Development of kefir-based probiotic beverages with DNA protection and antioxidant activities using soybean hydrolyzed extract, colostrum and honey

• Kefir-like beverages were produced from soybean milk, colostrum and honey.
• Kefir grains increased the functional quality of all substrates tested.
• Honey-based kefir beverage showed DNA protection and antioxidant activities.
• Honey-based kefir beverage had a high buying intention compared to milk kefir.

The aim of this study was to evaluate the use of different functional substrates (soybean hydrolyzed extract, colostrum and honey) to design novel probiotic beverages using kefir grains as starter culture. The fermentations were carried out at 30 °C for 24 h and physical-chemical composition and functional aspects were determined. It was found that fermentation processes with kefir grains increased the functional quality of all substrates evaluated. Honey-based kefir beverage had higher antioxidant activity and its microbial composition was assessed using molecular approaches (Rep-PCR and 16S rRNA gene sequencing). High levels of lactic acid bacteria and yeast populations (over 106 CFU/mL) were found in the product and were mainly composed of potential probiotic strains of Lactobacillus statsumensis, Leuconostoc mesenteroides, Bacillus megaterium, Saccharomyces cerevisiae and Lachancea fermentati. In addition, the honey-based kefir beverage showed protection effect on DNA damage and had a high sensory quality compared to traditional kefir beverage. The results demonstrated that honey could be an ideal alternative substrate for the production of functional cultured beverage, especially for vegans and lactose intolerant consumers.