Yam flour (Dioscorea alata) was processed in a single-screw extruder, for manufacturing snacks. Response Surface Methodology was employed to evaluate the effects of moisture (16, 20, 24%), extruder temperature (120, 150, 180ºC) and die diameter (3, 4, 5mm) on extrudates characteristics. Temperature was the most important variable, influencing all the studied properties. Specific volume and specific length increased when temperature increased and moisture and die diameter decreased, while at the same time, fracturability and strengthness decreased. Expansion decreased when temperature increased from 120 to 180ºC. Two experimental conditions to obtain snacks with desirable properties (high specific volume and low strength and fracturability) were selected and the products were evaluated by non trained sensorial panels. These pointed out that the better snack was that extruded at 17% moisture, 170ºC and 4mm die diameter. This snack obtained 80% acceptability when evaluated by 140 consumers.
yam; extrusion; flours; snacks
