Effect of Maltodextrin and Gum Arabic Concentration on the Rheological Behavior of Sapote (Calocarpum sapota Merr) Pulp

Abstract

The aim of this research was to measure the effect of maltodextrin and gum Arabic on the rheological behavior of the sapote pulp. The rheological behavior of fruit pulp is modified with the addition of encapsulants which in turn influences the energetic performance of spray drying. In such processes, both maltodextrin and gum arabic are used as encapsulants of fruit pulp and acting as sugars protectors and thus reducing caramelization reactions. The experiment was conducted under a completely randomized design with 2×4 factorial arrangements (Factors: encapsulants and concentration). A Rheometer (AR 1500ex) was used for conducting the flow trials on continuous ramp on the pulp with encapsulants concentrations of 15, 20, 25 and 30% (w/w). Ostwald de Waele’s model was adjusted to apparent viscosity data with determination coefficients greater than 0.994, apart from that, the consistency index (k) and the flow behavior index (n) showed significant differences (p≤0.05) between encapsulants and concentrations used. Those n values lower than one characterize the encapsulated pulp as pseudoplastic flow and the presence of hysteresis among the ascending and descending curves indicate that this is time-dependent fluid with thixotropic nature. The apparent viscosity of the pulp increased with the rise in the encapsulants concentration for the same shear rate, being the gum arabic the one with the greater values. Results will contribute to the improvement of the pump systems design of spray dryers.