(1.湖南农业大学 食品科学技术学院, 湖南 长沙 410128;2.盐津铺子食品股份有限公司, 湖南 长沙 410000;3.长沙坛坛香调料食品有限公司, 湖南 长沙 410128;4.湖南省农业科学院 农产品加工研究所, 湖南 长沙 410125)
(1.College of Food Science and Technology, Hunan Agricultural University, Changsha 410128, China;2.Yanker Shop Food Co Ltd, Changsha 410000, China;3.Changsha Tantanxiang Biotechnology Co Ltd, Changsha 410128, China;4.Agricultural Product Processing Institute, Hunan Academy of Agricultural Sciences, Changsha 410125, China)
The free amino acids (FAAs) are involved in the synthesis of flavor compounds in peppers. The types and contents of FAAs are closely related to pepper varieties. FAAs contents of six cultivar peppers including Dahong, Qingjian, Luosi, Xiaomi, Xiaohong and Daqing in Hunan province were analyzed by high performance liquid chromatography-tandem mass spectrometry. The results showed that the FAAs composition of different peppers was different, which provided a theoretical basis for the rational development and utilization of pepper resources. Twenty-four FAAs were identified in six peppers. Cystine was not detected in Qingjian, Luosi and Daqing, and hydroxyproline was not detected in Dahong, Xiaomi and Xiaohong. The contents of asparagine, glutamine, aspartic acid, serine, γ-aminobutyric acid, and lysine were higher than other FAAs. The content of total free amino acids in six peppers ranged from 7.28mg/g to 19.36mg/g (dry weight). The content of total free amino acids in Dahong was the highest, while the lowest was Luosi. Through the analysis of taste active value, it was found that umami amino acid was the main delicious amino acids of peppers. Glutamic acid, aspartic acid, and lysine contributed a lot to the umami taste, and other flavor amino acids played a role in coordinating the flavor. Dahong and Xiaomi were more delicious than other peppers based on taste active value. Cluster analysis showed the quality of some peppers was close, including Dahong and Xiaomi, Daqing and Qingjian, Xiaohong and Luosi. Some amino acids such as threonine and asparagine, arginine and glutamine, leucine and isoleucine, phenylalanine and proline showed a strong correlation. Combined with principal component analysis and comprehensive evaluation, the quality of FAAs in Dahong, Xiaomi and Daqing was better than that in Qingjian, Xiaohong and Luosi.