tailieunhanh - Changes in volatile compounds during orthodox black tea (camellia sinensis) manufacturing

The content of volatile compounds in tea leaves at different stages of OTD black tea manufacture was measured. Aroma concentrate was prepared by Brewed Extraction Method (BEM) and analyzed by GC/MS. The results showed that volatile compounds were products of lipid breakdown (groupI) and derivatives from terpenoids, carotenoids and amino acids (group II). | Journal of Science and Technology 54 (4A) (2016) 1-6 CHANGES IN VOLATILE COMPOUNDS DURING ORTHODOX BLACK TEA (Camellia sinensis) MANUFACTURING Hoang Quoc Tuan*, Nguyen Thi Minh Tu Department of Quality Management, School of Biotechnology and Food Technology, Hanoi University of Science and Technology, 1 Dai Co Viet, Hanoi, Vietnam * Email: tuanhqibft@; Received: 15 August 2016; Accepted for publication: 4 October 2016 ABSTRACT The content of volatile compounds in tea leaves at different stages of OTD black tea manufacture was measured. Aroma concentrate was prepared by Brewed Extraction Method (BEM) and analyzed by GC/MS. The results showed that volatile compounds were products of lipid breakdown (groupI) and derivatives from terpenoids, carotenoids and amino acids (group II). During processing the changes of group I and group II were significantly different from each others and effect to the flavour index. A gradual increase of percentage relative content from to in the group I volatile compounds was noticed during withering. While during fermentation, the sum of group II compounds content was higher than than that of group I compounds therefore the value of flavour index, and the value of FI is higher than 1. Keywords: black tea, volatile compounds. 1. INTRODUCTION Black tea (Camellia sinensis) is the most widely consumed beverage in the world. The high acceptability of black tea due to many factors, one of the most contributory factors is its flavour. During the manufacture of OTD black tea from fresh tea leaves of Cammellia sinensis, compounds conferring flavour are generated by enzymic oxidation of the peptidase, lipoxygenase, carotenase etc and subsequent reactions, including coupled chemical oxidations, of the active intermediates generated. When the desired quality has been reached, drying is used to halt the reactions. Chemical change is not instantly arrested, but is initially accelerated by the increase