A b s t r a c t. Drying characteristics of Stevia rebaudiana (Bertoni) leaves using radiation drying, convection drying, sun drying, and shade drying treatments were investigated in a convective type. Results for all treatments indicated that drying took place in the falling rate period. . The results indicate that it is possible to select the drying treatment to obtain the best nutritional and biological properties. Convection drying and shade drying were the least aggressive treatments and leaf powders obtained by these drying methods could be used as sources of nutrients, fibre, and antioxidant compounds.

The leaf powders from two varieties of Stevia rebaudiana (Bertoni) cultivated in Yucatan, Mexico were analyzed for their proximate composition, dietary fiber composition and functional properties. The leaf powders were a good source of carbohydrates (64.06% -67.98%), protein (12.11% -15.05%), and crudefiber (5.92% -9.52%). Total dietary fiber content in the S. rebaudiana leaf powders were 28.61 (Morita II) and 29.12 (Criolla) g/100g sample, with most of this content represented by insoluble dietary fiber 87.79% (Morita II) and 70.02% (Criolla). Neutral detergent fiber (NDF), acid detergent fiber (ADF) and acid detergent lignin (ADL) were higher in Criolla (19.29%, 17.77%, 8.98%) than Morita II variety (18.11%, 14.16%, 2.28%). Hemicellulose and cellulose were higher in Morita II (3.96%, 11.78%) than criolla variety (1.51%, 8.79%). Functional properties of leaf powder from Morita II and Criolla were, water-holding capacity (2.87 -4.07 g/g sample), oil-holding capacity (6.49 -6.79 g/g sample), water-absorption capacity (3.41 -3.44 g/g sample), water-adsorption capacity (0.25 -0.28 g/g sample), and organic molecule absorption capacity (1.13 -1.81 g/g sample). These suggest that S. rebaudiana (Bertoni) leaf powders may be used as dietary supplement or as food additive.