鳙在冷藏和微冻贮藏下品质变化规律的研究

Quality changes of bighead carp(Aristichthys nobilis) during chilled and partial freezing storage

文章研究了鳙(Aristichthys nobilis)在不同贮藏温度下的品质变化规律。将经过前处理的鳙分别贮藏在4℃和-3℃中,通过测定其感官和理化指标,即总挥发性盐基氮(TVB-N)、硫代巴比妥酸(TBA)、鲜度K值、pH、汁液流失率和蒸煮损失率,评价不同温度对鳙品质的影响。结果显示,鳙分别在4℃贮藏至第10天和-3℃贮藏至第30天时失去感官食用品质。但K值在4℃贮藏至第6天和-3℃贮藏至第20天超过临界值。4℃下鳙的TVB-N显著高于-3℃。在整个贮藏过程中TBA均未超过2.00 mg.kg-1的限量值,说明TBA不适合单独用于评价鳙的品质变化。pH分别在4℃贮藏至第4天和-3℃贮藏至第10天达到最低值,分别为6.81和6.76。与4℃相比,-3℃下鳙的汁液流失率和蒸煮损失率较高,这可能与-3℃微冻条件下鳙肉组织冰晶生成导致持水力下降有关。综合K值和感官指标的变化,4℃和-3℃下鳙的货架期分别为6 d和20 d,且-3℃贮藏能明显延长鳙的货架期。

We investigated the effect of storage temperature （ - 3 ℃ and 4 ℃ ） on quality changes of bighead carp （Aristichthys nobil- is） by observing total volatile basic nitrogen （TVB-N） , 2-thiobarbituric acid （TBA）, K value, pH, drip loss, cooking loss and organoleptic properties. Results show that A. nobilis lost sensory and edible quality when stored at 4 ℃ at 10th day and at - 3 ℃ at 30th day. However, the K value exceeded the critical limit at 4 ℃ at 6th day and at - 3 ℃ at 20th day. The TVB-N at 4 ℃ was significantly higher than that at - 3 ℃. The TBA did not exceed the limit of 2. 00 mg.kg-1 at both - 3 ℃ and 4 ℃ throughout the storage, indicating that TBA is not a good indicator for assessing the quality changes of A. nobilis when used alone. The pH reached the minimum of 6. 81 at 4 ℃ at 4th day and of 6. 76 at -3 ℃ at 10th day. The drip loss and cooking loss at -3 ℃ were higher than those at 4 ℃, which may due to the reformation of ice crystals and decline of water-retaining capability. It is concluded that the shelf life of A. nobilis is 6 d at 4 ℃ and 20 d at - 3 ℃. Besides, partial freezing at - 3 ℃ can extend the shelf life significantly.