A Novel Base Catalyzed Esterification Reaction for Spectrophotometric Determination of Free Fatty Acid in Crude Palm Oil

Abstract

In the present work, a novel spectrophotometric method has been developed for determination of free fatty acid (FFA) in palm oil based on esterification reaction of FFA in crude palm oil (CPO) for conversion of FFA to hydroxamic acid (FHA) with excess of hydroxylamine hydrochloride in the presence of base catalyst. The detection was based on the complexation of FHA with V(V) to form a blue colour complex within 5 min; reaction temperature, 70 °C and base catalyst, N-bromosuccinamide (NBS). The intensity of first derivative spectra of the complex at 402 nm was correlated with FFA content in CPO due to the overlapping between spectra of FHA-V(V) and V(V) free in the solution. This developed detection system is able to detect down to 1.5 % FFA in CPO. The detection system was also validated against standard titration method satisfactory.