Incorporation of oat milk with probiotic Lacticaseibacillus casei AP improves the quality of kefir produced from goat milk

In this study, we evaluated the quality of kefir with combined additions of oat milk (8, 12, and 16% w/v) and Lacticaseibacillus casei AP (2 and 4% v/v), and observed the products’ physicochemical characteristics (nutrient content, pH and acidity, viscosity and syneresis, ethanol concentration, and fatty acid profiles), microbiological characteristics (total lactic acid bacteria, total plate count, total probiotic, and total yeast), and sensory characteristics. The result showed that an increasing level of oat milk addition decreased water content and improved viscosity. A combination of 16% oat milk and 4% (v/v) L. casei AP increased the viscosity and water content, and resulted in the highest favorability and acceptability of kefir products. However, the increased concentration of L. casei AP inoculum and oat milk quantity did not affect microbiological qualities. It can be concluded that incorporating 16% oat milk and 4% L. casei AP improves the physical quality and sensory characteristics of kefir products.