Structural characterization, rheological properties and bioactivities of polysaccharides from Rosa roxburghii Tratt...

Rosa roxburghii Tratt fruit polysaccharides (RPs) are known for their diverse biological activities and potential applications in functional foods and therapeutics. However, the different extraction methods influence the physicochemical properties and bioactivities of RPs. This study systematically investigated the impact of four extraction methods - acid extraction (CA), enzymatic extraction (EA), ultrasound-assisted extraction (UA), and ultrasonic-assisted enzyme extraction (UE) - on the yield, structural characteristics, and biological functions of RPs.

The extraction method notably influenced the yield, chemical composition, molecular weight distribution, rheological properties, monosaccharide ratios, antioxidant capacity, and antibacterial activity of the RPs, whereas their overall monosaccharide composition patterns and thermal stability remained relatively consistent. The highest extraction yield (7.38%) was obtained by using the UE method, followed by RPs extracted by EA (6.56%), UA (4.56%), and CA (3.87%). Rheological analysis revealed that RPs obtained via CA and UA exhibited pseudoplastic fluid behavior, with CA-extracted polysaccharides displaying superior viscosity and modulus values. All RPs possessed high antioxidant effects in vitro, and the antioxidant effects of RPs extracted by EA and UE were significantly higher than that of others. In addition, RPs extracted via EA with a high percentage of low-molecular-weight fraction had the highest inhibitory effects against Streptococcus mutans.

The findings offer a theoretical basis for selecting optimal extraction techniques to obtain RPs with desirable functional properties, thereby supporting their development as bioactive ingredients in food, pharmaceutical, and biomedical applications. © 2025 Society of Chemical Industry.