Extraction optimization, biological activities, and application in O/W emulsion of deep eutectic solvents-based phenolic extracts from olive pomace.

This study evaluated the phenolic compound extraction from olive pomace with deep eutectic solvents (DES) prepared with choline chloride ([Ch]Cl) and four (poly-)carboxylic acids. Temperature, water addition in the solvent, and solid-liquid ratio were evaluate in total phenolic content and antioxidant activity of extracts obtained with DES and ethanol, as control. Moreover, the antimicrobial activities of solvents and extracts were evaluated. Oil-in-water emulsion with DES extract was prepared, characterized and its oxidative stability analyzed. The extract with the highest total phenolic content was obtained with [Ch]Cl:malonic acid. Under optimal conditions, DES extracted 9 % more total phenolic content than ethanol. DES extract showed superior antibacterial activity to the ethanolic extract, and its presence in oil-in-water emulsion increased the induction time in 10-fold when compared to the one prepared with water. These results reinforce that DES are a potential solvent for phenolic compound extraction from olive pomace with antibacterial and technological benefits.

Choline chloride-based deep eutectic solvents as potential solvent for extraction of phenolic compounds from olive leaves: Extraction optimization and solvent characterization.

This study evaluates the use of deep eutectic solvents (DES) prepared with choline chloride ([Ch]Cl) and carboxylic acids for phenolic compound extraction from olive leaves. These extracts were then compared to those obtained using ethanol. The effects of temperature and water addition during DES- and ethanol-based extractions were analyzed using response surface methodology. Due to the lack of solid-liquid equilibrium (SLE) data for [Ch]Cl + acetic acid, SLE, and DES density and viscosity with and without water addition were measured and analyzed. [Ch]Cl:acetic acid (54.1 °C, 50.0% water addition) extracted 15% more phenolic compounds than ethanol (54.1 °C, 0.5% water addition), according to UHPLC-MS based analyses. SLE analyses showed that [Ch]Cl + acetic acid presented a eutectic region at close to a 1:2 molar ratio. DES precursors and water addition influenced solvent physical properties and phenolic compound yield. DES was confirmed to be an innovative, strong solvent for phenolic compound extraction from olive leaves.

Physical properties of Amazonian fats and oils and their blends.

Considering their diversity, this work evaluated physical properties of Amazonian fats/oils (murumuru, tucuma kernel, bacuri, pracaxi, patawa, and Brazil nut). Solid fat content (SFC) curves and crystallization/melting profiles were determined. We also explored the possibilities of combining these lipids into blends to improve their nutritional and technological aspects. Patawa, pracaxi, and Brazil nut oils presented high levels of mono- and polyunsaturated fatty acids, displaying low atherogenicity and thrombogenicity indexes (0.10 and 0.18; 0.23 and 0.70; 0.20 and 0.42), respectively. The SFC curves showed that murumuru fat could be used as a cocoa butter replacer, whereas bacuri fat was found to be a promising alternative to hydrogenated oils in shortenings and spreads formulations. The blends expanded fats' melting ranges and enriched their fatty acid compositions from a nutritional standpoint. This work shows that these fats, oils and their blends may be suitable for developing new products in the food industry.

Phase behavior of cholesterol in mixtures with hypo- and hypercholesterolemic lipids.

Some lipidic bioactives are largely reported to present hypocholesterolemic effects, for example, oleic acid, α-tocopherol, and octacosanol, found in rice-bran, olive, and sunflower oils. In contrast, some saturated and trans-unsaturated lipids found in animal fats or partially hydrogenated oils have been associated with the opposite effect. However, the mechanisms in which these lipids act for lowering or increasing cholesterol are not fully understood. In this context, this work was aimed at a fundamental physicochemical comprehension of how cholesterol phase behavior is affected in mixtures with these compounds. The complete solid-liquid equilibrium (SLE) phase diagrams of these mixtures were depicted by differential scanning calorimetry and microscopy, and also evaluated by the SLE thermodynamic theory. The minimal melting temperature (eutectic points) of the mixtures followed the order: α-tocopherol < oleic acid < elaidic acid < stearic acid < octacosanol. Among all biocompounds, stearic and trans-oleic acids promoted few changes in the normal thermodynamic behavior of cholesterol when in a mixture. In contrast, α-tocopherol induced a significant temperature depression in the system. Furthermore, at high concentrations of cholesterol (>90% molar fraction), the formation of solid solution was observed in all other systems, to a higher degree for oleic acid. The higher interactions of these beneficial compounds and the formation of solid solution that literature associates with the alteration of cholesterol enteric absorption probably correlates with their hypocholesterolemic effects.