超微粉碎-微粒化组合技术对乳清蛋白结构和加工特性的影响

Effect of Combination of Superfine Grinding and Microparticulation on the Structure and Processing Properties of Whey Protein

摘要:

研究了超微粉碎-微粒化组合技术对乳清蛋白结构和加工特性的影响，以期为其在乳清蛋白的深加工中的应用提供理论基础。采用傅立叶红外光谱研究了乳清蛋白的二级结构，发现超微粉碎、微粒化及其组合技术均能不同程度的改变乳清蛋白各二级结构元件的含量。荧光光谱扫描结果显示乳清蛋白的最大荧光吸收波长分别由333 nm红移至334 nm、356 nm和358 nm，说明了处理后的蛋白表面疏水性不同程度的增加。同时处理后的乳清蛋白的游离巯基含量24.11 μmol/g显著性减少至8.41μmol/g，说明了乳清蛋白三级结构发生改变。组合技术处理后，乳清蛋白的焓值由133.10 J/g下降到54.63 J/g，说明了聚集程度显著性下降。二级和三级结构的改变直接导致了热稳定性的增强、乳化性和乳化稳定性、起泡性和泡沫稳定性、持水能力和吸油性的增强。这些加工特性的增强说明超微粉碎-微粒化组合技术适宜在乳清蛋白基质脂肪模拟物中推广应用。

Abstract:

In order to evaluate the application of combination of superfine grinding technology and microparticulation in whey protein (WP) further processing, the effects on structures, processing properties and their relationship were investigated. The fitting results of FT-IR spectrum shows that the contents of secondary structure elements significantly changed. Fluorescence emission spectrums show that the maximum wavelength of whey protein red shifted from 333 nm to 334 nm, 356 nm and 358 nm, respectively. That means the improvement of surface hydrophobicity. The reduction of free sulfhydryl content (from 24.11 μmol/g to 8.41 μmol/g) means the change of tertiary structure. The decrease of enthalpy values (from 133.10 J/g to 54.63 J/g) indicates the lesser aggregation. The enhancement of thermostability, emulsifying properties, foaming characteristics, water holding capacity and oil binding capacity on different levels was due to the change of conformation. The improvement of processing properties means the applicable of combination of superfine grinding technology and microparticulation in whey protein-based fat mimetic.