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Explora: Environment
and Resource Microemulsion-based canola oil extraction

A

B

Figure 3. Comparison of the effect of different ratios of microemulsion premix components on the oil extraction rate of cooked canola meal with a constant
ratio. (A) #7 – 12, from left to right, and (B) #13 – 18, from left to right (Table 2).

latter includes transitional methods (including phase For instance, those prepared with Epikuron 135F were
inversion temperature and phase inversion composition) more turbid than those prepared with Epikuron 170.
and catastrophic phase inversion. In the phase inversion Epikuron 170 (semi-solid) was also very insoluble and
temperature method, by raising the temperature of a took a long time to dissolve. Moreover, Epikuron 135F
low-temperature system, an oil in water ME converts (partially purified lecithin) was surprisingly more effective
to water in oil ME by crossing a zero-curvature point. in oil separation than Epikuron 170 (highly pure) under
During cooling, the system will attempt to regain its initial the examined conditions (Figure 3B). While pure lecithin
structure. Moreover, in the Winsor III domain, increasing (i.e., Epikuron 170) demonstrated its capability for oil
7
the temperature causes the system to transition into three recovery, its oil release capability was comparatively low
different phases, allowing oil to be released. 15,16 These are (Figure 3B, #15 – 16). To elucidate the possible reasons, in
likely the reasons that heating improved oil separation. the next set of experiments, the lecithin content was halved.
As shown in Figure 3A, there were visual differences By reducing the lecithin content and slightly adjusting
between formulations. For instance, the oil phase in the premix formulation, new formulations were tested
samples 7 – 9 was clearly larger than in samples 10 – (Table 2, #17 – 18). As shown in Figure 3B (#17 – 18), the
12. Moreover, the oil phase in the former samples was oil recovery did not change significantly (compare #15 –
much darker than in the latter. This was due to different 16 with 17 – 18), indicating that further optimization was
(1- propanol: lecithin): water ratios, which were 1:1 and still required. However, the main question was why the size
1:4, respectively. These findings support the idea that of the separated oil phase in the case of partially purified
lecithin, in combination with a co-surfactant under lecithin was larger than with pure lecithin. To address this
optimized conditions, could recover part of the oil content issue, de-oiled CSM (i.e., samples de-oiled by hexane) was
of CSM. These observations align with previous reports. 13,14 used instead of conventional CSM in formulations #13
However, the question arises: if partially purified lecithin and #18. Surprisingly, a free oil phase was still observed in
could recover some oil from CSM, it is reasonable to formulation #13, whereas no oil phase was detected in #18.
expect that using pure lecithin and optimizing the premix This finding clearly suggests that the higher oil recovery by
formulation could further improve the oil recovery rate. To Epikuron 135F was likely due to its own oil content.
test this hypothesis, the most successful formulations (#9 Based on the product data sheet, Epikuron 135F
and 12) were selected, and larger samples were prepared contained only 54.2% of acetone-insoluble phosphatides
(#13 – 14, 15 – 16). In samples #15 – 16, Epikuron 135F (phospholipids). Therefore, at least 45.8% of the partially
was replaced with pure lecithin (Epikuron 170). purified lecithin was likely composed of carbohydrates,
Based on visual observations (data not shown), the fatty acids, triglycerides, and other components, most of
purity of lecithin affected the transparency of the premixes. which were likely soybean oil. Taking this into account, the

Volume 2 Issue 2 (2025) 6 doi: 10.36922/eer.6562