Metabolome and Microbiome Analysis to Study the Flavor of Summer Black Tea Improved by Stuck Fermentation

Lianghua Wen; Lingli Sun; Ruohong Chen; Qiuhua Li; Xingfei Lai; Junxi Cao; Zhaoxiang Lai; Zhenbiao Zhang; Qian Li; Guang Song; Shili Sun; Fanrong Cao

doi:10.3390/foods12183414

Metabolome and Microbiome Analysis to Study the Flavor of Summer Black Tea Improved by Stuck Fermentation

Foods. 2023 Sep 13;12(18):3414. doi: 10.3390/foods12183414.

Authors

Lianghua Wen¹, Lingli Sun², Ruohong Chen², Qiuhua Li², Xingfei Lai², Junxi Cao², Zhaoxiang Lai², Zhenbiao Zhang², Qian Li³, Guang Song⁴, Shili Sun², Fanrong Cao¹

Affiliations

¹ College of Horticulture, South China Agricultural University, Guangzhou 510000, China.
² Tea Research Institute, Guangdong Academy of Agricultural Sciences, Guangdong Provincial Key Laboratory of Tea Plant Resources Innovation & Utilization, Guangzhou 510640, China.
³ Guangdong Academy of Agricultural Sciences, Sericultural & Agri-Food Research Institute, Key Laboratory of Functional Foods, Ministry of Agriculture and Rural Affairs, Guangdong Key Laboratory of Agricultural Products Processing, Guangzhou 510610, China.
⁴ Guangzhou Yitang Biotechnology Co., Ltd., Guangzhou 510277, China.

Abstract

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, and Bacillus contribute to the reduction of bitterness and astringency in summer black teas after stuck fermentation, and Paenibacillus and Basidiomycota_gen_Incertae_sedis contribute 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: metabolic profile; microbial community; summer black tea; tea quality.

Grants and funding

This study was funded by Food nutrition and health Collaborative Innovation Center of GDAAS [Grant No. XT202229]; Agricultural competitive industry discipline team building project of Guangdong Academy of Agricultural Sciences [Grant No. 202126TD]; the open Project of Guangdong Provincial Key Laboratory of Tea Plant Resources Innovation and Utilization [Grant No. 2020KF05]; Guangdong Basic and Applied Basic Research Foundation [Grant No. 2021A1515010958, 2022A1515110190, 2023A1515010264]; Guangzhou Science and Technology Plan Projects [Grant Nos. 20212100005, 202201011455, 2023E04J0781]; Key-Area Research and Development Program of Guangdong Province [Grant No. 2020B0202080003]; Qingyuan Science and Technology Plan Projects, [Grant Nos. 2021ZDZX002]; Innovation Fund projects of Guangdong Academy of Agricultural Sciences [Grant Nos. 202115, 202135]; Special fund for scientific innovation strategy-construction of high level Academy of Agriculture Science [Grant Nos. R2019PY-JX004, R2022PY-QY010]; the Innovation Fund projects of Guangdong Key Laboratory of Tea Plant Resources Innovation and Utilization [Grant No. 2021CX02]; Special fund project for introduction of scientific and technological talents of Guangdong Academy of Agricultural Sciences [Grant No. R2021YJ-YB3014]. Funders did not have any role in study design, data collection, and data analysis.