Processing technologies affect the aroma but not the taste of teas: A study of Yunnan Biluochun, Jiangsu Biluochun, and other regular green teas

To evaluate the effect of the processing technology utilized on the quality of teas, the major water-soluble and volatile components of 24 Biluochun and regular green tea samples obtained in different production areas were determined using the sensory evaluation, Folin-Ciocalteu method, the phenol-sulfuric acid method, high-performance liquid chromatography, and headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry. There were small differences between the contents of the major water-soluble compounds identified in these samples. Sixty-five volatile compounds were identified in these teas. These molecules included 22 hydrocarbons, 18 alcohols, 8 ketones, 6 esters, 3 aldehydes, 3 heterocyclics, 2 nitrogens, 1 lactone, 1 acid, and 1 phenolic. Statistical analyses of these 65 compounds using principal component analysis and cluster analysis revealed that the contents of the Biluochun samples were highly similar and were different from those of the regular green teas. This study suggested that, although the geographical origin and cultivar influenced the aroma characteristics of tea products somewhat, processing technologies played an important role on tea aroma.