Ergothioneine extract from Aspergillus oryzae prevents lipid oxidation and increases bioactive compounds during the processing of germinated brown rice

Abstract

This study aimed to evaluate the impact of ergothioniene (ESH) concentrated extract (CE) to lipid anti-oxidation and γ-aminobutyric acid (GABA), γ-oryzanol (GORZ) biosynthesis during germinated brown rice (GBR) processing. To do that 0, 2, 4 and 6% ESH CE was supplemented to soaking stage of brown rice for 6 hr and determined changes about the quality of GBR during processing. The results showed when added 4% of ESH CE to soaking stage, total lipid was stable during four stages of GBR processing as 1.96, 1.87, 1.77, and 1.67 g/100 g corresponding to less increasing peroxide and thiobarbituric acid–reactive substances (TBARs) as 0.53, 0.54, 0.55, and 0.55 meq/kg lipid and 0.21, 0.23, 0.25, and 0.26 µmol TBARs/g while GABA and GORZ increased considerably to 2378.63 mg/kg and 222 mg/kg, respectively. The results indicated that ESH CE helps to increase GABA, GORZ and prevent lipid oxidation that contributes to improving the quality of GBR. Novelty impact statement GBR contains various bioactive compounds such as GABA, GORZ, which have positive effects for human health. So, it becomes one of the value-added products from rice. However, in GBR processing, there are still some problems that impact negatively on the quality of GBR such as low levels of GABA, GORZ and high levels of peroxide and TBAR values that may occur during processing. To address these problems, this study used ESH, a powerful antioxidant compound, which was biosynthesized from Aspergillus oryzae applying to GBR processing. The results show that ESH CE not only inhibits fat oxidation during GBR processing but also increases significantly GABA, GORZ level. So, this study contributed one of great solutions for improving the quality of GBR products.