Bioactive Properties and Phenolic Composition of Wood-Aged Beers: Influence of Oak Origin and the Use of Pale and Dark Malts

Abstract

Ageing beer in contact with wood is a common technological procedure that has been used for centuries to improve colour, structure, and certain flavours. Herein, the impact of the addition of French and American oak wood to two beer styles, pale and dark, on beer phenolic composition (total phenolics, total flavonoids, and HPLC-DAD) and bioactivity (FRAP, DPPH, anti-inflammatory activity in RAW 264.7, and antiproliferative in Caco-2 cells) was assessed. Thirteen phenolics were quantified with values according to previous reports. Dark malt resulted in higher values of total phenolics, to which m-hydroxybenzoic, syringic, p-coumaric acids, and xanthohumol contributed considerably; the exception was (+)-catechin and salicylic acid, which were found to be higher in pale beers. American oak significantly increased 3,4-dihydroxyphenylacetic, vanillic, and syringic acids up to roughly 3, 2, and 10 times, respectively, when compared with French wood. FRAP and DPPH values varied between pale and dark beers, with a less pronounced effect after wood addition. All samples presented considerable cellular antioxidant and anti-inflammatory as well as antiproliferative activity, but differences were found only for the antiproliferative activity, which was higher for the dark beers, which reached about 70% inhibition. Overall, the influence of malts was more pronounced than that of wood, in the studied conditions, highlighting the overwhelming impact of malts on the bioactivity of beer.

Addition of Spirulina to Craft Beer: Evaluation of the Effects on Volatile Flavor Profile and Cytoprotective Properties

“…Beer is generally characterized by the presence of polyphenolic compounds, such as phenolic acids and tannins, flavones and flavonols [43], which contribute to its typical organoleptic characteristics and stability as well as to its antioxidant properties [44][45][46]. We confirmed similar polyphenol levels and radical scavenging properties in our beer samples; a greater scavenging capacity against the ABTS radical was also highlighted for beer with 0.25% w/v spirulina compared to beer, thus suggesting that some compounds found in spirulina, such as fatty acids and/or sugars, may contribute to the increase in antioxidant power [47,48].…”