Preserving your daily bread

written by Terry Robson


All that glitters is not gold and all that’s bread can turn to mould. That is the full version of this quote is attributed to English 14th century poet Thomas Poleleaner although it is the first half that is most oft quoted. The previous sentence is of course a complete fiction, so if you see it turning up in a blog somewhere you’ll know the author is less than ardent in their relentless pursuit of truth. The corrupted quote itself however, contains two grains of truth (pardon the pun); it is true that not everything that appears precious actually is valuable and even the most delicious of breads if left long enough will eventually turn to mould. Indeed, modern breads would turn a lot mouldier a lot sooner if they were not so full of preservatives. The problem is that not everybody is happy about the preservatives used in breads and there is some concern about some preservatives used. That is why a new study showing that essential oils in packaging may be used to help preserve breads could be good news.

One of the preservatives used in breads has been calcium propionate. It is an agent that preserves bread by preventing the growth of mould. There has been concern raised about this substance, particularly in terms of its effect on children. Against this there are many who claim that calcium propionate (preservative 282 and its propionate cousins 280-3) is perfectly safe. In some instances manufacturers have started using whey, dextrose or wheat that has been cultured with propionibacteria to create a “natural” form of propionate, allowing the bread to be labelled as containing “no artificial preservatives”, although it still contains equivalent levels of propionate. For those who may want the natural nature of their bread to go beyond label dressing, new research has something to offer.

In the new study researchers incorporated oil from cloves and oregano into edible plastic films. They then purchased preservative free bread and wrapped it in the essential oil infused films. To some slices instead of putting them in the film they added propionate as a preservative. After ten days it was found that the propionate had lost its effectiveness but the film made with a few droplets of essential oils continued to restrict mould growth.

In another study published in the Journal of Food Process Engineering earlier in 2014 a sachet containing oregano essential oil was used in bread packaging. It was found that the oregano oil restricted the growth of E. coli, salmonella, and penicillium. However, in this study it was found that the oil altered the taste of the bread at certain concentrations. At concentrations above 10 per cent a bitter taste infiltrated the bread but at concentrations around five per cent mould and yeast growth was still restricted but the taste was not impacted.

As far as embedding the oils in plastic wrap goes, purchasing your bread in plastic wrap is not ideal. Clearly, the best way to go is to bake your own bread, bake what you need for a day and share the rest. The reality of modern living though is that we can’t all bake as we go and need to purchase our daily bread in some form. It is early days but the signs are that essential oils might live up to their name yet again and be a natural answer to the problem of mould growth on bread.

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Terry Robson

Terry Robson is the editor-in-chief of WellBeing.