OXYGEN CONTENT OF COMMERCIAL FROZEN ORANGE

Transcription

1 HGGART: OXYGEN CONTENT OXYGEN CONTENT OF COMMERCIAL FROZEN ORANGE CONCENTRATE R. L. HGGART Florida Citrus Commission Lake Alfred Incorporation air into citrus products du ring processing exposes tem to te action oxygen. Tressler and Joslyn () reviewed te extensive researc tat as been done on te effect oxygen on te quality canned citrus and oter fruit juices. Recently Webster () re ported te extension selflife in cilled orange juice by inline nitrogen sparging for removal dissolved oxygen. It was also reported tat tis procedure resulted in improved color and flavor canned orange juice over prolonged periods storage. Offflavors, usually described as cardboard or castor oil, occurred first during te sea son in commercial frozen d citrus juices during storage tese products at F. or lower. Olsen et al. (4) produced tese "oxi dized" flavors in frozen citrus s by te incorporation air into 4 and Brix products. 'Blair et al. () discussed tis problem and suggested te term "COF effect" for tese fflavors. Harwell (, ) reported te use nitrogen as advantageous in te processing orange. Te combination nitrogen stripped cutback juice blended wit evaporator under nitrogen, and nitrogen filled eadspaces in oz. cans, resulted in taste panel preference and sligtly iger flavor scores for te nitrogen processed orange wen compared wit a regularly processed product. Air Reduction Sales Company () also reported tat inline nitrogen sparging cutback juice and 4 Brix orange, prior to filling, improved product flavor, color and oter quality factors. Te purpose tis investigation was to de termine te oxygen content in commercial frozen d orange juices, packed in Florida during citrus seasons, and to find out if a relationsip between oxygen content and eiter flavor or apparent could be establised. lcooperative researc by te Florida Citrus Commission and Florida Citrus Experiment Station. Florida Agricultural Experiment Stations Journal Series No.. Experimental Procedures Collection. Samples commercial frozen d orange juices were collected semimontly. A total from Florida plants were obtained during te season and were collected from Florida plants during te season. Te from eac company ranged from to. During te season midseason were collected from December to Marc, inclusively, and late season products were obtained from April to June, inclusively. Seventyeigt midseason s were obtained during te season from December to February, inclusively, and late season were collected from Marc to June, inclusively. All were ex amined witin week after tey were received at te Citrus Experiment Station. Determination oxygen content. A Beckman MA oxygen meter adapter as sembly was used to determine te oxygen content te 4 Brix orange s. Tis assem bly consisted an oxygen electrode and an adapter unit wic permitted use te electrode wit a Beckman Zeromatic ph meter. Air at F. was used as te reference medium to calibrate te meter to a setting corresponding to te % by volume concen tration oxygen in air. Te oxygen content te sample was also determined at F. ± F. A calibration curve was obtained from Dr. J. Allen Brent te Minute Maid Company for conversion te percentage oxygen, as read on te Zeromatic ph meter, to milliliters oxy gen per grams 4 Brix. A conversion factor.4 was used. Determination apparent. Te apparent in centipoises te 4 Brix s was determined at F. wit a Brookfield LVT viscometer using te No. or No. spindle. Te reading was taken after minute at r.p.m. Determination flavor. grades for te 4 Brix s are based upon te opinions a member taste panel and a pro cedure previously described (). A point scoring scale was used wit corresponding to excellent flavor and to a product considered to be unpalatable. Eac sample was tasted twice

2 FLORIDA STATE HORTICLTRAL SOCIETY, by te panel members, initially and again after approximately monts, and an average grade determined. Results and Discussion Te minimum, maximum and average oxygen content commercial frozen concen trated orange juices from eac plant are pre sented in Table. Data in Table sow tat tere was considerable variation in te oxygen content te s witin many te individual plants. Tis was indicated by a maxi mum range to % or. to. ml. oxygen per grams. Tere was also a wide variation in values between te dif ferent plants wit minima, maxima and averages sowing ranges. to.,. to., and. to. ml./ g., respectively, for te season and. to.,. to., and. to. ml./ g., respectively, for te season. Frequency distribution tables te oxygen content from bot midseason and late season packs frozen orange are sown in Table. It is evident from tis data tat te range oxygen values was quite large. Comparison te results between te midseason and late season sows tat te oxygen content was, in general, less in te late season products. Te 4 Brix s obtained during te season, wen tere was a se vere freeze in te citrus area Florida, gen erally contained less oxygen tan tose collected during te season. Listed in Tables and 4 are averages for te oxygen contents, apparent viscosities and flavor grades for all orange ob tained from eac plant for te mid and late sea son periods during te citrus seasons. It was tougt tat a relationsip migt exist between te apparent and te oxygen content te s but none was found. It migt be noted tat te average viscosities ranged from 4 to for te and from 4 to for te s. Te larger viscosities during te season were probably due to te utilization frozen fruit, resulting from te freeze tat year. Te average flavor grades for te midseason obtained during te season in dicated a very sligt improvement in flavor as Table. Minimum, maximum and average oxygen content commercial frozen d orange juices from different Florida plants during te and citrus seasons j season season nunibgr I Oxygen concern; Oxygen l ml.o oxygen on Zeromatic Per grams ph meterg ^ u u k..... io.!o $ * o..o.ou ol.k ok..... Q $»..I.. O Oxyger on Seromatic ph meterss. l.... ml., oxygen per. LOO grams Mino Max. Av..... Oo o. O k..... $ O'.... oil.... Values calculated.

3 HGGART: OXYGEN CONTENT Table. Comparison frequency distribution tables oxygen content for from midseason and late season packs commercial frozen d orange juices collected semi montly durdiig te and ^^ citrus seasons Midseason late season Total per grams Season Samples % S samp] Les % %..O.QSO.O..H $>.O.. * o l*... ia * I*o..; o.. te average oxygen contents decreased. However, tis sligt trend is not evident in any te oter groups. Correlation coefficients were calculated between te oxygen content and flavor grade for all products collected during eac te seasons. A correlation coefficient. for te and. for te s indicated no practical re lationsip between oxygen content and flavor on te basis te data obtained during tis in vestigation. Since oter investigators (, ) ave reported flavor improvement in orange concen trate wit te use nitrogen stripping or sparging and since it as been demonstrated (4) tat COF or "oxidized" fflavors can be pro duced in orange by wipping air into tis product, it is believed tat te results tis investigation do not necessarily preclude te importance te elimination air from orange during its production. Te failure te data from tis investigation to establis a relationsip between te oxygen content and te flavor orange is believed to be due to te fact tat many factors () suc as Table. Average oxygen content, flavor grade and apparent commercial frozen d orange juices from different Florida plants citrus season midseason late season. per grams sample; grade per grams grade.*.*.....*.. * $$$ *..!ou.*.*.... * * * * *.* * ; * *...* *. *.O.... * * * * * * * * * * * l * *.... * * *.*... $ grades: Very good } Good ; Fair ; and Poor» *.

4 4 FLORIDA STATE HORTICLTRAL SOCIETY, Table i*. Average oxygen content, flavor grade and apparent commercial frozen d orange juices from different Florida plants ^ citrus season midseason late season per grams grade*' per grams grade * k...* * * * * Ik k i*.o. $. S> * *.*.*.*.* * * *. ** ** * * * * I* *.....*..... * * * * * *.*..... H*.*... grades: Very good a \ Good» ; Fair j and Poor *. fruit quality, extraction and finising procedures, oil content and oter processing procedures, in fluence te flavor orange. Tese oter factors may be equal or greater im portance to flavor quality tan tat te oxygen content and, terefore, prevented any relation sip between oxygen content and flavor from becoming apparent. Te effect using frozen fruit during te season may ave over sadowed oter flavor factors, as well as tat oxygen content, and caused te insignificant correlation coefficient indicated above for obtained during tis season. Only 4 from te total concen trates examined were graded "poor" in flavor because te presence COF or "oxidized" fflavors. Tese 4 products ad relatively ig oxygen contents.,.4,., and. ml./ g. Summary Te oxygen content, flavor and apparent vis cosity commercial frozen con centrated orange juice were determined. Tese products were collected from Florida plants during te and citrus seasons. A maximum range. to. ml. oxy gen per grams in from one plant sows te wide variation found in s from many individual plants. Tere was also a wide variation in values between pro ducts from different plants. Te average oxygen contents from eac te plants ranged from. to. ml./ g. In general, te oxygen content was less in late season s tan in. midseason pro ducts and te obtained during te season contained less oxygen tan tose from te season. No relationsip was found to exist between te apparent and te oxygen content te products examined. Te average viscosi ties midseason from eac plant ranged from 4 to ; te range for late season was from 4 to Low correlation coefficients between te oxy gen content and flavor grade all te orange s indicated no practical relationsip between tese caracteristics on te basis te data obtained during tis investigation. Te failure to establis a relationsip between oxygen content and te flavor orange is

5 ROSE, ATKINS, MOORE: PECTIC STDIES believed to be due to te fact tat many factors, suc as fruit quality, extraction and finising procedures, oil content and oters, influence te flavor orange. Tese oter factors may be equal or greater importance to flavor quality tan tat te oxygen content and, terefore, prevented any relationsip between oxygen content and flavor from becoming ap parent. Relatively ig oxygen content was found in te only 4 products tat were graded "poor" in flavor because te presence COF or "oxidized" fflavors. Acknowledgments Te autor desires to tank Dr. J. Allen Brent te Minute Maid Company, a Division te CocaCola Company, for supplying te curve for conversion te percentage oxygen, as read on te Zeromatic ph meter, to milliliters oxygen per grams. Appreciation is expressed to all te com panies wic supplied te frozen con centrated orange juice used in tis investigation and also to te personnel te.s.d.a. Agri cultural Marketing Service, Winter Haven, Flor ida, for teir aid in te collection tese. Te assistance Mr. R. W. Barron, wo made te determinations, and tat te taste panel is ereby acknowledged. Te members te taste panel were G. E. Alberding, R. W. Barron, Louise Cerry, M. H. Dougerty, E. C. Hill, M. D. Maraulja, S. K. Long, R. W. Olsen, Roger Patrick, and F. W. Wenzel. LITERATRE CITED. Air Reduction Sales Company.. Nitrogen treat ment frozen orange juice. Tecnical Data and Process Bulletin ADE. pp. '. Blair, J. S., Edit M. Godar, H. G. Reinke and J. R. Marsall.. Te "COF effect" in frozen citrus products. Food Tecnol.,.. Harwell, Turston W.. retention orange juice. Transactions Citrus Engineering Conference, Fla. Section, Am. Soc. Mec. Eng.,. 4. Olsen, R. W., E. L. Moore, F. W. Wenzel and R. L. Huggart.. Oxidized flavors in frozen citrus concen trates. Researc report at Sixt Annual Citrus Processors' Meeting. Florida Citrus Experiment Station, Lake Alfred, Fla. Oct. 4.. Tressler, Donald K. and Maynard A. Joslyn.. Fruit and Vegetable Juice Processing Tecnology. Te Avi Publising Company, Inc., Westport, Connecticut. PP.. nion Carbide Development Company.. retention process.. S. Patent,,.. Webster, Robert C.. Nitrogen treatment as a means extending selflife cilled and canned single strengt orange juice. Transactions Citrus Engineering Conference, Fla. Section, Am. Soc. Mec. Eng., 4.. Wenzel, F. W.. Te aroma and flavor Florida orange juices and s. Symposium on Volatile Fruit Flavours. Bern, Switzerland. International Federa tion Fruit Juice Producers. Reports te Scientific Tecnical Commission. JurisVerlog and Bucdruckerei Zuric, Switzerland.. Wenzel, F. W., E. L. Moore and R. W. Olsen.. Factors affecting te flavor frozen d orange juice. Citrus Station Mimeo Report. Researc report at Eigt Annual Citrus Processors' Meeting. Florida Citrus Experiment Station, Lake Alfred, Fla. Sept.. EFFECT OF SBFREEZING TEMPERATRES ON COMPONENT PARTS OF CITRS FRITS WITH PARTICLAR REFERENCE TO THE PECTIC CONSTITENTS A. H. Rouse, C. D. Atkins, and E. L. Moore Florida Citrus Experiment Station Lake Alfred Te wintry blast tat struck Florida Decem ber, lasted troug te 4t, lowered te temperature to subfreezing for many ours, and caused injury to bot citrus trees and fruit. Internal fruit injury resulting from subfreezing temperature is important to te processor be cause its adverse effect on quality and yield extracted juices. Many desirable pysical and cemical caracteristics citrus juices depend lcooperative researc te Florida Citrus Experiment Station and te Florida Citrus Commission. Florida Agri cultural Experiment Stations Journal Series No.. upon te pectic constituents in te various com ponent parts te fruit. To wat extent cold injury affected te component parts will be dis cussed in tis paper. A investigators (,,,, ) ave reported te effect freeze damage on color, sugar content, acid, specific gravity, ph, flavonoids, and flavor citrus juices. Bissett () conducted studies on various processing proce dures and presented te caracteristics orange s prepared from several varieties oranges wic ad been damaged in te freezes te season. Also, following te severe freezes te citrus season, Rouse et al. () presented information on te pectic canges and pectinesterase (PE) activity occurring in te juices from sound and freezedamaged Pine