Effect of Ultra-Violet B on Release of Volatiles in Tea Leaf

Abstract

Many volatiles in fresh tea leaf are in the forms bound with glycosides and they are released by action of ß–primeverosidase and ß-glucosidase during tea processing. Effect of ultra-violet B on release of volatiles in fresh tea leaves of two tea cultivars, “Maoxie” and “Anhui-9,” were investigated. Types of volatile and their concentration increased when ultra-violet B was applied at 3.0 μmol m⁻² s⁻¹ for 2 h and then decreased as the irradiation was extended to 6 h. The relation of expression of ß–primeverosidase and ß-glucosidase genes to the release of volatiles were also discussed.

Keywords:

• Camellia sinensis
• Tea flavors
• Cultivar
• UV-B irradiation
• Gene expression
• GC-MS
• Primeverosidase
• Glucosidase
• Hydrolase

ACKNOWLEDGMENT

The authors gratefully acknowledge the Ministry of Agriculture of China for financial grant (Agricultural Commonweal Project No. 3–35).