Antioxidant potential of Moringa stenopetala leaf extract on laagered beer stored at
room temperature

Controlling beer oxidation using natural antioxidants for better shelf-life stability is
the prominent objective of modern breweries. Flavour instability resulting from beer
storage and oxidations are the most important quality problems in the brewing
industry. This study evaluated the influence of the addition of 80% ethanol leaf
extract of Moringa stenopetala to lager beer at 400, 600 and 800 ppm concentrations
for 30-, 60- and 90-days storage at room temperature. The total phenolic and total
flavonoid contents were determined by Folin-Ciocalteu and aluminium chloride
method respectively. Antioxidant activity of each treatment was evaluated and
compared by using 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging
activity and total antioxidant using phosphomolybdate assay. The addition of the
extract in beer showed a linear increment in the total phenolic content from 46.79 up
to 88.30 milligrams of gallic acid equivalent per litre of beer (mg GAE/L) and total
flavonoid contents from 123.36 up to 167.09 mg of catechin equivalent per litre of
beer (mg CE/L). A similar increment was observed within the DPPH scavenging
potential, from 46.55up to 67.16% and total antioxidant power from 139.12 up to
216.67 milligrams of butylated hydroxytoluene equivalent per litre of beer (mg
BHTE/L). The result indicates a promising use of leaf extract of M. stenopetala as a
functional ingredient in beer to reduce beer oxidation probability and keep its
freshness for a period of storage time.