Food Sorption Isotherms Prediction Using the Ross Equation

Estimation of food sorption isotherms was developed using Ross, Raoult, Norrish and Henderson equations. Food average composition of main solutes (sucrose, glucose, fructose, xylose, maltose, lactose, and salts), nonsolutes (starch, protein, and fiber), and the solute solubility at different temperatures were taken into account. The individual water activity of a single solute was kept constant at moisture contents below saturation at given temperature. Water activities for non-solutes were evaluated with Henderson equation based on literature data for starch, protein and fiber. Sorption isotherms for apricot, raisins, potato, rice, bean and nonfat milk were predicted and compared with those reported in literature. Predicted isotherms represented an expected behavior of the experimental isotherms obtained by different authors.