Optimization of soymilk fermentation with kefir and the addition of inulin: Physicochemical, sensory and technological characteristics

Abstract

The demand for the development of beverages based on fermented soybeans for the market has increased in recent years. The objective of this work was to develop a soybean beverage fermented with kefir grains and supplemented with inulin. The fermentation conditions were optimized as follows: a ratio of 4 g:100 mL of kefir grains:soymilk, a soymilk concentration of 9°Brix and a fermentation time of 12 h. This formulation was supplemented with 3.5% (m/v) inulin and evaluated at 7 °C for 28 days. The beverage had a slightly yellow color, with positive values in the b* parameter. The firmness and syneresis of the beverages were higher when inulin was used. The use of inulin also decreased sedimentation in the beverages. At 28 days of storage, the cell count (Lactococcus, Lactobacillus and yeasts) was higher than 107 CFU/mL for both treatments. Soymilk was shown to be a good substrate for fermentation using kefir grains. The addition of inulin to the fermented soymilk efficiently maintained the microorganisms and increased sensory acceptability after 14 days of storage.