Pulverization Using Liquid Nitrogen Significantly Improves Physical Properties of Powder and Extraction Yield of Polysaccharides of Astragalus mongholicus

Abstract Astragalus mongholicus is a famous traditional Chinese medicinal herb because of its human health benefits and bioactive compounds. Pulverization process directly affects quality and dissolution of bioactive compounds of A. mongholicus. In the present study, liquid nitrogen was introduced to pulverization process of A. mongholicus. The pulverization with addition of liquid nitrogen (LNP) effectively retained powder color, crushed tissue fiber, and reduced hardness of A. mongholicus. Furthermore, LNP significantly improved elasticity and solubility of the powder, as well as soluble solid contents. In addition, extraction yield of polysaccharides, characteristic bioactive compounds in A. mongholicus, was increased by 10.5 % by combination of LNP and Tween-80 enzyme extraction. These results suggest that LNP can be a promising technology for preparation of A. mongholicus powder. The information will also contribute to improvement of manufacturing technology of Chinese medicinal herb.