The high acid content in tamarind pulp can inhibit consumer sensory acceptance of its products and cause problems during lyophilization, resulting in a powder with high hygroscopicity, and which is prone to caking due to its hydrophilic nature. Tamarind pulp, in turn, has great nutritional potential, and stands out in relation to other pulps because of its functional attributes that are under investigation due to its low glycemic index. This study sought to characterize tamarind pulp and the effects of acidity reduction on hygroscopic behavior. Tamarind pulp powder was evaluated by analyzing moisture content, hygroscopicity, degree of caking, and adsorption isotherms, by fitting experimental data to the GAB, BET, Henderson, and Oswin mathematical models. The results demonstrated that all tamarind powder treatments resulted in low moisture content and hygroscopicity values, but a high degree of caking. The GAB model represented the best fit to the adsorption isotherms, with coefficients of determination (R2) between 0.97 and 0.99 and average errors (E) < 5.67 %, presenting a type III behavior, characteristic of foods rich in sugar, and it is recommended to store this product in environments with a relative humidity below 60 %.