Comparison of Major Components in Black Teas Manufactured from Korea and Foreign Countries

Abstract

The objective of this study was to compare the quality of black teas manufactured from different countries by analyzing key chemical components in black teas. The major components of black teas manufactured from China, India, Japan, Korea, and Sri Lanka were compared using spectrophotometer and high performance liquid chromatography. Total amino acids and caffeine contents were similar among black tea products of selected countries with the range of 2.2% to 4.4% and 2.6% to 5.6%, respectively. Liquor colors were between 2.2% to 3.9% in Chinese, 1.2% to 3.1% in Indian, 2.3% to 3.1% in Japanese and in Sri Lankan, and 1.6% to 3.1% in Korean black teas. Total polyphenols (TPPs) contents ranged from 12.2% to 16.1% in Chinese, 17.7% to 25.2% in Indian, 7.7% to 10.1% in Japanese, 7.0% to 12.6% in Korean, and 14.8% to 20.7% in Sri Lankan tea products. Total catechins ranged from 21 mg∙g-1 to 45 mg∙g-1 in Chinese, 134 mg∙g-1 to 272 mg∙g-1 in Indian, 28 mg∙g-1 to 52 mg∙g-1 in Japanese, 34 mg∙g-1 to 74 mg∙g-1 in Korean, and 60 mg∙g-1 to 144 mg∙g-1 in Sri Lankan black teas. Total theaflavins (TFs) contents ranged from 2.3 mg∙g-1 to 2.8 mg∙g-1 in Chinese, 1.0 mg∙g-1 to 5.7 mg∙g-1 in Indian, 2.0 mg∙g-1 to 6.3 mg∙g-1 in Japanese, 2.9 mg∙g-1 to 4.6 mg∙g-1 in Korean, and 5.0 mg∙g-1 to 14.7 mg∙g-1 except one, 3.9 mg∙g-1 in Sri Lankan. Total thearubigins (TRs) contents ranged from 9.2% to 12.5% in Chinese, 5.8% to 14.9%, 10.4% to 11.0% in Japanese, 9.7% to 13.3% in Korean, and 9.5% to 18.7% in Sri Lankan. Isobutylmethylketone (IBMK)–souluble TRs fractions ranged from 1.2% to 3.1% in Chinese and Korean, 0.8% to 5.2% in Indian, 1.0% to 1.8% in Japanese, and 2.5% to 7.4% in Sri Lankan. IBMK-insoluble TRs fraction ranged from 5.5% to 8.1% in Chinese, 2.7% to 6.6% in Indian, 4.2% to 5.4% in Japanese, 3.0% to 5.9% in Korean, and 4.0% to 7.8% in Sri Lankan. The result in this study shown that Sri Lankan black teas contained the highest level of TFs and TRs. Indian black teas contained the highest content of TPPs and total catechins which are the dominant chemical components, followed by Sri Lankan tea. This indicates that Sri Lankan and Indian black teas are better than Chinese, Japanese, and Korean in terms of quality analyzing of tea components.