该研究通过体外模拟成人与婴幼儿胃肠道消化，比较羊乳酪蛋白（Casein, CN）、乳清蛋白（Whey Protein, WP）以及最接近母乳比例（40:60, m/m）的CN与WP的混合蛋白的消化特性。结果显示，在模拟成人与婴幼儿体外消化过程中，四种蛋白的消化率逐渐增加，其中婴幼儿胃消化120 min后混合蛋白的消化率达到最大值20.28%，显著高于羊乳（P<0.05），表明混合蛋白提高CN的比例后更易于被消化。在胃肠联合消化中，婴幼儿混合蛋白在胃肠联合消化30 min时肽含量释放最多为58.0 mg/mL，且在婴幼儿胃肠联合消化终点中对二肽基肽酶-4（Dipeptidyl Peptidase-4, DPP-IV）抑制活性相对较强，而CN在婴幼儿胃肠联合消化中表现出最高的抗氧化活性为34.11%。免疫原性分析表明，混合蛋白在婴幼儿胃肠消化中均呈现最低的免疫原性，其更不易引起过敏反应。可见，接近母乳比例的CN与WP混合蛋白有更好的消化性、更多的肽含量和较低的免疫原性，且具有一定的抗氧化活性。这些发现为优化婴幼儿配方全羊乳粉的蛋白质来源和比例提供了重要的数据支撑。

The digestibility of goat milk, casein (CN), whey protein (WP), and a mixture of CN and WP with a ratio similar to that in human breast milk (40:60, m/m) were assessed through in vitro simulation of digestion in the gastrointestinal tracts of adults and infants. The digestibility of all four proteins gradually increased during adult and infant in vitro digestion simulations. Mixed protein digestibility reached a maximum of 20.28% after 120 min of simulated infant gastric digestion, significantly higher than that of goat milk (P<0.05), suggesting that the mixed protein with a higher CN proportion was more easily digested. The mixed protein released up to 58.0 mg/mL peptide after 30 min of simulated infant gastrointestinal co-digestion. Dipeptidyl peptidase-4 inhibitory activity was relatively strong at the endpoint for the simulated infant gastrointestinal co-digestion. CN demonstrated the highest antioxidant activity of 34.11% during simulated infant gastrointestinal co-digestion. The mixed protein presented the lowest immunogenicity in simulated infant gastrointestinal digestion, indicating that the mixed protein is less likely to cause allergic reactions. Hence, the mixed protein combining CN and WP in a ratio similar to that in human breast milk provides improved digestibility, increased peptide content, reduced immunogenicity, and specific antioxidant activities. These findings provide important data to aid in the optimization of protein sources and ratios in whole goat milk-based infant formulas.

陕西省关键核心技术攻关项目（2024NC-GJHX-17）；陕西省科技计划项目（2022GY-361；2022KXJ-011）；陕西科技大学科研启动基金项目（2023BJ-20）；中国博士后科学基金项目（2020M673605XB）；陕西省自然科学基础研究计划项目（2021JQ-543）