多酚协同猪血浆蛋白水解物稳定植物油预乳状液的机理及其对肌原纤维蛋白凝胶特性的影响

Vegetable oil pre-emulsion, which used to incorporated into meat batter to produce traditional fabricated comminuted meat products, could total or partial replace the animal fat and maintain the original eating quality. However, due to their thermodynamically unstable and easily attacked by free radicals, the pre-emulsion tend to destabilize through flocculation (aggregation), coalescence, creaming and lipid oxidation, which will decrease the quality of meat products. Based on our previous work, first of all, procine plasma protein hydrolysates (PPPH) are used to prepare vegetable oil pre-emulsion to investigate the distribution of the PPPH in the pre-emulsion and the interface properties of the emulsion droplets. Secondly, because hydrolysates are distributed preferentially in the aqueous phase, which cannot effectively inhibit the oxidation in the oil phase and oil-water interface where exhibit more oxidation reaction, the synergistic antioxidative effect of both phenolic compounds and PPPH and its mechanism on antioxidation in liposomal model system and pre-emulsion will be elucidate. Thirdly, the influence of different processing conditions on the physical and oxidative stability of pre-emulsion will systematically illustrated. Finally, to explore the role of pre-emulsion on myofibrillar proteins gel properties, the inter-atomic forces and changes of microstructure will be evaluated. Through this research, we could build a good theoretical basis for enhancing the quality of pre-emulsion type food and increasing its application in low-fat meat products, which provide technical support for development of health and nutritious low-fat meat products.

尽管植物油预乳状液的添加能完全或者部分替代传统肉糜类制品的动物脂肪并保持其品质不变，但由于其热力学不稳定性以及自由基的攻击，预乳状液仍然存在容易絮凝、分层和氧化酸败等急需解决的问题。本项目在前期研究基础之上，首先重点研究猪血浆蛋白水解物在植物油乳状液中的分布以及乳化液滴的界面性质；然后，针对水解物在乳状液中大部分分布在水相环境中，无法有效作用于氧化反应最为集中的油相和油水界面中的问题，探讨多酚与猪血浆蛋白水解物在乳状液中联合抑制脂肪氧化及提高整个体系稳定性的协同作用机理，并进一步阐明不同加工条件对整个乳状液稳定性的影响；最后，研究植物油预乳状液对肌原纤维蛋白凝胶性能的影响，阐明其与肌原纤维蛋白基质分子间作用力及微观结构的变化相关性。通过本项目的研究，为提高乳状液类型食品的品质及其在低脂肉糜类制品中的应用奠定良好的理论依据，从而为生产高附加值的健康新型低脂肉糜制品提供创新性技术指导。

本面上基金项目在前期研究基础之上，首先重点研究猪血浆蛋白水解物（Porcine Plasma Protein Hydrolysates, PPPH）在植物油乳状液中的分布以及乳化液滴的界面性质；然后，针对水解物在乳状液中大部分分布在水相环境中，无法有效作用于氧化反应最为集中的油相和油水界面中的问题，探讨多酚与猪血浆蛋白水解物在乳状液中联合抑制脂肪氧化及提高整个体系稳定性的协同作用机理；并进一步阐明不同加工条件对整个乳状液稳定性的影响；最后，研究植物油预乳状液对肌原纤维蛋白凝胶性能的影响，阐明其与肌原纤维蛋白基质分子间作用力及微观结构的变化相关性。具体研究成果如下：.（1）与单独PPPH制备的乳状液相比，PPPH联合吐温-20制备的乳状液具有较高的乳化稳定性。与此同时，较低浓度的PPPH（2.5 mg/mL）和吐温-20能够形成具有最高稳定性的乳状液，这主要归因于PPPH和吐温-20在油滴表面的竞争性吸附。.（2）氧化单宁酸（oxidized tannic acid, OTA）和氧化绿原酸（oxidized chlorogenic acid, OCA）均能够与PPPH共价连接，具体表现为浊度的显著增加以及游离氨基含量显著降低。OTA或者OCA的修饰能够使PPPH具有更高的乳化稳定性指数和更强的抗氧化活性。.（3）在以PPPH作为乳化剂所制备的水包油型（O/W型）乳状液中添加不同浓度的OTA或者OCA，其中的醌类化合物可与肽链上的巯基、氨基反应生成C-N及C-S，从而促进肽链的交联，能够有效地在油滴表面形成覆盖和包裹，显著提高乳状液在整个贮藏期间的物理和氧化稳定性。.（4）将1%（w/v）OTA添加到以PPPH作为乳化剂所制备高稳定性的植物油预乳状液部分替代猪脂肪添加到法兰克福香肠中，在不影响产品品质的前提下，显著降低了产品中的饱和脂肪酸含量，提高了健康油脂比例，为其在低脂乳化肉糜加工中良好应用提供理论参数。