Studies on kolanut and cashew kernels: moisture adsorption isotherm, proximate composition, and functional properties

Kolanut (Cola nitida) and cashew (Anacardium occidentale) kernels were analysed and their moisture adsorption isotherms, proximate composition, and functional properties were compared. The dried powdered sample of kolanut contained 69% carbohydrate, 18% crude fat and 3.1% ash by weight, while the cashew sample had 51% crude fat, 36% crude protein, 0.3% ash and 3.4% carbohydrate. These differences significantly affected their relative water and oil absorption capacities, least gelation concentration, bulk density, and emulsion properties. However, both samples would retain nutritional integrity when stored in atmospheres with water activities of up to 0.68 for kolanut and 0.85 for cashew kernels. The Brunauer–Emmett–Teller (BET) and Henderson mathematical models described both isotherms with less than 2% mean relative deviation.