Investigation of the effects of using some hydrocolloids and dietary fibers on cake batters and cake qualities

In this study, influence of adding quinoa flour, pear pomace powder and xanthan gam to the gluten free cake formulations to the dough rheology and cake quality parameters were investigated. Pear pomace powder which has high dietary fibre concentration, were produced by milling of pear pomace. In the first part of the study, gluten-free cake formulations which have quinoa flour, rice flour and potato starch at different ratios (0/50/50, 25/37.5/37.5, 50/25/25, 75/12.5/12.5) were tested with the purpose of determination the most acceptable quinoa flour ratio. In this part of the study influence of quinoa flour on the rheological properties of batters and physical, chemical properties and quality parameters of cakes were investigated. It was observed that the density of cake batters increased with the increasing in quinoa flour ratio (p<0.05). According to the rheological studies, it was found that Herschel-Bulkley is the most suitable model to represent the rheological characteristics of cake batters (p<0.05). Also, rheological measurements showed that, an increase in quinoa flour ratio resulted in an increase in elastic modulus (G') ve viscous modulus (G'') values of the samples (p<0.05). An increase in quinoa flour ratio of the samples resulted in an increase in moisture and ash contents of the cake samples (p<0.05). Also it was observed that, cake volume and porosity values of the cakes increased but hardness values of the cakes decreased with the increase in quinoa flour content (p<0.05). Also it was determined that, cake which has 50% quinoa flour is the most acceptable sample according to the analysis (p<0.05). In the second part of the study, the influence of addition of APT (0, 4, 8 and 12% (w/w)) and/or xanthan gum (0, 0.5 and 1% (w/w)) at different levels on the rheological properties of the cake batters and the physical, chemical and quality parameters of the cake samples which has 50% quinoa flour, were investigated. It was observed that density of the cake batters increased with an increase in the use of APT and/or xanthan gum (p<0.05). It was found that Herschel-Bulkley is the most suitable model to represent the rheological characteristics of cake batters (p<0.05). Also rheological measurements showed that, an increase in APT and/or gum ratios of the flour blends, resulted in an increase in elastic modulus (G') and viscous modulus (G'') values (p<0.05). Also it was ascertain that, cake volume and porosity values of the cakes decreased but hardness values of the cakes inceased with the increasing of APT contents of the samples (p<0.05). It was observed that, with the addition of gum to the cake samples, volume and the porosity values of the cakes increased and hardness values of the samples decreased (p<0.05). According to the sensory analysis suc as cake color, texture, appearance, flavor and overall acceptance, cake sample which has 4% APT got the highest scores (p<0.05).