冻藏的温度波动对三文鱼化学指标值及持水力的影响

Effect of Temperature Fluctuation on Chemical Index and Water Holding Capacity of Salmon in Frozen Storage

在短期冻藏时,为了提高三文鱼的冻藏温度,减少冻藏能耗与运行成本。研究了冻藏期间(6个月)在−18℃冻藏环境下,温度波动幅度对三文鱼的挥发性盐基氮(TVB-N)值、硫代巴比妥酸(TBARS)值、K值等化学指标值与持水力的影响,并与(−50±0.1)℃冻藏品质对比。结果表明:三文鱼的TVB-N、TBARS、K值、持水力的冻藏初始值分别为6.21 mg N/100 g、0.11 mg MDA/kg、9.87%、86.31%,在(−18±0.5)、(−18±1)、(−18±2)℃环境下冻藏6个月后,TVB-N值分别增大到19.06、23.25和25.91 mg N/100 g,TBARS值分别增大到1.65、1.89、1.96 mg MDA/kg,K值分别增大至43.28%、55.38%、63.54%,持水力分别下降至57.16%、53.49%、51.67%,即温度波动越大,化学指标增加越显著,持水力下降越明显;通过减小冻藏期间温度波动幅度至±0.5℃,可以在3个月内有效提高三文鱼的冻藏温度至−18℃,并保证三文鱼的TVB-N值、TBARS值、K值及持水力与在(−50±0.1)℃冻藏6个月时相当,从而节约成本并降低能耗。以冻藏时间和温度波动幅度为自变量,以持水力为因变量,建立了多元线性回归拟合方程,为建立货架期预测提供依据。

In the short-term frozen storage,in order to improve the frozen storage temperature of salmon,reduce the energy consumption and operation cost of frozen storage.The effects of temperature fluctuation on TVB-N value,TBARS value,K value and water holding capacity of salmon were studied under the frozen storage environment at−18℃during the frozen storage period(6 months),and compared with the frozen storage quality at(−50±0.1)℃.The results showed that:the initial values of TVB-N,TBARS,K value and water holding capacity of salmon were 6.21 mg N/100 g,0.11 mg MDA/kg,9.87%and 86.31%,respectively.The TVB-N values increased to 19.06,23.25 and 25.91 mg N/100 g,TBARS values increased to 1.65,1.89,1.96 mg MDA/kg,K values increased to 43.28%,55.38%,63.54%,and water holding capacity decreased to 57.16%,53.49%and 51.67%,respectively after frozen for 6 months at(−18±0.5),(−18±1)and(−18±2)℃,which indicates that the greater the temperature fluctuation,the more significant the increase in chemical indicators,and the more obvious the drop in water holding capacity.By reducing the temperature fluctuation to±0.5℃,the frozen storage temperature of salmon can be effectively increased to−18℃within 3 months,and the TVB-N value,TBARS value,K value and water holding capacity of salmon can be ensured to be equivalent to those of salmon frozen at(−50±0.1)℃for 6 months,so as to save cost and reduce energy consumption.Taking the frozen storage time and temperature fluctuation as independent variables and water holding capacity as dependent variables,a multiple linear regression fitting equation was established to provide a basis for shelf life prediction.