Effect of barrel temperature and blending ratio on the sensory and physical properties of cassava-extruded snacks

Abstract

Cassava is one of the most important food crops in Uganda. Despite its potential for processing into various value-added shelf-stable products, there are limited processed cassava products on the Ugandan market. Extrusion cooking is one of the technologies that provides several options for production of value-added products from cassava. This study aimed at evaluating the effects of processing conditions on the sensory and physical properties of cassava-based extruded snacks. Two factors namely; barrel temperature; 110°C, 130°C, and 150°C and cassava-maize flour ration; 60:40, 50:50, and 40:60 were investigated. The effect of these factors on the diameter, expansion ratio and sensory properties of the cassava-based extrudates was evaluated using standard methods. The study findings indicated an increase in the expansion ratio of the extrudates with increase in barrel temperature and amount of maize added. The results also indicated that the mean force required to puncture extruded sample reduced with increase in barrel temperature. Sensory evaluation results showed that the degree of liking for hardness of the extruded snacks was high for products produced at high barrel temperature and high maize flour rations. Findings from this study indicated that the best cassava-based extrudates were obtained at a barrel temperature of 150°C and at a mixing ratio of 40 parts of cassava to 60 parts of maize flour. The study highlighted the need to maximize other processing parameters like extruder screw speed, feed rate and the moisture content of the feed in order to get a more appealing product.

Keywords

• extrudates
• barrel temperature
• rations
• expansion ratio