Novel Enzymic Degradation of Insoluble Polysaccharide-Analysis of Product Fixation and Its Application-

对酶解不溶性多糖，特别是淀粉颗粒的新现象进行了分析，得到了以下基本结果。(1)根据不同植物源淀粉颗粒对葡萄糖淀粉酶消化的敏感性，将其分为三类。在反应初始阶段，总葡萄糖的10-40%在颗粒中被发现，这被称为“产物固定”。对于α -淀粉酶，约10%的产物在颗粒中。在同工淀粉酶催化的消化过程中，产物固定率最高，为30-60%。(2)对最耐葡萄糖淀粉酶消化的淀粉，马铃薯、松子、淀粉-7，在其糊化温度下加热，制备糊化淀粉。糊化淀粉对淀粉酶水解的敏感性比天然淀粉高2 ~ 15倍，产物与颗粒的结合率没有变化。(3)研究了异淀粉酶催化水解产物在糊化淀粉上的固定。在反应混合物中加入乙醇改变其疏水性。颗粒中产物的量随乙醇浓度的增加而增加。乙醇浓度为80%时，产物完全固定。考察了反应温度对产物固定的影响，结果表明，在较低温度下，糊化淀粉中的产物较多。结果表明：1)长链产物具有较高的固定度；2)在糊化温度下加热引起的淀粉颗粒结构的轻微变化增加了对淀粉酶消化的敏感性，保持了产物的固定；3)在低温和高度疏水条件下，产物的量增加，因此认为氢键对产物的固定起主要作用。

Analysis on the novel phenomenon in the enzymatic degradation of insoluble polysaccharide, especially of starch granule, was done to obtain the fundamental results as follows.(1) Starch granules from various botanical sources were classified into three types of groups by the susceptibility to digestion of glucoamylase.In the initial stage of reaction, 10-40% of total glucose produced was found in the granule, which was termed "product fixation." As for alpha-amylasc, about 10% of product was in the granule. The most product fixation was observed in the isoamylase-catalyzed digestion, giving 30-60% product inside.(2) The starches most resistant against glucoamylase digestion, potato, shoti, amylomaize-7, were heated at their gelatinization temperatures to prepare the gelatinized starches.The gelatinized starches showed the 2-to 15-fold higher susceptibility to amylases hydrolysis than native ones with no change in the ratio of product which bound to granules.(3) The product fixation of isoamylase-catalyzed hydrolysis on the gelatinized starches was investigated. To the reaction mixture, ethanol was added to change the hydrophobicity. The amount of product in granule increased with the increase in the concentration of ethanol. Ethanol concentration of 80% gave the complete fixation of product. The effects of reaction temperature on the product fixation were examined, elucidating that at low temperature more product was in the gelatinized starches.The findings shows 1) that the product of long chain gave the high degree of product fixation, 2) that the mild structural change of starch granule given by heating in gelatinization temperature increased the susceptibility to amylases digestion and retained the fixation of product, and 3) that hydrogen bond was considered to contribute the product fixation mainly since the amount of product increased at low temperature and in the highly hydrophobic condition.