Abdisa, Melesse(PhD)Reta, Nigusse(Prof)Melkie, Adugna2022-03-282023-11-092022-03-282023-11-092011http://10.90.10.223:4000/handle/123456789/30932The effect of blending ratio and cultivar on the quality characteristics of cookies made from orange-fleshed sweetpotato and wheat composite flour were studied. A constrained, simplex lattice design was used to blend the composite flour and five different blending ratios of OFSPF: SWF (0:100, 12.5:87.5, 25:75,37.5:62.5 and 50:50) were found. The OFSP.F was processed from two different cultivars of OFSP roots, namely Tulia and Ku/fo, where as the soft wheat flour which has 17% gluten was purchased from the local market. Functional properties of the composite flours as well as physical, sensory and nutritional qualities of cookies developed from various composite flours were analyzed. Consequently, as the ratio of OFSPF increased in the blend, the water absorption capacity of the composite flour was found to be significantly higher (p< 0.05). The oil absorption capacity and moisture content were significantly higher (p< 0.05) fo'r SWF while bulk density and dispersibility were significantly higher (p< 0.05) for OFSPF. Blending ratio also had a significant effect (p< 0.05) on the quality characteristics of cookies. Increased ratio of OFSPF in the blend caused significant increase (p< 0.05) in moisture, ~-carotene, crude fiber, ash and Calcium content of cookies and resulted in a significant decrease (p< 0.05) in protein, carbohydrate, iron and energy value of cookies. Blending ratio also significantly affected (p< 0.05) the other quality parameters of .cookies (spread and sensory acceptability); the more OFSPF in the blend, the less spread and the less sensory -------,a""c''"c""e'pOf,"a'DiTi y. owever, coo ies made from 25: TSor-OFSPF:5WrnaC!s imria overa 11 ----acceptability with cookies made from 100% SWF. On the other hand, cultivar was found to have effect on the quality parameters of cookies. Cuukies made from Tulla-OFSPF and SWF blend had significantly higher (p< 0.05) spread and better sensory acceptability in terms of color, crispiness, taste, flavor .and overall acceptability than cookies made from Kulfo- OFSPF and SWF blend. It was also observed that the moisture, fiber, fat, ~-carotene, energy and Calcium contents were significantly higher (p< 0.05) for cookies made from Ku/fo-OFSP and SWF blend. However, the ashes, protein, Phosphorus were significantly higher (P< 0.05) for Cookies made from Tulla-OFSPF and SWF blend. Thus, formulation of composite flour for cookie making was optimized from Tulla-OFSPF and SWF blend and found that cookies developed from 71.0655% SWF and 28.935% Tulla-OFSPF blend could be the best to attain all the desired properties optimally with prediction value of 0.714 for desirability. In general, the result of this study indicated that supplementation of orange-fleshed sweet potato flour to wheat flour is possible and very promising to develop ~-carotene rich cookies. Key words: - Cookies, OFSP, VAD, ~-carotene, Blending ratio, Cultivar, Nutritional quality, Physical property, Sensory property, Optimization.enCookiesOFSPVADB_caroteneBlending ratioCultivarNutritional qualityPhysical propertySensory propertyOptimizationThesis