June 9/Barcelona, Spain/Journal of Technology & Science -- According to recent research published in the journal European Food Research and Technology, "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, tarch-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 cm(3)/g) than starch-based breads (3.1-3.3 cm(3)/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," wrote B. Minarro and colleagues, University of Barcelona.

The researchers concluded, "No major changes in shelf-life could be attributed to differences in formulation."

Minarro and colleagues published their study in European Food Research and Technology ("Influence of Unicellular Protein on Gluten-free Bread Characteristics." European Food Research and Technology, 2010;231(2):171-179).

For additional information, contact M. Capellas, Autonomous University of Barcelona, CERPTA, CeRTA, XiT, Dept. of Ciencia Animal & Aliments, Bellaterra 08193, Spain.

From the June 21, 2010, Prepared Foods E-dition