Use of hop extract in the biotechnology of kefir beverage

Abstract

The shelf life of fermented dairy products is only 3-5 days and is extended by the addition of preservatives to the production process, but the biological value of the kefir beverage is reduced. The purpose of this study was to determine the feasibility of using hop extract in the biotechnology of fermented milk beverage. Three samples of kefir beverage were produced: control (K) – using traditional technology based on dry starter “Kefir VIVO”; experimental (D1) – with the above type of starter in the amount of 0.05% by weight of milk and hop extract in the amount of 5% by weight of milk. The experimental sample (D2) was fermented using hop extract (10% by weight of milk). It was found that when using only hop extract for fermentation of the prototype kefir beverage, the duration of the technological process of its production is the same as when using dry starter and does not exceed 7-8 hours. The number of beneficial viable lactic acid microorganisms (Lactococcus lactis ssp.) in the fermented milk beverage made based on hop extract was 1.0∙107 CFU/cm3 . These microorganisms have probiotic properties, which makes it possible to classify beverages enriched with hop extract as functional foods. In the experimental samples made using hop extract, yeast colonies were found in the amount of 3∙107 and 8∙107 CFU/cm3 , respectively. During the experimental storage period, the pH of all product samples was (4.71-4.46). Therewith, the acidity of the sample (D2) increased more slowly. Its organoleptic characteristics were improving. The shelf life has been extended to 10-15 days. The results of the study showed that milk can be fermented with hop extract, resulting in a new functional type of kefir beverage with high organoleptic characteristics, viability of beneficial microflora (lactic acid bacteria and yeast) and extended shelf life