Properties of kefir made from milk from different oilseeds

Objective: It is aimed to produce additive-free and sugar-free kefir from vegetable milk, which is thought to be an alternative to cow's milk, for consumers with health problems such as cow's milk protein allergy and lactose intolerance and for individuals on a vegan/vegetarian diet. Method: In this study, plant milk was produced from oil seeds such as cashew, hazelnut, peanut, walnut and almond. Kefir was produced by fermenting cow's milk and plant milks with kefir starter culture. Kefir samples were stored at 4oC for 30 days and physicochemical, microbiological and sensory analyzes were performed on the 1st, 15th and 30th days of storage. Results: The highest energy value was determined in hazelnut milk and hazelnut kefir. It was found that the pH value of kefir samples increased during storage, while the total carbohydrate and total organic acid content, apparent viscosity, thixotropy, flow behavior index and consistency coefficient values decreased. The highest total organic acid value was determined in cashew kefir. It was determined that ethyl acetate was the highest amount of volatile organic compound detected after ethanol in kefir samples produced from plant milk. It was determined that the highest total saturated fatty acids, total monounsaturated fatty acids and total polyunsaturated fatty acids values during storage were in cow kefir, hazelnut kefir and walnut kefir, respectively. The highest average total aerobic mesophilic bacteria, lactococcus, lactobacilli and acetic acid bacteria counts were determined in cow kefir, and the highest yeast count was determined in peanut kefir produced. It has been determined that the lightest color is in cow kefir, the darkest color is in walnut kefir, and peanut kefir and hazelnut kefir are preferred more. Conclusion: Milk obtained from oilseeds creates a challenging environment for fermentation with its high fat content and low carbohydrate content. Since the carbohydrate content of plant milk is low, fermentation takes place more slowly than cow's milk. As a result of fermentation the metabolite concentration of the fermented product formed is lower and the pH value is higher. Key words: Plant milk, kefir, physicochemical, rheology, microbiology