Evaluation of the Impact of Pre-Drying and Blanching Treatments on the Acceptability of Crisps from Sweet Cassava Roots (Manihot esculenta Crantz)

Abstract

Fresh sweet cassava is highly perishable due to its high-water content. In order to reduce its postharvest losses, a new consumption form  was proposed through crisps production. Red sweet cassava roots were sliced, and divided into two batches. One batch was pre- dried and another was blanched at different times and finally fried to obtained cassava crisps. The pre-drying treatments were carried  out at 60±2°C for 0, 5, 10, 15, 20, 25, 30, 35, 40, 45 and 50 min whereas blanching was done at 90±2°C for 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 and 10 min.  Pretreated samples were fried at 160°C for 6 min to obtain crisps. The sensorial and physicochemical analyses of the produced crisps were evaluated using standard methods. The produced pre-dried and blanched cassava crisps were generally accepted in terms of  their sensory characteristics namely color, texture and overall acceptability. Among the preferred pre-dried and blanched crisps, sample  made by blanching 2 min had the best sensory scores for all sensory quality attributes. The results of the physicochemical analyses of the  preferred sample revealed that, the average moisture content of the accepted pre-dried and blanched crisps was in the range of 2.39-4.44  % and 6.89-8.43 % respectively. There was a significant loss of mineral for the blanched samples and this was illustrated by the  drop of ash content (up to 9.26%) compared to the control sample. With respect to the texture analysis, pre-dried samples were friable  than blanched samples. The hardness values ranged from 93.79-159.65 N and 42.79-74.36 N respectively for pre-dried and blanched samples. Color analyses of preferred crisps revealed that those blanched were lighter compared to pre-dried and the control crisps.