Evaluation of Spreadable Kefir Produced from Different Milks in Terms of Some Quality Criteria

Abstract

Kefir, which has many beneficial effects on health, is one of the most consumed fermented milk products worldwide. It is important to increase consumption of the fermented product for public health. In this study, it was aimed to increase the beneficial effects of kefir on public health. Therefore, kefirs produced from different types of milk (cow, buffalo, sheep, and goat) were concentrated, and obtained spreadable kefir samples were investigated in terms of their microbiological characteristic (lactic bacilli, lactic cocci, yeasts and moulds, total bacteria, and coliform bacteria), benzoic acid content, physicochemical properties (fat, total solid, ash content, acidity, pH, syneresis, viscosity, colour, and rheological properties), and sensory characteristic. It was determined that APC, lactic bacilli, lactic cocci, and yeast counts of the concentrated kefir samples changed between 6.90 and 8.64, 6.89 and 8.61, 7.42 and 8.72, and 2.17 and 5.39 log CFU/g, respectively, during storage. Mould and coliform bacteria were not detected in the samples. The concentrated kefir samples contained benzoic acid in the range of 18.30-119.58 mg/L. Results from this study showed that type of milk caused differences on APC, lactic bacilli, lactic cocci and yeast count, total solids, ash, fat, acidity, pH, syneresis, colour, viscosity and rheological parameters, and benzoic acid content. In addition, milk type affected sensory properties of the kefirs. Concentrated kefirs produced from cow and buffalo milk were the most liked by panellists. Finally, it was determined that concentrated kefir was favoured as a new product by most of the panellists.

Keywords: Concentrated kefir; Microbiological characteristic; Rheology; Sensory properties.