Zou Qiang, Chen Yuyou, Liu Yudie, Luo Linghui, Zheng Yuhan, Ran Guilian, Liu Dayu
School of Food and Biological Engineering, Chengdu University, Chengdu 610106, China.
Meat Processing Key Laboratory of Sichuan Province, School of Food and Biological Engineering, Chengdu University, Chengdu 610106, China.
Foods. 2024 Oct 14;13(20):3264. doi: 10.3390/foods13203264.
The effects of salt-enzyme-alkali progressive tenderization treatments on porcine cortical conformation and collagen properties were investigated, and their effectiveness and mechanisms were analyzed. The tenderization treatment comprised three treatment stages: CaCl (25 °C/0-30 min), papain (35 °C/30-78 min), and NaCO (25 °C/78-120 min). The textural, microscopic, and collagenous properties (content, solubility, and structure) of pork skin were determined at the 0th, 30th, 60th, 90th, and 120th min of the treatment process. The results showed that the shear force, hardness, and chewability of the skin decreased significantly ( < 0.05), and the elasticity exhibited a gradual increase with the progression of tenderization. The content and solubility of collagen showed no significant change at the CaCl treatment stage. However, the soluble collagen content increased, the insoluble collagen content decreased, and the collagen solubility increased by 18.04% during the subsequent treatment with papain and NaCO. Meanwhile, the scanning electron microscopy results revealed that the regular, wavy structure of the pig skin collagen fibers gradually disappeared during the CaCl treatment stage, the overall structure revealed expansion, and the surface microscopic pores gradually increased during the papain and NaCO treatment stages. The findings of the Fourier transform infrared spectroscopy analysis indicated that the hydrogen bonding interactions between the collagen molecules and the C=O, N-H and C-N bonds in the subunit structure of collagen were substantially altered during treatment and that the breakage of amino acid chains and reduction in structural ordering became more pronounced with prolonged treatment. In the tertiary structure, the maximum emission wavelength was blue-shifted and then red-shifted, and the fluorescence intensity was gradually weakened. The surface hydrophobicity was slowly increased. The salt-enzyme-alkali tenderization treatment considerably improved the physical properties and texture of edible pork skins by dissolving collagen fibers and destroying the structure of collagen and its interaction force.
研究了盐-酶-碱渐进嫩化处理对猪皮层构象和胶原蛋白特性的影响，并分析了其有效性和作用机制。嫩化处理包括三个处理阶段：氯化钙（25℃/0 - 30分钟）、木瓜蛋白酶（35℃/30 - 78分钟）和碳酸钠（25℃/78 - 120分钟）。在处理过程的第0、30、60、90和120分钟测定猪皮的质地、微观结构和胶原特性（含量、溶解度和结构）。结果表明，猪皮的剪切力、硬度和咀嚼性显著降低（<0.05），随着嫩化进程弹性逐渐增加。在氯化钙处理阶段，胶原蛋白的含量和溶解度无显著变化。然而，在随后的木瓜蛋白酶和碳酸钠处理阶段，可溶性胶原蛋白含量增加，不溶性胶原蛋白含量减少，胶原蛋白溶解度增加了18.04%。同时，扫描电子显微镜结果显示，猪皮胶原纤维的规则波浪状结构在氯化钙处理阶段逐渐消失，整体结构呈现扩张，在木瓜蛋白酶和碳酸钠处理阶段表面微观孔隙逐渐增加。傅里叶变换红外光谱分析结果表明，处理过程中胶原分子间的氢键相互作用以及胶原蛋白亚基结构中的C=O、N-H和C-N键发生了显著改变，随着处理时间延长，氨基酸链的断裂和结构有序性的降低更加明显。在三级结构中，最大发射波长先蓝移后红移，荧光强度逐渐减弱。表面疏水性缓慢增加。盐-酶-碱嫩化处理通过溶解胶原纤维、破坏胶原蛋白的结构及其相互作用力显著改善了可食用猪皮的物理性质和质地。
