Lactic acid bacteria could limit toxin and mould growth in bread, report

According to a review published in the journal Food Control ​economic losses related to the presence of moulds in bread are estimated to be more than €200m per year in Europe.

LAB are microorganisms that are widely used for the production of fermented foods and are also part of intestinal microflora, and the reviewers found that using LAB to control mould growth could be an interesting alternative to physical and chemical methods because these bacteria have been reported to have strong antimicrobial properties.

Biopreservation, the control of one organism by another, has received much attention in the last ten years, they added, noting a study which shows that the use of LAB in the formulation of mixed starter cultures together with S. cerevisiae​ was found to significantly improve bread quality and prevent spoilage from mould.

However, the authors note that another study on the topic concluded that while a well-designed selection of potential antifungal LAB could reduce the problem of toxinogenic moulds, the use of antifungal LAB requires a thorough knowledge of the parameters that modulate their antifungal properties.

And the reviewers also report that little is known at this time about the stability and toxicity of LAB–mycotoxin complexes with many questions, they say, still to be answered before LAB can be practically used at the industrial level.

In order to minimise the negative influence on organoleptic properties that could result from LAB use, several strategies are under investigation, report the reviewers.

“The most promising one concerns the direct use of antifungal metabolites or chemical binders (such as peptidoglycan compounds), produced via fermentation by native or genetically-engineered organisms, purified and added to foods as pure chemicals,” ​their investigation found.​

They add that two additional strategies are currently being evaluated: incorporation of LAB into biofilms and encapsulation processes.

“LAB cultures with high antifungal, antimycotoxigenic and mycotoxin binding potential could be of immense value in limiting mycotoxin exposure. However, the introduction of large scale biopreservation of food requires careful safety assessment and risk analysis,” ​concluded the reviewers.

Source: Food Control
Published online ahead of print: doi:10.1016/j.foodcont.2009.07.011
Title: Lactic acid bacteria – Potential for control of mould growth and mycotoxins: A review​
Authors: DKD Dalié, A.M. Deschamps, F Richard-Forget