Abstract Starch digestion in the proximal small intestine of pigs exceeds in vitro predictions, suggesting a currently underestimated role for the stomach in starch digestion kinetics. This study aimed to investigate the role of amylase action in the porcine stomach on starch digestion kinetics, including hydrolysis by porcine saliva and degradation by bacterial enzymes present in the stomach. We studied the hydrolysis of starch in pigs fed barley based diets, in which starch was included as isolated powder, ground barley, or extruded barley. We identified soluble maltodextrins originating from starch breakdown in stomach digesta, especially in pigs fed extruded barley. Furthermore, we observed bacterial cells embedded in granular starch with electron microscopy, for pigs fed diets containing isolated barley starch. These observations lead us to measure starch hydrolysis in a dynamic stomach model over the course of a 225 min incubation, in which the pH was step-wise decreased from 6.5 to 2.0. Using this method, feed was either exposed to an enzyme extract obtained from stomach digesta or to porcine saliva. Up to 30 % of starch was hydrolysed into maltodextrins with a degree of polymerisation (DP)

中文翻译：

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猪胃中淀粉酶作用对淀粉消化动力学的重要性

摘要 猪近端小肠中的淀粉消化超过了体外预测，表明目前胃在淀粉消化动力学中的作用被低估了。本研究旨在研究淀粉酶在猪胃中对淀粉消化动力学的作用，包括猪唾液的水解和胃中细菌酶的降解。我们研究了以大麦为基础的饮食喂养的猪中淀粉的水解，其中淀粉以分离的粉末、磨碎的大麦或挤压大麦的形式存在。我们鉴定了源自胃食糜中淀粉分解的可溶性麦芽糊精，特别是在喂食挤压大麦的猪中。此外，对于饲喂含有分离大麦淀粉的日粮的猪，我们用电子显微镜观察了嵌入颗粒淀粉中的细菌细胞。这些观察结果使我们在 225 分钟的孵育过程中测量动态胃模型中的淀粉水解，其中 pH 值从 6.5 逐步降低到 2.0。使用这种方法，饲料要么暴露于从胃消化物中获得的酶提取物，要么暴露于猪唾液。高达 30% 的淀粉水解成具有一定聚合度 (DP) 的麦芽糊精