Modeling and Thermodynamic Analysis of the Water Sorption Isotherms of Cottonseed Products

Due to their hygroscopic characteristics, equilibrium moisture contents of agricultural products and byproducts are important factors quality. Defatted cottonseed meal (CSM), washed (WCSM) protein isolate (CSPI) can be used as energy sources animal feedstuff or industrial raw materials. Information on adsorption behaviors is needed for storage conditions quality control. Thus, this work measured the sorption isotherms CSM, WCSM CSPI, at 15, 25, 35 45 °C. When samples were compared a constant temperature, general trend decreasing content was in order CSPI < CSM water activity <0.6, but reversed >0.6. Relevant isotherm equations tested accurate fit data. Modelling results indicated that G.A.B. (Guggenheim-Anderson-de Boer) model consistently good data among all sample types temperatures. This provides some insight designing selecting appropriate procedures handling, aeration, processing these products. In particular, it suggests should kept around 8% safe room temperature (around 25 °C) below 5% when they exposed higher (e.g., >45 °C).