南极磷虾冻藏温度下的品质变化及其货架期分析

摘要

以出肉率及化学变化(pH、TVB-N、TBARS、Ca2-ATPase活性)为指标,结合感官评价,探讨了南极磷虾冻藏温度下(-8、-18和-28℃)的品质变化及货架期.实验结果显示,南极磷虾感官评分与冻藏时间和冻藏温度均有显著的相关性(r=0.982和0.981),-8℃条件下20 d后南极磷虾感官不可接受,-18和-28℃条件下南极磷虾分别在75和120 d时感官不可接受；出肉率与冻藏时间有显著的相关性(r=0.953),在-8、-18和-28℃条件下南极磷虾出肉率在货架期终点分别达到31.62％、31.21％、34.52％；pH与冻藏时间和冻藏温度相关性不明显,不适宜用作反映南极磷虾冻藏条件下的品质指标,但随时间的延长pH仍呈增长趋势,在货架期终点3种冻藏温度下南极磷虾pH分别达到7.94、7.99、7.84；TVB-N和TBARS分别与冻藏时间有显著相关性(r=0.944和0.935),但TVB-N只与-8℃条件下的温度有显著相关性,TBARS只与-18和-28℃冻藏温度有显著相关性,在货架期终点时(感官不能接受)3种冻藏温度下南极磷虾TVB-N和TBARS分别为21.43、20.49、19.74 mg/100g和0.88、0.78、0.66 mg MA/kg,均低于腐败水平阈值；Ca2+-ATPase活性下降显著,与冻藏时间呈显著相关性(r=- 0.929).南极磷虾感官指标、出肉率、TVB-N、TBARS、Ca2-ATPase活性均在冻藏期间有明显变化,且与冻藏时间有明显的相关性,可以考虑用作反映冻藏条件下南极磷虾品质变化指标.因此,综合各项指标并结合感官评价,可以判断实验过程中3种冻藏温度下南极磷虾货架期终点分别为20、75、120 d.%Quality changes and shelf-life of Antarctic krill were investigated by testing the indexes of dressing percentage,chemical( pH,TVB-N,TBARS,Ca2 + -ATPase activity) and sensory evaluation at the frozen temperature( -8, -18 and -28℃). The results showed that sensory evaluation of Antarctic krill obtained significant correlations with frozen time and frozen temperature ( r - 0. 982 and 0. 981 respectively) ,sensory evaluation was unaccepted on 20th day at -8℃ ,75th and 120th day were unacceptable for -18 and - 28 ℃ respectively. Dressing percentage exhibited significant correlations with frozen time (r=0.953) .dressing percentage were 31. 62% ,31. 21% and 34. 52% at the end of the shelf-life (sensory evaluation unaccepted) at -8, -18 and -28℃, respectively. No significant correlations were found between pH and frozen temperature, and pH, consequently, was not considered as the suitable parameter for reflecting quality changes of Antarctic krill under frozen storage. However,pH increased as time extended, pH got 7. 94,7. 99 and 7. 84 at the end of shelf-life respectively. Significant correlations were obtained between TVB-N,TBARS and frozen time ( r = 0. 944 and 0. 935), whereas, only frozen temperature at -8 t has good correlations when TVB-N,and frozen temperature at - 18 and -28℃ attained strong correlations with TBARS,TVB-N and TBARS reached 21.43,20.49,19. 74 mg/100 g and 0.88,0.78,0.66 mg MA/kg at the end of the shelf-life at three frozen temperatures respectively. Those results were lower than the limitation. Ca2+-ATPase activity decreased sharply with significant correlations with frozen time (r= -0. 929). Changes of sensory evaluation, dressing percentage, TVB-N, TBARS and Ca2 + -ATPase activity were sensitive and had significant correlations with frozen time, therefore they could be considered as right testing indexes for Antarctic krill at frozen temperature. So shelf-life of Antarctic krill at three frozen temperature,based on the testing indexes and sensory evaluation, was estimated at 20,75 and 120 days respectively during the whole study.