Izvorni znanstveni članak
https://doi.org/10.15567/mljekarstvo.2018.0305
Microbiological, physicochemical, and sensory characteristics of kefir produced by secondary fermentation
Filiz Yıldız-Akgül
; Adnan Menderes University, Agriculture Faculty, Department of Dairy Technology, Aydın 09100, Turkey
Atila Yetişemiyen
; Ankara University, Agriculture Faculty, Department of Dairy Technology, Ankara 06110, Turkey
Ebru Şenel
; Ankara University, Agriculture Faculty, Department of Dairy Technology, Ankara 06110, Turkey
Zeliha Yıldırım
; Ömer Halisdemir University, Engineering Faculty, Department of Food Engineering, Niğde 51240, Turkey
Sažetak
In this study, the microbiological, physicochemical, and sensory properties and volatile aromatic compounds of kefir produced by secondary fermentation were investigated. Cow milk samples containing 1.5 % fat were fermented with kefir grains until the pH reached certain levels (pH 5.0-5.5), and then each of them was inoculated with a different starter culture (thermophilic, probiotic, mesophilic aromatic, and yeast) for secondary fermentation. In kefir samples produced traditionally or by secondary fermentation, the pH values, carbon dioxide levels, and tyrosine and lactic acid contents increased during storage. However, the counts of lactococcus, lactobacillus, leuconostoc, and yeasts decreased. Acetaldehyde and ethanol increased during storage, but diacetyl decreased in kefir samples produced traditionally or by secondary fermentation. The butanone contents changed very little but they showed an upward trend within the storage period. Kefir samples produced by secondary fermentation found greater acceptance during sensory testing than samples produced by the traditional method. Kefir inoculated with mesophilic aromatic and yeast cultures were the most preferred by panelists.
Ključne riječi
kefir, secondary fermentation; microbiology; physicochemical properties; volatile aroma compounds; sensory quality
Hrčak ID:
202361
URI
Datum izdavanja:
28.6.2018.
Posjeta: 2.765 *