Predigested Mixture of Arachidonic and Docosahexaenoic Acids for Better Bio-Accessibility.

A predigested product from arachidonic acid oil (ARA) and docosahexaenoic acid (DHA) oil in a 2:1 (w/w) ratio has been developed and evaluated in an in vitro digestion model. To produce this predigested lipid mixture, first, the two oils were enzymatically hydrolyzed up to 90% of free fatty acids (FFAs) were achieved. Then, these two fatty acid (FA) mixtures were mixed in a 2:1 ARA-to-DHA ratio (w/w) and enzymatically esterified with glycerol to produce a mixture of FFAs, mono-, di-, and triacylglycerides. Different glycerol ratios and temperatures were evaluated. The best results were attained at 10 °C and a glycerol-to-FA molar ratio of 3:1. The bio-accessibility of this predigested mixture was studied in an in vitro digestion model. A total of 90% of the digestion product was found in the micellar phase, which contained 30% monoacylglycerides, more than 50% FFAs, and a very small amount of triacylglycerols (3% w/w). All these data indicate an excellent bio-accessibility of this predigested mixture.

Combination of Dehydration and Expeller as a Novel Methodology for the Production of Olive Oil.

An alternative olive oil (OO) production process has been developed based on the combination of olive dehydration, followed by extraction with an expeller press. This procedure eliminates the utilization of water and avoids the malaxation stage. Hence, no water residues are generated. In this study, the mentioned alternative methodology was compared to conventional extraction methods. High extraction yields and oil recovery were obtained with our novel procedure. On the contrary, substantial percentages of by-products were generated with conventional methodology. The quality indexes (acidity and peroxide values) of the oils obtained by the combination of dehydration and expeller (dOO) were 0.4% of oleic acid and 3 meq O2/kg of oil, respectively. Furthermore, none of the applied processes affected the resulting OO's fatty acid composition and lipid profile. Total phenolic content was up to four times higher for dOO than for other olive oils and it showed resistance to oxidation with an oxidative stability index about five times higher than that for conventional olive oils.

Anti-inflammatory effect of two pomegranate seed oils obtained by green technologies in Caco-2 cells using the bioaccessible fraction from in vitro gastrointestinal digestion.

Pomegranate seeds contain up to 20% oil with a high content of punicic acid (85%), which is responsible for several biological activities. In this work, two pomegranate oils obtained by a two-step sequential extraction, first with an expeller and then via supercritical CO2 technologies, have been studied in a static gastrointestinal in vitro digestion model to evaluate their bioaccessibility. The micellar phases obtained were evaluated by an in vitro model of intestinal inflammation and Caco-2 cells exposed to the inflammatory mediator lipopolysaccharide (LPS). Inflammatory response was assessed by measuring the production of interleukins IL-6 and IL-8, and tumor necrosis factor α (TNF-α), and by evaluating the monolayer integrity. The results obtained indicate that expeller pomegranate oil (EPO) provides the highest amount of micellar phase (ca. 93%) with free fatty acids and monoacylglycerols as major components. The micellar phase obtained with supercritical CO2 pomegranate oil (SCPO) is ca. 82% with similar lipid composition. Micellar phases of EPO and SCPO showed high stability and adequate particle size. EPO shows an anti-inflammatory response, reducing the production of IL-6, IL-8 and TNF-α in LPS stimulated caco-2 cells and increasing the integrity of the cell monolayer as measured by transepithelial electrical resistance (TEER). In the case of SCPO, the anti-inflammatory effect was only evident for IL-8. The present work demonstrates good digestibility, bioaccessibility and anti-inflammatory response of both EPO and SCPO oils.

A comparative study of in vitro gastrointestinal digestion of three strategic edible oils.

Three strategic edible oils, that is, olive oil, microalgae oil, and shea butter, with a significantly different composition of fatty acids (FA), have been studied in a static in vitro digestion model to evaluate the rate of hydrolysis, bioaccessibility, and micellar phases formed in the process. Lipid composition of each phase and how the lipids are distributed in the different phases have been obtained using this in vitro digestion model. We demonstrate that the composition in FA and the physical properties of the oil are the key factors determining the distribution of lipids in the different phases. The fastest rate of hydrolysis was observed for olive oil and the highest triacylglycerol conversion was attained for shea butter. In contrast, the most abundant precipitate phase was obtained for shea butter, which also produces the highest co-crystallization of cholesterol among the three edible oils studied. This study reveals that digestibility of edible oils is directly related with the initial rate of hydrolysis.