Strategy to reduce the glycemic response of gluten-free breads: Integrating metabolic, in vitro digestibility, and transport across Caco-2 cells to understand the effect of different ingredients.

Abstract

The association of celiac disease with diabetes, and the high glycemic index of commercially available gluten-free breads (GFB) show the urgency of solutions to reduce the glycemic response of this product, which is consumed daily by 93% of Brazilian celiac patients. Thus, the objective of this work is to evaluate the potential of different ingredients for reducing the glycemic response of GFB, through a panoramic study integrating metabolic markers, in vitro bioaccessibility, and transport through Caco-2 cells for a better understanding. The effects of replacing 50% of the flour base (rice flour and potato starch) with alternative raw materials (sorghum, millet, buckwheat, beans and pine nuts) in the GFB formulation will be investigated. These formulations have already been tested in previous studies by our research group and, like the control, they present adequate baking properties and consumer liking (overall liking e 8 on the 10 cm hybrid hedonic scale). The breads will be characterized in terms of proximate and bioactive composition, in addition to antioxidant activity before and after in vitro digestion. The permeation and expression of the sglt1 and glut2 transporters in Caco2 cell models will be evaluated, as well as the ability of GFB after digestion to inhibit the activity of the enzymes ±-amylase and ±-glucosidase in vitro. 15 healthy volunteers will be recruited for the clinical study, making it possible to verify the effect of consuming different breads on biochemical markers of glycemic, insulin and satiety responses. It is expected to obtain GFB with a low glycemic response, source of nutrients and bioactive compounds, which are viable alternatives for the gluten-free products market, contributing to the reduction of the nutritional risk to which consumers of gluten-free products are currently exposed, due to the low nutritional quality and high glycemic response of the products.