Supercritical fluid extraction of Bulgarian Achillea millefolium

Novel bioactive extract from yarrow obtained by the supercritical antisolvent-assisted technique inhibits lipid metabolism in colorectal cancer

Background: Altered lipid metabolism in cancer is associated to dissemination and prognosis. Bioactive compounds naturally occurring in Achillea millefolium L. (yarrow) have been reported to exert antitumour activities. Food biotechnology may provide on-demand mixtures of bioactive compounds with complementary activities in cancer treatment. Methods: Supercritical-antisolvent-precipitation (SAS) has been applied to fractionate the bioactive compounds from an Ultrasound-Assisted-Extraction yarrow extract resulting in two extracts with distinct polarity, yarrow-precipitate-(PP) and yarrow-separator-(Sep). Total phenolic content and relevant essential oils have been characterized. Antioxidant, anti-inflammatory and antiproliferative activities have been compared. Moreover, the effect on the inhibition of colorectal cancer cells' bioenergetics has been evaluated. Results: Yarrow-PP exerted the highest antioxidant activity, even higher than the complete UAE-yarrow extract, meanwhile yarrow-Sep showed the highest anti-inflammatory activity, even higher than the complete UAE-yarrow extract. Interestingly, yarrow-Sep inhibited key lipid metabolic targets in CRC cells extensively shown to be implicated in cancer dissemination and prognosis -SREBF1, FASN, ABCA1 and HMGCR- and epithelial to mesenchymal targets-CDH1, ATP1B1, CDH2 and Vimentin-augmenting cell adhesion. Conclusions: In summary, SAS technology has been applied to provide a novel combination of bioactive compounds, yarrow-Sep, which merits further research to be proposed as a potential complementary nutraceutical in the treatment of CRC.

Effect of Moisture and Oil Content in the Supercritical CO2 Defatting of Hermetia illucens Larvae

The supercritical defatting of H. illucens was scaled up at 450 bar and 60 °C from a 270 cm³ extraction cell to a vessel five times larger. Then, eight different H. illucens larvae batches, with variable content of oil (16.80-29.17% w/w) and moisture (4.45-15.95% w/w) were defatted. The effect of these parameters on yield and oil composition was analyzed. The presence of moisture in the larvae batch, in the range of the values studied, had no negative effect on the oil recovery efficiency, which was mainly determined by the initial content of oil in the larvae samples. Furthermore, no differences were determined in the fatty acid profile of the oils recovered, which were rich in saturated fatty acids, mainly lauric acid (ca. 50% w/w). Minor lipids, such as squalene and phytosterols, were determined in all the oil samples. The moisture content in the oils extracted was in the range of 0.118-1.706% w/w. Therefore, some samples exceeded the limits recommended for volatile matter in edible fats and oils (0.2%, including moisture). Yet, concerning the oil peroxide index, values were much lower than those corresponding to the oil extracted using hexane.

Antioxidant, Anti-Inflammatory, and Antibacterial Properties of an Achillea millefolium L. Extract and Its Fractions Obtained by Supercritical Anti-Solvent Fractionation against Helicobacter pylori

The main objective of this work is to evaluate the potential utility of an Achillea millefolium extract (yarrow extract, YE) in the control of H. pylori infection. The supercritical anti-solvent fractionation (SAF) process of YE allowed the obtaining of two different fractions: yarrow’s precipitated fraction (YPF), enriched in most polar phenolic compounds (luteolin-7-O-glucoside, luteolin, and 3,5-dicaffeoylquinic acid), and yarrow’s separator fraction (YSF), enriched in monoterpenes and sesquiterpenes, mainly containing camphor, artemisia ketone, and borneol. YE was effective in reducing reactive oxygen species (ROS) production in human gastric AGS cells by 16% to 29%, depending on the H. pylori strain. YPF had the highest inhibitory activity (38–40%) for ROS production. YE modulated the inflammatory response in AGS gastric cells, decreasing IL-8 production by 53% to 64%. This IL-8 inhibition also showed a strain-dependent character. YPF and YSF exhibited similar behavior, reducing IL-8 production, suggesting that both phenolic compounds and essential oils could contribute to IL-8 inhibition. YSF showed the highest antibacterial activity against H. pylori (6.3–7.1 log CFU reduction, depending on the strain) and lower MIC (0.08 mg/mL). Results obtained have shown that YE and SAF fractions (YPF and YSF) were effective as antioxidant, anti-inflammatory, and antibacterial agents regardless of the H. pylori strain characteristics.

Appraisal of the suitability of two-stage extraction process by combining compressed fluid technologies of polar lipid fractions from chia seed

Although triacylglycerols (TAG) are the major constituents of chia oil, it also contains minor lipid fractions that include phospholipids (PL) among other desirable components. Its amphiphilic character and excellent biocompatibility make PL appropriate for numerous applications with technological and nutritional significanceand potential health benefits. Given the difficulties entailed by the PL isolation, the efficiency for extracting such compounds using two environmental friendly techniques, pressurized liquid extraction (PLE) and supercritical fluid extraction (SFE) was evaluated. By using PLE with food-grade ethanol (EtOH), an oil recovery close to 100% was achieved in just 10 min. This oil extract was particularly rich in α-linolenic acid (ALA; 70%) as compared to the oil extracted by SFE (56%). In the case of SFE, the oil recovery was only 87% but increased to 99% when ethanol was added to CO₂. However the use of co-solvent did not affect the fatty acid profile of the supercritical extracts or their TAG composition, where the high molecular weight TAG species were the predominant in all cases. With the exception of SFE without co-solvent, all methods applied were capable of extracting the PL fraction, although the content and distribution of the individual components present in this fraction differed markedly depending on the extraction conditions used. In this context, the use of a sequential extraction process, combining SFE and PLE was particularly interesting. The re-extraction by PLE of the chia cake, previously defatted by SFE, allowed to obtain an oil extract highly enriched in PLs, whose content exceeded 16% and with a higher PL species than the rest of the oil extracts.

Simultaneous Supercritical Fluid Extraction of Heather (Calluna vulgaris L.) and Marigold (Calendula officinalis L.) and Anti-Inflammatory Activity of the Extracts

Heather (Calluna vulgaris L.) and marigold (Calendula officinalis L.) are two rich sources of bioactive pentacyclic triterpenes. The supercritical carbon dioxide (SCCO2) extraction of these two plants was explored at a pressure range of 25–50 MPa, 50 °C, with or without fractionation, different extraction times (1.5–4.0 h) and using ethanol as a co-solvent (0 and 10% w/w). In order to determine potential synergisms, a combined extraction (heather + marigold 50:50) was also studied. In general, higher extraction yields were achieved when the co-solvent was added. Higher concentrations of total triterpenic acids were obtained in heather extracts, specially using ethanol. The co-solvent did not increase the terpene concentration in marigold extracts. For the combined extraction, an antagonist effect in the triterpene concentration was observed in absence of a co-solvent, whereas a synergistic effect was exhibited in its presence, especially for ursolic acid. In general, the extracts showed a certain anti-inflammatory effect, although a straight correlation with the analyzed triterpenic acids concentration was not exhibited. Moreover, the combined extraction exposed a similar anti-inflammatory activity in comparison with the individual plant extracts.

Production of omega 3-rich oils from underutilized chia seeds. Comparison between supercritical fluid and pressurized liquid extraction methods

Chia seeds constitute a promising source of α-linolenic acid (ALA). In the present work, an underutilized and cheaper set of chia seeds, which were discarded after the harvest according to quality criteria - named in this work as low oil content seeds (LOCS) - have been evaluated as a potential source for obtaining PUFA-enriched oils against the commonly studied high-quality chia seeds denoted as high oil content seeds (HOCS) in this study. Two efficient and environmental friendly techniques, supercritical fluid extraction (SFE) and pressurized liquid extraction (PLE), were evaluated to optimize the extraction process of chia oil. At 60 °C, by using pressurized food-grade ethanol, recoveries close to 100% were achieved from both sets of seeds in a short extraction time (10 min). By using SFE, the greatest oil extraction yield (>95%) was attained at the highest pressure and temperature conditions (45 MPa and 60 °C) after 240 min. At the early stage of SFE extraction, both LOCS and HOCS exhibited a similar kinetic behavior, reaching oil extraction rates of 0.59 g oil/min and 0.64 g oil/min, respectively. No differences were found between the fatty acid profile of the oils extracted from LOCS and HOCS both by PLE and SFE. ALA and linoleic acid (LA) concentrations ranged between 65-68% and 17-23% respectively, and a predominance of high molecular weight triglycerides (≥ CN50), was found in all extracted oils. In conclusion, LOCS might constitute a new suitable raw material for the production of ALA-enriched oils. Concerning the extraction methods assayed, the oil was almost entirely recovered by both PLE and SFE at the used conditions.

Optimization of ultrasonic assisted extraction of fatty acids from Aesculus hippocastanum fruit by response surface methodology

The effectiveness of ultrasound-assisted extraction (UAE) of Aesculus hippocastanum fruit oil was investigated using methanol as a solvent. The study compared extraction yields using UAE and methanol with soxhlet. The effects of three extraction parameters, namely temperature, time and the ratio of solvent (volume) to plant material (weight) were optimized using both a Box-Behnken design (BBD) and response surface methodology (RSM). The highest extraction yields were obtained for UAE at 60 °C and 56.5 min with a ratio of solvent to plant material weight of 45:1. The extraction yield using UAE varied by 21.82% (w/ w) but was, regardless, significantly greater than Soxhlet extraction.

Correlating supercritical fluid extraction parameters with volatile compounds from Finnish wild mushrooms (Craterellus tubaeformis) and yield prediction by partial least squares regression analysis

Supercritical fluid was applied to extract volatile compounds from Finnish wild mushrooms (Craterellus tubaeformis). The effects of extraction pressure, temperature and supercritical carbon dioxide volume on extraction yield and the content of mushroom alcohols in the extracts were investigated in the range from 80 to 95 bar, 35 to 55 °C and 30 to 70 mL, respectively. The correlation between extracted volatile compounds and supercritical fluid extraction parameters was studied and prediction models of ten extracted aroma compounds were established by partial least squares regression (PLSR). The calibrated and validated models of 2-octen-1-ol (R _cal = 0.96, R _cal 2 = 0.91, R _val = 0.94, R _val 2 = 0.88) and geranyl acetone (R _cal = 0.96, R _cal 2 = 0.92, R _val = 0.95, R _val 2 = 0.90) were satisfactory, and had the predictive capability of 88% and 92%, respectively. Moreover, the predictive equations for other extracted aroma compounds were also proved to be sufficiently accurate. Hence, the present study provides useful reference for extraction of volatile compounds from mushrooms using supercritical fluid for further industrial applications.