Viscosity Analysis Of Honey

Honey is a sweet substance having therapeutic value which can be adulterated very easily with cheap sweeteners. It contains water which is the second major constituent of honey varying from 17-20% depending upon the botanical origin, geographical region, etc. Hence the flow property of honey has become one of the important parameters that determine quality of honey. In the present study, the rheological characteristics of six honey samples adulterated with different concentrations of jaggery syrup were determined. The viscosity of these samples was measured using rotational rheometer with parallel plate geometry. Different modes and parameters were chosen to measure rheological properties i.e. at constant stress, temperature gradient, shear rate ramp with varying shear rate and oscillatory measurements. The viscosity of the honey samples along with the adulterated samples was determined as a function of temperature and percentage of adulteration. All the honey samples behaved as non-Newtonian fluid. The viscosity increased linearly with increase in concentration of adulteration. The temperature dependence of viscosity was evaluated using Arrhenius model. Honey possesses high viscosity at low temperature and high concentration of adulteration. The viscosity varied from 2.48- 4.80 Pas as adulteration increases from 5% to 30%. The viscosity of honey for 30% adulteration sample was 4.80 Pas. Oscillatory tests were performed to find the possible effect of storage time on different honey samples. It was found that adulteration decreases the shelf life of honey because lesser time will be required by the samples to solidify. So, rheology can be considered as one of the important parameters to determine quality of honey.

Keywords: India...

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...owed that crystallization of honey is depended on botanical origin, temperature and storage time28.

The present study aims to study the rheological characteristics of honey samples adulterated with jaggery at different concentration. Jaggery is commonly available in North India which is also known as Gur .Jaggery consists of 30-35 g/100g of water, 40-60 g/100g of sucrose, 15-25g/100g of invert sugars and trace elements29.Its addition in honey changes the viscosity. Dynamic rheology of honey varies with adulteration which indicates the viscous and elastic behaviour with respect to time on different jaggery adulterated honey samples. Hence, the objective of the present work is to study the effect of jaggery adulteration on the rheological behaviour of honey. Honey samples under study were prepared by mixing honey with jaggery syrup having same brix value as in honey.