Evaluation of the potential of partial replacement of wheat by orange fleshed sweet potato puree in making chapattis.

Abstract

The increasing prices of wheat flour in Uganda have necessitated the need for its substitution with local alternatives in confectioneries. These local alternatives used include cassava flour, pumpkin flour among others. This study evaluated the potential of orange fleshed sweet potato (OFSP) puree as a substitute for wheat in making of chapattis. The OFSP variety used in the study was of NASPOT 8. The effect of partial substitution of wheat flour with OFSP puree on sensorial and proximate composition of the chapatti was investigated. Wheat flour was replaced with different proportions of OFSP puree (20% – 80%). Chapatti was made from the ingredients (Jiko bakers flour, salt, onions and baker’s fat) using the straight dough method followed by frying with cooking oil. Sensory evaluation of chapattis made from formulations was carried out using a 9-point hedonic scale with a panel of 30 people. This was done to determine the most acceptable and the most economically feasible mixing ratio of wheat flour to OFSP puree. This was determined to be the chapatti with 60:40 substitution (OFSP: wheat flour). Proximate composition analyses were done using standard methods to determine the composition of the chapatti with 60% substitution. Moisture content, dietary fiber, carbohydrates, crude protein, ash, beta carotenoids and crude fat were evaluated. The moisture content , dietary fiber, ash and beta carotenoids increased with the substitution of wheat with 60% OFSP puree i.e. (from 20.2 to 25.0, 1.7 to 2.1, 1.9 to 3.9, 0.3 to 1.0) g/100g respectively. This was in comparison to a control chapatti that contained 100% wheat flour. Carbohydrates and crude proteins decreased with the substitution of wheat with 60% OFSP puree i.e. (from 76.8 to 63.2, 2.6 to 1.7) g/100g respectively. There was no change in the concentration of crude fat with the substitution of wheat with 60% OFSP puree.