不同温度胁迫条件下太平洋牡蛎挥发性化合物的变化

Changes in Volatile Compounds in Pacific Oysters under Different Temperature Stress Conditions

为探究温度胁迫后太平洋牡蛎挥发性成分的变化,该研究采用感官评定、气相色谱-离子迁移谱(Gas Chromatography-Ion Mobility Spectroscopy,GC-IMS)、气相色谱-质谱联用(Gas Chromatography-Mass Spectrometer,GC-MS)结合多元统计分析的方法,对不同温度胁迫条件(12、22、32℃)的太平洋牡蛎挥发性成分进行了检测,同时测定了其存活率以及脂肪酸含量的变化。结果显示,胁迫6 d后,低温12℃组的存活率达到97.90%,n-3型多不饱和脂肪酸(Polyunsaturated Fatty Acid,PUFA)含量升高。感官评定、GC-IMS以及GC-MS结果显示辛醛等鱼腥味醛类成分含量下降,而呈紫罗兰气味的(E,Z)-2,6-壬二烯醛升至12.15%,提供了愉悦的气味。高温32℃胁迫后存活率降至26.00%,n-3 PUFA含量下降从46.07%下降至39.59%,同时饱和醛等腥味醛类含量显著上升,加重了太平洋牡蛎的腥味,导致牡蛎的品质严重下降。最后通过统计分析筛选6种关键成分:己醛、辛醛、(E,Z)-2,6-壬二烯醛、(E)-2-壬烯醛、(E,E)-2,4-庚二烯醛以及3-辛酮。温度对太平洋牡蛎的存活率、n-3 PUFA含量及挥发性成分有较大影响,该研究为提升太平洋牡蛎品质提供了有益参考。

The changes in volatile components in Pacific oysters under temperature stress were investigated using multiple methods,including sensory evaluation,gas chromatography-ion mobility spectroscopy(GC-IMS),gas chromatography-mass spectrometry(GC-MS),and multivariate statistical analysis.The analysis was conducted under different temperature stress conditions(12,22,and 32℃).Concurrently,survival rate and fatty acid content of Pacific oysters were determined.After 6 days of stress,the 12℃group exhibited a 97.90%survival rate,accompanied by an increase in n-3 polyunsaturated fatty acid(PUFA)content.Sensory evaluation,GC-IMS,and GC-MS results indicated a decrease in the content of aldehydes associated with fishy flavor,including octanal,and an increase in the content of(E,Z)-2,6-nonadienal(12.15%),which associated with fruity flavor,providing a pleasant odor to Pacific oysters.In contrast,exposure to high temperature stress at 32°C resulted in a decrease in survival rate to 26.00%,accompanied by a decrease in n-3 PUFA content from 46.07%to 39.59%.Concurrently,there was a considerable increase in the content of aldehydes associated with fishy flavor,such as saturated aldehydes,intensifying the fishy smell of Pacific oysters and resulting in a notable deterioration in quality.In other words,high temperature stress caused a serious decline in oyster quality.Statistical analysis revealed significant differences in six key volatile components:octanal,hexanal,(E,Z)-2,6-nonadienal,(E)-2-nonenal,(E,E)-2,4-heptadienal,and 3-octanone.The survival rate,n-3 PUFA content,and volatile component composition of Pacific oysters were remarkably influenced by temperature stress.This study provides a valuable reference for enhancing the quality of Pacific oysters.