Enzymatic degradation of epichlorohydrin crosslinked starch microspheres by α-amylase
Enzymatic degradation of epichlorohydrin crosslinked starch microspheres by α-amylase
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DOI：
10.1023/a:1018878120100
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发表时间：
1999-06-01
影响因子：
3.7
通讯作者：
Ponchel, G
中科院分区：
文献类型：
--
作者：
Hamdi, G;Ponchel, G
目的.研究了化学参数对环氧氯丙烷交联淀粉微球对α-淀粉酶酶解敏感性的影响。以环氧氯丙烷为交联剂制备淀粉微球。它们的溶胀度，反映了在聚合物网络中的甘油二醚桥的数量，和对应于表氯醇与淀粉的副反应的非交联单甘油醚基团的数量进行了测定。采用微量容量法测定了微球在猪α-淀粉酶存在下的降解速率。α-淀粉酶的降解是表面控制的，并且可以通过在聚合物网络中引入以下物质来调节：（i）与生淀粉中支链淀粉的存在相关的不可水解的α-1，6键，（ii）甘油二醚和（iii）单醚基团，所有这些都可能阻断α-淀粉酶的活性。在高交联微球的情况下，甘油单醚侧链的数量对降解速率有主要影响，其范围在10（-2）和10（-5）min（-1）之间。可以同时调节肿胀。通过调节交联反应过程中的化学参数，提高了交联度和淀粉微球的酶降解性。
Purpose. The influence of chemical parameters on the sensitivity to enzymatic degradation by alpha-amylase of starch microspheres crosslinked by epichlorohydrin was studied.Methods. Starch microspheres were prepared using epichlorohydrin as a crosslinking agent. Their swelling degree, reflecting the number of glycerol diether bridges in the polymeric network, and the number of non-crosslinking monoglycerol ether groups corresponding to a side-reaction of epichlorohydrin with starch were determined. Degradation rates of the microspheres in presence of porcine alpha-amylase were deter mined by a microvolumetric method.Results. Degradation by alpha-amylase was surface-controlled and could be modulated by the introduction in the polymeric network of: (i) nonhydrolysable alpha-1,6 bonds related to the presence of amylopectin in the raw starch, (ii) glycerol diether and, (iii) monoether groups, all of these being likely to block, the activity of alpha-amylase. In the case of highly cross-linked microspheres, the number of glycerol monoether pendent chains had a predominant effect on the degradation rate which ranged between 10(-2) and 10(-5) min(-1).Conclusions. It was possible to modulate simultaneously the swelling. degree and the enzymatic degradability of starch microspheres by adjusting the chemical parameters during the crosslinking reaction.