优化老年人营养供给策略,需深入理解食物结构对消化行为的影响。然而,针对阴离子型膳食纤维调控乳制品蛋白质在老年胃肠环境下凝乳与水解特性的研究仍较少。该研究基于体外模拟老年胃肠条件,系统探讨了海藻酸钠(sodium alginate,SA)对牛奶蛋白消化过程的影响,重点分析其对胃内凝乳形成、流变特性及蛋白水解动力学的调节作用。实验设置对照组及添加5、10、15、20 mg/mL SA组进行比较。结果显示,0~15 mg/mL SA可通过降低凝乳质量和粒径及体系黏度,促进碎片化凝乳形成,从而增强酶的扩散性,使蛋白水解率随质量浓度升高显著增加(对照组:29.31%,SA-Milk-15:39.50%)。当SA质量浓度增至20 mg/mL时,黏度升高限制了酶-底物接触,水解率下降(32.64%)。综合表明,适量SA有助于提高牛奶蛋白消化效率,15 mg/mL时效果最佳。该结果为开发适宜老年人食用的高纤维乳制品配方提供了理论依据。
Optimizing nutritional strategies for the elderly requires a clear understanding of how food structure affects digestive behavior.However, studies on the effects of anionic dietary fibers on milk protein coagulation and hydrolysis under elderly gastrointestinal conditions remain limited.This study systematically investigated the impact of sodium alginate (SA) on milk protein digestion using an in vitro elderly digestion model, focusing on its effects on gastric clot formation, rheological properties, and proteolysis kinetics.Milk samples with 0 (control), 5, 10, 15, and 20 mg/mL SA were compared.Results showed that 0-15 cmg/mL SA promoted the formation of smaller, fragmented clots by reducing clot mass and particle size and adjusting system viscosity, which enhanced enzyme diffusion and increased the degree of proteolysis (control:29.31%, SA-Milk-15:39.50%).However, at 20 mg/mL, excessive viscosity restricted enzyme-substrate interactions, reducing proteolysis (32.64%).Overall, an appropriate SA concentration (15 mg/mL) optimally improved protein digestibility.These findings provide scientific evidence for designing high-fiber dairy products better suited to elderly digestive needs.
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