Sourdough improves quality of par-baked frozen breads, study

21-May-2013 - Last updated on 21-May-2013 at 15:43 GMT

Industry can tackle quality issues of par-baked frozen bread with sourdough, finds study

Use of certain sourdough cultures can improve volume and crumb firmness in partially baked whole wheat bread, finds new research.

Research published in the International Journal of Food Science & Technology found that sourdough can successfully improve technical and sensory qualities in partially baked frozen breads. However, researchers highlighted that the choice of sourdough is important.

“Quality of partially baked frozen whole wheat bread can be largely improved by adding sourdough; however, this depends on sourdough characteristics and amount,” the researchers wrote.

They found that use of 15-22.5% of sourdough fermented with mixed starter of Lb. plantarum and C. humilis produced the best results. The lactic to acetic acid is higher than previously recommended for traditional sour breads.

This level and type of sourdough ensures the end product has a physical and sensory resemblance to conventional whole wheat bread along with a longer shelf-life after re-baking, they said.

The firming rate of the bread was slowed by 74-94% and specific volume was improved by 25-28% compared to partially baked frozen bread without sourdough.

The par-baked frozen challenge…

The process of partially baking and freezing breads is becoming increasingly common practice as industry moves to deliver large amounts of specialty baked goods, fresh to consumers.

However, while the process can prolong shelf-life, the researchers said it diminishes the volume and crumb texture of the bread.

“The freezing process and storage can have a negative effect on bread quality. Partially baked frozen breads after re-baking have a lower volume, denser structure and harder crumb than directly baked breads,” they wrote.

Industry has a number of tools available to improve the quality in such breads, including hydrocolloids, enzymes, antioxidants and emulsifiers but the researchers said sourdough fermentation is a natural option.

Source: International Journal of Food Science & Technology
Published online ahead of print, doi: 10.1111/ijfs.12197
“Quality attributes and firming kinetics of partially baked frozen wholewheat bread with sourdough”
Authors: D. Novotni, N. Čukelj, B. Smerdel and D. Ćurić