Extraction of lipids from post-hydrolysis spent coffee grounds for biodiesel production with hexane as solvent: Kinetic and equilibrium data

Improved solvent economy and rate of rice bran lipid extraction using hydrolyzed rice bran with hexane as solvent

“…2b), over 95% of the lipids were extracted and dissolved in hexane at equilibrium, which could be achieved in a short period of 1-2 h. These results are consistent with what has been previously reported by Zuniga-Diaz et al [17], where lipid extraction from the bran of Morelos rice with hexane at an SSR of 10 mL g − 1 allowed the extraction of over 95% when the extraction was carried out at 60 • C. The advantage of PHRB is that, despite having higher lipid contents, the same extraction efficiency could be achieved within the same extraction period. This observation is consistent with the work reported by Te et al [11] and Go et al [27], on the lipid extraction from post-hydrolysis copra cake and spent coffee grounds, respectively. To have a better understanding of the lipid extraction process involving PHRB and hexane, sections that follow focuses on the influence of temperature and SSR on the extraction, modeling of the extraction kinetics, thermodynamic, and equilibrium information of the extraction process.…”

Kinetics of aqueous extraction of phenolic compounds from processed yerba mate leaves

“…In the diffusive mechanism, the kinetic constant k_d values decrease with increasing temperature (p<0.05), which can be attributed to changes in the mixing behaviour or dilution effects [38].…”

“…In general, in two-stage extraction mechanisms, the highest speed and concentration is observed in the first extraction or washing stage [26,37], a phenomenon indicative of the fact that these compounds are readily available on the surface of the solid, allowing their rapid extraction [38]. Although the extraction process is favoured at higher temperatures in the initial extraction stage, the equilibrium concentration is not significantly influenced by temperature [37].…”

“…The study and modelling of extraction kinetics is essential to optimize the extraction systems. First-order or steady-state [6,10,28,29,30], second-order [31,32,33,34] and second-order diffusion [26,35,36,37,38] kinetic models are often used to describe the solid-liquid extraction mechanism and the variables involved in the process.…”

In-situ (trans)esterification of lipid-dense post-hydrolysis rice bran at ambient pressures with low acid loading

“…About 10 g of sample were packed in a cellulosic thimble and subjected to exhaustive extraction for 8 h. The collected extracts were then separated from hexane using a rotary evaporator until constant weight and the obtained extract was taken as the crude lipid contained in the samples. The collected lipid samples were then dissolved in ethyl acetate (25 mg/mL) and subjected to gas chromatographic (GC) analysis following the conditions previously established [23]. The GC system used was Shimadzu GC-2010 Plus equipped with a split injector, Rxi-5HT column (15 m × 0.32 mm x 0.1 μm), and flame ionization detector.…”