Effects of xanthan and guar gums on starch digestibility and texture of rice flour blend bread

Background and objectivesThe effects of adding xanthan and guar gums on starch digestibility and textural properties were examined in rice and wheat flour blend breads. FindingsThe addition of xanthan gum to the bread formula had a high impact on the staling of the crumb compared with guar gum. The addition of gums suppressed the recovery of the crumb after compression. The extent of starch digestion of the bread crumb was determined by an invitro method using two types of bread crumb samples, milled samples after freeze-drying and ground samples after moistening. Starch digestibility of the bread crumb reduced after the addition of gums. Xanthan gum resulted in a more pronounced suppressive effect, which was concentration-dependent. The addition of xanthan gum at concentrations 1% to the bread formula caused a significant decrease in the extent of starch digestion in both the samples. ConclusionsThe bread crumb containing xanthan gum had a dense structure and formed an agglomeration after grinding, resulting in delayed enzyme penetration into the crumb structure and thus delayed the enzymatic hydrolysis of starch. Significance and noveltyAddition of xanthan gum to the formula of rice and wheat flour blend breads significantly retards the starch digestibility of bread crumb.