COMPARISON BETWEEN THE ISOTHERMS OF TWO COMMERCIAL TYPES OF TEXTURED SOY PROTEIN

Textured soy proteins (TSP) are functional ingredients used in food applications. This study aims to compare the sorption isotherms of two commercial types of TSP at 10, 20, 30 and 40 degrees C; the best fit to the experimental data was selected from eight classical models. The curves obtained for TSP type I showed that the equilibrium moisture content decreases as temperature increases for water activities up to 90%. At higher water activities, the moisture content showed an inverse behavior. This inversion did not occur for TSP type 11 due to the absence of sugars in this type of TSP. The Chirife, GAB and Peleg equations presented the best fit for the curves.