提高甘薯淀粉中抗消化淀粉含量的技术研究

Enhancement of Resistant Starch Content in Retrogradation Sweet Potato Starch

抗消化淀粉是一种具有保健功能作用的淀粉,老化淀粉是制备抗消化淀粉最主要的方法。本文研究了酶水解预处理和冷冻解冻循环处理对甘薯老化淀粉中抗消化淀粉形成的影响,得到了提高甘薯淀粉中抗消化淀粉含量的适宜的工艺路线和参数,即:先用300U／g淀粉的普鲁兰酶水解2h,再用10U／g淀粉的α- 淀粉酶水解0．5h,浓度为12％的酶处理淀粉胶在4℃条件下老化20h后,再经冷冻(-20℃,2h)-解冻(50℃, 30min)-老化(4℃,6h)循环处理3次,淀粉中RS含量可达31．21％。实验结果表明,甘薯淀粉通过普鲁兰酶和α-淀粉酶复合水解处理和冷冻解冻循环处理能明显提高老化淀粉中抗消化淀粉的含量。

Starch retrogradation is the main method for preparing resistant starch （RS） which have health function. The effects of enzyme -hydrolysis and freeze -thawing treatment on the RS contents in sweet potato starch was studied, and the condition for enhancing RS content in the starch was optimized. The following optimum technological process and condition of enhancing RS are shown in the result ：hydrolyzing 10% starch with pullulanase （300Units/g starch） at 42℃ for 2h, then with α - amylase （ 10U/g starch） at 55℃ for 0.5h; after cooling at 4℃ for 20h, treating the gelatinized starch paste （ 12% starch hydrolyzed by enzymes） by freeze （ - 20℃, 2h） - thawing （ 50℃, 30min） -cooling（4℃ ,6h）cycle for 3 times. The RS content in sweet potato starch treated with the process is 31. 21% . The study reveals that the RS content in sweet potato starch can be obviously enhanced by hydrolysis with pullulanase and α -amylase, and freeze -thawing cycles.