Dept. of Biological and Agricultural Engineering, 1308 Bainer Hall University of California, Davis, 1 Shields Avenue, Davis, CA 95616, USA.
Food Funct. 2020 Mar 26;11(3):2255-2267. doi: 10.1039/c9fo03033f.
Buffering capacity is defined as the ability of a material to resist changes in pH after addition of acid or alkali. Food buffering capacity is important to consider during gastric digestion as it will impact the intragastric pH and gastric secretion rate. These factors will further influence the pepsin activity and acid hydrolysis, which will ultimately impact food breakdown and gastric emptying. The objective of this study was to determine the influence of composition and initial properties of thirty commercially available foods on buffering capacity. Protein content, fat content, particle size distribution, and buffering capacity were measured. A regression model was developed to evaluate which of the tested properties had the greatest contribution to the food buffering capacity. Overall, protein content and initial pH of the food were the most important factors in determination of buffering capacity. Foods were then classified into 6 classes based on their protein content. Foods in class 6, with higher protein content (average 22.3%), had significantly higher buffering capacity than foods in class 1, with lowest buffering capacity (average 0.6% protein) (p < 0.0001). Within dairy and meat products, higher fat content produced a lower buffering capacity. The interaction between initial properties and composition also influenced buffering capacity. For example, buffering capacity in foods with low protein content (<1.4%) was influenced by the organic acid content and initial pH. Particle size was an important factor for buffering capacity, but its role is influenced by protein content. Understanding the key factors contributing to the buffering capacity of foods is crucial for digestion studies as it will impact physicochemical and enzymatic reactions during digestion.
缓冲能力是指物质在加入酸或碱后抵抗 pH 值变化的能力。在胃消化过程中，食物缓冲能力很重要，因为它会影响胃内 pH 值和胃分泌率。这些因素将进一步影响胃蛋白酶的活性和酸水解，从而影响食物的分解和胃排空。本研究的目的是确定 30 种市售食品的组成和初始特性对缓冲能力的影响。测定了蛋白质含量、脂肪含量、粒度分布和缓冲能力。建立了一个回归模型来评估测试特性中哪些对食物缓冲能力的贡献最大。总的来说，蛋白质含量和食物的初始 pH 值是决定缓冲能力的最重要因素。然后根据蛋白质含量将食物分为 6 类。蛋白质含量较高（平均 22.3%）的第 6 类食物的缓冲能力明显高于蛋白质含量最低（平均 0.6%）的第 1 类食物（p<0.0001）。在乳制品和肉类产品中，脂肪含量较高会导致缓冲能力降低。初始特性和组成之间的相互作用也会影响缓冲能力。例如，蛋白质含量较低（<1.4%）的食物的缓冲能力受到有机酸含量和初始 pH 值的影响。粒度是缓冲能力的一个重要因素，但它的作用受到蛋白质含量的影响。了解影响食物缓冲能力的关键因素对于消化研究至关重要，因为它会影响消化过程中的理化和酶反应。
