辐照对中华鳖裙边和肌肉挥发性成分的影响

Effect of irradiation on volatile components of Trionyx sinensis calipash and meat

为探究不同辐照剂量对中华鳖裙边和肌肉风味的影响,采用顶空固相微萃取结合气质联用仪(headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry,HS-SPME-GC-MS)检测分析辐照处理后裙边和肌肉中挥发性成分的变化,通过气味活度值(odor activity value,OAV)和正交偏最小二乘判别分析(orthogonal partial least squares-discriminant analysis,OPLS-DA)确定关键风味物质和辐照异味产生情况。结果表明,裙边和肌肉中分别检测到38种、27种挥发性物质,其中壬醛、癸醛、辛醛、苯乙醛、香叶基丙酮、β-环柠檬醛、十一醛和己醛对中华鳖风味贡献较大。经3 kGy及以下辐照剂量处理后,壬醛、辛醛、癸醛等腥味物质的OAV值降至较低,改善了整体风味,7 kGy及以上时,产生了具脂肪气味的(E,E)-2,4-癸二烯醛、(E)-2-壬烯醛、(E)-2-十二烯醛等异味物质。OPLS-DA在裙边中筛选到5种特征标志物[变量重要性(variable influence on projection,VIP)值大于1],分别为壬醛、苯甲醛、苯乙烯、苯乙醇和β-环柠檬醛,在肌肉中筛选到苯甲醛、(E)-2-十二烯醛、β-环柠檬醛、苯乙醇和壬醛5种标志物。OPLS-DA和聚类分析表明,可根据特征标志物含量有效区分不同辐照剂量样品,3 kGy时裙边和肌肉能较好保持原有风味,且有效减轻了腥味和油脂味,7 kGy和9 kGy时,辐照异味较明显。该研究可为中华鳖加工提供参考。

To investigate the irradiation effect on Trionyx sinensis calipash and meat,the volatile components in it irradiated with different doses were investigated by headspace-solid phase micro-extraction-gas chromatography(HS-SPME-GC-MS).The odor activity value(OAV)analysis and orthogonal partial least squares-discriminant analysis(OPLS-DA)were used to determine key flavor substances and irradiation odors.Results showed that 38 and 27 volatile substances were detected in the Trionyx sinensis calipash and meat respectively.Nonanal,decarian,octanal,phenylacetaldehyde,geranilacetone,β-cyclocitral,undecydehyde,and hexanal contributed greatly to Trionyx sinensis odor.After the irradiation dose of 3 kGy and below,the OAV values of nonanal,octanaldehyde,dechardehyde,and other fishy substances were reduced to a lower level,which improved the overall flavor.At 7 kGy and above,fatty odor substances such as(E,E)-2,4-decadienal,(E)-2-nonenal,and(E)-2-dodecenal were produced.Five characteristic markers(variable influence on projection,VIP>1)were screened by OPLS-DA,including nonanal,benzaldehyde,styrene,phenethyl ethanol,andβ-cyclocitral,five markers were screened in muscle,including benzaldehyde,(E)-2-dodecenal,β-cyclocitral,phenethyl ethanol,and nonanaldehyde.OPLS-DA and cluster analysis showed that the sample with different irradiation doses could be distinguished according to the content of characteristic markers,the calipash and meat could maintain the original flavor,and effectively reduce the fishy and greasy odor at 3 kGy,but irradiation at 7 kGy and 9 kGy would cause off-odor obviously.This study provides a reference for the utilization of Trionyx sinensis.