Antimicrobial potential and consumer acceptance of a herbal hand sanitiser with Mimosa pudica leaf extract and minimal alcohol

Abstract

Hand sanitisers (HS) prevent infections by transient microflora. The WHO-recommended HS are alcohol-based (75% isopropyl alcohol), which could cause dry skin. Previously, a herbal hand sanitiser (H-HS) was produced with 40% alcohol, adding a leaf extract of Mimosa pudica L. The current study aimed to determine the Minimum Inhibitory Concentration (MIC) of the prepared H-HS and conduct a sensory evaluation test to compare its consumer acceptability with WHO-HS and a commercial HS (C-HS). The MIC of H-HS was determined using 1,000-100,000 mg/L of the alcoholic extract of M. pudica with 40% isopropyl alcohol, by a well diffusion assay, against Escherichia coli ATCC25922, Pseudomonas aeruginosa ATCC27853, Staphylococcus aureus ATCC25923, Candida albicans ATCC10231 and Candida tropicalis ATCC13803. Organoleptic parameters (viscosity, colour, feel, aroma) and overall acceptability on 30 panellists (14 males and 16 females; aged 20 – 70 years) were determined using a hedonic scale: 9 = extremely like to 1 = extremely dislike. A Kruskal-Wallis test and a Mann-Whitney test were performed to determine significance and for median separation, respectively. The MIC against all test organisms was 10,000 mg/L. Its inhibitionzone diameters were significantly lower (p = 0.05) than WHO-HS for the bacteria, while Candida spp. did not show a significant difference. The average median scores (range) for each organoleptic parameter were; colour 6 (5 – 8), 7 (5 – 9), 8 (6 – 9), feel 8 (6 – 9), 6 (5 – 9), 8 (5 – 9), aroma 8 (5 – 9), 7 (5 – 9), 8 (2 – 9) for H-HS, WHO-HS and C-HS, respectively. Colour, feel, and aroma were significantly different (p = 0.01), with the H-HS having the lowest score for colour. Medians of feel and aroma were similar for C-HS and H-HS, while those of WHO-HS were significantly lower. The consumer acceptance of H-HS was similar to C-HS and higher than WHO-HS except for colour. In conclusion, the H-HS effectively inhibits all test organisms and is comparable to WHO-HS, while being consumer acceptable.