Stretched exponent rheological model of gum candy

Creep-Recovery Tests (CRT) were measured with a Stable Micros Systems TA.XT-2 precision penetrometer with 75 mm diameter cylinder probe and with different loading stress and creeping-recovery times on gelatine-based candy gum samples, purchased from the local market. The loading force changed from 1 N up to 10 N and the creeping time varied from 30 s up to 120 s. The creeping and the recovering part of CRT curves were approached by Burgersmodel with stretched exponential function. The two elastic moduli and the two viscosities increased linearly in the function of the applied stress. One elastic modulus and the two viscosities also increased, but another elastic modulus slightly decreased in the function of the creeping time. The stretching exponent β practically linearly decreased as the creeping time increased. Based on theoretical considerations, the Kelvin-Voigt-element of Burgers-model can describe the rheological behaviour of sugar content, and the Maxwell-element of Burgers-model can describe the rheological behaviour of gelatine-mesh

A possible rheological model of gum candies

An appropriate rheological model can be used in production of good quality gum candy required by consumers. For this purpose Creep-Recovery Test (CRT) curves were recorded with a Stable Micro System TA.XT-2 precision texture analyser with 75 mm diameter cylinder probe on gum candies purchased from the local market. The deformation speed was 0.2 mm s−1, the creeping- and recovering time was 60 s, while the loading force was set to 1 N, 2 N, 5 N, 7 N, and 10 N. The two-element Kelvin-Voigt-model, a three-element model, and the four-element Burgers-model were fitted on the recorded creep data, and then the parameters of the models were evaluated. The best fitting from the used models was given by the Burgers model