研究了不同超高压条件(0、50、150、300、450和600 MPa,保压处理15 min)对鳙感官、色度、硬度、pH、氨基氮含量、Ca² -ATPase活性和超微结构的影响。结果表明,超高压处理改善了鱼肉的气味、滋味和咀嚼度,300、450和600 MPa处理能够显著提高鱼肉的感官品质(P<0.05);改变了鱼肉的色度,使L*值和b*值升高,a*值下降。150 MPa以上的高压能够显著提高鱼肉的硬度(P<0.05)。氨基氮含量在高压处理后显著升高(P<0.05),50和300 MPa处理组的氨基氮含量比对照组分别上升了15.19%和17.89%。鱼肉的pH随着压力的升高而上升。超高压抑制了肌球蛋白Ca² -ATPase活性,当压力≥150 MPa时,Ca² -ATPase的失活速度明显加快。超高压对肌原纤维的超微结构也有较大影响,150 MPa处理后,肌节收缩,肌原纤维变粗,M线、Z线和H区消失,A带和I带断裂。450 MPa处理后,肌节结构被完全破坏,肌原纤维间隙消失,肌原纤维凝胶化现象严重。综合感官和理化测定结果可知,超高压在改善鳙品质方面具有潜在的应用前景。

The effects of high pressure processing(HPP)(0,50,150,300,450 and 600 MPa for 15 min)on the sensory quality,color,firmness,pH,amino nitrogen,Ca² -ATPase activity and ultrastructure of Aristichthys nobilis muscle were investigated.The odor,taste and chewiness were modified by HPP,and the sensory quality improved significantly after treatment at 300,450 or 600 MPa(P＜0.05). L* and b* value increased while a* reduced after HPP.The firmness of the muscle increased pronouncedly(P<0.05)with pressure beyond 150 MPa.HPP treated samples had higher content of amino nitrogen(P<0.05)compared to the control with increases of 15.19% and 17.89% for 50 and 300 MPa pressurized samples,respectively.pH showed a positive correlation with the pressure.The activity of Ca² -ATPase was inhibited by HPP,and pressures beyond 150 MPa inactivated Ca² -ATPase more rapidly.Moreover,HPP had a great impact on ultrastructure of A. nobilis muscle.After treatment at 150 MPa,sarcomeres contracted and myofibrils looked thicker than the control.In addition,disappearance of Z-line, M-line and H-zone and breakage of A-band and I-band were observed.The structure of sarcomeres was completely destroyed,intermyofibrillar space disappeared and gelation of myofibrils was observed when pressurized by 450 MPa.Our results indicated that the HPP could serve as a promising technique for commercial quality enhancement of A. nobilis muscle.

嘉兴市科技局计划项目(2009BZ6004)