PASTÖRİZE KEÇİ SÜTÜNÜN DONDURULMASI VE DONDURARAK DEPOLAMASI SIRASINDA MEYDANA GELEN DEĞİŞMELER

Year 2015, Volume: 40 Issue: 4, 217 - 224, 01.08.2015

Hülya Yaman Hayri Coşkun

Abstract

Bu araştırmada, tam yağlı keçi sütünün pastörize edilip dondurulması esnasında ve dondurulan sütlerin12 aylık depolama süresi boyunca sütte meydana gelen değişmelerin belirlenmesine çalışılmıştır. Buamaçla, tam yağlı keçi sütü örnekleri süzüldükten sonra 65 °C’de 30 dakika pastörize edilerek farklıhacimdeki ambalajlara aktarılmış ve iki farklı sıcaklık derecesinde (-15 ve -35 °C) dondurulmuştur.Dondurulan sütler yine iki farklı depolama sıcaklığında (-18 ile -28 °C) bir yıl süre depolanmışlardır.Depolama süresince keçi sütlerinin toplam mezofilik aerobik bakteri sayısı, koliform bakteri sayısı, pH,titrasyon asitliği, viskozite, sedimantasyon, asitlik derecesi, oksidasyon, renk ve duyusal özellikleriincelenmiştir. Araştırmadan elde edilen sonuçlarına göre; keçi sütü örneklerinde koliform bakteri sayısındaazalma belirlenirken toplam mezofilik aerobik bakteri sayısında değişim gözlenmemiştir. Titrasyon asitliğimiktarlarında önemli değişme olmamış; pH, sedimentasyon, oksidasyon ve ADV değerlerinde önemliartışlar saptanmıştır. Dondurma ve depolama esnasında renk değerlerinde azalmalar tespit edilmiştir.Keçi sütlerinin koku, renk ve görünüş değerleri depolama boyunca değişmemiş, ikinci aydan sonra vizkozite değerlerinde artışla (p<0.05) hafif partiküllü yapı belirlenmiştir. Genel olarak değerlendirildiğindeproje çıktıları, pastörize keçi sütünü dondurarak saklamak suretiyle, kalitesinde hissedilir bir değişimolmadan raf ömrünün uzatılabileceğini de göstermiştir

Keywords

Keçi sütü, pastörize keçi sütü, dondurulmuş pastörize keçi sütü

THE CHANGES IN PASTEURIZED GOAT MILK DURING FREEZING AND THE FROZEN STORAGE

Abstract

In this research, it was aimed to determine some properties of the pasteurized whole fat goat milk afterfreezing and the frozen storage for twelve months. For this purpose, the goat milk samples were filteredand pasteurized at 65 °C for 30 min, and transferred into two different packages, then frozen at -15 and-35 °C. The packages were stored at -18 and -28°C for one year. During storage period goat milk sampleswere investigated in terms of their microbiological (total aerobic mesophilic bacteria and coliformbacteria), chemical and biochemical properties (pH, titration acidity %, viscosity, sedimentation, aciddegree value, oxidation and colour) and sensory characteristics. According to the results obtained, whilethe effect of storage time on the counts of coliform bacteria were found to be significant, there were nodifference at total aerobic mesophilic bacteria count. At the same time, colour values were observed tobe significantly reduced during freezing and storage period. During the storage time; odour, colourand appeareance of goat milk samples were not changed, after the second month, the mild particlestructure was determined with increasing in viscosity values (P <0.05). An overall evaluation the obtainedresults showed that the freezing and keeping in the frozen storage of pasteurized goat prolonged theshelf life of pasteurized milk without any important change in the quality

Keywords

Goat milk, pasteurized goat milk, pasteurised-frozen goat milk

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