Quantitative analysis of macro and micro-structure of gluten-free rice cakes containing different types of gums baked in different ovens

The effects of different gums on macro-structure of gluten-free rice cakes baked in conventional and infrared-microwave (IR-MW) combination ovens were investigated by using the images obtained by scanner and scanning electron microscopy in this study. The gum types used were xanthan, guar, locust bean, kappa-carrageenan and xanthan-guar blend. Cake containing no gum was used as control. It was observed that both addition of different types of gums affected the pore area fraction and percent number of pores of the rice cakes. The highest pore area fraction was obtained in cakes containing xanthan and xanthan-guar blend. Cakes baked in IR-MW combination oven had higher porosity than those baked in conventional oven. Micro-structure of gluten-free rice cakes was also analyzed. According to these results, conventionally baked cakes showed more starch granule deformations. Both granular starch residues and deformed starch structure were observed together in cakes baked in IR-MW combination oven. All of the starch granules did not lose their identity and did not disintegrate completely. (C) 2010 Elsevier Ltd. All rights reserved.