1) Muğla Sıtkı Koçman University, Fethiye Faculty of Health Sciences, Department of Nutrition and Dietetics, Karaçulha 48300 Fethiye/Muğla, Turkey; 2) Niğde Ömer Halisdemir University, Faculty of Engineering, Department of Food Engineering, 51240 Niğde, Turkey
Nilgün Öncül1), Ayşe Özbey2), Hakan Erinç2), Zeliha Yildirim2)
In this study, the microbiological properties, physicochemical characteristics, antimicrobial and antioxidant activities of Turkish commercial kefir products were investigated. The enumeration of Lactococci, aerobic lactobacilli, anaerobic lactobacilli, acetic acid bacteria (AAB) and yeast were performed by spread plate technique and counted as 7.35, 6.62, 6.85, 6.24 and 2.35 log CFU/g, respectively. Antimicrobial activity of kefir was evaluated using the disk diffusion method. Ten microorganisms, including seven Gram-positive strains and three Gram-negative strains were tested. While Listeria monocytogenes, L. ivanovii and Escherichia coli were the sensitive bacteria for all kefir samples, L. plantarum, Staphylococcus aureus, Bacillus cereus and E. coli O157:H7 are the resistant bacteria. The means of pH, total phenolic content, Trolox Equivalent Antioxidant Capacity (TEAC) and lipid peroxidation were 4.03, 4.39 mg GAE/100 mL, 0.15 µmol Trolox/mL and 7.23%, respectively. From the beneficial health properties point of view, kefir appears to be a promising food.
Keywords: antimicrobial, antioxidant, commercial, kefir, pathogens
Arch Lebensmittelhyg 72,
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