Abstract
Due to their hygroscopic characteristics, equilibrium moisture contents of agricultural products and byproducts are important factors of their quality. Defatted cottonseed meal (CSM), washed cottonseed meal (WCSM) and cottonseed protein isolate (CSPI) can be used as energy and protein sources of animal feedstuff or industrial raw materials. Information on their moisture adsorption behaviors is needed for their storage conditions and quality control. Thus, this work measured the equilibrium moisture sorption isotherms of CSM, WCSM and CSPI, at 15, 25, 35 and 45 °C. When the moisture contents of the samples were compared at a constant temperature, the general trend of decreasing moisture content was in the order of CSPI < WCSM < CSM for water activity <0.6, but the trend reversed to the order of CSM < WCSM < CSPI for water activity >0.6. Relevant sorption isotherm equations were tested for accurate fit to the moisture adsorption data. Modelling results indicated that the G.A.B. (Guggenheim-Anderson-de Boer) model was a consistently good fit for the data among all sample types and all temperatures. This work provides some insight on designing or selecting appropriate procedures for the handling, aeration, storage and processing of these cottonseed meal products. In particular, it suggests that moisture content should be kept at around 8% for safe storage of these products at room temperature (around 25 °C) but below 5% when they are exposed to higher temperature conditions (e.g., >45 °C).
Highlights
Cotton (Gossypium hirsutum L.) is a major crop grown in the USA [1,2] and worldwide [3,4,5,6]
Sorption isotherms of cottonseed meal (CSM), washed cottonseed meal (WCSM) and cottonseed protein isolate (CSPI) were determined at four working temperatures at 15, 25, 35 and 45 ◦ C were determined through the static gravimetric method [13,17,25]
When the moisture contents of the samples were compared at a constant temperaWhen the moisture contents of the samples were compared at a constant temperature, ture, the general trend of decreasing moisture content was in the order of CSPI < WCSM
Summary
Cotton (Gossypium hirsutum L.) is a major crop grown in the USA [1,2] and worldwide [3,4,5,6]. The protein-rich defatted cottonseed meal (CSM) can be used as an energy and protein source for animal feedstuff or industrial raw materials [10,14,15,16] Due to their hygroscopic characteristics, equilibrium moisture contents of agricultural products and byproducts are very important for their quality [17,18,19,20,21,22]. Thermodynamic properties (e.g., the isosteric heats of sorption) can be estimated from sorption isotherms and used for analysis and design of appropriate bioproduct processing and for studying moisture–solid interactions [26] For this purpose, Tunc and Duman [13] measured the moisture adsorption isotherms of fuzzy cottonseed, delinted cottonseed, whole cottonseed kernel, blended cottonseed kernel and its protein isolate at 15, 25, 35 and 45 ◦ C. This work will provide novel insight on the effect of the composition difference on the moisture behaviors of cottonseed products, and shed light on the impacts of oil content on moisture thermodynamics of seed products from a more general scope
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
