The highest yield of SC-CO2 extraction reached 1.55% (by
weight of wet sample), which was obtained at a temperature
of 353 K and pressure of 20 MPa for 300 min. This corresponds
to 66.7% recovery based on the total amount of essential
oil. This yield was over 13 times higher than that
obtain by cold press method, which was the lowest. Based
on the results, in terms of yield or recovery of essential oil,
SC-CO2 extraction method was considered to be better
compared to that of the conventional cold press method.
Pioana et al. [13] have also compared the yields obtained between
wet and dry materials. They reported that the essential
oil obtained was about 1.9% v/w from the fresh peel and
about 8.4% v/w when dried. In this case, water content of
peel decreased from 80% to 19%.