尼罗罗非鱼暂养阶段挥发性成分的变化

Changes of Volatile Components in Nile Tilapia during Purging Process

以尼罗罗非鱼为原料,通过固相微萃取和气质联用仪对挥发性成分进行萃取和分离鉴定,测定尼罗罗非鱼肉的气味组成,并对暂养阶段的挥发性成分变化做初步分析。结果表明:从尼罗罗非鱼肉中检测出挥发性醛类、烷烃类、芳烃类、醇类、酯类和烯类等31种有效成分,其中含量由高到低依次为醛类、芳烃类和烷烃类,暂养初期和末期分别占挥发性化合物总量的36.97%、17.85%、20.70%和44.49%、34.65%、8.66%。暂养时间为8d时,辛醛和壬醛含量有明显的下降,有利于脱除不良风味;辛三烯和环己烯同时未检出,消除了不良气味的潜在因素;苯甲醛、苯环芳烃类物质含量相对于0d也有一定程度的增加,这有利于罗非鱼良好风味的形成。

The volatile compounds in the muscle of Tilapia nilotica during 12 days of purging in autumn were extracted by solid phase micro-extraction （SPME） and analyzed by gas chromatography-mass spectroscopy （GC-MS）. Totally 31 kinds of volatile compounds were isolated and identified including aldehydes, hydrocarbons, Kwai alkenes, aromatic hydrocarbons, alcohols, esters, terpenes, and others, in which aldehydes, aromatic hydrocarbons and hydrocarbons were the top three most abundant compounds, with a relative level to total volatile compounds of 36.97%, 17.85%, 20.70% at the beginning of the purging period and 44.49%, 34.65%, 8.66% at the end of the purging period, respectively. After 8 days of purging, the contents of octanal and nonanal significantly decreased, and neither octatriene nor cyclohexene were detected, which is desirable for the elimination of undesirable odor. Meanwhile, the contents of benzaldehyde and aromatic benzene ring increased, which was helpful in promoting the formation of desirable flavor in tilapia.