Yoghurt and curd cheese addition to wheat bread dough: Impact on in vitro starch digestibility and estimated glycemic index

Abstract

The effect of yoghurt and curd cheese additions on pasting properties, starch digestibility and estimated glycemic index of wheat bread were studied. Yoghurt and curd cheese incorporations (6% up to 25% w/w) promoted considerable changes on starch performance based on gelatinization and final dough consistency properties. These changes led to a significant impact on starch digestibility, reducing significantly the rapidly digestible starch while increasing the resistant starch. The estimated glycemic index reflected the changes promoted on starch performance from both dairy products addition, at higher level tested (25%): a significant reduction of around 30% for yoghurt bread and 38% for curd cheese bread, was obtained, resulting in medium to low (55-69) glycemic index breads. Correlations were found between pasting properties, starch digestibility and glycemic index, revealing that the effects observed are proportional to the levels of dairy products added. Microstructure images of the starch granules supported these findings.

Keywords: Curd cheese; Digestibility; Glycemic index; Wheat bread; Yoghurt.