Chemical characterisation, antioxidant and antimicrobial screening for the revaluation of wine supply chain by-products oriented to circular economy

Abstract

Aim of the project was the bioassay guided optimisation of extraction methods applied to wine chain by-product to obtain extracts, fractions and biologically active biomolecules with a possible use in the nutraceutical and cosmeceutical industry. Exhausted red and white grape marc were extracted using water:ethanol 50:50 with ultrasound assisted extraction and Naviglio® technology; and also with supercritical fluid extraction (SFE) and steam-distillation obtaining different phytocomplexes. Each extract was characterised by different molecular category: exhausted red grape marc (VCR) by anthocyanins, exhausted white grape marc (VCB) by flavonoids, and grapeseed (VIN) by proanthocyanins. SFE and steam-distillation, instead, highlighted the presence of fatty acids and their ester in every matrix, but terpenoids were not revealed at level major or equal than 0.1%, except for manoyl oxide in VCR (2.89%). VIN was the most abundant matrix in polyphenols (506.24 ± 55.91 mg gallic acid/g dried extract), and it showed the highest antioxidant activity (IC₅₀ of 4.30 μg/mL). Regarding the antimicrobial activity, the hydroalcoholic extracts from VCR, VCB and VIN were tested but no noteworthy activities have been recorded.

Keywords:

• Waste-revaluation
• exhausted grape marc (EGM)
• ultrasound
• Naviglio^®
• steam-distillation
• supercritical fluid extraction (SFE)
• antioxidant
• antimicrobial

Acknowledgments

Many thanks go also to all the partnership of the project: Terra&Acqua Tech lab. (UNIFE), CIRI-EA (UNIBO), CRPA Lab., LEAP, Caviro Distillerie Srl, CBC-Europe Srl (Biogard), AmbrosiaLab Srl, Sadam Spa.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This research was performed in concert with the Valsovit project. The Valsovit project – Sustainable valorization of grape pomaces for the chemical and health industries – is funded by the Emilia-Romagna Region (POR-FESR 2014-2020) and is aimed at the second-generation valorization of by-products for the production of high added-value molecules by sustainable methodologies.