Improvement of resveratrol production from waste residue of grape seed by biotransformation of edible immobilized Aspergillus oryzae cells and negative pressure cavitation bioreactor using biphasic ionic liquid aqueous system pretreatment

•A new method of biotransformation for increasing the yield of resveratrol was investigated.•The yield of resveratrol after fermenting was 4.36-fold to the untreated sample.•The method could be potentially applied in the food industry.

A biotransformation method of producing resveratrol with immobilized Aspergillus oryzae negative pressure cavitation bioreactor (ICNPCB) with biphasic ionic liquid aqueous system pretreatment was investigated. Subsequently, the biotransformation conditions were optimized for the resveratrol production under types of ILs [C4MIM]Br, concentration of ILs 0.75 M, temperature 31 °C, ratios of solid to liquid 1:15 (mg/L), time 60 h and pH 6.0, the yield of resveratrol reached 224.61 ± 0.35 μg/g, which increased 4.36-fold to that of untreated one. The conversion rate of piceid reached 85.21%. The residual activity of immobilized microorganism was 82.26% after used for 15 runs. The developed method could be an effectively alternative biotransformation method for producing resveratrol from the waste residue of wine.