干制方式对腌腊草鱼脂肪氧化和挥发性风味成分的影响

Effects of Different Drying Methods on Lipid Oxidation and Volatile Flavor Components of Cured Grass Carp

以不同干制方式制得的腌腊鱼(水分质量分数40%)为对象,基于菌落总数、酸价(acid value,AV)、过氧化值(peroxide value,POV)、硫代巴比妥酸(thiobarbituric acid,TBA)含量、总脂含量与总脂肪酸组成、挥发性风味物质、感官评分等指标,探讨了光照和温度对腌腊鱼风味品质的影响。结果显示:冷风避光组腌腊鱼样品的菌落总数最高,而热风光照组最低,分别为4.42、2.91(lg(CFU/g))。光照组腌腊鱼的脂质氧化指标均高于避光组,两者总脂含量无显著差异(P>0.05);热风组腌腊鱼的POV和TBA含量均显著高于冷风组(P<0.05),AV和总脂含量显著低于冷风组(P<0.05)。多不饱和脂肪酸含量占腌腊鱼总脂肪酸含量的40%左右。无论是温度还是光照均对以二十二碳六烯酸为代表的n-3系多不饱和脂肪酸有显著影响(P<0.05)。感官评价结果表明,冷风组和光照组腌腊鱼样品香气得分均显著高于热风组和避光组(P<0.05)。本研究共从4种腌腊鱼样品中检出了82种挥发性物质,筛选确定了2-壬烯醛等14种气味活性物质。相同温度下,光照组样品的气味活性值总和显著高于避光组(P<0.05),表明光照更有利于香气物质的生成。本研究可为腌腊鱼生产企业改善产品品质提供理论依据。

The study investigated the effects of light and temperature on the flavor quality of cured grass carp produced by different drying methods(all with a moisture content of 40%).For this purpose,the aerobic plate count,acid value(AV),peroxide value(POV),thiobarbituric acid(TBA)content,total fat content,total fatty acid compositions,volatile flavor components and sensory evaluation of the cured fish samples were measured.The results showed that total number of colonies was the largest(4.42(lg(CFU/g)))in the cured fish dried with cold air in the dark,while it was the smallest(2.91(lg(CFU/g)))in the cured fish produced by hot air drying in light.The indexes of lipid oxidation were larger in the cured fish dried in light than in darkness,but no significant difference in total fat content between the two groups was observed(P>0.05).Furthermore,POV and TBA content of the cured fish dried by hot air were significantly larger than those of the cured fish dried by cold air(P<0.05);however,AV and total fat content were opposite.Polyunsaturated fatty acids(PUFAs)accounted for about 40%of the total fatty acids in the cured fish,and both light and temperature had a significant effect on n-3 PUFAs such as docosahexaenoic acid(P<0.05).The sensory evaluation results showed that drying with cold air and in light gave significantly higher sensory scores for the aroma of cured fish when compared with drying with hot air and in darkness,respectively(P<0.05).A total of 82 volatile compounds were identified from all four cured fish samples,14 of which were recognized as odor-active compounds including 2-nonenal.The sum of odor activity values was significantly higher in the cured fish dried in light than in darkness(P<0.05),indicating that light may be favorable for the generation of aroma components.The results from this study provide a theoretical basis to improve the quality of cured fish in the future.