A new perspective of a well-recognized raw material: phenolic content, antioxidant and antimicrobial activities and α- and β-acids profile of Brazilian hop (Humulus lupulus L.) extracts

Abstract Hop is a plant with several biological properties. Many factors affect both the presence and concentration of hop compounds, such as cultivar, location and growth conditions. Recently, the interest of hop cultivation in Brazil has grown despite the tropical weather and it has been possible to obtain hop completely cultivated in Brazilian soil. This study analyzed the chemical composition and verified the antioxidant and antimicrobial activities of Brazilian hop hydroethanolic extracts in comparison to a commercially available hop cultivar. Brazilian hops were a good source of flavonoids (5.72 – 12.82 mg CE/g dw), and presented a high content of phenolic compounds, in particular the Canastra cultivar (35.1 mg GAE/g dw). The Brazilian cultivars showed interesting antioxidant and antimicrobial proprieties. Gram-positive and Gram-negative bacteria were susceptible to hop hydroethanolic extracts and Staphylococcus aureus was inhibited by the extracts of all cultivars. The extracts presented antifungal activity against Byssochlamys nivea and significant growth inhibition at the higher concentration tested (20 μl/ml). The hydroethanolic extracts exhibited a high content of α- and β-acids, mainly the Vitoria, Columbus and Canastra cultivars, reaching almost 60% (w/w). These characteristics evidenced the potential application of Brazilian hops as raw materials in both pharmaceutical and food industries.