No abstract

The olive oil industry produces large volumes of wastes, which are also potential sources of bioactive compounds by developing healthy and/or functional foods. Extraction of phenolic compounds from the residues of the olive oil is mainly carried out with solvents. However, there is currently a growing public awareness about the use of organic solvents in food processing, which has pointed out the need for the application of clean technologies such as pressurized liquid extraction (PLE). Therefore, the aim of this research was to optimize the phenolic compound extraction from olive pomace by PLE, establishing the qualitative and quantitative phenolic profile by HPLC-ESI-TOF/MS. The extraction design to recover phenolics from olive pomace demonstrates a great compositional variability of PLE extracts obtained under different experimental conditions. Indeed, quantitative results have pointed out the selectivity of PLE extraction when this technique is applied to the treatment of olive pomace. PLE-optimized conditions showed higher total phenolic compound content than conventional extraction (1659 mg/kg d.w. and 281.7 mg/kg d.w., respectively). Among these phenolics, the quantity of secoiridoids and flavonoids in the optimized PLE extract was three and four times higher than in conventional extracts. Furthermore, optimal PLE conditions allowed to obtain an enriched hydroxytyrosol extract which was not detected in the conventional one.

Over the last few years, people have been concerned about the narrow relationship between nutrition and health leading to an increasing demand of nutraceutical products and functional food. Lemon verbena (Lippia citriodora Kunth) has been traditionally used for respiratory, digestive, and muscular diseases, showing effects that are promoted by the antioxidant activity of its phytoconstituents. The antioxidant power of several lemon verbena extracts has been tested but its isolated compounds activity has not been described. The aim of the present work was to isolate phytochemicals from a commercial lemon verbena extract through a semi-preparative high-performance liquid chromatography approach for further evaluation of its individual antioxidant activity using three different methods. The structure-antioxidant activity relationships revealed the influence of substitutions in the strong antioxidant power exerted by glycosylated phenylpropanoids, in contrast to the low antioxidant capacity showed by iridoids. Development of enriched extracts in these compounds could lead to greater antioxidant effects and improved functional ingredients to prevent chronic diseases.

Increased levels of reactive oxygen species (ROS) and a low-grade chronic inflammation in multiple organs have been demonstrated in obesity. Morus alba leaves extracts (MAEs) have been used in traditional medicine as anti-inflammatory agents. In this work, the bioactive compounds of different genotypes of M. alba L. (Filipina, Valenciana Temprana, Kokuso, and Italia) were analyzed not only by reverse phase high performance liquid chromatography–electrospray ionization-time of flight-mass spectrometry (RP-HPLC-ESI-TOF-MS) and hydrophilic interaction chromatography–electrospray ionization-time of flight-mass spectrometry (HILIC-ESI-TOF-MS), but also screened for in vitro and in vivo antioxidant activity by means of DPPH· radical scavenging assay and Caenorhabditis elegans model. These MAEs were administered daily in a model of diet-induced obesity in mice. Filipina and Italia genotypes significantly reduced weight gain, the glycemic levels in high fat diet, as well as, levels of LDL-cholesterol and triglycerides. Filipina and Italia MAEs also reduced the expression of proinflammatory mediators such as Tnf-α, Il-1β, Il-6 and increased the levels of adiponectin and AMPK, which exert anti-inflammatory effects. Moreover, Italia genotype ameliorated the intestinal barrier function. In conclusion, Filipina and Italia methanolic extracts show the highest antioxidant and anti-inflammatory effect, due to the presence of compounds such as protocatechuic acid or quercetin-3-glucoside, and they could be developed as a complementary treatment for obesity and metabolic disorders.