Study on extraction process and purification of polysaccharide from red beet.

The experiment was conducted to explore the extraction effect of different extraction methods on red beet polysaccharide. In the experiment, red beet was used as raw material, water extraction and alcohol precipitation method and ultrasonic assisted water extraction method were used respectively. Orthogonal design was carried out to optimize the extraction process on the basis of single factor experiment, and the effect of liquid to solid ratio, extraction temperature and extraction time on the extraction rate of red beet polysaccharide were investigated. The crude polysaccharides were purified by Sevag reagent, activated carbon and petroleum ether. The results showed that the optimal extraction conditions of red beet polysaccharide by water extraction and alcohol precipitation were as follows: Liquid to solid ratio of 90 mL/g, extraction temperature of 70 °C, and an extraction time of 1.5 h. Under the conditions, the extraction yield of red beet polysaccharide was the highest, reaching 2.33%. The optimal extraction process of ultrasonic assisted water extraction was as follows: Liquid to solid ratio 40 mL/g, extraction temperature of 40 °C, extraction time of 30 min. Under the conditions, the extraction rate was 6.85%. The removal rates of protein, pigment and fat were 29.73%, 3.88% and 2.76%, respectively. The study indicates that ultrasonic assisted water extraction method is more suitable for the extraction of red beet polysaccharide with less solvent, shorter time, lower temperature and higher extraction rate. [ABSTRACT FROM AUTHOR]