Beer, a widely consumed carbonated beverage, is made from malted cereal, hops, yeast, and water. Rich in carbohydrates, minerals, vitamins, amino acids, and polyphenols, it provides essential nutrients [1]. However, the brewing process generates significant solid waste, including hot trub, a slurry of wort, hop particles, and coagulated proteins formed during wort boiling [2]. Given the environmental impact of agro-industrial waste, sustainable methods to repurpose these by-products into bio-products are essential. The aim of this study was to evaluate the potential of transforming these by-products into biologically active extracts suitable for use as functional ingredients in cosmetic and pharmacological formulations. The prepared extracts included one alcoholic and one hydroalcoholic extract obtained through Soxhlet extraction, as well as a hydroalcoholic extract prepared via maceration. Antioxidant activity was assessed using the DPPH radical scavenging assay and the ferric reducing antioxidant power (FRAP) method. Additionally, the extracts were analysed for total flavonoid content using the aluminium chloride colorimetric method and total phenolic content using the Folin–Ciocalteu method. The results demonstrated that the different extracts exhibited antioxidant activity, with the alcoholic extract showing the best performance in both methods, obtaining a value of 61.31±0.39 mmol FeSO4/g extract for the FRAP assay and a value of 11.74±0.57 mmol TE/g extract for the DPPH assay. Furthermore, the alcoholic extract displayed the highest levels of total phenolic content (3.66±0.17 mg GAE/g extract) and total flavonoid content (22.61±2.68 mg QE/g extract). These findings suggest that beer wastes could serve as a promising source of natural polyphenolic compounds, offering potential as an eco-friendly antioxidant ingredient. Such compounds could be incorporated into nutraceutical formulations or applied in pharmaceuticals and cosmetics, contributing to waste valorisation and sustainability.
- Costa, Senna et al. (2021). DOI:10.1007/s12649-020-01163-6
- Thiago, R. et al. (2014) DOI:10.5897/JBD2014.0043
