Abstract

Effect of konjac flour (0.5 and 1%) incorporated with soy protein isolate (SPI) (5 and 10%) against wheat flour on physical, chemical and sensory properties of reduced-fat chiffon cakes prepared with 50% vegetable oil replacement with water were investigated. The addition of konjac flour and SPI produced reduced-fat cakes with significantly lower (p < 0.05) in specific volume, but higher (p < 0.05) in weight loss and water activity. All reduced-fat formulations were significantly darker (p < 0.05) than the control. The high concentration of SPI produced the cakes with higher L*(lightness) but lower a*(red) and b*(yellow). The addition of konjac flour incorporated with SPI significantly decreased (p < 0.05) hardness, cohesiveness and springiness of reduced-fat cakes. Sensory results indicated that the cakes with konjac flour and SPI tended to be darker, juicy, sweet and flavour, but less hard than the control; nevertheless, the cake with 0.5% konjac flour and 10% SPI was rated as tender as the control. Also, the reduction of fat and total caloric value of this cake were about 37.9 and 14.6%, respectively, whereas the increment of protein was 24.5% in relation to 100 g of the control cake.

Key words: Chiffon cake, bakery products, konjac flour, soy protein isolate.

Abbreviation

SPI, Soy protein isolate; SEM, scanning electron microscopy.