Determination of the physico-chemical composition, microbial quality and free radical scavenging activities of some commercially sold honey samples in Aba, Nigeria: The effect of varying colours

Abstract

The effect of colour on the physico-chemical composition, microbial quality and free radical scavenging activities of some commercially sold honey samples (A,B,C,D,E) in Aba, Nigeria was studied using standard techniques. The colour of the five honey samples(A,B,C,D,E) based on their absorbance at 560nm and colour chart decreased in the order: E>A>B>C>D. Most of the samples contained moderate amounts of moisture and ash but significant quantities of phenols, flavonoids and their pH ranged from 4.32 to 4.85. The samples possessed higher scavenging activities on DPPH radical than standard quercetin (P 0.05). Microbial analysis revealed that the mean coliform counts of the samples ranged from 0 to 5.0 x 10 ³ cfu/ml for bacteria and 0 to 1.5 x 10 ³ cfu/ml for fungi. The microorganisms isolated include: Staphylococcus , Fusarium and Penicillum. There was a positive correlation between the colour of the honey samples versus their pH (0.879), phenol (0.850), ash (0.622), inhibition of DPPH radical (0.769) and flavonoid contents (0.157) but a negative correlation between the colour of the samples versus reducing sugars (-0.707), ash (-.560), bacteria (-0.252) and fungi counts (-0.170). We recorded a positive correlation