紫外减菌联合低温对草鱼肉品质及挥发性风味的影响

Effect of UV sterilization on the quality of grass carp meat during the chilling storage

目的:研究紫外减菌前处理联合低温冷藏对草鱼鱼肉质构品质及挥发性风味物质的影响,并确定最佳的紫外照射时间。方法:以草鱼为试验对象,采用30 W紫外灯照射不同时间(0,30,60,90,150 min)预处理,测定鱼肉冷藏期间(0,3,6,9 d)各品质参数(鱼肉表面细菌总数、汁液流失率、质构参数、色泽、气味感官)及挥发性成分变化。结果:当紫外照射时间为0~150 min时,照射时间越长,草鱼鱼肉表面减菌效果越好,汁液流失率越低,出现腐败气味越晚,但对鱼肉的质构、色泽及冷藏后期(6~9 d)细菌总数影响较小。冷藏期间共检测到90种挥发性风味物质,主要为醛类、酮类、醇类、酯类和酸类,其中辛醛、壬醛、己醛、2,5-辛二酮、1-己醇、1-辛烯-3-醇为紫外处理草鱼肉的主要挥发性成分,且冷藏后期酯类和酸类物质含量逐渐增多。对比控制组,紫外处理可有效延缓冷藏草鱼肉腥味的产生和香味的下降。当紫外照射时间为90 min时,冷藏鱼肉表现出最佳的综合效果,随着照射时间的延长,鱼肉综合得分有所下降。结论:紫外减菌联合低温处理有利于延缓贮藏前期草鱼鱼肉质构品质劣化及风味下降,但对贮藏后期草鱼肉品质影响较小。

Objective:The effect of UV sterilization on the texture quality and flavor substances of the frozen grass carp meat was studied,and the best UV irradiation time was determined.Methods:The grass carp meat was pretreated with different UV irradiation times(0,30,60,90,150 min)at 30 W of UV radiation,then the quality parameters(apparent morphology,total number of bacteria on the surface of fish,juice loss rate,texture parameters,color,odor and sensory)and volatile components of the fish meat during chilling storage(0,3,6,9 d)were measured.Results:It showed that the longer the UV irradiation time(0~150 min),the better the bacteria reduction effect on the surface of fish,the lower the juice loss rate,and the later the putrefaction smell appeared.However,it had little effect on the texture,color of the fish,and the total bacteria during the latter of chilling storage(6~9 d).In the detection of flavor substances,90 volatile components were detected,mainly aldehydes,ketones,alcohols,esters,and acids.Octanal,nonanal,hexanal,2,5-octadione,1-hexanol,and 1-octen-3-alcohol were the main volatile components after UV treatment.In the later stage of cold storage,esters and acids were increased gradually,which might be related to the formation of the characteristic aroma of fish meat.Compared with the control group,UV irradiation time of 90 min showed the best comprehensive effect,and the quality was decreased with the extension of irradiation time.Conclusion:UV sterilization pretreatment can delay the deterioration of quality and the decline of flavor of refrigerated grass carp meat in the early stage of chilling storage but has little effect on the quality of grass carp meat in the later stage of chilling storage.