Multimode Ultrasonic Extraction of Polysaccharides from Maca (Lepidium Meyenii): Optimization, Purification, and in Vitro Immunoregulatory Activity

Abstract

This study aimed to evaluate the effect of multimode ultrasound on the extraction efficiency and immunoregulatory activity of polysaccharides from Lepidium meyenii Walp. (LMP). The separation and purification of maca polysaccharides were also investigated by the DEAE-52 cellulose column, and the monosaccharide compositions were identified by HPGPC. Its immune activity was analyzed by the secretion of cytokines (TNF-α and IL-6). The results showed that the optimal extraction conditions were energy aggregation alternation dual-frequency ultrasound (EADU) with frequency combinations of 20/35, extraction time 15 min, material/water ratio 1:10 g/mL, ultrasonic power intensity 150 W/L, intermittent time ratio 4 s/ 3 s, and extraction temperature 50 °C. The extraction rates of purified polysaccharides (US3) increased by 44.90%. The LMP extracted by EADU contained arabinose, galactose, and glucose in the molar ratios of 2.9:2.72:5.05. In addition, US3 exerted remarkable immune activity, which could be an excellent functional additive in food or medicine.

Keywords: Maca polysaccharide, Ultrasonic-assisted extraction, Purification, Macrophage, Immunoregulatory activity