沈阳师范大学粮食学院杨庆余教授等|疏水改性木薯淀粉的制备及其对肌原纤维蛋白乳化特性的影响

为了提高木薯淀粉的疏水性，使其作为颗粒乳化剂改善肌原纤维蛋白（myofibrillar protein，MP）的乳化特性，实验利用辛烯基琥珀酸酐（octenyl succinate anhydride，OSA）对原料木薯淀粉（native tapioca starch，NTS）进行疏水改性处理，得到不同改性水平和取代度（DS值）的疏水改性木薯淀粉（octenyl succinate tapioca starch，OSTS），并利用OSTS与MP制备复合乳化液。通过XRD、FT-IR、SEM和PLM分析了OSTS的结构变化，并测定了乳化液的乳液指数（EI值）、乳化活性（emulsifying activity index，EAI）、乳化稳定性（emulsion stability index，ESI）、Zeta-电位、粒径分布、巯基含量和界面蛋白含量。结果显示，在木薯淀粉分子中成功引入了疏水基团，疏水改性处理对木薯淀粉颗粒的晶体结构基本无影响；随淀粉改性水平和DS值的增加OSTS-MP复合乳化液的EAI和ESI呈显著增加趋势（P<0.05），3.0% OSTS-MP复合乳化液稳定性最好；淀粉与MP在复合乳化液中的相互作用对MP空间结构产生了影响，二者在乳化液滴界面存在竞争吸附作用，且改性水平和DS值越高，这种影响和作用越强。研究结果为OSTS在乳化肉糜制品中的应用提供了理论依据。

 In order to improve the hydrophobicity of tapioca starch, and used it as a granular emulsifier to improve the emulsification properties of myofibrillar protein (MP). In this study, a hydrophobic modification of native tapioca starch (NTS) by octenyl succinate anhydride (OSA), which produced ocentyl succinic tapioca starch (OSTS) with different modification levels and degrees of substitution (DS), and the compound emulsions were prepared using OSTS and MP. The structural changes of the OSTS were analyzed by XRD, FT-IR, SEM, and PLM, and the emulsion index (EI), emulsifying activity index (EAI), emulsion stability index (ESI), Zeta-potential, particle size distribution, sulfhydryl content, and interface protein content of the emulsions were determined. The results showed that the hydrophobic groups were successfully introduced in the tapioca starch molecules, and the hydrophobic modification treatment had basically no effect on the crystal structure type of the tapioca starch particles. The EAI and ESI of the OSTS-MP compound emulsions improved significantly (P<0.05) with increased starch modification levels and DS values, which of the 3.0% OSTS-MP compound emulsion had the best stability. The interaction of starch and MP in the compound emulsion impacted on the spatial structure of MP, both of them had a competitive adsorption effect at the emulsion droplet interface, and which of these were enhanced with modification levels and DS values. The results obtained provided a theoretical basis for the application of OSTS in emulsified comminuted meat products.