Yellow pigment fraction from Monascus-fermented durian seed: thermal stability and bioactivities

Abstract

Angkak is a functional product made by fermenting rice with Monascus purpureus. Studies have shown that agro-industrial by-products such as durian seeds are able to support Monascus growth, thus the potential of producing Monascus-fermented products with similar functional activities as angkak. Utilization of durian seeds to produce Monascus-fermented durian seed (MFDS) would improve durian production sustainability. Monascus yellow pigment (MYP) fraction was separated from MFDS and evaluated for its thermal stability by time (30 and 60 mins) and temperature treatments (40℃, 60℃, 80℃ and 100℃), antioxidant activity with 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity assay, and anti-diabetes activities by measuring α-glucosidase inhibition activity. MYP showed increasing stability when treated with increasing incubation temperature, ranging from 90.87±0.35% to 96.33±0.00% (p < 0.05). MYP reached the highest stability when incubated at 100℃ for 60 mins. The antioxidant activity of MYP was detected to be 51.84±0.17%. MYP showed anti-diabetes activity ranging from -0.72±0.27% (10 μg/mL) to 29.40±4.27% (100 μg/mL). There was an increase in α-glucosidase inhibition activity along with increasing MYP concentration. Monascus yellow pigments extracted from Monascus-fermented durian seed have the potential to be used as a functional ingredient in the food industry.