Production of oleoresin from ginger (Zingiber officinale) peels and evaluation of its antimicrobial and antioxidative properties

Abstract

Dried ginger (ginger peel, peeled and unpeeled ginger) extracts were produced using acetone, and subjected to antimicrobial and anti-oxidative properties. In the antimicrobial assay using agar well diffusion technique the extracts were inoculated with five different organisms (Escherichia coli, Staphylococcus aureus, Salmonella typhimurium, Aspergillus niger and Bacillus subtilis) at different concentrations of 0.5, 1.0 and 1.5 ml, respectively, which were compared with the zero (0.00 ml) concentration of the extracts (control). The results showed that the three extracts (ginger peel, peeled and unpeeled ginger extracts) were effective against B. subtilis and A. niger at the different concentrations but were ineffective against E. coli, S. aureus, and S. typhimurium. The antioxidant activities of the three ginger (peel, peeled and unpeeled) extracts were found to be 75.50±0.70%, 73.01±0.00% and 51.01±0.41% for ginger peel, unpeeled ginger and peeled ginger respectively with the peel extract having highest antioxidant activity. These were compared with that of the control-synthetic antioxidant-butylated hydroxytoluene (BHT) which had activity of 98.5±0 0.70%. This showed that ginger peel extract could be used as an antioxidant in the place of synthetic antioxidants in foods and related products.