Abstract

MEZA, Bárbara E.; BEUTER, Daiana A.; BRUMOVSKY, Luis A.  and  PERALTA, Juan Manuel. Drying and effective diffusion coeficient estimation of confectionery coatings with low-sugar content. Rev. cienc. tecnol. [online]. 2021, n.35, pp.61-70. ISSN 1851-7587.

The drying kinetics and the estimation of the effective diffusion coefficients of confectionery coatings with low-sugar content were studied, made with a commercial stevia-based sweetener. Formulations were prepared in triplicate using defatted cocoa powder, icing sugar, commercial steviol glycosides solution (7% w/w) as sugar substitute, and soybean oil. Different contents of stevia (75% and 50%) were evaluated as sugar replacement, considering the formulation with 100% sugar as control sample. The drying process was carried out in an oven with natural convection at 50 ((1)°C and relative ambient humidity of 17 ((2)%. The loss of moisture over time was analysed by applying the logarithmic thin layer mathematical model. For the estimation of the effective diffusion coefficients, a simplified mathematical model derived from Fick's second diffusion law was used. The calculation of equilibrium moisture contents was performed by determining the water desorption isotherms at 50°C. The obtained results indicated that drying parameters and effective diffusion coefficients could be obtained, being useful information for further studies about mass transfer that may occur during a coating process.

Keywords : Confectionery coatings, Moisture desorption; Stevia; Natural sweeteners.