Effect of kefir grain concentration on rheological, microbiological, andphysicochemical characteristics of bovine colostrum kefir

Bovine colostrum has high nutrition content such as protein, fat, peptide, micro-nutrients, antimicrobial components and bioactive compounds that benefit the body. Kefir is one way of diversifying food products as fermented beverage products to increase the utilization and functional properties of bovine colostrum, which has a unique taste. Production of colostrum kefir requires the right concentration of kefir grains to obtain high-quality characteristics. Evaluating the effect of kefir grain concentration on the rheological, microbiological, and physicochemical characteristics of bovine colostrum kefir was the purpose of this research. This study used one factorial design with the variation of kefir grain concentrations 10% (T1), 20% (T2), and 30% (T3) (w/v) with seven replications. Rheological analysis was conducted, followed by total lactic acid bacteria, yeast, microbes, protein, fat, ash, water content, carbohydrate, pH, total dissolved solids and alcohol content. Based on the result, different kefir grain concentrations significantly decreased total LAB, yeast, microbes, protein, ash, pH, and total dissolved solids but increased carbohydrate and water content with the addition of kefir grain concentration. Rheology behavior, fats, and alcohol content had no significant difference. Treatment of 10% of kefir grain concentration is the most suitable as it contains the highest total LAB and yeast.