Correlation of rheological properties of honey with its antibacterial activities

Abstract

Honey was serially diluted with different percentages of glucose, fructose and water and each was analysed rheologically at room temperature of 27°C. The rheological profiles of pure and adulterated honey samples were determined using RV DV-III ultra programmable rheometer at low shear rate (0.0-4.16s^-1). A structural kinetic model was developed which provided good correlation with the rheological data. The new model was used to classify honey samples using their average molecular weights as one of the distinguishing properties. Also, the order of the kinetics in the new model predicts the number of active components in the “honey undergoing deformation”. Pure honey exhibits a peculiar non-Newtonian rheological behaviour. The behaviour of glucose and fructose tends towards Newtonian. Antibacterial activities of honey and serially adulterated samples against Staphylococcus aureus and Pseudomonas aeruginosa were also analyzed. The antibacterial analyses of honey were conducted using Kirby Bauer’s well diffusion method. The results indicated that pure honey exhibited a zone of inhibition against both organisms. Also, the diameter of the zone of inhibition decreased with increasing adulteration of honey, suggesting a correlation with the rheological method.

Keywords: Honey, rheology, structural kinetic model, honey adulteration, antibacterial properties