Effect of grape pomace from red cultivar 'Nero d'Avola' on the microbiological, physicochemical, phenolic profile and sensory aspects of ovine Vastedda-like stretched cheese

Abstract

Aims: The purpose of this study was to functionalize an ovine stretched cheese belonging to 'Vastedda' typology with red grape pomace powder (GPP) of Nero d’Avola cultivar and to characterize the microbiological, physicochemical, phenolic profile and sensory characteristics of the final cheeses. Methods and Results: Before cheeses production, GPP was characterized for its microbiological profile, antibacterial activity and polyphenolic content. No colonies of bacteria and yeasts were detected in the GPP. GPP showed a large inhibition spectrum against spoilage and pathogenic bacteria. Three classes of polyphenolic compounds belonging to flavan-3-ols, flavonol and phenolic acids were identified. Two cheeses [0 and 1% (w w−1) of GPP] were produced with pasteurized ewe's milk and commercial starter cultures. Plate counts and randomly amplified polymorphic DNA analysis demonstrated the ability of the starter strains to drive the fermentation process in the presence of GPP. GPP enrichment resulted in an increase of protein, phenolic compounds, sensory traits and reduced fat. Conclusions: GPP addition to cheese represents an optimal strategy for the valorization of winemaking by-products and to obtain polyphenol-enriched cheese. Significance and Impact of the Study: This study allowed to achieve an ovine cheese with specific physicochemical, nutraceutical and sensorial characteristics able to enlarge the functional dairy product portfolio.