Impact of Storage Time on the Content of Kefir

Abstract

Kefir is assumed as a functional beverage out of its probiotic content and its consumption has been increasing continually worldwide for few decades. This study was conducted to monitor the effect of storage time on the pH, acidity, total dry matter and total free amino acid content of kefir at cold storage (+4°C) for 7 days. The characteristics of kefir were analysed daily to observe the changes occurring during the storage. Total free amino acid content measurements were achieved via spectrophotometric method. The pH values of kefir inclined to decrease from 4.25 to 4.02 steadily during the storage. The acidity contents of kefir were within the range of 0.77- 0.92 g lactic acid/100 mL and have shown fluctuations in the storage duration. Levels of total dry matter augmented until the middle of the storage time and then showed fluctuations. While the highest amounts of total free amino acids were detected at the second day of storage, total free amino acid values were varying between 0.0214 and 0.0431 g/100 mL (as leucine equivalent) and storage caused significant differences on this trait of kefir.

Keywords

• Kefir
• fermented milk beverage
• functional beverage
• storage
• content

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