A comparative study of various oil extraction techniques from plants

Abstract

<jats:title>Abstract</jats:title><jats:p>Researchers have shown that techniques such as microwave-assisted extraction, ultrasound-assisted extraction, pressurized liquid extraction, and supercritical fluid extraction developed for extraction of valuable components from plants and seed materials have been successfully used to effectively reduce the major shortcomings of the traditional method such as Soxhlet extraction. These include shorter extraction time, increase in yield of extracted components, decrease in solvent consumption, and improvement of the quality of extracts. This review presents a detailed description of the principles and mechanisms of the various extraction techniques for better understanding and summarizes the potential of these techniques in the extraction of oil from plants and seed materials. Discussions on some of the parameters affecting the extraction efficiency are also highlighted, with special emphasis on supercritical fluid extraction. A comparison of the performance of traditional Soxhlet extraction with that of other extraction techniques is also presented.</jats:p>

Dielectric properties in microwave‐assisted solvent extraction—Present trends and future outlook

“…High performance and short extraction time with less solvent consumption and also the protection offered to heat sensitive (thermolabile) constituents are some of the attractive features of MAE . Besides, MAE is comparable with other modern extraction techniques, that is, ultrasound‐assisted extraction, pressurized liquid extraction, and supercritical fluid extraction in terms of performance, simplicity, and equipment costs …”

The relevance of pharmacognosy in pharmacological research on herbal medicinal products

“…The efficiency of classical extraction methods can be enhanced either by application of microwaves (microwave-assisted extraction, MAE) or ultrasonic waves (ultrasound-assisted extraction, UAE) [100][101][102]. Further, advanced extraction techniques feasible for the extraction of herbal material are conducted under enhanced pressure [61,103].…”

“…The method allows processing of plant material at low temperatures, thereby avoiding thermal degradation, and supercritical CO 2 is cheap, inert, environmentally friendly, nontoxic, and generally regarded as safe by the FDA [103,104]. The technique is mainly employed for the extraction of bioactive nonpolar compounds, like lipids, carotenoids, and essential oils [100]; in order to extract more polar compounds such as flavonoids, lignans, and simple phenolics, small amounts of modifiers like ethanol, methanol, acetone, and water have to be added [103,104]. Further methods involving pressurized liquids, like pressurized liquid extraction (PSE) or pressurized hot water extraction, are also frequently used for extraction of herbal material but not yet well established in an industrial scale [61,103].…”

A parametric investigation of castor oil (Ricinus comminis L) extraction using supercritical carbon dioxide via response surface optimization

“…This depends on whether the solvent density or the solute vapor pressure is the predominant factor. On the other hand, the low yield may be attributed to: (1) the solubility of polar organic compounds in SC-CO 2 is limited, and their extraction with SC-CO 2 is not possible [13]; (2) the extraction time was probably not enough for the solute solubility in SC-CO 2 [13] ; (3) and couple with the fact that oil extraction from SC-CO 2 (are pure) and further refining processes are needless [13]. A temperature increase may also result in breakdown of cell structure and increases the diffusion rate of the oil in the particles, therefore accelerating the extraction process.…”

“…tion yields, has no fractionation capabilities, leaves solvent residue in the product, allows manipulations of limited variables, damage the heat-sensitive components of the materials and the requirement of post-extraction process for solvent removal [8][9][10][11][12]. Supercritical fluid extraction (SFE) is a technique that can overcome these drawbacks of the conventional solvent extraction process [13]. The negligible environmental impact of this process represents a prospect for changing the relative concentration of the various lipid moieties [14].…”