Considering that Brazil nut presents high nutritional potential, low consumption in Brazil, low added-value and is an organic product; that cassava has high productivity and low cost; and that the technology of thermoplastic extrusion presents wide applicability and considerable advantages, the objective of this work was to use these three variables, formulating Brazil nut and cassava flour mixtures and processing them by extrusion, with the aim of obtaining ready-to-eat extruded products containing high levels of vegetable protein. Semi-defatted Brazil nut cake and cassava flour were used to formulate the mixtures for extrusion. A complete factorial central composite design (2³) with 3 independent variables, and the response surface methodology were used to evaluate the results of the proximate composition and caloric value, according to the variations in the quantity of nut, moisture content and temperature. The results indicate that the mixtures with higher Brazil nut levels present higher levels of protein, fat and ash, while the mixtures with less Brazil nut present higher levels of carbohydrate. The average regression coefficients of the statistical model for the responses are: moisture 7.40; carbohydrate 51.09; protein 15.34; fat 11.77; total fibre 9.92 and kcal 371.65. The trials with lower quantities of Brazil nut and higher quantities of flour are more expanded and of a lighter colour, while those with more Brazil nut do not expand and are greyish in colour. It is concluded that the addition of Brazil nut to cassava flour results in a mixture that could be submitted to extrusion, producing an extruded product that could serve as a ready-to-eat source of vegetable protein, and attend the demands of consumers who do not consume proteins of animal origin.
Brazil nut; thermoplastic extrusion; proximate composition; response surface methodology
