Results and discussion
3.1. Total phenol contents
Table 1 shows the total phenol contents of coconut oils extracted
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 methods
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 phenolic
substances. In the cold extraction method, the phenolic substances
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 emulsion
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 incorporated
into coconut oil at low temperatures. The phenolic conT