Characterizing the Mechanical and Rheological Properties of Aerated Confectionery Gels

Abstract

This study varied the gelatin content, gelatin Bloom strength, and density of confectionery gels in order to ascertain the effects of the variables on mechanical and rheological properties. Rheological and texture profile analyses were conducted on the samples, and micro-computed tomography scans were taken to provide images of the internal bubble structure. Statistical analyses including data modeling and ANOVA were performed. Bloom strength did not appear to have a significant effect on any of the measured parameters, with the exception of hardness of non-aerated gels. Increased gelatin content increased hardness, elasticity, and overall stiffness. Increased air content reduced adhesiveness; the effects of aeration on hardness and viscoelasticity were dependent on bubble size distribution. These results indicate that the air cell structure of an aerated confectionery gel significantly impacts its mechanical and rheological properties. Furthermore, the increases in hardness, stiffness, and elastic properties with gelatin content indicate that the junction zone mechanism by which gelatin gels is effective regardless of air content. These results may be useful for adjustment of commercial marshmallow formulations and serve to establish a baseline for an eventual comparison with plant-based gelatin substitutes.