Influence of unicellular protein on gluten-free bread characteristics

The objective of this work was to study the characteristics of three gluten-free bread formulations and the effect of the inclusion of unicellular protein. Bread recipes were starch-based, starch-vegetable-based and flour-based and the same recipes with added unicellular protein. Flour-based breads had lower specific volume values (2.2-2.3 cm³/g) than starch-based breads (3.1-3.3 cm³/g). Starch-based and starch-vegetable-based formulations with unicellular protein showed less bake loss (18.3 and 17.8%) than their counterparts (21.1 and 19.6%) probably due to increased water retention caused by unicellular protein. Flour-based recipes resulted in the firmest crumb, mainly caused by the high content in dietary fiber. The addition of unicellular protein resulted in a darker crumb color, and significant differences were also found in crumb color because of ovalbumin addition. Confocal scanning laser microscopy results showed a more compact microstructure in flour-based recipes compared with starch-based and starch-vegetable-based formulations. Starch-vegetable-based formulations without unicellular protein were the most preferred by consumers, followed by starch-vegetable-based formulations with added protein. Main differences detected by consumers were related to texture attributes. No major changes in shelf-life could be attributed to differences in formulation.