Study on foaming, rheological and thermal properties of gelatin-free marshmallow

Marshmallow is an aerated confectionery product, which consists mainly of gelatin, sugar solutions, glucose syrup and a foaming agent such as egg albumin. Gelatin is generally used as a foaming and gelling agent, but due to its limitations for consumption, many attempts have been made to use hydrocolloids as replacements. In this research, xanthan and guar gum, were added to formulations with the xanthan (x): guar (g) ratios of 100:0, 25:75, 50:50 and 75:25 and a control sample containing only gelatin (G). Analysis of Brix and moisture content, pH, water activity (a(w)), density, overrun, texture, thermal, rheological and sensory properties were carried out. According to the results, density, a w and moisture content of the sample containing x25/g75, revealed no significant difference with the sample containing gelatin (p > 0.05). Texture results showed that x25/g75 sample led to a hardness similar to the control. The formulation containing x25/g75, had thermal behavior closer to the control, which exhibited melt in mouth behavior, gel strength and functionality properties similar to the control. Positive correlation was also observed between the hardness, melting temperature, and enthalpy. The study of viscoelastic properties showed that the values of storage modulus (G') and loss modulus (G '') were dependent on frequency and the G' were always higher than G '' in all samples. Also, considering the desirable sensory properties of the samples, xanthan/guar with a ratio of 25:75 (x25/g75) having positive interaction with other ingredients can be suggested as good alternative for gelatin in production of gelatin-free marshmallow.