The use of the jatoba trees (Hymenaea stigonocarpa Mart) by the timber industry poses an ecological problem in Brazil. The objective of this research was to investigate the use of jatoba flour for the production of snacks by the thermoplastic extrusion of a composite flour consisting of jatoba and cassava starch. Chemical analysis showed that the jatoba fruit provides high-fibre flour (486 g kg(-1)) with 66 g kg(-1) protein, and 398 and 88 g kg(-1) of insoluble and soluble fibre, respectively. Such flour is of potential use for the production of high-fibre snacks, allowing for the economical exploitation of the jatoba while preserving the tree. Composite flours with jatoba flour and cassava starch mixtures (150:850, 300:700, 450:550), conditioned to moisture levels of 170, 200 and 230 g kg(-1) were processed in a Brabender single-screw extruder. The extrusion conditions were 150 rpm screw speed, 4 mm die diameter and 125, 150 and 175 degrees C of barrel temperatures. The snacks produced were evaluated as to their sensory characteristics and response surface methodology was used to optimise the extrusion process. Response surface and contour diagrams revealed that all mixtures conditioned to 170 g kg(-1) moisture and extruded at 150 degrees C produced snacks of acceptable quality, higher levels of jatoba flour leading to significant quality losses with respect to sensory characteristics. (C) 1998 Society of Chemical Industry.781596
