Fang Ting, Tu Zong-Cai, Wang Hui, Huang Wu-Jun, Zou Guo-Hui, Shan Shan, Sha Xiao-Mei
National R&D Center for Freshwater Fish Processing, College of Life Science, Jiangxi Normal University, Nanchang, Jiangxi, 330022, China.
National R&D Center for Freshwater Fish Processing, College of Life Science, Jiangxi Normal University, Nanchang, Jiangxi, 330022, China; State Key Laboratory of Food Science and Resources, Nanchang University, Nanchang, Jiangxi 330047, China.
Int J Biol Macromol. 2025 Mar;296:139646. doi: 10.1016/j.ijbiomac.2025.139646. Epub 2025 Jan 8.
This study investigated the progressive structural changes of fish gelatin in thermally reversible (TR) and irreversible (TI) states, formed through microbial transglutaminase (MTGase) cross-linking during in vitro gastric digestion. The focus was on dynamic structural changes and gastric digestion characteristics. Free amino content and SDS-PAGE analyses showed that both TR and TI groups were hydrolyzed into smaller fragments by pepsin during digestion. Surface hydrophobicity and endogenous fluorescence analyses revealed that hydrophobic groups in TR samples became embedded, whereas those in TI samples were exposed as digestion progressed. The microstructure of fish gelatin varied states and changed over digestion time. Two digestion patterns were observed: the fitted curves of TR groups exhibited initially increasing that later stabilized, whereas the TI samples followed an S-shaped curve with three distinct stages-an initial stable phase, followed by a rise, and concluding with a final stabilization. A schematic model illustrated the dynamic structural changes of fish gelatin in different states during simulated gastric digestion. This study provides a basis for the development of high-quality collagen supplement products.
本研究调查了在体外胃消化过程中，通过微生物转谷氨酰胺酶（MTGase）交联形成的处于热可逆（TR）和不可逆（TI）状态的鱼明胶的渐进性结构变化。重点在于动态结构变化和胃消化特性。游离氨基含量和SDS-PAGE分析表明，在消化过程中，TR组和TI组均被胃蛋白酶水解成较小的片段。表面疏水性和内源荧光分析显示，随着消化的进行，TR样品中的疏水基团被包埋，而TI样品中的疏水基团则暴露出来。鱼明胶不同状态的微观结构随消化时间而变化。观察到两种消化模式：TR组的拟合曲线最初上升，随后稳定，而TI样品遵循S形曲线，有三个不同阶段——初始稳定阶段，随后上升，最后再次稳定。一个示意图模型展示了模拟胃消化过程中不同状态下鱼明胶的动态结构变化。本研究为开发高质量胶原蛋白补充产品提供了依据。
