Abstract:

Objective: To develop an effective pretreatment method using enzymatic hydrolysis for the determination of content of polysacchrides in Chinese yam. Methods: Polysacchrides in Chinese yam were extracted under three different treatments, such as amylase hydrolysis, immersion in warm water and boiling extraction. The content of polysacchrides was determined by titration and sulphuric acid-phenol spectrophotometric methods. Results: The contents of polysacchrides extracted by three above methods were 3.53%, 0.44% and 8.77%, respectively. Conclusions: The content of polysacchrides extracted by warm water immersion is too low. In contrast, the content of polysaccharides extracted by boiling extraction is too high due to so much starch inside. Compared with both extraction methods, amylase hydrolysis treatment of Chinese yam could remove the effect of starch in raw materials so that the extraction efficiency of polysacchrides was significantly improved. Therefore, enzymatic hydrolysis treatment is a simple and efficient method to extract polysacchrides in Chinese yam.

Key words: Chinese yam, amylase, polysacchride