Improved functionality of soft soybean curd containing Monascus fermented soybean ethanol extract

Monascus fermented soybeans (MFS) were produced by solid state fermentation and ethanol extractions were carried out to recover monacolin K (MK) and isoflavones from the MFS. About 99 and 87% of monacolin K (891 mg/kg) and isoflavones (895 mg/kg) were recovered by 80%(v/v) ethanol extraction. The 80% ethanol extract also showed significantly higher antioxidant activities (DPPH, ABTS radical scavenging activity, and ferric reducing antioxidant power) than the other ethanol extracts prepared by either 40 or 60% ethanol. The 80% Monascus fermented soybeans extract (MFSE) also contained significant α-glucosidase inhibitory activity (2.7 acarbose g equivalents/g MFS). Based on the results, MFSE can be used to enrich bioactive MK and isoflavone aglycones in soft soybean curd products.