Pressing and supercritical carbon dioxide extraction of walnut oil

Extraction of oil and minor lipids from cold-press rapeseed cake with supercritical CO2

“…Figure 3 and Figure 4), extraction conditions (pressure) affect the concentration of carotenoids more than the concentration of tocopherols. These results agree with those of Martínez et al (2008) for the SC-CO 2 extraction of walnut oil, who found that, under isothermal conditions, an increase in operating pressure above 20 MPa caused a significant increase in β-carotene yield. When we fitted a response surface model to the carotenoid extraction yield (the product Y oil C car ), we obtained an equation that was qualitatively similar to Equation (7), indicating that the carotenoid extraction yield depended highly on the concentration of carotenoids in the oil (results not shown).…”

“…The oil extracted with SC-CO 2 (IT = 18 min) had a significantly lower (p < 0.05) oxidative stability than the one extracted with hexane (IT = 12.6 h). Martínez et al (2008) reported IT values ranging from 18 to 47 min for walnut oil extracted with SC-CO 2 at 20-40 MPa and 50-70 ºC. Table 4 shows no difference in fatty acid composition between rapeseed oils extracted with SC-CO 2 and hexane.…”

Walnut and almond oil screw-press extraction at industrial scale: Effects of process parameters on oil yield and quality

“…Using screw-pressing at pilot plant scale, the highest oil recoveries from both walnut and almond kernels were obtained at similar moisture contents (Martínez et al, 2008;. In each case, the oil extraction performance was also dependent on the pressing temperature and other processing conditions.…”

“…These consist of a number of unit operations such as cracking, cooking, flaking, drying or moistening (Wiesenborn et al, 2001;Martínez et al, 2008;Savoire et al, 2013;Martínez and Maestri, 2015;Martínez et al, 2017). Seed moisture content appears to be a key process variable, as reported in several research projects with various oilseeds (Singh and Bargale, 1990;Hamm and Hamilton, 2000;Wiesenborn et al, 2001;Singh et al, 2002;Martínez et al, 2008;2012;2017).…”

“…Both walnut and almond kernels contain high levels of oil (52 -70 and 48 -67%, respectively) (Martínez et al, 2008;Martínez et al, 2013;Martínez and Maestri, 2015). Walnut oil (WO) is mainly composed of polyunsaturated fatty acid (linoleic and linolenic acids together represent 65 -75% of the total fatty acid (FA) content).…”