不同工艺条件对腐乳质构和流变性质的影响
Effect of different fermentation conditions on texture and rheological properties of fermented bean curd
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摘要: 采用腐乳的传统生产制作方法,比较四种不同条件对腐乳物性的差异影响,主要使用了质构仪和流变仪进行研究。结合水分和氨基态氮含量的结果,表明:大豆品种、凝固剂、后发酵温度、毛霉培养时间对腐乳的品质都有影响。大黄豆制作的腐乳比小黄豆凝胶结构更完整;用内酯做凝固剂时与盐卤相比,显著降低了腐乳的硬度,同时提高了腐乳的粘弹性;后发酵温度采用30℃时能提高腐乳氨基态氮含量;毛霉培养时间对腐乳流变性质影响最大,培养5d时腐乳氨基氮含量和粘弹性最小。在所有加工条件下,腐乳样品G’始终大于G″,而且检测线没有出现交叉点,表现出了腐乳的弱凝胶特性。随剪切频率增大,腐乳蛋白质网络结构可以进一步重组产生新的结构。Abstract: Effects of processing conditions-Soybean varieties, coagulant, second fermentation temperature and Actinomucor elegans culture duration on fermented bean curd were investigated. Food texture analyzer and rheometer equipments were employed to compare differences of texture and rheology properties in sufu, combining with analysis of moisture content and amino acid nitrogen.The quality of fermented bean curd was found to be greatly affected by the four processing conditions.The gel structure of fermented bean curd made from big soybean variety was more integrity in structure than that from small soybean.Compared with salt coagulant, lactone coagulant significantly reduced hardness of fermented bean curd and improved viscoelasticity. The secondary fermentation temperature of 30℃ significantly improved nitrogen content of amino acids. Incubation duration of mucor also affected rheological property of fermented bean curd, as with 5 days of incubation, nitrogen content of amino acids and viscoelasticity of sufu were greatly decreased.For all samples investigated, G' values was always bigger than G″ values and no intersection appeared on the detection line. This indicated a weak gel structure in sufu.Protein network can be switched to a new structure through further restructuring with the increase of cutting frequency.