三倍体虹鳟鱼片不同部位品质差异

Quality Difference in Different Parts of Triploid Rainbow Trout Fillets

【目的】综合分析三倍体虹鳟(Oncorhynchus mykiss)鱼片品质异质性,为三倍体虹鳟品质研究及综合利用提供数据基础。【方法】分别对三倍体虹鳟背前、背中、背后、腹前、腹中和腹后鱼片的肉色、肉质、风味、脂肪酸组成及含量和挥发性气味物质进行分析。【结果】肉色方面,三倍体虹鳟鱼片腹后部位红色值显著高于其他部位(P<0.05),为17.39。肉质方面,腹部鱼片鱼肉的硬度和破裂力显著高于背部相应区域(P<0.05),其中腹中部鱼肉硬度、破裂力和咀嚼性最高(P<0.05),分别为8.58 N、14.37 N和23.83 mJ,背中部鱼肉弹性显著高于其他部位(P<0.05),为12.03 mm。腹中部和腹后部鱼肉粗灰分相对较高(P<0.05),分别为1.42%和1.34%。背部和腹部鱼片的粗脂肪和粗蛋白含量从前往后均呈现逐渐增高的趋势(P<0.05)。风味方面,中部鱼片的总挥发性醇类、酮类和醛类含量低于前部和后部,腹前和腹后部鱼肉具有较高含量的芳香类和烷烃类(P<0.05)。气味活度值贡献较大的特征性气味物质有1-辛烯-3-醇、己醛、辛醛、壬醛、(E)-2-壬烯醛和(E,E)-2,4-壬二烯醛,从前段到后段鱼肉的蘑菇、类金属、新鲜及脂肪味逐渐减弱,前段相较于中后段特征性气味更为突出。与背部相比,腹部鱼肉肌苷酸(IMP)含量相对较高(P<0.05),尤其是腹中部IMP质量摩尔浓度均值最高,为7.72μmol/g。脂肪酸方面,腹中部的脂肪酸C16:0、C16:1n-7、C18:2n-6、C20:5n-3(EPA)、C22:6n-3(DHA)、单不饱和脂肪酸(MUFA)、多不饱和脂肪酸(PUFA)和n-6系列脂肪酸质量分数显著高于其他部位(P<0.05),分别为7.79、2.39、13.51、0.89、3.39、23.48、19.85和4.49 mg/g。【结论】三倍体虹鳟鱼片总体具有较高的品质,其鱼片的不同部位品质存在差异。鱼片前部特征性气味更为浓郁,中、后部具有丰富的蛋白质。背中部的鱼肉更加富有弹性,腹中部鱼肉不仅质地坚实,且具有较高的脂肪酸营养。腹部前部和中部的鱼肉滋味鲜美,腹后部鱼肉肉色更加鲜艳。

【Objective】To comprehensively analyze the quality heterogeneity of triploid rainbow trout(Oncorhynchus mykiss)fillets,providing a data foundation for quality research and comprehensive utilization of triploid rainbow trout.【Method】Triploid rainbow trout fillets were analysed separately inflesh colour,flesh texture,flavour,fatty acid composition and content and volatile odour substances in the dorsal anterior,dorsal middle,dorsal posterior,ventral anterior,ventral middle and ventral posterior.【Results】In terms of flesh color,the red value(17.39)of the ventral posterior of triploid rainbow trout fillets was significantly higher than that of other regions(P<0.05).In terms of flesh quality,the hardness and breaking force of the flesh of abdominal fillets were significantly higher than that of the corresponding regions of the back(P<0.05),and the hardness,breaking force and chewing property of the flesh of the ventral middle part of the fillets were the highest(P<0.05),8.58 N,14.37 N and 23.83 mJ respectively,and the elasticity(12.03 mm)of the fish flesh in the dorsal middle was significantly higher(P<0.05)than that of the other regions.The crude ash contents of the fish flesh in the ventral middle and ventral posterior regions wererelatively high(P<0.05),1.42%and 1.34%,respectively.The crude fat and crude protein content of the fish fillets increased gradually from the anterior to the posterior sections(P<0.05).Flavor,the total volatile alcohols,ketones,and aldehydes in the middle section of the fish fillet were lower than those in the anterior and posterior sections,while the ventral anterior and ventral middle fish meat had higher contents of aromatic and alkane compounds(P<0.05).The key odor-active volatiles contributing significantly to the overall aroma included 1-octen-3-ol,hexanal,octanal,nonanal,(E)-2-Nonenal,and(E,E)-2,4-nonadienal.The mushroom,metalloid,fresh,and fatty flavors gradually diminished from the anterior to the posterior sections,with the anterior section exhibiting more pronounced characteristic aromas compared to the middle and posterior sections.Compared to the dorsal section,the abdominal fish meat had a relatively higher content of inosine monophosphate(IMP)(P<0.05)leading to fresh flavor,particularly in the ventral middle which had the highest mean IMP content of 7.72μmol/g.In terms of fatty acids,the ventral middle hadsignificantly higher contents of fatty acids C16:0,C16:1n-7,C18:2n-6,C20:5n-3(EPA),C22:6n-3(DHA),monounsaturated fatty acids(MUFA),polyunsaturated fatty acid(PUFA),and n-6 series fatty acids compared to other sections(P<0.05),7.79,2.39,13.51,0.89,3.39,23.48,19.85 and 4.49 mg/g,respectively.【Conclusion】The triploid rainbow trout fillets have high quality,with differences existing in different parts of the fillets.The anterior section hasmore pronounced characteristic aromas,while the middle and posterior sections are rich in protein.The dorsal middle fillets are more elastic,and the ventral middle fillets have a solid texture and higher nutritional fatty acid content.The ventral anterior and middle sections offer a delicious taste,while the ventral posterior fillets present a more vibrant color.