Effects of High-Intensity Ultrasound Pretreatment on the Exopolysaccharide Concentration and Biomass Increase in Cheese Whey Kefir

Cheese whey (CW) is the liquid by-product of cheese and yogurt making. This potential pollutant has high-quality nutrients exploitable through fermentation processes. Using high-intensity ultrasound on dairy products has shown several technological advantages for bioprocesses. Therefore, this study aimed to investigate the effect of high-intensity ultrasound (HIUS) on kefir grains biomass increase and specific metabolites in CW kefir. Fresh CW was ultrasonicated at 9.0 & PLUSMN; 2.7 and 18.0 & PLUSMN; 3.0 W/cm(2) for 30 and 180 s, inoculated with kefir grains, and fermented for 40 h. Total exopolysaccharide production, kefir grains biomass increase, titratable acidity, pH, and soluble solids were analyzed every 8 h. CW pretreated with 18.0 & PLUSMN; 3.0 W/cm(2) for 180 s and fermented for 16 h had significantly higher (p < 0.05) total exopolysaccharide concentration than the control: 212.7 & PLUSMN; 0.0 and 186.6 & PLUSMN; 0.0 mg/L, respectively. Ultrasonicated CW at 18 W/cm(2) for 30 and 180 s at 24 h fermentation time had significantly higher kefir grains biomass (p < 0.05) than the control: 44.2 & PLUSMN; 0.8 and 43.6 & PLUSMN; 0.9 g/L, and 40.5 & PLUSMN; 0.4 g/L, respectively. Fresh CW pretreated with HIUS enhanced the biosynthesis of kefir beverage total exopolysaccharides concentration and kefir grains biomass.

Automated summary

High-intensity ultrasound treatment of cheese whey enhances the biosynthesis of total exopolysaccharides concentration in kefir beverage and kefir grains biomass.