Optimisation of tripalmitin-rich fractionation from palm stearin by response surface methodology

Solvent fractionation is effective in improving separation at low temperature, resulting in higher yield and purity of the final product. Tripalmitin (PPP) is an important substrate for the synthesis of human milk fat substitute (HMFS). In this study a fraction rich in PPP was separated from palm stearin by solvent fractionation.

The PPP-rich fraction was concentrated from palm stearin by acetone fractionation. Response surface methodology (RSM) was employed to optimise PPP purity (Y(1), %) and PPP content (Y(2), g kg(-1) palm stearin) with the independent variables fractionation temperature (X(1), 25, 30 and 35 degrees C) and weight ratio of palm stearin to acetone (X(2), 1:3, 1:6 and 1:9). The predictive models for PPP purity and PPP content of the solid fraction were adequate and reproducible, with no significant lack of fit and satisfactory levels of R(2). PPP purity showed a positive correlation with temperature and acetone ratio, whereas PPP content exhibited a negative correlation. The optimised fractionation condition for a targeted PPP-rich fraction with > 92% PPP purity and > 225 g kg(-1) PPP content from palm stearin was predicted.

The RSM model for optimising PPP purity and PPP content in the PPP-rich fraction from palm stearin by acetone fractionation was valid. The scaled-up PPP-rich fraction obtained can be used as a substrate for the synthesis of 1,3-dioleoyl-2-palmitoylglycerol, which is a main component of HMFS in infant formulas.