掺入外源淀粉的魔芋豆腐体外消化和发酵性能研究

通过体外模拟口腔、胃、小肠消化,探讨掺入淀粉的魔芋豆腐体外消化性能,并将消化后的剩余部分作为小鼠盲肠内容物体外发酵底物,研究其在盲肠中的发酵性能。结果表明,纯魔芋豆腐在口腔、胃、小肠中均不被消化,掺入魔芋豆腐中的淀粉从口腔开始被水解,在胃部不被水解,进入小肠后20 min内即可完成大部分水解,但与纯淀粉相比,掺入魔芋豆腐中的淀粉的快消化淀粉含量减少,总水解率无显著变化,说明脱乙酰基魔芋葡甘聚糖可延缓淀粉消化,但不能阻止淀粉消化。体外模拟盲肠发酵过程中,掺入淀粉的魔芋豆腐降低pH值的能力高于纯魔芋豆腐,但前者生成的短链脂肪酸及发酵24 h后乳酸菌含量少于后者。综上表明,食用掺入淀粉的魔芋豆腐相较纯魔芋豆腐会快速升高血糖和降低魔芋豆腐的肠道益生作用。

External digestion and fermentation characteristics of konjac tofu adding exogenous starches

;In this article,the external digestion of konjac tofu mixed with starch was studied by simulating oral,gastric and small intestine digestion,and the remaining part of the digestion was used as a substrate for in vitro fermentation of mouse cecum,and its fermentation performance in the cecum was studied.The results showed that pure konjac tofu was not digested in the mouth,stomach and small intestine,and the konjac tofu mixed with starch could be partially hydrolyzed in the mouth and not hydrolyzed in the stomach,most of the hydrolysis can be completed withm 20 mm.But compared with pure starch,the rapidly di-gestible starch of the starch incorporated into konjac tofu was reduced,the total hydrolysis rate did not change significantly.It shows that deacetylated konjac glucomannan can delay starch digestion,but can't prevent starch digestion.In the process of cecal fermentation,the ability of konjac tofu with starch to decrease pH is higher than that of pure konjac tofu,but the short chain fatty acid and lactic acid bacteria content produced by fermentation for 24 h by the former are less than the latter.It is indicated that eating konjac tofu with starch will rapidly raise blood sugar and reduce the intestinal probiotic effect of konjac tofu.