Physicochemical properties, structural characteristics and bioactivities of Pyracantha fortuneana polysaccharides prepared by six methods

Abstract

This research follows the current trend of value addition to wild unexploited resources through scientific and technological means. The effect of extraction techniques on the structural and functional characterization of active polysaccharides was investigated, filling the existing knowledge gap. Six extraction techniques (alkaline, enzymatic, ultrasound-assisted, hot water, microwave-assisted, and acidic) were applied to obtain Pyracantha fortuneana polysaccharide (PFP) from the fruit of P. fortuneana. The yield, physicochemical properties, structural characteristics, and bioactivities of the six polysaccharides, namely Al-PFP, E-PFP, U-PFP, H-PFP, M-PFP, and Ac-PFP, were comparatively analyzed. The results showed that the six polysaccharides were pectic polysaccharides with similar functional groups and excellent thermal stability, containing abundant branched chains. The molecular weight ranged from 34.33 kDa (U-PFP) to 247.81 kDa (H-PFP). Among them, Ac-PFP had the highest yield (12.30%), uronic acid content (73.15%), and galacturonic acid content (57.89%). In terms of biological functional analysis, PFPs exhibited strong antioxidant and α-glucosidase inhibitory activities, particularly Ac-PFP, which showed the highest activity. Hence, this study highlights that alkaline, enzymatic, ultrasonic, microwave, and acidic methods degrade polysaccharides differently than hot water extraction while causing changes in microstructure and properties. Furthermore, alterations in the molecular weight and monosaccharide composition resulting from the extraction method are the primary factors influencing the antioxidant and hypoglycemic activity of PFPs.