Influence of xanthan gum and gluten on <i>in vitro</i> digestibility and textural properties of rice bread

Starch digestibility of gluten-free bread has been expected to be suppressed for the purpose of decreasing glycemic response. The objective of this study was to investigate the effects of adding xanthan gum and gluten on starch and protein digestibility of rice bread prepared using the developed recipe involving pickering stabilization of foams and emulsions. The extent of starch digestion of gluten-free bread was suppressed by adding 2% xanthan gum from 79.8% to 57.3%. This suppressive effect was diminished by using gluten and that of rice bread containing 2% xanthan gum and 20% gluten was 75.5%. The extent of starch digestion of gluten-free bread was similar or less than that of bread containing gluten. The gluten-free bread with 2% xanthan gum had significantly lower loaf volume, porosity, and sticker structure of breadcrumb than the control. The suppressive effects of xanthan gum on starch and protein digestion were mainly dependent on reducing accessibility of the enzyme into the inner structure.