Foods
·
2023
·Vol. 12
·期 18
·3414
·
IF 5.2
Lianghua Wen,Lingli Sun,Ruohong Chen,Qiuhua Li,Xingfei Lai,Junxi Cao,Zhaoxiang Lai,Zhenbiao Zhang,Qian Li,Guang Song,Shili Sun,Fanrong Cao
Tea is the most popular and widely consumed beverage worldwide, especially black tea. Summer tea has a bitter and astringent taste and low aroma compared to spring tea due to the higher content of polyphenols and lower content of amino acids. Microbial fermentation is routinely used to improve the flavor of various foods. This study analyzed the relationship between the quality of black tea, metabolic characteristics, and microbial communities after microbial stuck fermentation in summer black tea. Stuck fermentation decreased the bitterness, astringency sourness, and freshness, and increased the sweetness, mellowness, and smoothness of summer black tea. The aroma also changed from sweet and floral to fungal, with a significant improvement in overall quality. Metabolomics analysis revealed significant changes in 551 non-volatile and 345 volatile metabolites after fermentation. The contents of compounds with bitter and astringent taste were decreased. Sweet flavor saccharides and aromatic lipids, and acetophenone and isophorone that impart fungal aroma showed a marked increase. These changes are the result of microbial activities, especially the secretion of extracellular enzymes.Aspergillus,Pullululanibacillus, andBacilluscontribute to the reduction of bitterness and astringency in summer black teas after stuck fermentation, and Paenibacillus andBasidiomycota_gen_Incertae_sediscontribute positively to sweetness. In addition, Aspergillus was associated with the formation of fungal aroma. In summary, our research will provide a suitable method for the improvement of tea quality and utilization of summer tea, as well as provide a reference for innovation and improvement in the food industry.Keywords:summer black tea;tea quality;metabolic profile;microbial community
研究领域:
食品科学
·
微生物学
·
化学生态学
·
农学
✓ 已验证
DOI
PubMed
高影响因子
LWT-FOOD SCIENCE AND TECHNOLOGY
·
2023
·
IF 6
Yongyi Yang,Juan Peng,Qingqing Li,Qinfei Song,Quentin Cronk,Biao Xiong
Dark hawk tea, produced through pile-fermentation of Lauraceae family leaves, which is rich in various beneficial ingredients and health functions, relies heavily on microbial activity for its unique characteristics. However, the processing technology of dark hawk tea and the microorganisms' dynamic changes during its pile-fermentation remain largely unknown. In this study, based on the previous work, we optimized pile-fermentation parameters for analyzing changes in dark hawk tea's chemical components, volatile substances, and microbial diversity. The tea exhibited superior sensory scores and biochemical qualities under optimal conditions (35 °C, 62% water, 24 h), measuring 5.7 mg/g amino acid content. Gas chromatography-mass spectrometry (GC-MS) identified 108 volatile compounds, notably terpenes, ketones, and esters. Microbial analysis revealed Bacteroides and Faecalibacterium as dominant bacteria and Cladosporium and Mortierella as dominant fungi. Cladosporium prevailed in early fermentation, shifting to Mortierella later. Predicted metabolic pathways highlighted microbial functional genes predominantly participated in carbohydrate, amino acid, and energy metabolism during the pile-fermentation. These results hold important implications for expanding the variety of hawk tea products and deepening our understanding of microbial community dynamics through the pile-fermentation of dark hawk tea.
研究领域:
食品科学
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微生物学
·
生物化学
·
植物科学
✓ 已验证
产品关联
DOI
高影响因子
FOOD CHEMISTRY
·
2021
·
IF 7.514
Wenji Zhang,Junxi Cao,Zhigang Li,Qiuhua Li,Xingfei Lai,Lingli Sun,Ruohong Chen,Shuai Wen,Shili Sun,Zhaoxiang Lai
Each type of tea has a unique volatile profile due to its variety, processing technologies and origin. Using HS-SPME and GC/MS, we analyzed the changes of volatile components in cultivar Yinghong No. 9 during pile-fermentation every 10 days. A total of 94 compounds showed significant differences during a total of 60 days mainly including alkanes, ketones, esters, terpenes, aromatics and heterocyclic compounds. Interestingly, 13 metabolites were progressively reduced during the first 20 days and remained unchanged in subsequent procedures, while 17 metabolites remained unchanged in the early stage and progressively increased during the last 20 days of pile fermentation, indicating that they are characteristic volatile compounds of raw material sun-dried green tea and dark tea, respectively. β-ionone, phenylethyl alcohol, and a-ionone could be the top three contributed aroma compounds in the final dark tea. Our study provides a theoretical basis for process and quality improvement of Yinghong No. 9.
研究领域:
食品科学
·
分析化学
·
茶叶加工技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Food Chemistry-X
·
2024
·
IF 6.5
Tiehan Li,Yuming Wei,Mingxia Lu,Yida Wu,Yanqun Jiang,Han Ke,Aiju Shao,Jingming Ning
Piling fermentation (PF) is crucial for Pu-erh tea aroma, yet its microbial and moist-heat impact on aroma quality is poorly understood. Solid-phase microextraction, solvent-assisted flavor evaporation, and gas chromatography–mass spectrometry were used to detected and analyses the samples of sun-green green tea, sterile PF and spontaneous PF. Microbiological action promotes the formation of stale aromas. Moist-heat action promotes the formation of plum-fragrance and sweet aroma. 20 microbial markers and 28 moist-heat markers were screened from 184 volatile components. Combining odor activity values and gas chromatography-olfactometry, 22 aroma-active compounds were screened (1,2,3-trimethoxybenzene, linalool, 1,2,4-trimethoxybenzene …), and analyzed during PF processing. Aroma omission and addition experiments verified its importance. Gallic acid addition experiments successfully verified that microorganisms are the main contributors to the synthesis of methoxybenzenes. Finally, Blastobotrys, Rasamsonia , and Thermomyces showed positive correlation with the synthesis of 1-ethyl-4-methoxybenzene, 1,2,4-trimethoxybenzene, 1,2,3-trimethoxybenzene, and 1,2-dimethoxybenzene. The formation mechanism of Pu-erh tea's aroma was clarified. Exploring microbial and moist-heat effects on Pu-erh tea volatiles and understanding the methoxybenzene formation mechanism using molecular sensory science.
研究领域:
食品科学
·
微生物学
·
感官科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
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