循环流体浸渍速冻工艺对鲻鱼贮藏品质的影响

Effects of Quick-freezing by Circulated Fluid Impregnation on the Quality of Mullet during Storage

为探究循环流体浸渍速冻工艺对鲻鱼冻结过程及后期贮藏品质的影响,本文对比了经过-25℃循环流体浸渍速冻和-18℃风冷式冷柜直冻两种预处理后再置于-18℃冷柜中贮藏的鲻鱼样品,观察其冻结曲线及在0 d、3 d、6 d、9 d、14 d和30 d的保水性(解冻汁液流失率和蒸煮损失率),新鲜度(总挥发性盐基氮、TVB-N、感官评定和质构特性),油脂氧化(硫代巴比妥酸值,TBARS)与肌原纤维蛋白氧化(羰基含量、总巯基值和二聚酪氨酸含量)四项品质指标。实验表明:速冻组样品的各项指标均优于直冻组,理化品质下降程度低于直冻组。第30 d时,速冻组样品的解冻汁液流失率、蒸煮损失率分别为10.36%和10.16%(p<0.05);TVB-N值为11.40×10^(-2)mg/g,依然在新鲜范围内;油脂氧化与肌原纤维蛋白氧化程度远小于直冻组(p<0.05),TBARS值为0.14 mg MDA/kg,羰基值为6.52 nmol/mg蛋白,总巯基值为58.11 nmol/mg蛋白,二聚酪氨酸含量为8911.50±15.58 A.U.。

We investigated the use of circulated fluid impregnation（CFI） as a novel quick-freezing technique for Mullet and its impact on storage quality. Experimental Mullet fillet samples were subjected to -25 ℃ CFI treatment before storage at -18 ℃, while the control samples were directly stored at -18 ℃, for 0, 3, 6, 9, 14, and 30 d. The freezing curve was then monitored and the properties of Mullet after storage（up to 30 d） were also evaluated with regard to changes in 4 indicators. These included water holding capacity（drip loss rate and cooking loss rate）, freshness（total basic-nitrogen [TVB-N], sensory evaluation, and texture）, lipid oxidation（thiobarbituric acid reactive substances, TBARS）, and myofibrillar protein oxidation（carbonyl content, total sulfhydryl content, and bityrosine content）. The results indicated that samples from the experimental group were superior with regard to all indicators compared to the control group during the entire storage experiment; the decline in their physical and chemical qualities was also lower. By 30 d, the drip loss rate and cooking loss rate of the experimental group were 10.36% and 10.16%, respectively（p〈0.05）, while the TVB-N value was 11.40×10-2mg/g, which was within the accepted range of freshness. In addition, the degree of lipid oxidation and protein oxidation in the experimental group was also significantly lower than that in the control group（p〈0.05） with a TBARS value of 0.14 mg MDA/kg, carbonyl content of 6.52 nmol/mg protein, total sulfhydryl content of 58.11 nmol/mg protein, and bityrosine content of 8911.50±15.58 A.U..