Effect of different hydrocolloids on the quality and aging of gluten-free bread based on pre-hydrated rice grains

Abstract

This study assessed the physicochemical (specific volume, water content and activity, cell area, color, and crumb hardness; before and after storage) and sensory properties of gluten-free rice bread formulated with hydrocolloids, including native, gelatinized, and chemically modified starches. The inclusion of hydrocolloids significantly influenced bread characteristics, including crust and crumb appearance. Breads with hydrocolloids exhibited lower initial hardness (from 8.5 N) compared to the control sample (28.6 N). After 48 h of storage, none of the breads retained their original hardness levels; however, the smallest increase was observed in breads containing xanthan gum (XG), chia seeds (Ch), native cassava starch (CS-N) and native plantain flour (PF-N). Nevertheless, XG and Ch also led to a ~30 % reduction in volume compared to the control (3.44 ml/g), with XG yielding the smallest cell area (0.58 mm2). In contrast, the highest volumes were achieved with the addition of pectin (3.82 ml/g) and gelatinized cassava starch (3.71 ml/g). Cell area was not correlated with bread volume and ranged between 0.58 (xanthan gum) and 3.68 (chemically modified plantain flour) mm2. In general, chemical modified starches did not enhance bread quality compared to the control, and gelatinization offered no functional advantage over native starches or flours. Sensory analysis of selected formulations (control, XG, CS-N and PF-N) showed an overall acceptability index above 70 %, except for those containing plantain flour. In conclusion, xanthan gum and native cassava starch delivered the most favorable results across the parameters tested.