不同蛋白原料条件下常温再制干酪制品析水性和质构特性研究

Effect of Different Protein Raw Materials on Water Precipitation of Room Temperature Processed Cheese Products

常温再制干酪制品是指经超高温瞬时灭菌(Ultra-high temperature treated, UHT)处理后可常温贮藏的灭菌型干酪制品,是我国乳品工业的新热点。然而,干酪在UHT处理后易失稳发生凝胶结构重构,在贮藏期间出现析水等质构问题,影响产品品质。为阐明蛋白原料对常温再制干酪制品析水性的影响及机制,筛选了3种不同的蛋白原料:膜过滤酪蛋白胶束、浓缩牛奶蛋白、凝乳酶酪蛋白,分析其蛋白质含量、组成以及粒径、电位、水合性和钙离子分布等理化特性,进而分析了蛋白原料对常温再制干酪制品析水性和质构特性的影响规律,并从水分分布和微观结构层面解析蛋白原料对常温再制干酪制品析水性的影响机制。结果表明:3种蛋白原料的蛋白质含量和组成存在显著差异,浓缩牛奶蛋白的乳清蛋白占总蛋白质量分数比膜过滤酪蛋白胶束高7.81个百分点,而凝乳酶酪蛋白中不含乳清蛋白;在水合性方面,浓缩牛奶蛋白和膜过滤酪蛋白胶束相近,均显著高于凝乳酶酪蛋白。蛋白原料显著影响常温再制干酪制品析水性,贮藏90 d时,由凝乳酶酪蛋白制备的常温再制干酪制品析水率最高,而由浓缩牛奶蛋白制备的常温再制干酪制品的析水率最低,表面析水率和离心析水率分别为0.42%和1.10%。水分分布和微观结构结果显示,蛋白原料通过影响干酪制品中水分的存在状态和三维网络空间结构,从而影响常温再制干酪制品的析水性。研究解析了不同蛋白原料对常温再制干酪制品析水性的影响及机制,为常温再制干酪制品析水性的改善提供了理论依据。

Room temperature processed cheese products,referring to the sterilized cheese,can be stored at room temperature after being treated by ultra-high temperature treated(UHT).It is a hot spot in China’s dairy industry.However,processed cheese is prone to instability after UHT treatment,resulting in gel structure reconstruction,water precipitation and other texture problems during storage,which affect the product quality.It was intended to clarify the effect of protein raw materials on the water precipitation of room temperature processed cheese products and its mechanism.Three different protein raw materials:membrane filtration casein micelle,concentrated milk protein and rennet casein were screened,and their protein content and composition as well as their physical and chemical properties such as particle size,potential,hydration and calcium ion distribution were analyzed.Secondly,the effects of protein raw materials on the water precipitation and texture properties of room temperature processed cheese products were analyzed.The mechanism of the effect of protein raw materials on the water precipitation of room temperature processed cheese products was analyzed from the aspects of water distribution and microstructure.The results showed that there were significant differences in protein composition among the three protein materials.The whey protein content of concentrated milk protein was 7.81 percentage points higher than that of membrane filtration casein micelles,while rennet casein did not contain whey protein.In terms of hydration,concentrated milk protein and membrane filtered casein micelles were similar and significantly higher than rennet casein.Protein raw materials significantly affected the water precipitation of room temperature processed cheese products.When stored for 90d,the water precipitation rate of room temperature processed cheese products prepared from rennet casein was the highest,while that of room temperature processed cheese products prepared from concentrated milk protein was the lowest,and its surface water precipitation rate and centrifugal water precipitation rate were 0.42%and 1.10%,respectively.The results of water distribution and microstructure showed that the protein raw material affected the water precipitation of room temperature processed cheese products by affecting the existing state and three-dimensional network spatial structure of water in processed cheese.The effect and mechanism of different protein raw materials on the water precipitation of room temperature processed cheese products was analyzed,which provided a theoretical basis for improving the water precipitation of room temperature processed cheese products.