Abstract
The study presents results of water sorption tests of whole milk powder in the temperature range of 5–35 °C and water activity (aw) from 0.11 to 0.97. The experimental procedure used was the manometric static method. Four sorption models recommended in literature sources (Chung-Pfost, Halsey, Henderson, Oswin) were analysed and evaluated with the aim of aw prediction. The modified Oswin’s equation was the best model for moisture adsorption and desorption of the whole milk powder. Critical values of the equilibrium moisture content (EMC) from the viewpoint of microorganism growth corresponding to the aw = 0.6 were calculated for the temperature range tested. The critical EMC was 7.82% and 8.51% wet basis (w.b.), for water adsorption and desorption, respectively, at the temperature of 20 ºC. Sorption capacity of samples tested decreased as temperature increased, and vice versa. The differences between the EMC values at a constant aw were small in the temperature range measured, and rehydration of the dried material resulted in hysteresis but this effect was non-significant.
Sign-in/Register to access full text options 
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 callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
