Investigation of rheological properties of different gluten free cake batter formulations by using LAOS method

In this study, the effect of dietary fiber (orange fiber) addition on gluten free batters from rice flour and buckwheat flour rheological properties was investigated.In the first part of the study, the influence of addition different dietary fiber level (0/100, 4/100, 8/100, 12/100, 16/100) on rheological properties of cake batter were determined. The rheological analysis was carried out using the large amplitude oscillatory shear (LAOS) technique. In the second part of the study, the effect of different amount dietary fiber on physical, chemical properties and quality parameters of gluten free cakes were investigated.Results showed an increase in storage (G') and loss (G") moduli values with the addition of dietary fiber in the gluten free batter. According the Lissajous figures, the amount of distortion from an elliptical shape increased with increased strain for all samples. As the strain increased, the phase angles (δn) increased, shifting the dominant behavior in most samples from elastic to viscous. At 1% strain, all samples showed elastic dominant behavior. At 0-60% strain range in the nonlinear area, Chebysev coefficient instensity (e3/e1) values of control and %4 DF samples above zero and e3/e1 values indicates strain stiffening behavior. However, at higher strains, e3/e1 values of these samples below zero and showed strain softening behavior. The extent of the positive range of elastic e3/e1 values increased with increased dietary fiber level of cake batters. Normalized viscous Chebysev coefficients (v3/v1) for all samples indicated shear thinning behavior at 0-300% strain range.According to obtained results, cakes specific volume increased with an increase in dietary fiber level (p<0.05). Dietary fiber addition in gluten free cakes decreased mouisture and protein contents of cakes. Also, it was observed that, hardness values of the cakes decreased with increase in dietary fiber amount (p<0.05). The sensory quality of produced gluten free cakes was defined based on evaluation of appearance, color, texture, flavor and overall acceptance and cake sample which has %4 dietary fiber got better results.