Effects of processing techniques and cold storage on ellagic acid concentration and some quality parameters of pomegranate juice
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Dosyalar
Tarih
2011
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Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Bu çalışmanın amacı, farklı işleme teknikleri ile üretilen nar sularının işleme ve 4 °C'de 150 gün depolama boyunca ellajik asit içeriğinde ve diğer bazı kalite parametrelerinde (renk, suda çözünür kuru madde (°Briks), pH) meydana gelen değişimlerin karşılaştırmalı olarak incelenmesidir. Narlar meyve suyuna üç farklı geleneksel yöntemle işlenmiştir. İlk yöntemde, bulanık meyve suyu üretilmiştir, ikinci yöntemde, durultma yardımcı maddelerin ilavesiyle berrak nar suyu üretilmiştir. Üçüncü yöntemde ise termal evaporasyonla üretilen 65-70 °Briksteki konsantreden rekonstitüsyonla berrak nar suyu elde edilmiştir. Isıl işlemler ve depolama boyunca ellajik asit konsantrasyonunun, yüksek molekül ağırlıklı ellajitanenlerin depolimerizasyonuna bağlı olarak, önemli oranda azaldığı gözlenmiştir. Depolama boyunca ellajik asit içeriğindeki azalmanın, berrak nar sularında bulanık olanlara kıyasla, daha belirgin olduğu görülmüştür. Bu durumun nar suyunda serbest ellajik asidin depolama süresince suda çözünmeyen sediment oluşumuna katılmasından kaynaklandığı düşünülmektedir.
The purpose of this study was the comparative assessment of the alterations in ellagic acid concentration and some quality parameters (soluble solid (°Brix), pH and colour) of pomegranate juices throughout different conventional processing techniques and storage at 4 °C for 150 days. Three different conventional methods were used to process pomegranates into juice. In the first method, a unclarified juice was produced. In the second method, a clear juice was obtained by addition of fining agents. In the third method, a clear juice was obtained by reconstitution from the concentrate at 65-70 °Brix produced by thermal evaporation. A significant increase was observed in ellagic acid concentration during thermal processing and storage period which is likely due to depolymerization of the high molecular weight ellagitannins. Variations during storage were more significant in clear juice compared to unclarified pomegranate juice, which may be due to the contribution of free ellagic acid to the development of insoluble sediments in pomegranate juice during storage.
The purpose of this study was the comparative assessment of the alterations in ellagic acid concentration and some quality parameters (soluble solid (°Brix), pH and colour) of pomegranate juices throughout different conventional processing techniques and storage at 4 °C for 150 days. Three different conventional methods were used to process pomegranates into juice. In the first method, a unclarified juice was produced. In the second method, a clear juice was obtained by addition of fining agents. In the third method, a clear juice was obtained by reconstitution from the concentrate at 65-70 °Brix produced by thermal evaporation. A significant increase was observed in ellagic acid concentration during thermal processing and storage period which is likely due to depolymerization of the high molecular weight ellagitannins. Variations during storage were more significant in clear juice compared to unclarified pomegranate juice, which may be due to the contribution of free ellagic acid to the development of insoluble sediments in pomegranate juice during storage.
Açıklama
Anahtar Kelimeler
Gıda Bilimi ve Teknolojisi, Pomegranate Juice, Ellagic Acid, Ellajitannen, Clarification, Concentration, Storage, Nar Suyu, Ellajik Asit, Ellajitannen, Berraklaştırma, Konsantrasyon, Depolama
Kaynak
GIDA
WoS Q Değeri
Scopus Q Değeri
Cilt
36
Sayı
5