Adsorption Isotherms and Isosteric Heat of Dry Fermented Cocoa Beans (theobroma Cacao L.)
Navarro-Pinedo, Euler
Garay-Montes, Richer
Medina-Vivanco, Mari L.
Mendieta-Taboada, Oscar W.

How to Cite

Navarro-Pinedo E., Garay-Montes R., Medina-Vivanco M.L., Mendieta-Taboada O.W., 2024, Adsorption Isotherms and Isosteric Heat of Dry Fermented Cocoa Beans (theobroma Cacao L.), Chemical Engineering Transactions, 109, 589-594.


The San Martín region, located in the northeast of Peru, is the area with the highest cocoa production in the country, highlighting the cocoa clones CCN-51, ICS-39 and ICS-95, of which their physicochemical behavior under storage conditions in the region is unknown. The objectives of present work were: Determine the equilibrium humidity of cocoa bean clones at different temperatures and relative humidity (water activity), model the experimental values of equilibrium humidity and water activity using different sorption equations, estimate the water content monolayer for the different temperature and relative humidity conditions used, and to evaluate the sensory attributes of cocoa beans during storage. The isotherms were obtained by the static gravimetric method, using saturated saline solutions of known water activity, in the range of 0.1 to 0.9. The mathematical models used were GAB, BET, Chung–Pfost, Harkins–Jura, Henderson, Smith, Halsey, Caurie and Kuhn, evaluating the quality of fit to the experimental data by means of the coefficient of determination (R2). The isotherms obtained were sigmoid, characteristic of type II. The GAB model presented the best degree of adjustment to the experimental data, with R2 values greater than 0.92. The parameter values of the proposed models showed dependence on temperature.