Comparative evaluation of the composition of vegetable essential and fixed oils obtained by supercritical extraction and conventional techniques: a chemometric approach

Abstract

Summary We compared by a chemometric approach the composition of essential (EO) and fixed (FO) oils previously obtained from several vegetable matrices by supercritical CO2 extraction (CO2‐SFE) and conventional techniques (n‐hexane in a Soxhlet apparatus and hydrodistillation). A multivariate approach, by determining the principal components analysis (PCA) applied to data of FO fatty acids and EO volatile compounds, generally indicated that the vegetable oils extracted with CO2‐SFE tightly clustered with those obtained by conventional methods. The graphical distances calculated in the PCA plots between the score of each SFE oil and the corresponding conventional oil revealed that the CO2‐SFE FO and EO profiles were quite similar to conventional oils, with the additional benefit of not having unwanted traces of solvent. SFE FO were more similar to conventional oils than SFE EO (mean values of calculated graphical distances were 0.83 and 1.46 for FO and EO, respectively). Our results strongly corroborate the role of CO2‐SFE as a suitable, environmentally safe and efficient method alternative to the traditional ones for the extraction of natural vegetable oils for food and pharmaceutical applications.

Fatty Acid Ratios as Parameters to Discriminate Between Normal and Tumoral Cells and Compare Drug Treatments in Cancer Cells

“…PCA is considered an unsupervised analysis as allows the exploration of the distribution of the sample without prior classification. [ 26 ] The PCA scores plot reveals any inherent clustering of groups of data, trends, or outliers, based purely on the closeness or similarity between the samples, while the PCA loadings plot describes the influence of the variables in the model. An important feature is that directions in the scores plot correspond to directions in the loadings plot, and vice versa.…”

“…The following formula: [ 26 ] $$$$\begin{equation}d\left( {{P_{\rm{A}}},{P_{\rm{B}}}} \right) = \sqrt {{{({x_{\rm{B}}} - {x_{\rm{A}}})}^2} + {{({y_{\rm{B}}} - {y_{\rm{A}}})}^2}} \end{equation}$$$$(where: P B is the control HeLa cells and P A the HeLa cells treated with a specific drug concentration; x B is t[1] of control cells; x A is t[1] of treated cells; y B is t[2] of control cells; y A is t[2] of treated cells) was used to calculate in the PCA plot for HeLa cell treatment with different drugs the distance between the score of control HeLa cells and the score of treated cells in the same experimental set.…”

“…An important feature is that directions in the scores plot correspond to directions in the loadings plot, and vice versa. [28] The following formula: [26] d…”

“…[22][23][24][25] These natural compounds were selected based on their ability to affect lipid/FA profile in cancer cells, maybe acting as inhibitors of FAS and SCD enzymes. [22][23][24][25] Principal com-ponent analysis (PCA), a statistical procedure amply used to summarize and compare the total FA profile of oils, [26] marine organisms, [19] and cell lines/tissues, [27] was comparatively applied to cell FA and FA ratio data to validate the role of FA ratios as useful reproducible metabolic parameters for cell characterization/discrimination, and the comparison of different drug treatments, alternative to total FA profile. Last, a small set of selected FA ratios was calculated for other cell lines, previously cultured/analyzed in our laboratories under similar experimental conditions, and compared by PCA in the perspective to assess their role in discriminating between cancer and normal cells.…”

Optimization of hydration method for efficiently separating high‐quality oils from macadamia seed kernels

“…Solvent extraction method is not environmentally friendly though it is currently the most efficient method. Supercritical CO 2 extraction method has been used in a number of oil extraction procedures recently and can be operated in batches with small scale (Piras et al, 2021) and may have benefit over other conventional extraction techniques (Miao et al, 2022). Enzyme-assisted aqueous method has a low recovery rate of free oils with the use of expensive enzymes and the discharge of large quantities of waste water.…”