Dynamic change of the carotenoid metabolic pathway profile during oolong tea processing with supplementary LED light

Zixin Ni; Yun Yang; Yining Zhang; Qingcai Hu; Jiaqi Lin; Hongzheng Lin; Zhilong Hao; Yuefei Wang; Jihong Zhou; Yun Sun

doi:10.1016/j.foodres.2023.112839

Dynamic change of the carotenoid metabolic pathway profile during oolong tea processing with supplementary LED light

Food Res Int. 2023 Jul:169:112839. doi: 10.1016/j.foodres.2023.112839. Epub 2023 Apr 17.

Authors

Zixin Ni¹, Yun Yang², Yining Zhang², Qingcai Hu², Jiaqi Lin², Hongzheng Lin², Zhilong Hao², Yuefei Wang³, Jihong Zhou³, Yun Sun⁴

Affiliations

¹ College of Horticulture/Key Laboratory of Tea Science in Fujian Province, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Department of Tea Science, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310058, China.
² College of Horticulture/Key Laboratory of Tea Science in Fujian Province, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
³ Department of Tea Science, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310058, China.
⁴ College of Horticulture/Key Laboratory of Tea Science in Fujian Province, Fujian Agriculture and Forestry University, Fuzhou 350002, China. Electronic address: sunyun1125@126.com.

PMID: 37254414
DOI: 10.1016/j.foodres.2023.112839

Abstract

Carotenoid-derived volatiles are important contributors to tea aroma quality. However, the profile of the carotenoid pathway and carotenoid-derived volatiles (CDVs) artificial regulation in oolong tea processing has yet to be investigated. In the present work, the content and varieties of carotenoid-derived volatiles, the genome-wide identification of carotenoid cleavage dioxygenase (CsCCD) gene family, the expression level of CsCCD and other key genes in the carotenoid pathway, and the profile of carotenoid substances were analyzed by multi-omics and bioinformatics methods with innovative postharvest supplementary LED light during oolong tea processing. The results showed that during oolong tea processing, a total of 17 CDVs were identified. The content of β-ionone increased up to 26.07 times that of fresh leaves and its formation was significantly promoted with supplementary LED light from 0.54 μg/g to 0.83 μg/g in the third turning over treatment. A total of 11 CsCCD gene family members were identified and 119 light response cis-acting regulatory elements of CsCCD were found. However, the expression level of most genes in the carotenoid pathway including CsCCD were reduced due to mechanical stress. 'Huangdan' fresh tea leaves had a total of 1 430.46 μg/g 22 varieties of carotenoids, which mainly composed of lutein(78.10%), β-carotene(8.24%) and zeaxanthin(8.18%). With supplementary LED light, the content of antherxanthin and zeaxanthin in xanthophyll cycle was regulated and CDVs such as α-ionone, β-ionone, pseudoionone, damascenone, 6,10-dimethyl-5,9-undecadien-2-one, citral, geranyl acetate and α-farnesene were promoted significantly in different phases during oolong tea processing. Our results revealed the profile of the carotenoid metabolism pathway in oolong tea processing from the perspective of precursors, gene expression and products, and put forward an innovative way to improve CDVs by postharvest supplementary LED light.

Keywords: Carotenoid cleavage dioxygenase; Carotenoid-derived volatiles; Gene family; Light-emitting diode; Oolong tea processing; Tea plant.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Carotenoids* / metabolism
Metabolic Networks and Pathways*
Tea
Zeaxanthins / metabolism

Substances

beta-ionone
Zeaxanthins
Carotenoids
Tea