METHOD OF SEPARATELY DETERMINING TANNIN AND CATECHINS (ON CONVERSION TO GALLIC ACID) IN TEA

摘要

FIELD: analytical methods in food industry. SUBSTANCE: method includes sampling, determination of tannin by conductometric titration technique involving precipitation mechanism (reaction with gelatin), extraction concentration with isobutyl alcohol, and determination of catechins in extract by indirect conductometry technique involving complex formation with Fe(III). EFFECT: simplified analysis and improved its accuracy. 1 dwg, 2 tbl