Nutritional Quality Evaluation of Cookies Enriched with Orange-fleshed Sweet Potato Flour, Starch, and Residue

Abstract

The orange-fleshed sweet potatoes were washed, peeled, sliced, dried and milled to flour. The starch and non-starch residue were also produced from the orange-fleshed sweet potatoes. Different proportions of wheat and flour, wheat and starch and wheat and non-starch residue of orange-fleshed sweet potato with increasing levels of orange-fleshed sweet potato at 10, 20, 30 and 40 % addition in wheat were prepared. Control samples were 100 % wheat flour (A0), 100 % orange-fleshed sweet potato flour (A1), 100 % orange-fleshed sweet potato starch (B1) and 100 % orange-fleshed sweet potato non-starch residue (C1). Cookies from these different proportions were produced. The essential amino acids compositions and chemical scores of the cookies and their composites were determined using standard procedures while the most prepared cookies were further subjected to in-vivo protein quality evaluation. Also, the nutritional quality of the most preferred cookies was also determined using standard procedures. The GENSTAT Statistical Software (version 17.0) was used for data analyses. The essential amino acids of the cookies ranges for lysine (1.35-4.93 g/100g), valine (4.01-7.03 g/100g) and leucine (5.95-8.31 g/100g) respectively. The result of the chemical scores of the cookies essential amino acids have the following ranges for tryptophan (0.04-0.78 g/100g), methionine (0.33-0.67 g/100g), threonine (0.16-0.61 g/100g), isoleucine (0.22-0.68 g/100g) and phenylalanine (0.23-0.89 g/100g) respectively. The most preferred cookies samples from the sensory evaluation were used to prepared a diet and coded A2C: 90:10 Wheat flour and orange flesh sweet potato flour cookies diet, AOC: Wheat flour cookies diet (ref) A3C: 80:20 Wheat flour and orange flesh sweet potato flour cookies diet, B4C: 70:30 Wheat flour and orange flesh sweet potato starch flour cookies diet, B5C: 60:40 Wheat flour and orange flesh sweet potato starch flour cookies diet, C2C: 90:10 Wheat flour and orange flesh sweet potato non starch residue flour cookies diet, C5C: 60:40 Wheat flour and orange flesh sweet potato non starch residue flour cookies diet. The body weight changes of rats feed with cookies diets ranged from -22.67-111.47 g, -0.82-3.96 g, 34.93-98.66 g and 0.25-0.32 g for TWG/L, MDWG/L, PI and FN respectively having the BD, PD of -100.01 g, 50.15 g; -3.61 g, 1.79 g; ND, 63.32 g and 0.31 g, 0.24 g respectively. The nutritional quality of the cookies samples ranged respectively for FER (-0.04-0.11), FCE (-111.86-19.57), PER (-0.12-1.23), NPR (-0.11-0.01) and AD (97.50-99.02 %).