EFFECT OF USING SWEET POTATO AND POTATO FLOURS ON PHYSICAL, CHEMICAL AND SENSORY PROPERTIES OF SPONGE CAKE

Abstract

Sponge cake was prepared by replacement sweet potato andpotato flours (refused small size) at levels 10, 20 and 40%. Chemicalcomposition of sweet potato and potato flours showed that sweet potatohad lower moisture and fiber contents. ß- carotene content, increasedfrom 12 to 30 and 40 mg/100g when sweet potato was incorporatedfrom 0 to 40 % into the sponge cake formulation. Farinograph readingsindicated that water absorption increased significantly from 58.2 % to65 % with increase sweet potato flour to 40 %. Resistance to extensionvalues are increased with increasing the sweet potato to 10 % anddecreased at the other levels. Regarding physical characteristics ofsponge cake, results revealed that sweet potato flour at levels 10 % and20 % caused increase in sponge cake volume. Also, the specific volumeof sponge cake increased with each increase of substitution. On theother hand, it was noticed that, organoleptic scores of sponge cakesupplemented with sweet potato at level 20 % and potato flour at 10 %increased, otherwise there was no significant differences betweencontrol and supplemented sponge cake. The results showed also thatsweet potato and potato flours had antimicrobial effect .In general, theoverall acceptability of sponge cakes was improved by 20 % sweetpotato and 10 % potato flours substitution.