机械活化木薯淀粉及其乙酰化淀粉的消化性能研究

Digestibility of Mechanical Activated Cassava Starch and Acetylated Starch

采用In-Vitro消化模型和美国谷物化学协会(AACC)的76-13标准方法,以消化速度和抗酶解淀粉含量为评价指标,研究机械活化淀粉及其乙酰化变性处理产品的消化性能和抗酶解性能。结果表明,机械活化对木薯淀粉颗粒的消化性能有显著的强化作用,活化时间越长,消化速率越大,抗酶解淀粉的含量越低。主要原因是机械活化使木薯淀粉紧密的颗粒表面及晶体结构受到破坏,结晶度下降,提高了淀粉颗粒对酶的敏感性,增加反应活性。活化淀粉经乙酰化变性可加快其颗粒的消化性能,降低其糊的消化性能,破坏和阻止抗酶解淀粉的形成,并随取代度提高,淀粉颗粒和糊的消化速度呈下降趋势,抗酶解淀粉含量降低。

In-Vitro model and 76-13 standard method of the American Association of Cereal Chemistry（AACC） were used to evaluate the digestibility and enzymatic resistance of mechanical activated cassava starch and its acetylated starch.Results indicated that mechanical activation significantly improved the digestibility of cassava starch granules.Meanwhile,longer activation time could result in enhanced digestion rate and less enzymatic resistance starch.The major reason was due to the damage of crystal structure and compact granule surface of cassava starch,which improved the sensitivity of starch granule digestibility and reactivity.Acetylation also resulted in an increase in digestibility of activated starch granules,a reduction of digestibility of starch pastes,and destroyed and inhibited the formation of enzymatic resistance starch.However,decreases in digestion rate of starch granules and pastes and enzymatic resistance starch content were also observed due to increasing degree of substitution（DS）.