不同循环次数凝胶用水的理化性质及其对油炸鲢鱼丸表面结构的影响

Physicochemical properties of circulating water and its effect on the surface properties of fried silver carp(Hypophthalmichthys molitrix)balls

循环凝胶用水生产的鲢鱼丸经油炸后表面经常会产生孔洞和皱缩,影响鱼丸美观,降低鱼丸品质。为优化生产工艺、提高循环凝胶用水生产的油炸鱼丸品质,本研究基于工厂油炸鱼丸生产参数,模拟油炸鲢鱼鱼丸的生产过程,探究循环凝胶用水对鱼丸表面性状的影响。本研究对比了实验室模拟和工厂制作油炸鱼丸的循环凝胶用水pH、蛋白质含量和等电点指标,结合SDS-PAGE和Nano-HPLC-MS/MS技术对凝胶用水中的蛋白质组成进行鉴定。此外,通过向纯净水中添加蛋清和降低pH来验证不同蛋白含量和pH的凝胶用水对鱼丸表面性状的影响。结果表明,随着生产批次的增加,实验室模拟和工厂连续制作油炸鱼丸凝胶用水的pH都不断下降,蛋白质含量逐渐增加,等电点均维持在4.55~4.65,凝胶用水循环利用次数越多,生产出来的油炸鱼丸表面孔洞越多,皱缩越严重,且凝胶用水中沉积的蛋白质主要是卵白蛋白。增加凝胶用水中的蛋清含量、降低凝胶用水pH均会导致油炸鱼丸表面性状劣化,蛋清的添加会造成鱼丸更严重的表面性状劣化。油炸鱼丸表面性状劣化的主要原因是循环凝胶用水中蛋白质含量的增加和pH的降低,蛋白质主要是来自于鱼丸制作配料蛋清中的卵白蛋白。

The Hypophthalmichthys molitrix balls gelled by circulating water often show holes and shrinkage on the surface during the later process of frying,which can affect the surface beauty and reduce the quality of silver carp balls.In order to optimize the factory production process and improve the gel quality of fried silver carp balls gelled by circulating water,this study simulates the production process of fried silver carp balls in the laboratory based on the factory production parameters,and explores the effect of circulating water on the surface properties of fried silver carp balls.The effect of circulating water on the deterioration of surface properties of fried silver carp balls was investigated by evaluating pH value,protein content,isoelectric point,SDS-PAGE and Nano-HPLC-MS/MS.Furthermore,the influence of different protein content and pH on the surface properties of fried silver carp balls was analyzed by adding egg white in the water and decreasing its pH.As the increase of the gelation cycles,the pH decreases gradually and the protein content increases significantly in the circulating water,and the isoelectric point maintains at pH 4.55-4.65.The more cycles of gelation in circulating water,the more holes and shrinkage on the surface of fried silver carp balls.The main protein deposited in the circulating water was identified as ovalbumin.The increase of protein content with egg white and the decrease of pH in the circulating water had a deteriorating effect on the surface appearance of fried silver carp balls.The group with 40g egg white addition shows the lowest overall surface score.The key reason for the deterioration of the surface properties of fried silver carp balls is the increase of protein content and the decrease of pH in the circulating water.The protein is mainly ovalbumin derived from silver carp balls.