The rosehip seeds separated from the
dried fruit was used as an oil seed material. They reported that the
fatty acids composition was influenced by the extraction conditions.
The aforesaid studies emphasized that there are no significant
changes in fatty acid profiles of the obtained oils from rosehip
seeds by Soxhlet, cold press and scCO2 extraction methods. However,
Illes et al. [26] reported that scCO2 extraction is more than
efficient in extracting such precious micronutrients when compared
to Soxhlet extraction with n–hexane. Szentmihalyi et al. [30]
showed that the biologically active substances of rosehip seeds can
be extracted in favorable yields by supercritical CO2 and propane,
and also scCO2 extraction results in an oil less rich carotene as
compared to Soxhlet, microwave and ultrasound extractions with
n–hexane. The effect of entrainer contribution in the scCO2 extraction of RHSO has not been carried out so far. Ethanol may enhance
the extraction of polar compounds in original or waste oil seeds
of the rosehip because of their lower solubility in scCO2. Temelli
[41] emphasized that an important aspect in oil extraction is the
use of entrainers to increase solvent loading and to recover polar
components as CO2 is selective for non–polar compounds. Because
specialty oils as RHSO are receiving growing interest due to their
high concentrations of bioactive components which have various
health benefits. Therefore, ethanol addition would be advantageous
in an extraction process if the selectivity can be improved due to
specific intermolecular interactions between the co–solvent and
specific components of a mixture [42,43]. In this study, the percentage
of linoleic acid in the extracted oils from the original and
waste oil seeds did not change significantly with the contribution
of 5%vol. ethanol into scCO2 at the conditions of 40 ◦C, 30 MPa and
0.045 L/h. The percentage of oleic acid increased when using 5%vol.
ethanol, but the percentage of linolenic acid decreased. These tendencies
for both original and waste oilseeds are similar. As shown
in Table 3, the extraction with supercritical fluids of RHSO in both
original and waste oil seeds resulted infavorable fatty acid compositions.
Linoleic acid content in RHSO obtained by Soxhlet extraction
is higher than the supercritical fluids. In contrast, oleic and linolenic
is lower than