ABSTRACT
Abbreviations ................................................................................................................................. 741 36.1 Introduction.......................................................................................................................... 742 36.2Physical Methods .................................................................................................................. 746
36.2.1Spray Drying ............................................................................................................. 746 36.2.2Atomization by Supercritical Fluids ......................................................................... 747
36.3 Physicochemical Methods .................................................................................................... 748 36.3.1Cooling of Emulsions ............................................................................................... 748 36.3.2Emulsication-Solvent Removal Methods ............................................................... 748 36.3.3Acidic Precipitation .................................................................................................. 750 36.3.4Methods Based on Ionic Interactions ....................................................................... 750
36.3.4.1 Ionic Gelation ............................................................................................. 750 36.3.4.2Layer-by-Layer Process.............................................................................. 751 36.3.4.3Complex Coacervation ............................................................................... 751
36.3.5Methods Based on Hydrophobic Interactions ........................................................... 751 36.3.5.1 Micelles...................................................................................................... 751 36.3.5.2 Liposomes .................................................................................................. 753
36.4Chemical Methods ................................................................................................................ 755 36.4.1In Situ Polymerization .............................................................................................. 755 36.4.2Interfacial Cross-Linking Using Acid Dichlorides................................................... 755
36.5Other Encapsulation Methods .............................................................................................. 755 36.5.1 Molecular Encapsulation .......................................................................................... 755 36.5.2 Cocrystallization ....................................................................................................... 757 36.5.3Encapsulation in Yeasts............................................................................................ 757
36.6 Conclusion............................................................................................................................ 757 References ...................................................................................................................................... 757
PVA polyvinylic acid ROSreactive oxygen species sc-CO2 supercritical carbon dioxide SDSsodium dodecylsulfate SOD superoxide dismutase TPP tripolyphosphate UV ultraviolet
Polyphenolics are aromatic compounds bearing several phenol groups. These secondary metabolites are produced in plants by the shikimate pathway and/or the polyacetate pathway (Figure 36.1).1,2 This large family of molecules (several thousands) has been grouped into various classes, and their structures vary around a few chemical skeletons in terms of degree of oxidation, hydroxylation, methylation, glycosylation, and possible connection to other molecules (carbohydrates, lipids, proteins, other phenolic compounds, etc.). Among the different classes, avonoids are the most abundant, and have been divided into subclasses (avones, avanols, avanones, anthocyanins, proanthocyanidols, etc.). Natural polyphenols like avonoids or tannins possess a well-known protective effect towards oxidation, which can be used against pathologies in which free radicals are incriminated, like cancer.3,4 In cosmetic formulations, these antioxidant molecules are useful to protect the constitutive elements of skin, like collagen or elastin, against degradations or cross-linking reactions responsible for a decrease in elasticity and the appearance of wrinkles with ageing.5
