Rheological behavior of different honey types from Romania

Abstract

Fifty two honey samples from different regions of Romania were used in order to define the rheological properties and their relations with the sugar composition and palynological characteristics. The botanical origin of the samples was tested by a pollen analysis. The result let to classify 14 samples as linden honey, 11 as black locust, 11 as rape, 4 as sun-flower, 3 as honeydew and 9 multifloral honeys. The carbohydrate profile is performed by HPAEC with pulsed amperometric detection. Six sugars were identified and quantified. The glucose, fructose, maltose and sucrose are present in all the samples, while melezitose and trehalose are detected only in honeydew samples. The mean values of glucose and fructose are 33.3 and 39.8%, respectively. The dynamic rheological measurements show that G″ was much greater than G′, confirming the viscous nature of honey. The rheograms of honey samples at different temperatures (10–40°C) show the Newtonian behavior of all the samples, excepting rape and honeydew honeys which formed a hysteresis loop.