Low-Cost Device for Constructing Sorption Isotherms

Abstract

Water activity is the main criterion for characterizing the storage and drying behavior of biological products. As current standardized devices are expensive, a cheaper apparatus was designed and built. After preliminary tests, functional specifications were determined. This gravimetric device was tested and validated on microcrystalline cellulose and then used for the characterization of various tropical products. This operational equipment, easy to handle, robust, and four times cheaper than the reference apparatus, was able to obtain accurate sorption isotherms.

Keywords:

• Equipment design
• Functional specifications
• Sorption
• Validation

Notes

∗Control level mean, using a low inertia and response time thermometer.

^a Means with different small letters in the same row are not significantly different at 95% confidence level.

∗Wolf et al. ^[2]

∗∗Water content (g water/100g dry matter).

∗∗∗Water content (g water/100g dry matter) according to Jowitt et Wagstaffe. ^[3]