engleski

Effect of fructose syrup addition on the rheological behaviour of Croatian honeys

Adulteration of honey is well-known problem and many methods of analysis are available to detect its adulteration with various types of sugars and/or with inexpensive sugar syrups. Honey is essentially a mixture of sugar and water, in certain proportions, and its viscosity is one of the most significant physical and sensorial characteristics, which affects the quality of the product. The addition of syrups produces commercial honey with lower quality. The objective of this work was to characterize the rheological behaviour of two Croatian honeys in comparison with honeys adulterated with different amounts of syrups. Viscosity of honey was measured in acacia and chestnut honeys at their initial moisture content (14.2-17.4%) as well as addition of fructose syrup at 5, 10 and 20% into pure honeys. The rheological measurements of honey samples were carried out on rotational viscometer within the temperature range of 5 to 40 °C. Both, pure as well as honey samples with syrup addition, exhibited Newtonian behaviour with viscosity reduction as the temperature was increased. The honeys with higher moisture were of lower viscosity, with some exceptions of that with 5% syrup addition. The effect of temperature on the viscosity of the honey samples followed an Arrhenius-type relationship. Results showed that measurements of the rheological behaviour in combination with other analytical techniques could be valuable for detecting of honey adulteration.

honey; rheological behaviour; fructose syrup

nije evidentirano