Influence of flavonoids from Phellinus igniarius on sturgeon caviar: Antioxidant effects and sensory characteristics

The antioxidant differences between two flavonoid extracts from fruiting body and fermentation broth of Phellinus igniarius were determined, and the effects of flavonoid addition on the sensory characteristics of sturgeon caviar were investigated. Both extracts exhibited moderate antioxidant activity with EC50 values of 4.98 and 2.39 mg/mL, the extract of fermentation broth exhibiting higher antioxidant efficiency. Flavonoids were added at 0.01% and 0.02% to sturgeon caviars, which were then stored at 4 or 20 °C for 12 days. Peroxide values (meq/kg) were determined after regular intervals. The 0.02% level of flavonoids from fermentation broth of P. igniarius had stronger antioxidant effect than vitamin C, very close to that of butylated hydroxyanisole (BHA). Flavonoid addition improved the sensory profile of caviar, and the flavonoid extract from the fermentation broth had a more desirable effect on flavour and aroma than that from fruiting bodies.