2 1.1 3.6 4.7 C 0.3 4*3 5.1 D 1.1 3.® 4.7

Average o.§ 3.9 4.8

•Controls ver« froMQ without th© additi on of ascorMe aoid as an antioxidant.

dftfc droasoovtole &oida respectively. The total ascorbic acid

values for these pi®® are 5.8, 8#*?, and *?.4 milligram## Sim-

ilarly, apricots with added ascorbic a©Id when made into pies

provided trait only slightly superior to th© peaches. These

findings indicate that the use of 128 milligrams of ascorbic

acid per pint of fruit cannot be recotrsraended as a means of

increasing the ascorbic acid value of frozen fruit a ?v«pa#9&

as fruit pies*

The pits mad® from commercially frozen peaches contain

less reduced aeeoAic acid than those »ade with peaches pre-

pared with added ascorbic acid in the present study, The

lalels on th# commercial packs state that ascorbic acid ha*

been added as an antioxidant to the peaches# but none spec*

ify the quantity added. The reduced ascorbic acid values

for these pies are 0*8 and 1*1 milligrams, with the dehydro-

ascorbic aeid ranging from 5.6 to 4.3 milligrams per serv-

ing. All of the commercially frozen peaches gave pies with

Ids® total ascorbic acid than those prepared in the present

study*

The addition of 125 milligrams of ascorbic acid per

pint of fruit did not noticeably increase the ascorbic acid

value of the fruit cooked in pies, whereas this amount

makes the otherwise low aseorbi© acid value of frozen

peaches and apricots equal to grapefruit, while the amount

present in cantaloupe is doubled.

SUfMAEY

fh# reduced and dehydroascorbic acid content of three

lot® of peaches and on® lot each of apricots and of canta-

loup® mm determined prior to and during a five-month frozen

storage period. The fruits are prepared, mixed, sampled,

and analyzed before the pints of fruit are prepared for

freezing. One hundred twenty-five milligrams of ascorbic

acid are added as an antioxidant to eaoh plat of fruit

with the exception of the controls. Two controls are pre- '

pared from each lot of fruit, one to be analyzed in the

fresh state and the other as fruit pie at the end of the

five-months storage period. One pint of fruit from each

lot is removed,, stapled, and analysed at one month inter*-

vals during a five-month frozen storage period. Ascorbic

acid values are also determined for pits mad# from four

brands of commercially frozen peaches.

The reduced ascorbic acid content of all the fruits

analyzed in the present study changed more during the

five-months storage period than did the dehydroascorbic

acid. The decrease in reduced ascorbic acid is usually

accompanied by a alight increase in dehydroascorblc acid.

In all cases total ascorbic acid is less at the end of the

five months of storage. The average per cent of total

ascorbic acid remaining at the end of storage ranged from

m

27

SI to 82 for the peaches, 80 for the apricots, and 7? per

cent for the cantaloupe.

There is little difference in the ascorbic acid ccm-

tent of pies mad© from commercially frozen peaches and those

prepared in this study# In no instance Is the ascorbic acid

value equal to that of the frozen, uncooked fruit*

One hundred twenty-five milligrams of ascorbic acid per

pint of fruit are used in the present study. With this ad**

dition, fresh peaches end apricots are changed from poor

source® to good sources of ascorbic acid# A serving of

these fruits provides as much ascorbic acid at a serving of

grapefruit, The Initial good ascorbic acid value of canta~

loupe is nearly doubled by this addition of the antioxidant

ascorbic acid prior to freezing. Furthermore the effect of

the added ascorbic acid antioxidant on the ascorbic acid

value of the fruit is evident at the end of five months of

frozen storage#

APPENDIX

DIRECTIONS FOR PR1PAOTG THE SOLUTIONS

Reagents and Solutions for the Determination

of Redueed Aseorfele AcId

Solution of pure ascorbic aold» Oat hundred milligrams of

asoorhl© &eid were dissolved In §00 milliliters of on*

per oent metaphosphori© acid.

Solution gf one per mnt aetaphosphorl© agld, f m grams of

metajhosphorlo aold stick were dissolved la ©90 milli-

liters of distilled water#

Pre solution. Thirty milligrams of sodium dichloro'benzenoin-

dtphenol vers dissolved la 1 liter of distilled water.

Reagents and Solutions for the Determination

of Dehydroasoorblo Agld

Standard solution of dehvdroaseorble acid« Twenty-five mil-

ligrams of asoorfele aold wer* dissolved In 25 milli-

liters of 5 per oent metaphosphorio.acid and treated

with two drops of bromine«

Solution of. 5 per oent metaphpsphorio aold and j. per cent

thiourea. Fifty grams of met&phosplhorle aold stlok and

10 grams of, thiourea were dissolved In 940 milliliters

of distilled water#

28

29

Solution of j| 2®r o m t 1 - J - dlnltrophenylhsdraslne in

approximately 9, N sulfuric aold« Twenty grams of 2 - 4 -

dlnltroph»nylhydraalne w#r® dissolved in 980 milliliters

of 0 1 sulfuric acid*

Concentrated osotle aold.

30

TABLE 5

BASIC CHEMICAL DATA OP REDUCED ASCORBIC ACID CONTENT OF FRESH A ® FROZEN FRUITS

Fruit and Ix>t

Tim® Sample Wt*

Sample I ,.$anpl#. II Fruit and Ix>t

Tim® Sample Wt*

Dilu* ticai

Read-ing

Curr® Value tlon •

Read-• Ing

Curv* Value

mo* pt« ss 1 * »g. ml. mg# F**«ah

mg#

Peaches Lot 1 0 10 80 25*0 .0035 80 25*0 *0035

Lot 2 6. 10 80 21*5 .0018 80 22#S *0022

Lot 2 0 10 SO 31.0 .0064 80 32*5 *0071 5 10 30 24.0 .0030 80 24*0' .0030

Lot 3 0 10 80 32*5 .0071 SO 32*5 *0071 5 10 80 24,0 .0030 80 23.5 *0028

Aprteots 0 10 80 32.0 *00®f 80 31*3 •oois s 10 80 25 *0 *003© 80 25.5 *003®

Canta-*003®

loupe 0 10 80 76.0 .0322 80 74*0 *0318 5 10 SO 44*0 .0130 80 44*0 .0130

Fi»0S5®n# Peaches Lot 1 1 10 80 59.0 .0210' 80 59.0 *0210

2 10 80 88.0 *020® 80 59*0 *02X0 a 10 00 57.5 *0201 80 57*5 ' *0201 4 10 80 54.0 .0181 80 *0190 § 10 SO 55.5 *0190 80 55*5 *0190

Lot 3 1 10 80 @9.5 *021§ 80 60.5 *0820 2 10 80 §9*0 .0210 80 89*0 *0210 5 10 80 58.5 *0208 80 58.0 .0206 4 10 SO 55*5' *0100 80 57*5 .0201 5 10 @0 55.5 .0190 80 is tst OQ*D .0190

Lot 3 1 10 80 60.0 *0218 80 60*0 *0218 2 10 80 60.0 *0218 80 59.5 .0216 8 10 80 59.0 .0210 80 59*0 *0210 4 10 80 57.5 *0201 80 57.5 *0201 5 10 80 54.0 *0181 SO 57*5 *0201

Apricota 1 10 80 @0.5 *0220 80 60.5 *0220 2 10 80 59.0 *0210 80 §9*0 .0210 3 10 80 59.0 .0210 80 58*0 *02011 4 10 SO m ff m

5i #11 *0201 80 55.5 .0190

5 • 10 80 #11* 15 .0190 80 55.5 *0190 Canta* 1 10 80 79.5 .0360 80 80*0 *0361 loupe 2 10 80 79.8 *03§0 |0 79,§ .0360 loupe

•3 10 80 78.S *0350 80 78.5 .0350 4 10 80 77.5 *0344 ' '80 78*0 *034© g 10 80 78*0 .0345 80 77. S .0344

ascorbic acid used as l&dioa' an aat

ed as imsh h oxidant per p

y& IS nt oi

® ag|. o.

3 1

fABLE 5 * » C m t i n u M

S a m p l e I I I S « $ © T « f 7

D i l u - S u i t # Av® . ' M M . "

l i f t f i T O I ft D i l u - R#|y|«* C u r r e R e c o v -

t i o n Ixig Yalta# * * © y U * w«i> v

A d a t i o n i n g Vrnlm e r y

m l • rag. m* m g . m l . mg* i

8 0 m*o • 0 0 5 5 . 0 0 3 5 Alt •UP

8 0 2 6 * 5 • 0 0 4 1 96 § 0 2 2 . 0 • 0 0 » . 0 0 3 0 . 0 5 8 0 2 3 . 0 • o o a 6 96 8 0 31.5 , 0 0 6 8 . 0 0 6 8 . 0 5 8 0 3 3 . 0 . 0 0 7 4 9 6 8 0 2 4 * 0 . 0 0 3 0 *0030 , 0 5 8 0 2 6 . 5 • 0 0 3 6 96 8 0 3 0 . 5 . 0 0 7 1 . 0 0 7 1 • 0 5 8 0 3 4 . 0 • 0 0 7 7 96 8 0 1 4 * 5 *0052 • 0 0 3 0 • 0 5 8 0 2 5 . 5 • 0 0 3 6 96 SO ai«e . 0 0 6 8 . 0 0 6 8 • 0 5 8 0 3 3 . 5 • 0 0 7 6 1 1 0 8 0 8 5 * 0 . 0 0 3 5 • 0 0 3 5 • 0 5 8 0 2 6 » 5 • 0 0 4 1 96

80 7 4 . 5 . 0 3 2 0 . 0 3 2 0 • 0 5 8 0 7 5 * 5 • 0 3 m 96 ' 8 0 4 4 . 0 . 0 1 3 0 . 0 1 3 0 • 0 5 8 0 J IK IS

4 © • O . 0 1 3 8 1 1 0

8 0 59*0 . 0 2 1 0 . 0 8 1 0 • 0 5 8 0 59*5 ' • 0 2 1 6 9 6 8 0 § 8 . 5 .0208 . 080® • 0 5 8 0 59 • 5 •021® 1 1 0 8 0 §7. a •0201 • 0 2 0 1 . 0 5 8 0 . 58 .5 • 0 2 0 8 1 1 0 8 0 5 7 . S . 0 0 0 1 . 0 1 9 0 • OS 8 0 5 7 , 0 • 0 1 9 7 1 1 0 SO 8 5 . S . 0 1 9 0 . 0 1 9 0 . 0 5 8 0 5 7 . 0 • 0 1 9 7 1 1 0 8 0 6 0 . 0 •0818 . 0 2 1 8 • 0 5 8 0 6 1 . 0 . 0 2 2 5 1 1 0 3 0 S9#0 . o i l © . 0 2 1 0 • 0 5 8 0 5 9 . 5 • 0 2 1 6 96 @0 § 9 . 0 . 0 2 1 0 • 0 2 0 0 • 0 5 8 0 m * 5 •021® 1 1 0 8 0 § 4 . 0 • 0 1 8 1 • 0 1 9 0 • 0 5 8 0 5 7 . 0 • 0 1 9 7 1 1 0 8 0 5 5 * 5 . 0 1 0 0 . 0 1 9 0 • 0 5 8 0 5 7 * 0 • 0 1 9 7 1 1 0 8 0 6 0 . 0 .0218 • 0 2 1 8 • 0 5 8 0 61.0 • 0 2 S 5 1 1 0 8 0 6 0 , 5 ,0220 #0218 • 0 5 8 0 6 1 . 0 • 0 2 0 5 1 1 0 8 0 5 0 * 0 • 0 3 1 0 *0110 • 0 5 8 0 5 9 . 5 #0216 96 8 0 5 7 . 5 ' . 0 2 0 1 .0801 . 0 5 8 0 5 8 * 0 •0206 96 8 0 5 5 . S • 0 1 9 0 . 0 1 9 0 • 0 5 8 0 5 6 , 5 • 0 1 9 6 96 8 0 6 0 . 5 • 0 2 8 0 . 0 2 0 0 • 0 5 8 0 6 1 . 5 • 02B§ 96 8 0 5 9 . 0 .0810 , 0 2 1 0 • 0 5 8 0 5 9 . 5 *0816 96 8 0 5 8 . 5 . 0 2 0 8 . 0 2 0 0 •OS 8 0 5 9 , 5 *05310 1 1 0 80 5 4 . 0 • 0 1 8 1 . 0 1 9 0 • 0 5 ©0 5 6 . 5 • 0 1 9 6 96 8 0 5 5 . 0 . 0 1 9 0 . 0 1 9 0 . 0 5 8 0 0&*D • 0 1 9 6 96 8 0 7 9 . 5 . 0 5 6 0 . 0 3 6 0 • 0 5 8 0 8 0 * 5 • 0 3 6 7 1 1 0 8 0 7 9 . 5 . 0 3 6 0 . 0 3 6 0 • 0 5 8 0 8 0 . 5 • 0 3 6 7 1 1 0 8 0 7 8 . 5 . 0 5 5 0 • 0 3 6 0 • 0 5 8 0 7 9 , 0 • 0 3 5 6 96 8 0 7 7 . 5 . 0 5 4 4 • 0 3 4 4 • 0 5 8 0 7 8 . 5 • 0 3 5 0 96 so 7 7 . 5 . 0 3 4 4 , 0 3 4 4 • 0 5 8 0 7 8 . 5 • 0 3 5 0 96

32

TABLE 6

BASIC CHEMICAL DATA OF REDUCED ASCORBIC AQW COHTENT OF PUS MADE FROM HOME

AID COMMERCIALLY FROZEI FRUIf

Fruit S< ample ! I $mpU II and T 4*

fta# Sample t»f4» Dilu* Read- Curve Dilu- H@ ad*- Gurr© l*Q% wl# tlon lag V&tm tion ing ¥al u*

mo* m* ml* m* ml * Kg.

Horn® Fvos#n Fmltn

Peaches Lot 1 Conti?ol* 5 10 80 19*0 •000© so 80*0 *0011 Exp. 8 10 80 81*5 .0018 so 88*6 *0028

Lot 8 Control 5 10 80 18.5 •QOOS so 18*,§ *0005 Exp, § 10 80 ai.o *0014 to 21*0 *0014

Lot % Control s 10 80 19,5 *0008 so 19.© *0008 Exp. i 10 80 •oosa 60 81* § *0018

Apricots Control s 10 80 to*o *0011 SO 19*0 «0006 Exp. ft 10 80 sa*o *0026 SO 25*0 *0006

Coiam@reially frozen Peaeh*; s

A • 1 10 80 21.0 *0014 80 21*0 *0014 A «•* S 10 SO no*o *0011 SO 30*8 *0012 1 * 1 10 80 20.5 *0012 so to*o *0011 B » 2 10 80 21*0 *0014 to 81*0 *0014 C 10 80 20,$ *0012 m 10* @ #0018 D 10 to 21*0 .0014 so 21*0 *0014

•^Controls were fpozftn without th# addition of ascorbic acid as an antioxidant.

33

f ABLE 6—Continued

Sample XXI AT#.

Recovery

Dllu* Read* Curre AT#. Added. ft tfUr dot Vmjfck M Jm Dilu- Mend* Curve Reo ov~

tiOB lag falm# Amff}0rO3.9 Aeid tion lag. Value dry

ml. 3&g« mg. ml. ®g* % Hem# Frozen Fruita

80 19,5 ,0008 ,0008 .05 80 21.0 *0014 96 80 22*0 •0020 *0020 *05 80 25.0 .002® ©6 •

80 18*5 *0005 .0005 .OS 80 20.0 *0011 90 80 21*0 •0014 *0014 *05 80 22*0 *0020 96

80 IS.5 *0008 .0008 *06 80 21*0 *0014 96 80 22*0 *ooao .0020 .05 80 23*0 .0026 96

SO 19..S •0008 .0008 .00 80 21.0 .0014 9® 80 25*0 .0026 *002© *05 SO 23.0 *0032 96

0OM&@rcl&lly Frozen P©aches

80 21*0 .0014 .0014 .OS 80 28.0 .0020 96 80 80. 5 •0012 .0012 .05 80 21*5 *0018 96 80 SO, 5 •0012 .0012 .OS 80 21*5 .0018 9® 80 21,0 .0014 .0014 .05 80 22*0 *0020 96 @0 20* § *001 £ .0012 .05 80 21.® .0018 @6 80 21*0 .0014 .0014 .08 80 82*0 *0020 98

34

fABLE 7

BASIC CHEMICAL DATA Of DEJODRQASCGRBIC ACID GOTOIf OF FRESH AMD FIOZEI FRUITS

FVttlt and Lot

flm® Sample Sample ,X

Dilu-tion

Read-ies

Otayr# ¥alu#

Sample tl

Dilu-tion

Read-Ijag

Curre Valu*

Pvaah Peaches Lot 1

Lot 2

Lot 3

Aprieots

Canta-loup©

f?ogis* Peaches Lot 1

Lot 2

Lot $

Aprioots

Canta-

mo*

0 5 0 5 0 5 0 5 0 s

1 ' 2

3 4 5 1 2 3 4 § 1 2 5 4 i 1 2 5 4 5 1 2 5 4 5

10 10 10 10 10 10 10 10 10 10

10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10

ml*

210 810 210 210 210 210 210 010 210 210

210 210 210 210 210 210 210 210 210 210 210 210 tlO 210 210 210 610 210 210 210 210 010 210 210 210

•7.5 ©7*5 98.5 m,5 96,0 96,5 ii.o 97. S 60*8 92.8

88*0 87.5 85.5 86.0 35*0 87.0 86.6 87.5 85.5 86.0 86.0 1.5

85*5 85*5. 85.0 Set m w* P 85*5 ftt jg> 85.5 85.1 85.5 84*5 5.0

82.5

meg*

0.50 0.50' 0*25 0.25 1*00 0*80 1*50 0.50 S.10 2.50

4*00 4.20' 4.80 4.50 5.10 4*40 4*50 4*20 4.80 4.60 4*50 4*50 4*80 4* iO 5*10 4,50 4.80 4.80 4*80 4.80 5.80 $•80 5*20-5.90 8.00

ml.

210 210 210 210 210 210 210 210 210 210

210 210 210 210 210 210 210 210 210

210 210 210 210 210 43 JuW 210 210 M A 210 •21© @10' 210 210 210

©5.0 97.5 r\m fit <70 m H 98*5 Q*f tr i?/#a 98*5 97* S 96*0 90*5 95*0

87*0 87*5 £}*& m

85*0 6.0

87*5 86.5 1*5

85*5 85*5 88-* 0 8®#0 85.0 85*5 85.5 8§*S 88*0 87*5 85*5 85*0 BM 84*5 84*0 8S.0 82.5

1*50 0*50 0 * 8 0 0*25 0*50 0*25 0*50 1 * 0 0 3*10 1.50

4.40 4*20 4*50 5.10 4*§0 4*20 4.50 4*50 4*80 4*80 4*80 4.80 5.10 4*80 4*80 4*50 4*6© 4.20 4 #S0 5*10 5.80 5*20 5*50 8*90

#411 samples not Indicated as fresh have 125 mg. of ascorbic aeid used as an antioxidant per pint of fruit.

35

TABLE 7~»0onfclxmea

Sara.pl® I X I D i l u -t i o n

Read-ing

§Hf?l Valut

Ave. Added Aseoyoic

A«ift ® i l w t lon

f teai* f .Qg

Curve V*1m

R®@ov» •jpy

j s l . meg. meg. Big, m l . meg. %

210 9§.0 1*00 1.00 0.2 210 98*8 2.00 108 8X0 97.8 0*80 0.80 0.2 210 98.0 1.80 108 2X0 97.1 0*80 0.80 0.2 210 98.0 JL « 50 108 2X0 98. 8 o»n$ 0*88 0.2 210. 98*8 1.88 108 2x0 96 .8 0.60 0.80 O.f 210 94.0 1.70 94 2X0 97.8 0*80 0.80 0.2 210 98.0 1.80 108 210 m* o 1*00 1.00 0 .2 210 98.8 2.00 108 210 0*80 0.80 0.2 210 94.0 • 1*70 94 2X0 m * s 3*10 8.X0 0.2 210 Si.O 4.00 94 2X0 ©s.8 2.00 2.00 0.8 210 91.0 8.00 108

t i o 87,8 4,80 4.20 0.2 210 84,8 8.20 108 8io 87.8 4*20 4.20 0.8 210 88.0 8.10 94 • 2X0 87.8 4.20 4.80 0.2 n o 84*0 8.80 108 2X0 88.8 4*80 4. SO 0.2 210 88.8 8.80 108 2X0 85 #8 4*80 4.80 0,2 210 as.8 8.80 108 ' 210 88,0 4.00 4.20 0.2 210 84*8 5.80 108 2X0 88.* 8 4.80 : 4*80 0.2 210 84.0 & t&fi Q » v U 108 8XQ 88.8 4.80 4.80 ' 0.2 210 84.0 Q « 8 0

108 i i o 88.8 4.80 4.80 0 .2 210 88.8 ' 8.80 108 210 88,0 8.10 4.80 0.2 210 88.8 8.80 108 8X0 88,0 4.80 4.80 0.2 210 84.0 8.80 94 210 88*8 4. §0 . 4.60 0.2 210 84,0 8.SO 94 810 88.0 4.80 4.80 0.2 210 88.8 5.80 108 8X0 88*8 4*80 4.80 0.2 210 88.8 8,80 108 210 88*0 4.80 4*80 0.2 • 210 85.8 8.80 108 010 8®+8 . 4.80 4.80 0.2 210 84.0 8.80 108 810 88*8 '4*80 4.80 0.2 210 84*0 8.80 94 • 210 86*8 4*80 ' 4.80 0.2 210 84.0 8.80 108 210 88*8 4.80 ' 4.80 0.2 210 83.8 8,80 108 8X0 88.0 4.80 4.80 0.2 210 88.8 8,80 108 810 83.5 8.80 8*80 0.2 210 81.8 6.70 94 . 810 84.0 8,80 8.80 0.2 210 80*0 6,40 94 210 88*8 §*•80 8.80 0.2 210 82.0 6.40 94 210 88*0 8.90 8.90 0.2 210 81.0 6.90 108 810 82.8 8.00 6*00 0.2 210 81.0 8.90 108

36

fmm a

BASIC CHEMICAL DATA OF DEBIDROASCORBIC AOIB C0HTH3T OF PUS MADS FROM HOME FROZEN

AID COMMERCIALLY FROZEN HUIS

Prmit and tot

Simple I Saupl* JCI Prmit and tot

Tim# Saiapl© wt» .

Pilu* tiotl.

R#ad- Cms*?® Value

Dilu-tion

Read* Curt© Valui

mo, gm. ml# mm* •ml* mag*

Home Frozen Fruits

P#aohes Lot X ^ Contror Exp.

$ 5 10 1 10

810 210 .

97*8 /*«» ft 0.80 2.00

210 210

97*5 92.5

0.50 2.50

Lot 2 Control Exp.

5 5

10 10

210 . 210 !

m *o 92*S

1.00 2.80

210 210

97*5 92.5

0*i0 2.50

Lot 3 Control Exp.

8 5

10 10

210 • 210

97,5 91,5

0.50 0*11©

210 210

96,5 •1*0

0*80 5 *'00

Aprieota Control Sxp»

5 S

10 10

21© 210;

ftff gt 97 #0 89*0

o.so 3.40

210 210

97*$ 92*1

0 .,50 2 *50

0< Wfift ially Frozen Fruit

A ** 1 A » 2 B » 1 B - 2 C »

10 ; 10 -' 10

10 10 10

210 p"irt • 210 210 210 210

92*0 94 * 0 -95*0 •4*0 93.5 94.0

2.50 1.70 1.50 1-70 •00 % § W*

2*00-1*70

• 210 210

. 210 210 "210 210

95, i 94*0 02.5 94*0 93*5 94*0

2.00 1*70 2.50 1*70 2*00 1.70

•K-Gontrols were frozen without - the addition of ascorbic* aeid as an antioxidant.

37

f ABUB 8»*Coatinm®d

Sample III

Dilu-tion

Read-ing-

OuTft • Ave. ' Added

Aseorbi© Aold tion

Bead-ing

SttFf© "Value

Recov-ery

ml* »tg# meg* • rag# - ml* meg* * Home F m m n Fruit#

210 210

97*6 §§*0 0.50 1*80

0*S0 2«00

0*8 . 0.2 ;

210 210

98.0 91.0

1*S0 5.00

xo® 108

210 @10

96.5 92*8

0.80 2.50

o*ao 2.50

0*8 0*2

210 210

94.0 89*0

1*70 3.40

94 94', >

210 210

98*0 91# S

1.00 2.S0

0.80 2*80

0.2 0.2

210 210

§4.0 88*8

1*70 3.80

94' 108

310 310

97*8 91*0

0.50 5«00

o*so 3*00

0*2 . 0*2

210 210

95.0 80*0

1*80 4.00

108 108

OoHsmerelally Frozen Fruit

210 98.0 1*80 2.00 0.2 210 91*0 3.00 108 210 94*0 1.70 1*70 0*2 210 92 • 0 2.60 94' 210 9$*$ ' 2*00 2,00 0*2 210 91,0 3*00 10S 210 94.0 1*70 1.70 0*2 2X0- 92*0 2*80 94 210 93.5 '• 2.00 2.00 0.2 210 91*0 3*00 108 210 94*0 1.70 1*70 0*2 210 92*0 2»®0 94

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*ABIB 9

NAMES OF BRAIDS Of FROZEN PEACHES* AWAUmm 11 THE PRESENT STUDY

Brand Amount

A - Donald Duck 12 oi* pkg*

1 * Pict Sweet 18 os. pkg.

c - Libby* s IS os. pkg.

D - Snow Crop 12 os« pkg*

^Labels of all f3?«8to packs of p©aoh®s used stated that ascorbic a,©Id had been added, but the quantity of ascorbic acid added was not stated.

BIBLIOGRAPHY

Baloney, 1. H,» and Kremmerer, A. R#, "Determination of Ascorbic Acid, A Simplification of the Roe Method," Journal ef Biological Chemistry, CDC? (1940), 377*573• .

Chen, Shlh Dyung, Elliott, K», and Schuck, Ceeilia, '"total, Behydro, and Reduced Ascorbic Acid In Cantaloupe," Journal of the American Dietetic Association* XXI? I H H T 7 fi3-0ii»

Cooper, Gladys E.» Hard, Margaret M., and Bedford, C. I.., "The Ascorbic Acid and Carotene Content of Frozen Peaches and Boysenberrles Defrosted with Dielectric Heat," Food Technology, III (1949), 408-410.

Dawson, Blsl# H,» Kirkpatrick, Mary E»» and Toepfer, Edward W«, "Amount of Ascorbic AcId Required for Home Freezing of Blberta Peaches," gocd Research. XVII (1952), 435-437,

Loeffler, H. J*, and Pontlng, J. D., "Rapid Determination in Fresh, Frozen and Dehydrated Fruits and Vegetables," Industrial and Engineering Chemistry, XI? (1948)* 846*

1©#, J. H., and Osterling, Jane, "Determination of Dehydro-ascorbic Acid in Plant Tissue by 2 - 4 - dinitrophenyl-hydrazine Method," Journal og BlolMt&ftiA Chemistry* CLII (1044), 511-5177

Straehan, C. 0#, and »cylt# A. w., "A#®oi%ie, Citric, and Mhydroxyraalelc Acids As Antioxidants in Frozen Packed Fruit#,* food Technology, III (1949), 327*332.

Tressler, D, K.f and BuBois, C., "Ko Browning of Cut Fruit by Hew Prooeea," Food Industry, XVI (1944), 75, 137-138.

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