Adsorption isotherms and thermodynamic properties of Carthamus tinctorius L. seeds

ABSTRACT Safflower is a crop of high economic value with oil concentration in its seeds and great industrial versatility, besides various benefits to human health. As other agricultural crops, it common store safflower make available different periods the year and, due hygroscopic characteristics, studies evaluating effect temperature air relative humidity on moisture content become relevant. Thus, objective present study was determine water adsorption isotherms analyze their thermodynamic properties. Moisture contents 6.5, 6.9, 7.3, 7.7, 8.3 9.1% (dry basis) were obtained by under controlled conditions (30 °C) (90%). The indirect static method at temperatures (10, 20, 30 40 °C). increased, for same content, there an increase activity constant activity, values equilibrium decreased increasing temperature. Chung-Pfost model showed best fit describe phenomenon hygroscopicity seeds. properties influenced seeds, reducing energy necessary absorption product adsorption, enthalpy-entropy theory enthalpy.