Influence of Guar Gum on Texture Profile Analysis and Stress Relaxation Characteristics of Carrot Sponge Cake

Stress relaxation has traditionally been employed as one of the principal means for measuring the viscoelastic behavior of foods. The objective of this study was to determine the texture profile analysis and stress relaxation characteristics of carrot sponge cake formulated with four different levels of guar gum (0, 0.25, 0.5 and 0.75 %). Texture profile analysis results showed a decrease in the carrot cake consistency, gumminess and chewiness with increasing the level of gum. The consistency and hardness values decreased from 4773.11 to 2260.60 g.s and 915.45 to 458.54 g with increasing guar gum levels from 0 to 0.75 %, respectively. The results showed that mechanical stress relaxation data of carrot sponge cakes were fitted well by both the Peleg-Normand and four-element Maxwell models. The F0 (initial force) and %SR (percentage stress relaxation) parameter of carrot sponge cakes decreased with increasing gum concentration (P<0.05). Although all decay forces (F1, F2 , F3 and F4) of the carrot sponge cakes obviously decreased with increasing guar gum concentration. The elasticity of the carrot sponge cakes was the highest at 0.75% guar gum concentration.