Research Progress on Structure and Bioactivity of Longan Polysaccharide

Longan originates from southern China and has high nutritional and health value. Recent phytochemistry and pharmacology studies have shown that polysaccharides are a main bioactive component of longan. Longan polysaccharides possess antioxidant, anti-aging, anti-tumor, immunomodulatory, and other bioactivities. Hot-water extraction, ethanol precipitation, and ultrasonic extraction are generally used to extract water-soluble longan polysaccharides. However, the relationship between the structure and bioactivity of longan polysaccharides remains unclear, requiring further investigation. The aim of this review is to evaluate the current literature focusing on the extraction, purification, structural characterization, and biological activity of longan polysaccharides. We believe that this review would provide a useful bibliography for further innovation and a basis for using long an polysaccharides in functional food.