Antioxidant activity of fermented Hazelnut milk

Characteristics of a hazelnut-whey based beverage fermented using kefir grains were determined. The total phenolic content (TPC), DPPH radical-scavenging activity, reducing power (RP), and ferrous-ion chelating ability (FCA) as a function of different culture temperatures (20-30A degrees C) and inoculum sizes (2-8% w/v) were investigated. During fermentation, DPPH radical scavenging activities and RP values increased significantly (p < 0.05) from 55.47 to 91.81% and 0.502 to 0.901 nm with an increasing inoculum size, while the TPC value decreased from 130.42 to 76.76 mg of GAE/100 mL, compared with controls. Fermentation had no significant (p > 0.05) effect on FCA values, compared with controls. Response surface methodology (RSM) was used to determine conditions for the highest antioxidant activities (radical scavenging and RP values). Hazelnut milk (HM) fermented at 25.91A degrees C with an 8% inoculum size was optimum. A 9-point hedonic scale was used for evaluation of organoleptic properties. HM varieties fermented under optimum conditions received high acceptance scores.