Quality and antioxidant properties of yellow layer cake containing Korean turmeric (Curcuma longa L.) powder

Turmeric (Curcuma longa L.) is a widely used food ingredient containing curcuminoids, which are important biologically active compounds. The antioxidant and anti-inflammatory properties of turmeric are well documented. We used turmeric powder in yellow layer cakes to study its effects on physico-chemical, sensory and overall product qualities. The viscosity of cake batter, cake volume, crumb color a and b values, crude fibre, curcuminoids content and total phenolic contents of baked yellow layer cakes increased with the addition of turmeric powder. The specific gravity in cake batter, crumb color L value, density, water activity and hardness of cakes decreased with the addition of turmeric powder. No significant differences were found among all the sensory parameters of control cakes and those with up to 6% turmeric substitution. However, cake that contained 8% turmeric was rated comparatively lower in crumb color, sweetness, flavour and overall acceptability. Turmeric yellow layer cakes showed good antioxidant activity, ferric (Fe³⁺) ion reducing power, scavenging ability for 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals and chelating ability on ferrous (Fe²⁺) ions. These results suggest that yellow layer cake can be developed as functional food with the addition of turmeric powder, which imparts improved physico-chemical and higher antioxidant properties to these cakes.