From Waste to Value: Phenolic Profile, Bioactivity, Functional Potential and Application Perspectives of Portugieser Wine Pomace

Wine pomace is the residue of pressed grapes from wine production. This research focuses on expanding the use of winery by-products by evaluating the bioactivity and safety of Portugieser wine pomace. Moreover, the study discussed that the valorisation of winery by-products can support circular economy principles and improve resource efficiency in agro-industrial management systems. Here, the phenolic profile and bioactivity of Portugieser wine pomace extract (WPE) were investigated. The (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide) (MTT) assay was carried out on malignant human neuroblastoma (SH-SY5Y) and normal human fibroblast cells (MRC-5). The MIC assay and growth dynamics were evaluated in probiotic and pathogenic Escherichia coli strains. WPE antioxidant activity and in vivo toxicity in Artemia salina were evaluated. Predominant WPE compounds included trans-cinnamic acid, gallic acid, catechin, and naringenin. Moderate cytotoxicity to SH-SY5Y cells has been detected (up to 41.7%). The growth capacity of probiotic E. coli has been enhanced. WPE showed notable antioxidant activity and good safety, as indicated by the Artemia survival rate (LD50: 2.27 mg/mL, 24 h). The results justify further rigorous testing of WPE to unambiguously confirm its potential as a functional ingredient and its application in the development of value-added products. Moreover, the study highlights the need for organisational strategies to foster the sustainable valorisation of by-products, such as wine pomace.