超声协同TG酶处理乳清蛋白/马铃薯蛋白水解物复合凝胶的特性

Gelation Properties of Whey Protein Isolate and Potato Protein Hydrolysate Composite Gel after Ultrasound and Transglutaminase Treatments

为开发乳清蛋白/马铃薯蛋白水解物复合凝胶,采用质构仪、流变仪、低场核磁和扫描电镜表征超声与TG酶处理对凝胶性质的影响。结果表明:超声协同TG酶处理凝胶的凝胶强度,胶黏性,回复性和咀嚼性低于对照组(P<0.05),但高于单独TG酶处理组(P<0.05)。在超声协同TG酶处理凝胶样品中,超声时间的增加,温度循环终点时凝胶储能模量与损耗模量增加;超声15和30 min协同TG酶处理样品的溶胀力相较于TG酶单独交联的样品提高了11.55%和55.02%,自由水含量相较TG酶单独交联样品分别提高了62.22%和111.11%。SEM微观结构表明,超声处理使凝胶中蛋白分子聚集体变大,蛋白网络致密但均一性不高;超声协同TG酶处理凝胶的聚集体较小,蛋白网络结构较为均一。研究表明超声协同TG酶交联会显著改变乳清蛋白/马铃薯蛋白水解物复合凝胶的性能及结构,为复合蛋白凝胶性质的调控提供了参考。

To develop a novel composite gel with whey protein isolate(WPI)and potato protein hydrolysate(PPH),their mixtures were pretreated using ultrasound and transglutaminase(TGase)before gel formation.The effects of ultrasound and TGase pretreatments on the properties of the composite gel were assessed using a texture analyzer,rheometer,low-field nuclear magnetic resonance(LF-NMR),and scanning electron microscopy(SEM).The results show that the hardness,gumminess,resilience and chewiness of gel samples pretreated using ultrasound and TGase were lower than those of the control samples(P<0.05),but were higher than those of the gel samples treated with TGase only(P<0.05).For the ultrasound and TGase pretreated composite gel,increasing the ultrasonic pretreatment time enhanced the final storage and loss moduli of the gel at the end of the heating and cooling cycles in the rheometer.The swelling ratio of the gel samples that underwent 15-and 30-minute ultrasonic and TGase pretreatments increase by 11.55% and 55.02%,respectively,compared with that of the gel samples with only TGase pretreatments.Simultaneously,the free water content increased by 62.22% and 111.11%,respectively.The SEM images of gels with ultrasound pretreatments only demonstrate larger protein aggregates,and a dense network with low uniformity in its microstructure.Contrarily,the gels with ultrasound and TGase pretreatments exhibited small protein aggregates,and a compact and homogeneous microstructure network.In conclusion,the combination of ultrasound and TGase pretreatments significantly affects the microstructures and properties of WPI and PPH composite gels.The findings facilitate the development of novel protein gels and provide a reference for adjusting the properties of composite gels.