Recovery of oils from press cakes by CO₂-based technology

Abstract

-In a context of a strong demand for vegetable oils, the development of new "green" processes is essential to provide methods that avoid the use of organic solvents, work at relatively low temperatures and preserve the quality of the final products. The supercritical fluid extraction (SFE) process meets these objectives. In this study, five meals (hemp, flax, sesame, poppy and walnut) were subjected to SFE at 45• C and 250 bar in the presence of ethanol as co-solvent. Using this method, between 77 and 98% of the lipids present in the meal could be extracted. Except for poppy, 50% of the lipids present in the cake were recovered as a separate oily liquid phase. SFE was not selective toward certain types of triglycerides: the oils obtained exhibited the same fatty acid profile than the total lipid extracts from the cakes. In contrast, the composition in minor lipid components was dependent on the type of meal investigated. For example, hemp lipid extract was particularly rich in chlorophyll.Keywords: Supercritical fluid extraction / press cake / oil recovery / oil quality Résumé -Technologie à base de CO 2 pour l'extraction d'huiles de tourteaux de pressage. Dans un contexte de forte demande en huiles végétales, le développement de nouveaux procédés « verts » est indispensable pour proposer des procédés évitant l'utilisation de solvants organiques, travaillant à relativement basse températures et préservant les qualités nutritionnelles et organoleptiques des produits finaux. Le procédé d'extraction par fluide supercritique (EFS) répond à ces objectifs. Dans cette étude, cinq tourteaux végétaux (chanvre, lin, sésame, pavot et noix) ont été soumis au procédé d'EFS à 45• C et 250 bar en présence d'éthanol comme co-solvant. Ce procédé a permis d'extraire entre 77 et 98% des lipides présents dans les tourteaux. À l'exception du pavot, 50% des lipides présents dans les tourteaux se retrouvent sous la forme d'une phase liquide huileuse indépendante. L'EFS n'est pas sélective vis-à-vis de triglycérides particuliers. En effet, l'huile extraite a le même profil en acides gras que les lipides totaux du tourteau. Néanmoins, selon la nature du tourteau considéré, la composition en composés lipidiques mineurs est très variable. Par exemple, la quantité de chlorophylle extraite est très importante dans le cas du tourteau de chanvre.

Supercritical CO 2 extraction of residual oil from pressed sesame seed cake: Optimization and its physicochemical properties

“…Moreover, Date et al, (2015) revealed the extracted oil obtained from pressed sesame seed cake using supercritical CO 2 extraction contained high amount of sesamin and sesamolin, accounted for ~24 mg/g oil. Bardeau et al, (2015) extracted residual oil from five press cakes (hemp, flax, sesame, poppy and walnut) under supercritical CO 2 extraction process with using ethanol as co-solvent. For sesame cake, the supercritical CO 2 extraction could recover residual oil ~56%.…”

“…However, the efficiency and selectivity of supercritical CO 2 extraction highly depends on the extraction factors and conditions, for example, extraction pressure and temperature. Although the effect of the process factors on extraction yield of sesame seed oil has been investigated (Bardeau et al, 2015;Corso et al, 2010;Döker et al, 2010;Hu et al, 2004), the effect on physicochemical properties and its bioactive compounds have less studied. Therefore, this research aims to extract residual oil from pressed sesame seed cake using supercritical CO 2 extraction method.…”

Analysis of the use of selection achievements in the production of oilseeds

“… increasing demand for oilseeds for biofuel production and other technical needs. The analysis of foreign research in the field of oilseeds processing has shown that the main research is aimed at using by-products of oilseeds processing-oil cake and meal as an energy source [5,6], the search for alternative uses of organic solvents for oil extraction [7,8], the study of products in the form of protein feeds obtained during oil extraction to replace more expensive feed ingredients [9], the search for technologies for obtaining food products such as polyphenols, isolates and hydrolysates of oil cake proteins, etc. [10].…”

Combination of existing and alternative technologies to promote oilseeds and pulses proteins in food applications

“…-Use of alternative solvents as supercritical fluids, alcohols, aqueous mixes (Bardeau et al, 2015;Phan et al, 2009;Russin et al, 2011;Sicaire et al, 2015). -Use of new technological approaches as enzymes cocktails (Rosenthal et al, 1996) or ultrasounds (Vilkhu et al, 2008).…”