Prosopis spp. powder: influence of chemical components in water adsorption properties

Prosopis alba and Prosopis nigra powders from pods were evaluated through chemical and mineral composition and other healthy food compounds such as polyphenols and fatty acids exhibiting antioxidant activity. P. nigra presented higher content of lipids and polyphenols leading to a higher antioxidant activity than P. alba. Although P. nigra presented lower amount (%) of fibre (20.1 vs. 23.3), the amount of total soluble sugars responsible of water retention was slightly higher (PN: 57.1, PA: 56.7). Moisture content, water activity and water absorption behaviours were different between both powders due to differences in their chemical composition. P. nigra powder presented higher amounts of polyphenols, antioxidant activity and lower initial equilibrium moisture content (a(w) = 0.7), with a lower a(w) at 20 degrees C at the same water content, suggesting that P. nigra powder would have less possibility of deterioration during storage.