Encapsulation of biological active phenolic compounds extracted from wine wastes in alginate-chitosan microbeads

Abstract

Grapes (Vitis vinifera) are produced in large amounts worldwide and mostly are used for winemaking. Their untreated wastes are rich in valuable secondary metabolites, such as phenolics. Thus, in this study, white and red wine wastes (Malagouzia and Syrah variety) were investigated for their added value phenolics, which were analysed by high performance liquid chromatography (HPLC) and electrospray ionisation-mass spectrometry (ESI/MS) and subsequently encapsulated in several polymers. Extracts from all wastes gave high amounts of total phenolics (13 ± 2.72–22 ± 2.69 mg g⁻¹) and possessed high antioxidant activity (67–97%). In addition to their significant antibacterial activity against gram-negative and gram-positive bacteria, interesting results were also obtained from their anti-inflammatory and antiplatelet activity, in vitro. Encapsulation of the extracts was selective, leaving out most of sugars and other organic compounds when alginate-chitosan was used. Encapsulation efficiency recorded for all extracts ranged from 55% to 79%. Release studies were also performed in several solutions aiming in their commercial use in food and pharmaceutical industries.

Keywords:

• Wine wastes
• phenolic compounds
• biological activities
• HPLC and MS analysis
• encapsulation
• chitosan
• alginate
• microbeads

Acknowledgements

The authors gratefully acknowledged Dr. Papi Rigini for her advices in the anti-inflammatory and antibacterial activities testing methods.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported and funded by IKY, through the Siemens programme: ‘IKY fellowships of excellence for postgraduate studies in Greece-Siemens program 2016–2017’.