2- Evaluate the chromatic and physicochemical properties of new polyphenolic compounds (native, structurally modified and/or encapsulated in different matrices) and to determine the respective kinetic and thermodynamic parameters aiming for putative technological applications in the food and pharmaceutical industries;
4- Formulate O/W emulsions and nanoemulsions containing antioxidants through a combination of high speed and high pressure homogenization processes to improve antioxidant dispersion into food matrices. Evaluate the physicochemical stability of these food-grade emulsions by measuring the physical properties of these emulsion systems (physical stability) and by determining their oxidative stability (chemical stability). The distribution of different sets of phenolic antioxidants (phenolipids) in food-grade emulsions is studied and their distribution correlated with their efficiency in inhibiting the oxidation. This contributes to establish a scientific basis to select the best antioxidant for a particular food application.
7- To recycle anthocyanins from industrial wastes, to use them as genuine forms (red coloured) or to chemically transform them into stable anthocyanin derivatives with other appealing colours (orange, blue). Taking advantage of both their colour features and bioactivity, they will be incorporated into formulations for the cosmetic industry targeted towards skin care prevention products.
The research group of Applied Organic Chemistry (QUINOA) from the Green Chemistry Laboratory (LAQV) has been developing an independent area of research focused on POLYPHENOL properties in foods, and namely: a) characterization of the polyphenol composition of some foods and beverages (grapes, olives, red wine, red fruits, fruit juice, etc.); b) establish a relationship between the polyphenol composition and the organoleptic properties of these foods; c) understand the mechanisms involved in the color and flavor of these foods and their changes during storage and ageing; d) innovate in the technological process in order to improve wine and fruit juice quality in collaboration with the industry; e) study the health-promoting effects of polyphenols and the biological mechanisms involved.
In order to accomplish these broad thematic objectives the group’s aims are:
1- Obtain (by isolation, synthesis or in some cases purchase commercially) and characterize: a) several structurally different polyphenols present in food matrices (red fruits, red wine and olive oil) by using modern analytical techniques, developing new synthesis approaches (both organic synthesis and enzymatic synthesis) and using cutting edge structural characterization apparatus; b) novel antioxidants (phenolipids); c) phenolic metabolites.
3- Study: a) the nutritional and sensory impact resulting from the interaction between polyphenols, proteins and carbohydrates; establishment of a mechanism of interaction between tannins and salivary proteins in a food model by using proteins isolated from human saliva; b) the influence of the presence of carbohydrates in these food tannin-protein interactions; c) the interaction of some food polyphenols digestive enzymes (pepsin, trypsin, and pancreatic elastase); d) the influence of food phenolics on the gliadin digestion and their interaction with the resulting peptides related to coeliac disease.
6- Study the biological properties of polyphenols of different food matrices (red fruits, olive oil, red wine, etc.) and their metabolites through testing their cytotoxicity towards various tumor cell lines, and the antioxidant properties of dietary polyphenols through the determination of some antioxidant features (antiradical power, reducing power, ability to retard lipid peroxidation) aiming to establish structure-activity relationships
5- Study the bioavailability of food phenolics, namely the determination of the ability of different classes of food polyphenols in crossing the gastric, intestinal and blood-brain barriers using cellular models.