Integral Valorization of Grape Pomace for Antioxidant Pickering Emulsions
Julen Diaz-Ramirez,
Senda Basasoro,
Kizkitza González,
Arantxa Eceiza,
Aloña Retegi,
Nagore Gabilondo
Affiliations
Julen Diaz-Ramirez
Materials+Technologies’ Group, Engineering School of Gipuzkoa, Department of Chemical and Environmental Engineering, University of the Basque Country (UPV/EHU), Pza. Europa 1, 20018 Donostia-San Sebastián, Spain
Senda Basasoro
Materials+Technologies’ Group, Engineering School of Gipuzkoa, Department of Chemical and Environmental Engineering, University of the Basque Country (UPV/EHU), Pza. Europa 1, 20018 Donostia-San Sebastián, Spain
Kizkitza González
Materials+Technologies’ Group, Engineering School of Gipuzkoa, Department of Chemical and Environmental Engineering, University of the Basque Country (UPV/EHU), Pza. Europa 1, 20018 Donostia-San Sebastián, Spain
Arantxa Eceiza
Materials+Technologies’ Group, Engineering School of Gipuzkoa, Department of Chemical and Environmental Engineering, University of the Basque Country (UPV/EHU), Pza. Europa 1, 20018 Donostia-San Sebastián, Spain
Aloña Retegi
Materials+Technologies’ Group, Engineering School of Gipuzkoa, Department of Chemical and Environmental Engineering, University of the Basque Country (UPV/EHU), Pza. Europa 1, 20018 Donostia-San Sebastián, Spain
Nagore Gabilondo
Materials+Technologies’ Group, Engineering School of Gipuzkoa, Department of Chemical and Environmental Engineering, University of the Basque Country (UPV/EHU), Pza. Europa 1, 20018 Donostia-San Sebastián, Spain
Full harnessing of grape pomace (GP) agricultural waste for the preparation of antioxidant Pickering emulsions is presented herein. Bacterial cellulose (BC) and polyphenolic extract (GPPE) were both prepared from GP. Rod-like BC nanocrystals up to 1.5 µm in length and 5–30 nm in width were obtained through enzymatic hydrolysis (EH). The GPPE obtained through ultrasound-assisted hydroalcoholic solvent extraction presented excellent antioxidant properties assessed using DPPH, ABTS and TPC assays. The BCNC-GPPE complex formation improved the colloidal stability of BCNC aqueous dispersions by decreasing the Z potential value up to −35 mV and prolonged the antioxidant half-life of GPPE up to 2.5 times. The antioxidant activity of the complex was demonstrated by the decrease in conjugate diene (CD) formation in olive oil-in-water emulsions, whereas the measured emulsification ratio (ER) and droplet mean size of hexadecane-in-water emulsions confirmed the physical stability improvement in all cases. The synergistic effect between nanocellulose and GPPE resulted in promising novel emulsions with prolonged physical and oxidative stability.
