PHYSICO-CHEMICAL EVALUATION OF THE NATURAL STABILITY OF COCONUT MILK EMULSION

Abstract

The stability of coconut milk emulsion against creaming at different pH levels was evaluated in terms of the concentration of oil, protein, total phosphorus and lipid phosphorus retained in the aqueous phase after a 6-hr standing. Better stability was generally observed in the pH regions where the coconut proteins were more soluble. Two stability maxima were observed: the higher one at pH 1.5-2.0 and the lower one at pH 6.5. Minimum stability was observed in the pH range of 3.5-6.0. The correlation coefficients between the oil concentration and lipid phosphorus, total phosphorus and protein concentrations were 0.923, 0.933 and 0.820, respectively, at the pH range of 1.0 to 10. At the pH range of 1.0 to 8.5 the correlation coefficient for protein was a very high 0.971. These results tend to show that there was a relatively tight and pH independent association between the oil and the phospholipids but the oil-protein association was more pH dependent.