超高压处理对冷藏鲍鱼保鲜效果与品质变化的影响

本文以鲍鱼为材料,研究了超高压处理对鲍鱼体内微生物的消减作用和不同压力超高压处理后的鲍鱼在冷藏过程中挥发性盐基氮值、p H、脂肪氧化值、肌肉组织与硬度的变化情况,对比了热加工和超高压处理对鲍鱼品质变化的影响。研究结果显示,超高压具有良好的杀菌效果,鲍鱼经400 MPa和500 MPa处理10 min,体内菌落总数达到未检出状态,贮藏20 d后,仍符合生食标准。超高压处理能有效抑制鲍鱼挥发性盐基氮的产生,在4℃条件下保存30 d后TVB-N值仍小于35 mg/100 g。经超高压处理后的鲍鱼p H显著高于未加工鲍鱼,但4℃贮藏30 d后,超高压处理后的鲍鱼p H反而显著低于未加工鲍鱼;相比热加工和未加工的对照条件,超高压处理能延迟TBA值的升高,抑制脂肪氧化;组织切片和质构实验发现经超高压处理的鲍鱼肌肉纤维凝聚,肉质硬度升高,但随着贮藏时间的延长,硬度逐渐下降。结果表明,鲍鱼经400 MPa压力处理10 min,冷藏20 d后仍可生食,同时品质得到良好的提升。 

Effect of High Pressure Processing(HPP) on the preservation and quality of abalone

The changes of different high pressure processing( HPP) conditions on microbial inactivation,total volatile basic nitrogen( TVB- N),p H,Thiobarbituric acid( TBA),muscle tissue and hardness of abalone during chilled storage were investigated.Quality changes of abalone by HPP were compared with heat processing( He P). The results showed that no microbe in abalone could be detected when the pressure conditions reached to 400 MPa and 500 MPa for 10 min and the microbiological shelf- life of raw- eaten abalone could be extended to 20 days at4 ℃. The change of TVB- N values by HPP was inhibited effectively. TVB- N levels for HPP during storage period did not reached 35 mg /100 g. HPP had significantly( p < 0.05) higher p H in abalone,but it was lower than untreated abalone after 30 days storage.The TBA values of abalone were increased slower after HPP compared with untreated and He P abalone. Abalone muscle fibers condensed under HPP according to the observation of tissue slice. The hardness of abalone were increased firstly and then decreased.The results indicated that the microbiological shelflife of raw- eaten abalone were can reached to 20 days after HPP at 400 MPa for 10 min and the quality were improved at the same time.