白鲢鱼鱼糜凝胶过程中水分及凝胶特性的变化

本文研究了白鲢鱼鱼糜凝胶过程中的水分及凝胶特性变化规律,主要考察了鱼糜在凝胶过程中持水力、低场核磁T2横向弛豫时间及T2峰比例、凝胶特性、色差及凝胶微观结构指标的变化,并通过TG-DTGA(Thermogravimetric-Derivative Thermogravimetry Analysis)分析鱼糜凝胶在两段式加热中的结晶水含量变化。鱼糜与淀粉、水、盐混合斩拌后,采用两段式凝胶进行凝胶化。结果发现,加热过程中鱼糜持水力显著增加,在第二段加热25 min时达到最大值为96.93%;T23弛豫时间呈现下降的趋势,并在第二段加热过程中下降速度较快,在第二段加热30 min时达到最低值为30.51 ms;T23峰比例呈现上升趋势且在第一段加热过程中升速较快,在第二段加热10 min后达到最大值为93.97%;弹性、硬度等显著增加;亮度和白度呈现显著上升的趋势;结晶水含量在二段加热中呈现先增加后减少的趋势,在第一段加热30 min时达到最大值为6.59%。

Changes in Water and Gel Properties of Silver Carp (Hypophthalmichthys molitrix) Surimi during Gelation Process

The pattern of changes in water and gel properties of silver carp surimi during gelation process was studied. Changes in water-holding capacity, T2 transverse relaxation time, T2 peak ratio at low field, gel properties, color, and microstructure of the gel during surimi gelation were investigated. Additionally, change in crystal water content of the surimi gel during two-step heating was analyzed by thermogravimetric-derivative thermogravimetry analysis (TG-DTGA). Surimi was chopped and mixed with starch, water, and salt, and gelation was performed by a two-step heating method. The results showed that the water-holding capacity of surimi increased significantly during the heating process, and reached the maximal value (96.96%) after 25 min of heating at the second step. T23 transverse relaxation time showed a downward trend; faster rate of the decline was observed during the second step, and the minimal value (30.51 ms) was reached after 30 min of heating at the second step. The peak ratio of T23 showed an upward trend; faster rate of the increase was observed during the first step, and the maximal value (93.97%) was reached after 10 min of heating at the second step. Elasticity, hardness, and other indices of gel properties all increased significantly; both brightness and whiteness showed an increasing trend; crystal water content increased first and then decreased and reached the maximal value (6.59%) after 30 min of heating at the first step.