title: Microencapsulation and storage stability of polyphenols from Vitis vinifera grape wastes.
abstract: Wine production wastes are an interesting source of natural polyphenols. In this work, wine wastes extracts were encapsulated through vibration nozzle microencapsulation using sodium alginate as polymer and calcium chloride as hardening reagent. An experimental design approach was used to obtain calcium-alginate microbeads with high polyphenol content and good morphological features. In this way, the effect of pressure, frequency, voltage and the distance to the gelling bath were optimized for two nozzles of 150 and 300 μm. Long-term stability of the microbeads was studied for 6 months taking into account different storage conditions: temperatures (4 °C and room temperature), in darkness and in presence of light, and the addition of chitosan to the gelling bath. Encapsulated polyphenols were found to be much more stable compared to free polyphenols regardless the encapsulation procedure and storage conditions. Moreover, slightly lower degradation rates were obtained when chitosan was added to the gelling bath.
authors.affiliation: Analytical Chemistry Department, University of the Basque Country (UPV/EHU), Barrio Sarriena s/n, 48940 Leioa, Spain. Electronic address: oier.aizpurua@ehu.es.
authors.forename: Oier
authors.initials: O
authors.lastname: Aizpurua-Olaizola
authors.affiliation: Analytical Chemistry Department, University of the Basque Country (UPV/EHU), Barrio Sarriena s/n, 48940 Leioa, Spain.
authors.forename: Patricia
authors.initials: P
authors.lastname: Navarro
authors.affiliation: Analytical Chemistry Department, University of the Basque Country (UPV/EHU), Barrio Sarriena s/n, 48940 Leioa, Spain.
authors.forename: Asier
authors.initials: A
authors.lastname: Vallejo
authors.affiliation: Analytical Chemistry Department, University of the Basque Country (UPV/EHU), Barrio Sarriena s/n, 48940 Leioa, Spain.
authors.forename: Maitane
authors.initials: M
authors.lastname: Olivares
authors.affiliation: Analytical Chemistry Department, University of the Basque Country (UPV/EHU), Barrio Sarriena s/n, 48940 Leioa, Spain.
authors.forename: Nestor
authors.initials: N
authors.lastname: Etxebarria
authors.affiliation: Analytical Chemistry Department, University of the Basque Country (UPV/EHU), Barrio Sarriena s/n, 48940 Leioa, Spain.
authors.forename: Aresatz
authors.initials: A
authors.lastname: Usobiaga
mesh_terms: D002392:Catechin / Q000737:chemistry*; D004339:Drug Compounding / Q000379:methods*; D059808:Polyphenols / Q000032:analysis / Q000737:chemistry*; D027843:Vitis / Q000737:chemistry*; D014920:Wine / Q000032:analysis*
chemical_list: D059808:Polyphenols; D002392:Catechin
keywords: (+)Catechin; (−)Epicatechin; Long-term stability; Vibration nozzle methodology; Wine wastes