DETERMINATION OF ACIDITY OF COFFEE BY FLOW-INJECTION ANALYSIS WITH ELECTROCHEMICAL DETECTION

The present study was conducted to establish a sensitive, rapid, relia ble, and accurate method for determining the acidity of coffee by flow injection analysis (FIA) using an electrochemical detector with a gla ssy carbon electrode and a carrier solution of ethanol containing 38 m M LiCLO4 and 3 mM 2-methyl-1,4-naphthoquinone (vitamin K-3, VK3) FIA s ignals for 21 coffee samples showed good correlation with titratable a cidity, a common chemical measure of the sourness of coffee. FIA signa ls were also related with sourness intensity determined by sensory pan el test. Change in the acidity of coffee, due to roasting of coffee be ans, was monitored by FIA. The present method was found adequate for d etermining coffee acidity.