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It pays to understand what goes into your dough; and as a growing number of bakers are discovering, this holds true when considering the use of deactivated yeast over L-cysteine.

To review, both L-cysteine and deactivated yeast are ingredients that can be added to dough to enhance its extensibility and reduce mixing time. Both are classified as reducing agents, as they work to break down disulfide bonds within the gluten-starch matrix during dough development, and in so doing, bring more relaxation to the dough's composition. Among the most common uses for L-cysteine and deactivated yeast are in goods consisting of high-protein flours and in those requiring high throughput and reduced final temperatures for during the processing of the dough.

The differences between both ingredients are, however, important. Deactivated yeast can be easily and directly sourced from the yeast; and where L-cysteine is an amino acid, deactivated yeast's functional ingredient is glutathione (GSH). As well, deactivated yeast is heat treated and dried, rendering it unable to produce CO2  gas which leads to fermentation. This makes it solely a reducing agent, and as such, its use can contribute to improved dough handling.

Science lessons aside, what does this mean for bakers? In short, deactivated yeast can contribute more to the baking process over L-cysteine and – more importantly for baking companies – it can provide a more consumer-friendly addition to market product labels.

“Deactivated yeast is largely considered to be more label friendly than L-cysteine because it can be labeled as either 'inactive yeast' or 'yeast', which can be more appealing to consumers, and also means the baker doesn’t have to add another ingredient to the label.” explains Sherrill Cropper, Bakery Formulation Specialist with Lesaffre Yeast Corporation, adding, “Deactivated yeast can also be directly added without influencing final product characteristics like colors and off-flavors. And, because it functions in the same way as L-cysteine to break down disulfide, deactivated yeast is a great replacement.”

As those in the industry are aware, deactivated yeast can run at a higher price than L-cysteine, and is required at higher usage levels. However, Cropper says baking companies are nonetheless responding to the marketability of deactivated yeast, noting its usage is better understood as an equivalency to L-cysteine: “For example, if using the most powerful deactivated yeast on the market – Saf Pro Relax 200 – at 1%, it brings the same reducing performance as 200 ppm of L-cysteine. This means that if a baker is using 20 ppm of L-cysteine , they can convert to using deactivated yeast at 0.1% on flour weight.”

These attributes have created high demand for deactivated yeast. For it's part, Lesaffre has been manufacturing deactivated yeast with guaranteed, specific relaxation properties for years. It is currently offering four deactivated yeasts with a variety of relaxation potencies, including one that is certified organic in North America.

Speaking to its cumulative benefits, Cropper adds, “Many of the larger industrial bakeries are trying to simplify their product’s ingredient list to make them more transparent and consumer acceptable, and deactivated yeast provides that ability while offering an ingredient that provides similar dough relaxation performance to L-cysteine .”

Sherrill Cropper is the Bakery Formulation Specialist with Lesaffre, a global producer and innovator in yeasts and fermentation. Learn more at www.lesaffre.com.\

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