INFLUENCE OF BLANCHING ON ANTIOXIDANT AND ANTIMICROBIAL ACTIVITIES OF RAW GARLIC (ALLIUM SATIVUM)

The present study was designed to delineate the influence of blanching on garlic, i.e. Allium sativum regarding in vitro antioxidant profile and antimicrobial activities. Common blanching methods like soaking at hot water at 80 degrees C for 4 minutes and heating in a microwave at high temperature for 90 seconds were engaged. The antioxidant assays performed were DPPH radical decolorization assay, reducing power assay, estimation of total polyphenols, total flavonoids and ascorbic acid. Antimicrobial activities of raw and blanched garlic were adjudicated against the common food borne pathogens like Bacillus cereus, Escherichia coli, Staphylococcus aureus, Klebsiella aerogenes, Enterobacter aerogenes and Bacillus subtilis. The study indicated that blanching by normal heating markedly improved DPPH radical scavenging ability in gallic acid equivalence scale (from 215.97 +/- 15.38 mu g/gm to 235.22 +/- 35.59 mu g/gm) but lowered contents of total phenolics and ascorbic acid. Flavonoid content was improved (from 35.01 +/- 2.88 mu g/gm to 45.67 +/- 3.14 mu g/gm). Blanching using microwave deteriorated the antioxidant profile. It was also observed that blanching have declining effect on antimicrobial activity of garlic although some of the activity was still retained. The study indicated that common blanching processes alone had a moderate effect on antioxidant potential and phytochemical constituents of garlic and had no positive effect on their antimicrobial activities.