温度对无铅腌制皮蛋凝胶特性的影响

Effects of Temperature on the Gel Properties of Lead-free Pickled Preserved Egg

目的研究腌制温度对皮蛋凝胶特性的影响机制,为无铅皮蛋的控温腌制技术提供理论基础。方法以皮蛋的无铅腌制工艺为基础,分析皮蛋凝胶形成过程中感官性状、蛋清游离碱度、质构特性、蛋白质维系结构的化学键等的变化情况。结果当腌制温度在30℃以上时,皮蛋凝胶快速形成,但凝胶并不稳定,在后期皮蛋容易出现烂头和化汤等现象;当腌制温度为15~25℃时,与前面相反。当腌制温度为25℃及以上时,蛋清游离碱度快速升高,并在后期维持在3.03 g/kg,明显高于腌制温度为15℃和20℃时的2.20 g/kg。在凝胶强度指标上,腌制温度为15℃和20℃组皮蛋的弹性、硬度、内聚性均高于腌制温度25℃以上实验组。腌制温度15℃组皮蛋的蛋白质总巯基含量相对最低,而离子键和二硫键含量相对最高。结论当腌制温度为15℃时,皮蛋内总巯基含量相对最小,转换的二硫键含量相对最高,能够促进离子键和二硫键等化学键的生成,使得皮蛋的凝胶强度较好,氢键和疏水相互作用基本不受温度或碱液的影响,因此对不同温度腌制皮蛋的凝胶结构产生的影响较小。

This paper aims to study the influence and its mechanism of curing temperature on the gel characteristics and provide a theoretical basis for the lead-free pickling technology of preserved eggs.Based on the lead-free pickling process of preserved eggs,the changes of sensory properties,free alkalinity,texture and chemical bond of protein reten-tion structure during the formation of preserved egg gel were analyzed.The results showed that when the temperature of marinating is above 30℃,preserved egg gel is formed quickly but the gel is not stable.In the later period,preserved eggs are prone to rotten head and soup,while the 15-25℃group is the opposite.The temperature of 25℃and above can in-crease the free alkalinity of egg white rapidly and maintain it at 3.03 g/kg in the later stage,which is significantly higher than 2.20 g/kg at 15℃and 20℃;In terms of gel strength,the elasticity,hardness and cohesion of preserved eggs at 15℃and 20℃All are higher than the test group above 25℃;the total sulfhydryl content of protein in 15℃groups is the lowest,while the content of ionic bond and disulfide bond is the highest.In summary,when the pickling temperature was 15℃,the content of total sulfhydryl groups in preserved eggs was relatively the smallest,and the content of converted disulfide bonds was relatively highest,which could promote the formation of chemical bonds such as ionic bonds and disulfide bonds,making the gel strength of preserved eggs better.Hydrogen bonds and hydrophobic interactions are hardly affected by temperature or lye,hence there is less influence on the gel structure of preserved eggs cured at different temperatures.