Shin Jin-E, Simsek Senay, Reuhs Bradley L, Yao Yuan
QTG-Tropicana, Barrington, Illinois 60010, USA.
J Agric Food Chem. 2008 Nov 26;56(22):10879-86. doi: 10.1021/jf801073u.
This study tested the hypothesis that an increased branch density (i.e., the percentage of alpha-1,6-glucosidic linkage) in water-soluble, starch-related alpha-glucans leads to reduced glucose release by pancreatin and amyloglucosidase. Malto-oligosaccharides and phytoglycogens were structurally analyzed and compared for their susceptibility to the enzymes. Malto-oligosaccharides were prepared by subjecting starch to alpha-amylase and beta-amylase followed by ultrafiltration to enrich alpha-1,6-glucosidic linkages. The branch density of the oligosaccharide products reached up to 17%, determined by (1)H NMR. Phytoglycogens were extracted from six sweet corn lines, and analysis showed similar chain length distributions and a branch density range from 8.8 to 9.5%, as compared with 4.6% for normal corn starch and 5.7% for waxy corn starch. The digestion behavior of these alpha-glucans was correlated to branch density: Highly branched malto-oligosaccharides had much reduced glucose release as compared with starch, whereas the reduction of glucose release from phytoglycogen was relatively low. Particularly, the reduction of glucose release associated with enhanced branch density was caused by reduced hydrolysis by amyloglucosidase.
水溶性淀粉相关α-葡聚糖中分支密度增加（即α-1,6-糖苷键的百分比）会导致胰酶和糖化酶的葡萄糖释放减少。对麦芽寡糖和植物糖原进行了结构分析，并比较了它们对这些酶的敏感性。麦芽寡糖是通过将淀粉用α-淀粉酶和β-淀粉酶处理，然后进行超滤以富集α-1,6-糖苷键而制备的。通过（1）H NMR测定，寡糖产物的分支密度高达17%。从六个甜玉米品系中提取了植物糖原，分析表明其链长分布相似，分支密度范围为8.8%至9.5%，而正常玉米淀粉为4.6%，糯玉米淀粉为5.7%。这些α-葡聚糖的消化行为与分支密度相关：与淀粉相比，高度分支的麦芽寡糖的葡萄糖释放大幅减少，而植物糖原的葡萄糖释放减少相对较低。特别是，与分支密度增加相关的葡萄糖释放减少是由糖化酶水解减少引起的。
