Process Optimization for Development of a Novel Water Kefir Drink with High Antioxidant Activity and Potential Probiotic Properties from Russian Olive Fruit (Elaeagnus angustifolia)

Kefir is a dairy-based probiotic beverage with high antioxidant activity, among other health benefits. To extend kefir’s beneficial effects to non-dairy consumers, studies on kefir fermentation using alternative matrices (referred as water kefir) are needed. As such, the purpose of this study was formulate novel Russian olive, product activity and potential properties. end, olive (RWK) process optimized maximize total phenolic content, microbial viability product. The experimental design set rotatable central composite response surface methodology (RSM). independent variables included substrate concentration (20–30% juice), time (24–48 h), incubation temperature (20–32 °C). optimal conditions were observed be 31.2 °C temperature, 24 h time, 30% juice concentration. Under these conditions, values for FRAP DPPH radical scavenging, TPC in RWK 0.22 (?mol FSHE/mL), 0.096 Trolox Eq/mL), 98.32 (?g GAE/mL), (of AAB, LAB, yeasts) 7.20, 7.06, 7.17 log10 CFU/mL, respectively.