Wang Rui, Liu Yongqing, He Ying, Feng Caiping, Xia Xiufang
Department of Biological and Food Engineering, Lyuliang University, Lvliang, Shanxi, China.
College of Food Science, Northeast Agricultural University, Harbin, Heilongjiang, China.
Front Nutr. 2025 Jan 8;11:1511698. doi: 10.3389/fnut.2024.1511698. eCollection 2024.
Frozen pork can reduce the quality of the meat and alter the digestibility and bioavailability of meat proteins in the human body. In this study, we investigated the changes in the basic composition during frozen storage and their effects on the structural properties of digestion products after protein digestion.
The impacts of frozen storage at different temperatures (-8, -18, -25, and -40°C) and for different times (1, 3, 6, 9, and 12 months) on the basic components and digestive characteristics of pork were evaluated.
The moisture, crude fat, and protein contents decreased with extended storage and increased temperature, whereas muscle juice loss increased ( < 0.05). During digestion of samples frozen at -8°C for 12 months, trichloroacetic acid (TCA)-soluble peptides were decreased by 25.46% and 14.37% in the gastric and small intestinal phases, respectively, compared with fresh samples. Confocal laser scanning microscope (CLSM) showed that samples stored at -8°C had the largest particle size after digestion. Disruption of protein structure was confirmed by the decrease in α-helix, β-turn, and fluorescence intensity (all < 0.05) and the increase in β-sheet, random coil, and maximum fluorescence wavelength of the digestion products of samples frozen at -8°C (all < 0.05).
Therefore, long-term high-temperature frozen storage brought about a significant decline in basic components of muscle and acceleration of loss of protein structural integrity after digestion.
冷冻猪肉会降低肉质，并改变人体中肉蛋白的消化率和生物利用率。在本研究中，我们调查了冷冻储存期间基本成分的变化及其对蛋白质消化后消化产物结构特性的影响。
评估了在不同温度（-8、-18、-25和-40°C）和不同时间（1、3、6、9和12个月）冷冻储存对猪肉基本成分和消化特性的影响。
随着储存时间延长和温度升高，水分、粗脂肪和蛋白质含量下降，而肌肉汁液损失增加（P<0.05）。与新鲜样品相比，在-8°C冷冻12个月的样品在胃和小肠消化阶段，三氯乙酸（TCA）可溶性肽分别减少了25.46%和14.37%。共聚焦激光扫描显微镜（CLSM）显示，在-8°C储存的样品消化后粒径最大。通过α-螺旋、β-转角和荧光强度降低（均P<0.05）以及-8°C冷冻样品消化产物的β-折叠、无规卷曲和最大荧光波长增加（均P<0.05），证实了蛋白质结构的破坏。
因此，长期高温冷冻储存导致肌肉基本成分显著下降，并加速了消化后蛋白质结构完整性的丧失。
