摘要
The effect of incorporation of defatted flour from seeds of sweet orange on wheat flour bread quality was investigated.Seeds were removed from the fruits of sweet orange,sun dried,milled and defatted with ethanol.The defatted orange seed flour was incorporated into wheat flour at 5,10,and 15%.The chemical composition and physicochemical properties of the composite flours were assessed.The composite flours were used to prepare breads and the nutrients composition,antioxidant,physical and sensory qualities of the breads were determined.The water absorption,oil absorption,emulsifying and swelling capacities increased while foaming capacity and bulk density decreased with the addition of the defatted seed flour in the blends.The addition of defatted seed flour increased significantly(P<0.05)the ash(1.98%–3.05%),crude fiber(1.26%–2.98%)and carbohydrate(47.78%–55.90%)contents but decreased the moisture(23.59%–20.37%),crude fat(12.43%–8.98%)and protein(12.96%–8.72%)contents of the breads.The calcium,sodium,iron and zinc contents improved but phosphorus and potassium levels decreased with the incorporation of the defatted seed flour.The phenols,flavonoids,alkaloids,saponins,and carotenoids contents varied from 85.03–18.59 mg/100g,3.11–7.83 mg/100g,7.30–12.06 mg/100g,1.87–2.06 mg/100g,and 5.46–15.84 mg/100g,respectively.The loaf volume,specific volume and oven spring of breads decreased while loaf weight increased with the incorporation of defatted flour.The antioxidant activities of breads containing 15%defatted seed flour increased over that the 100%wheat bread.The ratings for the sensory attributes decreased with the addition of defatted seed flour in the breads.However,the ratings for the sensory qualities of breads containing 5 and 10%defatted seed flours did not differ significantly(P<0.05)from those of the 100%wheat bread.It is concluded that defatted flour from seeds of sweet orange fruits could be used to substitute 10%wheat flour in bread without adversely affecting the qualities of the breads.
