. Results and discussion 3.1. Total phenol contents
Table 1 shows the total phenol contents of coconut oils ex- tracted under cold and hot conditions. The results indicate that HECO is richer in phenolic substances, compared with CECO. The coconut milk emulsion used in the cold and hot extraction meth- ods contains an aqueous phase and an organic (oil) phase that make the emulsion milky. Phenolic compounds are partitioned preferably in the aqueous phase because of the polar nature of phe- nolic substances. In the cold extraction method, the phenolic sub- stances are not properly incorporated into coconut oil due to the mild temperature conditions that are used in the cold extraction. However, in the hot extraction method the temperature of the coconut milk emulsion reaches above 100 °C. The concentration of the phenolic substances increases when the water in the emul- sion evaporates during the hot extraction process. Higher phenolic concentrations and higher temperatures favour the incorporation of more phenolic substances into coconut oil.
Phenolic contents also vary with the composition of endosperm, and this variation is significant only in the hot extraction method, indicating that even when phenolic substances are present at high concentrations in the aqueous phase, they are not efficiently incor- porated into coconut oil at low temperatures