Riddet Institute, Massey University, Private Bag 11222, Palmerston North, New Zealand; School of Food and Advanced Technology, Massey University, Private Bag 11222, Palmerston North, New Zealand.
Department of Biological and Agricultural Engineering, University of California, Davis, CA 95618, USA.
Food Chem. 2022 Nov 15;394:133410. doi: 10.1016/j.foodchem.2022.133410. Epub 2022 Jun 7.
How the stomach can serve as a biochemical environment for starch digestion and the implications on starch emptying are not well-understood. Biochemical changes during gastric digestion of cooked wheat- and rice-based diets of varying particle size and microstructure were investigated using a growing pig model. In larger-particle size diets (rice grain, rice noodle, pasta), pH >3 was maintained in the proximal stomach digesta even until 240 min digestion, resulting in extended remaining amylase activity and accumulation of maltose from starch hydrolysis in the stomach. In smaller-particle size diets (couscous, rice couscous, semolina porridge), gastric acidification occurred faster to produce homogeneous intragastric pH and deactivated amylase. The hypothesis of the study was that food macrostructure would impact gastric acidification kinetics, and the resulting biochemical environment for starch hydrolysis in the stomach may further affect the mechanisms of food breakdown in the stomach and gastric emptying of starch.
胃如何能够作为淀粉消化的生化环境，以及这对淀粉排空的影响还不是很清楚。本研究使用生长猪模型，研究了不同粒径和微观结构的煮熟的小麦和大米饮食在胃消化过程中的生化变化。在较大粒径的饮食（大米粒、米粉、意大利面）中，即使在 240 分钟的消化过程中，近端胃内容物的 pH 值仍保持在 3 以上，导致胃中剩余的淀粉酶活性延长，并使淀粉水解生成麦芽糖积累。在较小粒径的饮食（粗麦粉、蒸粗麦粉、粗粒小麦粥）中，胃酸更快酸化，产生均匀的胃内 pH 值并使淀粉酶失活。本研究的假设是食物宏观结构会影响胃酸酸化动力学，而胃中淀粉水解的生化环境可能进一步影响胃中食物分解的机制和淀粉的胃排空。
