超声辅助碱法提取对类PSE鸡肉蛋白提取率和功能特性的影响

为提高碱溶酸沉方法提取类PSE（pale, soft and exudative）鸡肉蛋白的提取率，采用超声辅助碱法（超声时间0、5、10、15 min）提取并研究其对类PSE鸡肉蛋白功能特性的影响。结果表明：与对照组相比，超声辅助提取类PSE蛋白的提取率由45.55%显著提高至68.58%（P＜0.05），蛋白含量显著提高25.32%（P＜0.05）；当超声辅助提取时间为10 min时，类PSE鸡肉蛋白具有较小的浊度、黏度和粒径；扫描电子显微镜结果进一步证实，超声辅助碱法提取的类PSE鸡肉蛋白结构变得更加疏松，碎片尺寸较小；超声处理后，类PSE鸡肉蛋白凝胶的蒸煮损失率显著降低61.77%（P＜0.05），表明蛋白凝胶的保水性增加，但其凝胶强度显著降低（P＜0.05）；此外，超声辅助提取得到的类PSE鸡肉蛋白溶解度、乳化活性指数和乳化稳定性指数分别提高38.56%、8.02%和12.94%。综上，超声辅助提取不仅可以提高碱溶酸沉法提取类PSE鸡肉蛋白含量，且可以改善类PSE鸡肉蛋白的功能特性。

Effect of Ultrasound-Assisted Alkali Extraction on the Yield and Functional Properties of Proteins from Pale,Soft and Exudative (PSE)-like Chicken Meat

In order to improve the yield of proteins from pale, soft and exudative-like (PSE-like) chicken extracted by alkali extraction followed by acid precipitation, an ultrasound treatment (5, 10 or 15 min) was introduced into the extraction process, and its effect on the functional properties of the proteins was studied. The results showed that the yield of proteins extracted from PSE-like chicken with ultrasound treatment was significantly increased relative to the control without ultrasound treatment ( 68.58% versus 45.55%) (P < 0.05), and that the protein content was significantly increased by 25.32% (P < 0.05) compared with the control group. The proteins obtained at 10 min of ultrasound-assisted extraction had low turbidity, viscosity and particle size. Scanning electron microscopy (SEM) further confirmed that the structure of the proteins extracted by ultrasound-assisted extraction was looser with smaller fragments compared with the control group. The cooking loss of heat-induced gels from the ultrasonically extracted proteins was significantly reduced by 61.77% compared with that from the control group (P < 0.05), indicating that the former had higher water retention capacity than the latter, whereas the gel strength of the former was significantly lower than that of the latter (P < 0.05). In addition, the solubility, emulsifying activity and emulsion stability of the ultrasonically extracted proteins were increased by 38.56%, 8.02% and 12.94% in comparison with those of the control group, respectively. In conclusion, ultrasound-assisted extraction not only increased the purity of proteins recovered from PSE-like chicken meat by alkali extraction followed by acid precipitation, but also improved the functional characteristics of the proteins.