Walnut-Leaf Extract Proves Effective as Food Preservative

A recent study published online in Food Chemistry (2008; 106(3):1,014-1,020) shows walnut-leaf extract to be a potent tool against oxidation. Because of growing health concerns over synthetic preservatives such as butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT), scientists have been studying natural alternatives.

For this study, an ethanol-water (4:6) extract from the leaves of the walnut tree (Juglans regia) was evaluated for its putative in vitro scavenging effects on reactive oxygen species and reactive nitrogen species.

The IC₅₀ value, a measure of the concentration at which 50% of the free radicals are scavenged, for reactive oxygen species was 47.6 µg per ml. The IC₅₀ for scavenging reactive nitrogen species was 1.80 µg per ml.

These results showed that J. regia leaf extracts can be used as an easily accessible source of natural antioxidants, concluded the researchers. However, they noted that toxicity studies are merited to determine safety before moving forward with use of the extract to replace synthetic preservatives like BHA and BHT.