关键词: 烟叶, 生物酶, 游离氨基酸, 感官品质

Abstract: To explore the differential regulatory effects of biological enzyme treatment on the characteristics of free amino acids and sensory quality of tobacco leaves with four functional modules of concentration（ND），smoke（YQ），fragrance（XQQ）and strong fragrance（XQN），four kinds of modular formula tobacco leaves were used as the object，based on the actual conditions of the tobacco threshing and redrying line，different proportions of compound enzyme preparations were sprayed，followed by incubation at 50 ℃ for 6 hours. Subsequently，the content of free amino acids was determined，and the data were analyzed combined with descriptive statistics，heatmap clustering and sensory evaluation.The results showed that proline was the highest proportion of free amino acids（49.38%—65.42%）in each module. After treatment with the optimized enzyme groups ND203 and YQ204，its content was significantly increased，thereby enhancing the sweet aroma of tobacco leaves. From the perspective of acid‐base classification，the coefficient of variation of basic amino acids was the highest（28.96%—42.34%），indicating that they were the most sensitive to enzyme treatment. The content of acidic amino acids increased by 47.48% under the treatment of XQQ201，which effectively strengthened the sour and fresh feeling of tobacco leaves. After treatment with the optimized enzyme groups（ND203，YQ204，XQQ201，XQN203）corresponding to the four modules，the off‐odor of tobacco leaves in each module was reduced by more than 20%，and the flue‐cured tobacco aroma，baked aroma and sweet aroma of flue‐cured tobacco were obviously improved. Among them，the fresh and moist aroma of ND，XQQ and XQN modules was weakened，and the roasted aroma of the XQN module was significantly enhanced.In summary，through the synergistic effect of multiple enzymes，the free amino acid composition of the module tobacco leaves can be directionally regulated，and the functional characteristics can be improved，which provides technical support for the large‐scale application of biological enzyme technology in the tobacco industry.

Key words: Tobacco leaf, Biological enzyme, Free amino acid, Sensory quality