Descriptive sensory analysis of Chinese and Assam drinking green teas from Thailand influenced by varying durations of rolling and pan-firing processes

Abstract

The sensory profiles were investigated of drinking Chinese green tea (Ch) and Assam green tea (As) processed for different durations of pan-firing (4 levels; 0 min, 5 min, 10 min and 15 min) and rolling (3 levels; 0 min, 2 min and 4 min) based on 24 samples. In total, 33 attributes from all tea samples were evaluated using generic descriptive analysis according to a tea cupping standard, followed by classification using principal component analysis. Based on the results, all the tea samples could be divided into three groups. The first group was influenced by the duration of the pan-firing and rolling processes used with Ch that contributed to the ‘Green’ and ‘Seaweed’ attributes. The second group, also Ch, had a positive correlation only to rolling duration that contributed to ‘Bitter aromatic’, ‘Tobacco’, ‘Brown’, ‘Dark Brown’, ‘Sweet aromatic’, ‘Floral’ and ‘Spice’ attributes. The third group associated with all the As samples was influenced by the duration of both pan-firing and rolling that contributed to ‘Dark green’, ‘Tea ID’ and ‘Ashtray’ attributes. The results revealed that aroma and flavor are important attributes that could be used to categorize the green tea samples into three groups depending on processing duration and the green tea variety. Therefore, the findings regarding green tea attributes could be utilized in tea processing development, especially regarding the pan-firing and rolling process conditions.