Zhang Qianying, Huang Yang, An Hongyue, Yang Shuanghong, Lei Jinshan, Wang Yue, Li Pinhe, Zhang Hongfei, Cai Wen, Jia Yun, Pang Yongqiang, Li Dongliang
Cigar Fermentation Technology Key Laboratory of China Tobacco, Cigar Technology Innovation Center of China Tobacco, China Tobacco Sichuan Industrial Co., Ltd., Chengdu, China.
Industry Efficient Utilization to Domestic Cigar Tobacco Key Laboratory of Sichuan Province, Great Wall Cigar Factory, Shifang, China.
Front Microbiol. 2024 Dec 13;15:1433656. doi: 10.3389/fmicb.2024.1433656. eCollection 2024.
In order to enhance the quality of cigar tobacco leaves (CTLs), a gradient variable temperature fermentation approach was employed.
The temperature gradient demonstrated a gradual increase from low temperature (35 ± 2°C) to moderate temperature (45 ± 2°C), and then to high temperature (55 ± 2°C). Each temperature gradient underwent a 10-day fermentation process, resulting in a total duration of 30 days. Changes in sensory evaluation, chemical composition, and bacterial absolute quantitative structure and function were examined throughout the process of gradient variable temperature fermentation.
Compared to constant temperature fermentation, gradient variable temperature fermentation improved the sensory quality of CTLs, reduced total sugar and cembrane degradation products, and increased the amino acid contents. It resulted in significant changes in bacterial quantity and function of CTLs, but had no significant effects on the richness and diversity of bacterial communities. The results of correlation analyses showed that sensory quality had significant correlation with chemical composition, which effected by predominant microbes. The gradient variable temperature fermentation process underwent a three-phase model to characterize the alterations of CTLs. Phase I (35°C) was the microbial stage, during which there was a significant decrease in both the total number and function of microorganisms. The dominant genera shifted from to and , and with high reducing sugar, polyphenol compound and low sensory score. Phase II (45°C) marked a chemical stage, with an enhancement in sensory evaluation. A total of 17 chemicals significantly decreased and six increased, and the decline of microbial populations persisted. The enhanced relative abundances of four microecological hubs, namely , , , and , had the potential to produce protease and lipase to the production of peptides, amino acids, and organic acid, catabolizing sugars and polyphenol compounds, through carbohydrate metabolism and amino acid metabolism, resulted an increase in sensory quality of CTLs. Phase III (55°C) indicated a relative mature stage with the highest score of sensory evaluation. Eight compositions from plamochromic pigments and polyphenol compounds exhibited gradual decreases, while relative contents of carbohydrate metabolism and amino acid metabolism increased.
The gradient variable temperature fermentation had demonstrated a significant positive influence on the quality of CTL by providing optimal fermentation temperature for microbial growth, metabolism, and the generation of quality-related chemical compositions.
为了提高雪茄烟叶的品质，采用了梯度变温发酵方法。
温度梯度呈现出从低温（35±2°C）逐渐升高到中温（45±2°C），再到高温（55±2°C）的变化。每个温度梯度进行10天的发酵过程，总时长为30天。在梯度变温发酵过程中，对感官评价、化学成分以及细菌绝对定量结构和功能的变化进行了检测。
与恒温发酵相比，梯度变温发酵提高了雪茄烟叶的感官品质，降低了总糖和西柏烷类降解产物的含量，并增加了氨基酸含量。它导致了雪茄烟叶细菌数量和功能的显著变化，但对细菌群落的丰富度和多样性没有显著影响。相关性分析结果表明，感官品质与化学成分显著相关，而化学成分受优势微生物的影响。梯度变温发酵过程经历了一个三相模型来表征雪茄烟叶的变化。第一阶段（35°C）是微生物阶段，在此期间微生物的总数和功能均显著下降。优势属从[具体属名1]转变为[具体属名2]和[具体属名3]，且还原糖、多酚化合物含量高，感官评分低。第二阶段（45°C）标志着化学阶段，感官评价有所提高。共有17种化学成分显著下降，6种增加，微生物数量持续下降。四个微生态核心，即[具体属名4]、[具体属名5]、[具体属名6]和[具体属名7]的相对丰度增加，它们有可能通过碳水化合物代谢和氨基酸代谢产生蛋白酶和脂肪酶，进而生成肽、氨基酸和有机酸，分解糖类和多酚化合物，从而提高了雪茄烟叶的感官品质。第三阶段（55°C）表明是一个相对成熟的阶段，感官评价得分最高。来自类胡萝卜素色素和多酚化合物的8种成分逐渐减少，而碳水化合物代谢和氨基酸代谢的相对含量增加。
梯度变温发酵通过为微生物生长、代谢以及与品质相关的化学成分的生成提供最佳发酵温度，对雪茄烟叶的品质产生了显著的积极影响。
