Comparative study on the physicochemical properties and bioactivities of polysaccharide fractions extracted from Fructus Mori at different temperatures
This study examined the effects of different extraction temperatures (30 °C and 90 °C) on the physicochemical properties and bioactivities of polysaccharides (MFPs-30-60, MFPs-30-80, MFPs-90-40, MFPs-90-60 and MFPs-90-80) extracted at same ethanol gradation (40, 60 and 80%). The polysaccharides were extracted from Fructus Mori, and their antioxidant, hypoglycemic and hypolipidemic activities were evaluated. The results showed that all the polysaccharide fractions contained the same monosaccharides but at different molar ratios. MFPs-30-80 had the highest content of glucose (30.33%), and MFPs-90-40 had the highest content of uronic acid (43.46%). In addition, compared to the extraction temperature of 30 °C, the higher temperature (90 °C) caused the degradation of the extracted polysaccharides. Generally, MFPs-30-80 showed superior antioxidant activity, MFPs-90-40 displayed good bile acid-binding ability, and both MFPs-30-80 and MFPs-90-40 exhibited the strongest inhibitory effects on α-amylase and α-glucosidase activity. This study concludes that the bioactivities of mulberry fruit polysaccharides depend on a combination of structural factors that are greatly affected by the extraction temperature.