速冻方式与温度对鲍鱼品质的影响

Effect of Freezing Method and Temperature on the Quality of Abalone

为了研究不同速冻方式和冻结温度对鲍鱼冻结过程中的品质影响程度、产生原因及机理,本文以鲜活鲍鱼为研究对象,对比采用2种速冻方法(空气速冻和液体速冻)、3种冻结温度(-20℃、-40℃、-60℃)进行冷冻,以蛋白质冷冻变性程度、肌肉组织结构和弹性作为理化和质构特性评价指标。试验结果表明:液体速冻的冻结速率始终比空气速冻高10倍左右,盐溶性蛋白溶解度下降率低2%左右,Ca2+-ATPase活性下降速度与Mg2+-ATPase活性上升速度均略缓慢,蛋白质变性程度低,解冻后鲍鱼肌肉组织间空隙小,弹性好;冻结过程中,冻结温度越低,冻结速率越快,盐溶性蛋白损失越少,蛋白质变性程度和解冻后的弹性无明显变化;综合考虑冻结速率、品质、能耗等因素,认为液体速冻是适合鲍鱼的速冻方法,-60℃液体速冻是相对最佳的速冻工艺。

In order to study the influence degree and mechanism of different freezing methods and temperatures on the quality of abalone during freezing, two freezing methods （air freezing, liquid freezing）, three freezing temperatures （-20 ℃, -40 ℃, -60 ℃） were used for flesh abalone freezing. Frozen denaturation degree, muscle tissue structure, springiness were used as the evaluation indexes. The results showed that the liquid freezing rate was 10 times higher than air freezing rate, while decline rate of salt-soluble protein solubility was 2% lower. The decreasing speed of Ca2^-ATPase activity and increasing speed of Mg2^-ATPase activity were very slow. Frozen denaturation degree of protein and salt-soluble protein loss were low. The space between muscle tissues was smaller and more flexible than that without thawing. During freezing process, lowering freezing temperature, improved the freezing rate, but decreased salt soluble protein loss. No obvious change between frozen denaturation degree and flexible was observed. Base on general consideration of factors such as freezing rate, quality, and energy, liquid freezing at -60 ~C was considered suitable for abalone freezing.