再制马苏里拉干酪的玻璃化转变测定及状态图研究

Determination of glass transition and state diagram of processed Mozzarella cheese

食品状态图能够对食品的贮藏稳定性进行预测,并为产品的适宜加工原料和加工工艺提供参考。再制奶酪是中国目前乳品行业热点,为深入了解再制干酪加工贮藏性质,该文研究了再制干酪的吸附等温线,构建再制干酪的状态图。结果表明,再制干酪吸附等温线为典型“J”型曲线,含有非冻结水干酪样品随着湿基含水率从0.008 g/g增大到0.068 g/g,玻璃转化温度(glass transition temperature,T g)从71.2℃降低至20.6℃;含有冻结水干酪样品随着湿基含水率从0.22 g/g增大到0.77 g/g,T g从-19.7℃降低至-29.7℃,再制干酪最大冻结浓缩状态的T g为-35.5℃,在此状态下的固形物湿基质量分数为79%。通过状态图可以直观了解再制干酪不同状态与物料的含水率和T g之间的关系,协助预测再制干酪在储藏过程中的稳定性,为再制干酪加工及贮藏提供理论基础。

The state chart of food can be used to predict the storage stability and provide reference for the suitable formulation and process of raw materials.Processed cheese is a popular dairy product in China.In order to understand the processing and storage properties of processed cheese,the adsorption isotherm of processed cheese was studied and a state diagram of processed cheese was built.The results showed that the adsorption isotherm of the processed cheese was a typical“J-shaped”curve.The glass transition temperature(T g)of the cheese containing non-frozen water reduced from 71.2℃to 20.6℃,with the wet base moisture content increased from 0.008 g/g to 0.068 g/g.T g of the cheese containing frozen water decreased from-19.7℃to-29.7℃,with the wet base moisture content increased from 0.22 g/g to 0.77 g/g.T g of the processed cheese under maximum freezing concentration state was-35.5℃,with a solid wet base mass fraction of 79%.The relationship between moisture content and T g could be visually understood through state diagram,which could help to predict the stability of processed cheese during storage and provide theoretical basis for its processing and storage.