鲍鱼预熟制及低温贮藏中的脂质氧化特性

为探究鲍鱼在不同预处理和贮藏条件下的品质变化,研究不同预熟制工艺和低温贮藏条件对其腹足脂质变化的影响。通过水蒸气蒸馏法、气相色谱-质谱联用仪检测硫代巴比妥酸反应物(thiobarbituric acid reactive substances,TBARS)值和脂肪酸组成。结果表明,新鲜鲍鱼样品的TBARS值为1.01 mg/kg,经4℃贮藏4 d、-18℃贮藏35 d、-80℃贮藏35 d后分别为4.12、4.31、3.40 mg/kg。而经80℃加热2 h预熟制处理鲍鱼的TBARS值为1.90 mg/kg,其在4℃贮藏4 d、-18℃贮藏35 d、-80℃贮藏35 d后分别为1.91、1.86、1.91 mg/kg,在贮藏过程中无明显变化。经预熟制处理的鲍鱼在-18℃冻藏21 d后的二十碳五烯酸和二十二碳五烯酸含量分别为9.78%和5.32%,明显高于直接冻藏(分别为8.76%和5.01%)的鲍鱼。因此,认为新鲜鲍鱼的脂质氧化主要发生在冻藏阶段,而预熟制工艺可以有效延缓冻藏过程中脂质氧化的发生。

Oxidative Lipid Changes of Abalone during Precooking and Storage at Low Temperatures

This study was focused on the oxidative lipid changes of abalone meat under different precooking and storage conditions in order to explore the quality changes. The thiobarbituric acid reactive substances (TBARS) value was tested by a steam distillation method. The fatty acid composition was determined by gas chromatography-mass spectrometry (GC-MS). Results showed that TBARS value was 1.01 mg/kg in fresh abalone samples, which increased to 4.12, 4.31 and 3.40 mg/kg, respectively after storage at 4 ℃ for 4 days, –18 ℃ for 35 days and –80 ℃ for 35 days. TBARS value in precooked (heating at 80 ℃ for 2 h) abalone was 1.90 mg/kg, and it remained stable at 1.91, 1.86 and 1.91 mg/kg after storage at 4 ℃ for 4 days, –18 ℃ for 35 days and –80 ℃ for 35 days. After storage at –18 ℃ for 35 days, the contents of eicosapentaenoic acid (EPA) and docosapentaenoic acid (DPA) in precooked samples (9.78% and 5.32%) were higher than those in unpretreated samples (8.76% and 5.01%). In conclusion, the oxidation of fatty acids was mainly observed in samples during cold storage, which was inhibited by the precooking treatment.