Effect of pH, temperature and time combinations on yield and degree of esterification of mango peel pectin: a box-behnken design based statistical modelling

Abstract

A 3-factor-3-level Box-Behnken design was employed to determine the effect of conditions: pH, temperature and time on yield and degree of esterification (DE) of mango peel pectin obtained using acid extraction method. Fifteen experimental runs with different combinations of pH (1.3, 2.5 and 3.7), temperature (60, 75 and 90°C) and time (45, 90 and 135 min) were performed on mango peel collected from fruit processing industry. Acid extraction method was used to extract pectin. Yield and the DE of mango peel pectin varied from 6.1 to 16.3% (dry weight basis) and 45.5 to 87.5%, respectively. Interactive effects of pH, temperature and time on the DE were significant at P<0.050. The empirical quadratic second degree polynomial model developed for DE in the study was significant (P=0.000) and well fitted to all experimental data with R2 of 99.48. The study highlighted that mango peel from fruit processing industry can be used to produce high methoxyl (DE >50%) or low methoxyl pectin (DE <50%) by controlling conditions during extraction and the model could be used to predict the DE of mango peel pectin for given conditions.