ERZURUM, KARS, ERZİNCAN ve GÜMÜŞHANE İLLERİNDE YETİŞTİRİLEN ÖNEMLİ ELMA ÇEŞİTLERİNDEN ASKORBİK ASİT KATILARAK ELDE EDİLEN ELMA SULARININ AMBARLANMASI SIRASINDA BÜNYELERİNDE MEYDANA GELEN KİMYASAL ve FİZİKSEL DEĞİŞMELER ÜZERİNDE ARAŞTIRMALAR

Abstract

OZET Bu arastirma, degisik uretim asamalarinda askorbik asit (C vitamini) kattlmis o/an/ar ile, katk1siz elma sularinin, oda sicakliginda ve buzdo/abll1da alti ay sure ile ambarlaninalari sirasmda, top/arn polifenol, askorbik asit, titre edilebilir asitlik, pH, sakkaroz, top/arn ve indirgen seker, toplam kuru madde ile renk .yonunden ugradik/ari degismeleri saptamak amaciyla yapi/mistir. Materyalolarak. Erzurum, Kars, Erzincan pe Gumushane illerinin elma yetistiriciligi yonunden onemli yorelerinde, b~hcede agaclarindan yeme olgunlugunda toplanan Amasya, Golden, Cam, Karadacik, Ak saki, Gobek ve Sinan elma cesitlerinden; elmalar parcalanir parcalanmaz 100 kg cibreye /00 g, pastodzasyondan hemen once 100 kg siraya 100 guzerinden askorbik asit katilarak elde edilen elma ~ulari i'e askorbik asit katdrnadan elde edilen elma sulm i kul/anilmistlf. Toplam polifenol .nicelikleri ambarlama suresince aitma ve aza/ma bicimiminde da/galanmalar gostermistir. Askorbik asit katkili elma sularinin polifenol miktarlari katkisizlardari daima· yuksek bulunmustur. A.~lwrbik asit kattlmadan islenen elma su/arrnin askorbik asil du' zeylerinin cok dusuk oldugu ve 2 aylik ambar/ama sonunda nicel o/arak belirlenemiyecel<. kadar azaldigi saptanmistir. Askorbik asit katkili elma sulannda askorbik asil kaybinin daha cok ilk 2 ay icinde oldugu belirlenmistir. Ambarlamanm ilk 2 ayinda onemli aialma gosteren titre edi/ebi/ir asit nicelikleri bundan sonra 6. ay sonuna kadar dec~ismemistir. Indirgen seker J1rcelikl~1 inin ambadama siiresince yukseldigi, bu durumun oda sicakliginda daha belirgin oldugu saptanm(Jtlr: SlikkaJ'oz duzeyleri ambarlama suresi boyunca azaldi.~i halde, sakkGl'oz ve indirgen seker toplami olan toplam seker deg;.smemistir. Ozellikle, elmalarm parcalanmasindan hemen sonra askorbik asit katilan elma sularinm renklerinin, ambartarna siiresince katklSlzlarinkinden cok daha acik kaldigi saptanmistir. SUMMARY INVESTIGATONS ON THE CHEMICAL AND PHYSICAL CHANGES OCCURING DURING THE STORAGE OF APPLE JUICES WHICH WERE MANUFACTURED WITH THE ADDiTON OF ASCORBiC AClD FROM THE iMPORTANT APPLE 'VARiETES GROW'iNG iN PROVINCES OF ERZURUM, KARS, ERZiNCAN AND GUMUSHANE This research has been inade to find out the changes accuring in same chemical and physi.cal proterties, of apple juices with or without addition of L- ascorbic acid i tl different processing steps, during six rnon.ths of st0rage in two diITerent temperatures. Apple juices obtained from the varietIes of Amasya, Golden. Cam Karadacik, Ak Sak. Gobek and Sina~ wliich were harvested from main apple growing districts of Erzurum, Kars Erzincan and Gumiishane pro vinces, were used in this expeiiinenL The experimental inaterials each apple variety were prepared as follow: 100 g ascorbic was added to 100 kg pulp inimediately after grindil1g;, _._- 100 g a~corbic acid was added to 100 kg juice just before their pasteurization.: -No ascorbic ,acid was during processing (control). All sample~ were ira nsfered into the colored bottle and pasteurized. After the pasteurization, half of the sainples e<ich treatment 16 were kept in a refrigerator and the other half kept at the room temparature for six months. The t'oHowing re,ulb have been obtained: i. it has been found out that the ascorbic acid conlent of apple .iuices proc.: essed without addition of ascorbic acid were 100 Jow, 2. The main decrease in the ascorbic acid content of fortified sainples has been seen in the fjrst 2 months, After this period decrease is not significant. Lower ascorbic acid content was found in the jucics prepared w'ith the <iddition of asorbic acid in early stages of processiug (i.e. just after ,gri iidi ng) than jucies prepared ,,;'ith the addition of ascorbic acid in later stages of processing U.e, jiist before pasteurization). 3. The polyphenol content of apple jucices obtained from different varieties was also difl'erent. Although the inflLlence of the processing steps which ascorbic acid was added on the po'yphenol amouiit is not significant, greater polyphenol content was found in fortified jucies. 4. Different titratable acidity was fourid for each vadeties. In the nrst two months of starage there were significant decreases in titratable acidities, after that period any chal1~ ge was not occured. Addition of ascorbic acid iIlcreased the acidity of apple jl:lIces significantly. 5. The amount of reducing sugar increased through the storage period. This was more prominent at room temperature starage eonditions. The redl.!ciiig sugar content of the varieties were different. Different. amounts of total sugar are found in varieties as their natural characteristics. 6. The color of apple juices mesaured by yellow and red color values of Lovibond Tintometer was different for each variety. The addition ascorbic acid to the pulp effected the color of juices and the lowest Lovibond color values obtained from these samples. The samples obtained by addition of ascorbic a«id just before pasteurization showed darker color than above treat· ment and samples without ascorbic acid gave the darkest color of all,