Anti-lipid-oxidation effects and edible safety evaluation of the oil extracted by a supercritical CO2 process from coix seed fermented by Monascus purpureus

Abstract

The physicochemical properties and composition of coix seed oil produced by Monascus purpureus fermentation and supercritical CO2 extraction were determined. Anti-lipid-oxidation and edible safety were evaluated using a cholesterol-fish oil model, acute oral toxicity assay, and genetic toxicity assay in vitro and in vivo, respectively. The results show that the extraction oil from fermented coix seed (FCS-O) had good physicochemical quality and abundant active components with physiological function. In particular, γ-tocotrienol, γ-oryzanol, coixenolide and oleic acid concentrations reached 72.83 µg/g, 745.96 µg/g, 9.65mg/g and 316.58 mg/100 g DW, respectively. The FCS-O exhibited higher antioxidant capability in inhibiting lipid oxidation and peroxidation. Compared to the blank control, the concentrations of 7-ketocholestreol and peroxide only were 8.42 µg/mL and 16.16 mmol/kg at 168 h of oxidation (P < 0.01). In addition, the FCS-O has been confirmed to be a very safe edible oil, with no acute toxicity (LD50 > 10 g/kg bw, considered actually non-toxic) and no induced mutagenicity, cytotoxicity or genotoxicity. These results serve as a good safety reference for future application of the oil from fermented coix seed. The development and utilization of this kind of oil will be beneficial as a food, food ingredient, nutritional supplement, or natural food antioxidant to promote good health function.