条斑紫菜烤制前后特征风味变化研究

为探讨烤制对条斑紫菜(Porphyra yezoensis)主要风味物质的影响，研究烤制前后条斑紫菜挥发性成分的变化。采用电子鼻、FlavourSpec®风味分析仪和固相微萃取–气相色谱–质谱联用(SPME-GC-MS)对比分析条斑紫菜在烤制前后挥发性风味物质的组成变化。电子鼻分析结果显示，条斑紫菜烤制前后的挥发性成分存在一定差异，二者的第一、二主成分相同，均为烃类、含氮类物质，但其对主成分的贡献率不同。风味分析表明，条斑紫菜烤制前后挥发性成分差异显著，烤制后出现吡嗪类特征风味物质。SPME-GC-MS分析表明，醛类、醇类、酮类和烷烃类构成了条斑紫菜的主体风味，烤制后吡嗪、甲基吡嗪、2,5-二甲基-吡嗪、2-乙基-5-甲基-吡嗪、3-乙基-2,5-二甲基-吡嗪和2-乙基-6-甲基-吡嗪等物质含量显著增加。综上所述，经过烤制，构成条斑紫菜的主要风味物质发生了明显变化，其中吡嗪类物质的相对含量显著增加。

Study on the characteristic flavor change of Porphyra yezoensis before and after roasting

With recent advances in detection technology the volatile substances in green algae, brown algae, red algae, and other algae have been identified. However, few studies have investigated the volatile substances of laver (genus Porphyra), especially, the analysis of the flavor change in Porphyra yezoensis after roasting. To address this issue, the electronic nose, FlavourSpec® flavor analyzer and SPME-GC-MS were used to compare the volatile components of P. yezoensis before and after roasting. The results of the electronic nose analysis showed that there were some differences in the volatile components derived from P. yezoensis before and after roasting. The two main components were the same, but the contribution of hydrocarbon compounds to the main components were different. Thus, the electronic nose was capable of discriminating the flavor differences in P. yezoensis before and after roasting. Flavor analysis showed that the volatile components of P. yezoensis before and after roasting were significantly different. The contents of nonanal, octanal, hexanal, valeraldehyde, benzaldehyde, and 2-ethyl-furan, were relatively higher in P. yezoensis. After roasting, the contents of methyl-pyrazine, 1-pentanol, furfural, 3-methyl-butanol, and 3-methyl-butanal were higher. The characteristic flavor and relative content of pyrazines also increased after roasting. The SPME-GC-MS analysis showed that the total volatile flavor compounds of laver samples before and after roasting were 83 and 86, respectively. The major volatile compounds of P. yezoensis were aldehydes, alcohols, ketones, and alkanes. The pyrazines consisted of methyl pyrazine, 2,5-dimethyl-pyrazine, 2-ethyl-5-methyl-pyrazine, 3-ethyl-2,5-dimethyl-pyrazine and 2-ethyl-6-methyl- pyrazine. These compounds increased significantly after roasting. In summary, the main flavor substances of P. yezoensis varied significantly after roasting, especially the content of pyrazines (increased significantly). This research clarifies how the roast flavor is generated, allowing us to optimize our processing technology. Future research is required to understand the mechanisms underlying the formation of flavor.