Getting a grip on starch is the first step towards a 20-day ambient shelf life.
Extending shelf life after the first baking is a primary hurdle in the lifecycle of par-baked bread stored at ambient temperature. With current market standards ranging from 10 to 15 days, new ways to keep the crumb feeling soft and fresh for longer are always of interest.
There are many good reasons for that. A longer shelf life creates opportunities to expand into remote distribution channels, stretch in-store display time and reduce waste – not to mention give consumers a sense of improved fresh-keeping quality.
Achieving a longer shelf life means starting at the heart of the staling process: the 70% starch content of wheat flour. From the moment par-baked bread emerges from the first baking, starch recrystallisation starts to influence crumb firmness. And staling has begun.
Slowing down staling
So how do you slow the process? At DuPont, we have been exploring that very challenge. Our goal: to extend the ambient shelf life of par-baked bread right up to 20 days after the first baking.
Our initial tests looked at the effect of an enzyme blend incorporating G+ enzyme and maltogenic amylase.
Through its production of the sugar maltotriose, G+ is able to influence recrystallisation of the amylopectin starch fraction during baking. In this way, softness is guaranteed. The maltogenic amylase balances the softness by providing the necessary resilience and reduced crumbliness.
Having established the positive impact of the enzyme blend, we turned our attention to amylose – another starch fraction with a role in bread staling. Here, distilled mono-diglycerides are a good strategic choice.
With their linear structure, these emulsifiers have the ability to form an insoluble complex with the helix-shaped amylose molecules. As a result, amylose is unable to recrystallise and contribute to staling.
In reach of the goal
By bringing the enzyme blend and emulsifier together in a par-baked bread test formulation, we produced our most promising results so far. The graph below shows that the 20-day goal for fresh-keeping shelf life is in reach – with improved softness, high resilience and moist mouthfeel all the way to the second baking.