噻唑类食品香料的研究进展

Research Progress of Thiazole Flavor Compounds

摘要:

噻唑类香料是一类重要的含硫杂环类香料,由于其香气浓郁、特征性强,一直备受调香师的喜爱。随着分析技术的不断发展,越来越多的噻唑类化合物在食品中被鉴定出来。目前,经美国食用香料与萃取物制造者协会(FEMA)安全评价的噻唑类香料有39种(噻唑类29种、噻唑啉类10种),我国GB 2760—2014中允许使用的噻唑类香料有29种。重点对经过FEMA安全评价的39种噻唑类香料的研究现状进行了汇总,介绍了其允许使用情况、香气特征和天然存在情况等。总结了食品加工过程中噻唑类风味化合物可能的形成途径,包括含硫化合物热降解和美拉德反应两类。在食品加工过程中,含硫氨基酸在较高温度下会经过脱氨、脱羧等发生热降解反应形成噻唑及其衍生物。此外,硫胺素加热时也可以降解成多种含硫和含氮挥发性风味物质,其中噻唑类降解产物主要有4-甲基-5-(β-羟基乙基)噻唑、4-甲基噻唑、4,5-二甲基噻唑、4-甲基-5-乙基噻唑等。从传统化学合成、光化学合成和电化学合成3个方面介绍了噻唑类化合物典型的化学合成方法及其反应机理。最后,指出突破合成香料行业中存在的香料新品种开发与创新不足、传统生产工艺落后及环境污染严重等瓶颈问题,是未来促进我国合成香料产业快速稳定发展的研究重点。

Abstract:

Thiazoles are important flavor of sulfur-containing heterocyclic class, which have always been favored by flavorists due to their dense aroma and intensive characteristics. With the continuous development of analytical technology, more and more thiazole compounds had been identified in food. 39 thiazole flavors (29 thiazoles and 10 thiazolines) have been evaluated and recognized as safe by the Flavor and Extract Manufacturers Association of the United States, and 29 thiazole flavors are allowed to be used in food according to flavor compound list in GB 2760—2014. Recent studies on permissible usage, aroma characteristics and natural occurrence of 39 thiazole flavors were introduced in this paper. The possible formation pathways of thiazole flavor compounds in food processing were reviewed, including thermal degradation of sulfur-containing compounds and Maillard reaction. During food processing, sulfur-containing amino acids underwent thermal degradation reactions such as deamination and decarboxylation at high temperatures to form thiazole and its derivatives. In addition, thiamine could also be degraded into a variety of volatile flavor substances containing sulfur and nitrogen when heated, and the thiazole degradation products mainly included 4-methyl-5-(β-hydroxyethyl) thiazole, 4-methylthiazole, 4,5-dimethylthiazole, 4-methyl-5-ethylthiazole, etc. The typical synthetic methods and reaction mechanisms of thiazole compounds were introduced from three aspects:traditional chemical synthesis, photochemical synthesis and electrochemical synthesis. Finally, it was pointed out that breaking through the bottleneck problems such as insufficient development and innovation of new flavors, backward traditional production technology and serious environmental pollution in the synthetic flavor industry would be the key points to promote the rapid and stable development of our country's synthetic flavor industry in the future.