Chemical composition and selected functional properties of sweet orange (Citrus sinensis) seed flour

Flour samples were prepared from dehulled and undehulled sweet orange (Citrus sinensis) seeds. The flour samples were evaluated for proximate composition, mineral content and selected functional properties. Proximate analysis showed a composition of 54.2% fat, 28.5% carbohydrate, 5.5% crude fiber, 3.1% crude protein and 2.5% ash for the dehulled orange seed flour (dry weight). Mineral analyses showed high levels of calcium and potassium in flour samples. Partially defatted and undefatted flour samples prepared from dehulled orange seeds had least gelation concentrations of 10 and 12% (w/v), respectively. Water absorption capacity for the defatted and undefatted dehulled flour samples were 240 and 220%, respectively. Defatting improved oil absorption capacity of the orange seed flour by 84%. Emulsion activity, emulsion stability and foaming capacity decreased following defatting of flour. Foam prepared from defatted flour was less stable than that from full-fat flour. Incorporation of NaCl up to 0.2 M improved the foaming capacity of orange seed flour.