Chemical composition and antioxidant activity of commercial flours from Ceratonia siliqua and Prosopis spp.

Ceratonia siliqua and some species of Prosopis (Fabaceae family) are commonly known as carob trees. The flours obtained from their pods are used in the food industry, as cocoa substitute in the confectionery and also used in beverages and mixed with products derived from cereals. The aim of this study was to compare and characterize the physical and chemical properties, specially the antioxidant activities, of the two commercial carob flours. Commercial Prosopis spp. (mainly from P. alba) flour exhibited high content of protein, starch and fat, while commercial flour from C. siliqua had a lower content of these compounds, but higher antioxidant activity. By nuclear magnetic resonance (NMR) the aqueous extracts of the two carob flours were analysed and concluded that they had similar content of sucrose, but C. siliqua had more monosaccharides and pinitol. This important cyclitol has beneficial physiological effects, improving the glycaemic level and, thus, having a great potential in the food industry. We conclude that the commercial flour of C. siliqua has a better nutritional potential than that of Prosopis spp., owing to dietary fiber, total phenols, pinitol and antioxidant activity. Our results corroborate the nutritional benefits of the commercial supplements already available for healthy food formulations.