冷链物流过程中温度变化对金枪鱼新鲜度的影响

Effects of temperature changes on freshness of tuna( Thunnus obesus) fillet in cold chain logistics

为研究物流过程中温度变化对金枪鱼新鲜度的影响,试验模拟3种不同物流过程,测定金枪鱼肉pH、高铁肌红蛋白相对百分含量、TBA、TVB-N、TMA-N、组胺以及菌落总数。结果表明,超低温冻藏大目金枪鱼肉的新鲜度受物流过程中温度变化影响显著,储运、销售过程始终保持在-55℃的完整冷链下能够使金枪鱼肉保持良好的新鲜度;储运过程中经历温度变化的金枪鱼肉在冷藏销售、消费期间新鲜度显著下降,在消费者家用冰箱4℃贮藏12h后pH、高铁肌红蛋白相对百分含量、TBA值分别为6.71、64.77%、1.277mg MDA/kg,TVB-N、TMA-N及菌落总数虽然均未超过限定值,但其新鲜度甚至低于物流过程中始终保持在-18℃温度恒定情况下的鱼肉。组胺在整个试验过程中变化不显著,所有试验组均在安全范围。由此得出,若运输过程不具备超低温冷藏设备,仅靠超低温贮藏并不能减缓鱼肉新鲜度下降,因此应尽量避免储运期间的温度变化。研究结果为金枪鱼储运和销售提供了理论参考。

To investigate the effect of temperature variation on quality and microstructure of tuna（ Thunnus obesus）when transported, changes in pH value, metmyoglobin formation, thiobarbituric values （TBA）, total volatile basicnitrogen （ TVB- N）, trimethylamine nitrogen （TMA- N）, histamine and microbiological were assayed periodically in 3diverse simulated situations of logistics.The results showed that the freshness of bigeye tuna stored in ultra-lowtemperature was significantly affected by temperature changes in the logistics process.Freshness of tuna could bemaintained under complete cold chain of-55℃ during transportation and sale,while the more the frequency andrange of temperature changes, the greater the deterioration would be.When transported at- 18℃ twice beforestored at 4℃ in domestic refrigerators for 12 hours, pH value, metmyoglobin percentage,thiobarbituric values of thetuna were 6.71 ,64.77%, 1.277mg malonaldehyde/kg respectively.Although TVB-N,TMA-N and TVC of tuna didn＇texceed the legal limits,it had lower freshness than those maintained at-18~C all the time.Histamine of tuna duringstorage did not change significantly, so all experimental groups were in the safe range.The lack of ultra-lowtemperature refrigerated trucks would result in lower freshness of fish. Therefore, temperature variation betweentransportation and storage should be avoided.In general,this study is going to provide reference for retaining thefreshness of tuna in stages of storage,transportation and sale.