超高压辅助制备乙酰化淀粉的特性研究

Characteristics of Acetylated Starch Prepared with Ultra High Pressure

乙酰化淀粉是一种重要的改性淀粉，广泛应用于食品及非食品加工等领域。本文以玉米淀粉为原料，乙酸酐为乙酰化试剂，利用超高压处理技术，在压力为300~400 MPa条件下，保压10~20 min以制备乙酰化淀粉。利用传统方法（30 ℃，0.1 MPa，60 min）制备的乙酰化淀粉作为对照样品，探讨超高压技术对乙酰化淀粉的取代度、热特性、溶解性、膨润力、凝沉性和糊的透明度等理化特性的影响，并利用红外光谱对乙酰化淀粉的结构进行了表征。研究表明超高压方法可缩短反应时间，提高乙酰化淀粉取代度，压力为400 MPa，保压20 min时取代度为0.0461，与传统方法相比，取代度提高约30%，超高压处理时间越长取代度越高。超高压方法工艺简单，反应时间短，节约能源，制备的乙酰化淀粉具有更好的抗凝沉性。

Acetylated starch as one of the most important modified starches is widely applied in food and non-food processing fields. The impact of ultra high pressure （UHP） on the physicochemical properties of the modified acetylated starch was investigated. Corn starch was substituted with acetic anhydride at pressure range of 300 to 400 MPa for 10 to 20 min. Conventionally prepared acetylated starch （30 ℃, 0.1 MP, 60 min） was conducted as control. Characteristics of acetylated corn starches in terms of degree of substitution, thermal properties, solubility, swelling power, retrogradation, paste clarity and so on were assessed, and the structure of acetylated starch was charactered by FT-IR. Compared with the conventional method, the UHP processing was favorable for shortening reaction time and increasing the degree of substitution. The degree of substitution reached to the maximum value of 0.0461 at 400 MPa for 20 min, and acetylated starches by using UHP had lower retrogradation.