Extraction and Purification of Asparagus Oligosaccharides

Abstract

The hot water method conditions of extracting oligosaccharides from asparagus are: extraction temperature: 80°C, extraction time: 90min, solid-liquid ratio: 1:20, ethanol final concentration: 80%, ethanol precipitation time: 8h and extraction times: 2. Different auxiliary treatments were tested to enhance the extraction ratio and it was improved from 3.842% to 9.638% after microwave freeze-thawing. Comparing of oligosaccharides contents between purple asparagus and green asparagus in different parts, the results showed that the oligosaccharides content in purple asparagus is about 3.5 times as that in green asparagus, and the oligosaccharides content of peel is higher than that of pulp in both asparagus. Different purification tests showed that combined action of papain and Sevag obtained a better effect.