Abstract

SILVA, Alessandra Eluan da; SILVA, Luiza Helena Meller da  and  PENA, Rosinelson da Silva. Hygroscopic behavior of açaí and cupuaçu powders. Ciênc. Tecnol. Aliment. [online]. 2008, vol.28, n.4, pp. 895-901. ISSN 1678-457X.  http://dx.doi.org/10.1590/S0101-20612008000400020.

The aim of this work was to evaluate experimentally the adsorption and desorption isotherm of açaí (Euterpe oleracea) and cupuaçu (Theobroma grandiflorum) powders using a hygrometer AQUAlab3TE of Decagon. Three levels of temperature (15, 25 and 35 °C) were tested. The type III curves obtained suggest the materials are rich in carbohydrates. Four mathematical models were fitted to the experimental data, Handerson, Oswin, GAB, and modified BET by nonlinear regression analysis using the software STATISTICA for Windows 5.1B. The Oswin and GAB models were better fitted to the açaí and cupuaçu powder sorption data, respectively. The monolayer for açaí and cupuaçu powders was determined. The desorption heat of the açaí powder was also determined.

Keywords : isotherm; sorption; modeling; monolayer; desorption heat.