Modulation of in vitro digestibility and physical characteristics of protein enriched gluten free breads by defining hydration

Abstract

The association of diabetes of celiac disease together with the high glycemic index of gluten-free breads makes necessary the pursuit of a solution to reduce this glycemic response. Protein enrichment and changes on hydration level may be tools to get it. Thus, the aim of this study was to analyze the effect of two proteins (pea and egg white) on the digestibility and physical characteristics of gluten-free breads, with either the same hydration or specific volume. Protein enriched breads were made blending starch and proteins (70:30). Breads prepared at constant hydration presented lower specific volume and weight loss during baking, and higher hardness than control. However, when the specific volume was matched, the breads with egg white protein presented lower weight loss and higher hardness, while the ones with pea protein were the less hard. Protein enriched breads showed higher SDS and lower RDS values than control with constant hydration, but lower SDS values and glucose release with constant specific volume. Therefore, the bread volume influenced not only the physical properties but also the bread digestibility.

Glycemic Response and Bioactive Properties of Gluten-Free Bread with Yoghurt or Curd-Cheese Addition

“…Similar results were obtained by other authors [ 10 , 11 , 30 ], on gluten-free bread enrichment with rich-protein sources.…”

“…The linear correlation ( R 2 = 0.855) calculated between TPC and FRAP activity supports this relation ( Section 3.5 , Table 3 ). Similar results were found by other researchers [ 10 ] studying the effect of Lycium ruthenicum addition to bread fortification and in vitro digestibility impact.…”

“…The glycemic response depends on several intrinsic properties of flour, such as starch grain structure and molecular size, protein and/or lipid content, and the amylose–amylopectin ratio [ 9 ]. Previous studies reported that the physical interaction between proteins and starch can decrease the glycemic response by forming a physical barrier that reduces the accessibility of enzymatic attack to starch granules, limiting the degree of starch hydrolysis [ 8 , 10 ], which can be an approach to reduce the glycemic response of gluten-free bread [ 11 ].…”

A Systematic Review on Gluten-Free Bread Formulations Using Specific Volume as a Quality Indicator

“…Of these 12 studies, 9 determined the texture profile, but the evaluated parameters were not the same. In general, the values for hardness varied between 0.70 N–22.34; for springiness, 0.95–1.03; 0.45–0.51 for cohesiveness; 0.21–13.61 for resilience; 13.83–583.6 for chewiness ( Table 1 ) [ 40 , 46 , 47 , 48 , 67 , 89 , 95 , 98 ].…”

Grain Proteins: Challenges and Solutions in Developing Consumer-Relevant Foods

“…The incorporation of nongluten proteins at up to 10% has been found to improve both the protein quantity and quality of bread; however, incorporation at more than 15% weakened the gluten network of doughs and hindered bread quality (21,65). In gluten-free breads, the addition of protein at up to 2% enhanced dough rheological properties and bread quality (i.e., specific volume, sensory quality, nutritional quality, and digestibility) (34,45). However, protein additions at more than 10% resulted in breads with darker color, lower volume, and greater hardness than the control (46).…”