Taking a new look at enzymes, part 4
May 22, 2014
by Laurie Gorton
Bakers use of enzymes has changed over the years as better, more purified versions of these useful ingredients have become available. But there’s still a lot to learn about how to put them to work as dough conditioners. In this exclusive Baking & Snack Q&A, Frank Devos, vice-president of R&D, Puratos, Cherry Hill, NJ, explains how xylanases work and introduces a new protease with specific functions in yeast-raised baked foods.
Baking & Snack: What are the most underutilized enzymes that have potential to improve baked products? What should formulators know about these to make best use of them?
Frank Devos: Enzymes are naturally present in wheat and consequently in wheat flour. However, their activity can fluctuate or vary from harvest to harvest due to growth conditions of the cereals as well the way the wheat and wheat flour are stored after harvest. Baking enzymes (as used in dough conditioners) standardize the activity of the already present enzymatic activity, which will standardize the baking process. With the use of a dough conditioner, the bread will have a more consistent result in terms of shape, volume and crumb structure fulfilling consumer expectations.
In the past, the traditional method of standardizing the breadmaking process was the usage of diastatic malt flour. The downside of this active malt flour is that the enzyme activity is not specific enough and cannot be sufficiently controlled: Active malt flour contains a variety of desired enzymatic activities but also undesired side effects such as loss of dough rheology and increased dough and crumb stickiness.
Over the years, we have seen that active malt flours have been replaced by fungal and/or bacterial amylases. These types of enzymatic preparations are purified, which results in the absence of undesired side effects. Apart from this commonly used enzymatic preparation, there is a growing use of other types of enzymes such as amylases for freshness as well as xylanases, phospholipases, oxidases and proteases.
Xylanases are used in breadmaking to strengthen the gluten development. This results in better process tolerance, a regular bread volume and a finer crumb structure.
Bacterial xylanases in particular are often underutilized. Contrary to older versions like fungal hemicellulases, modern xylanases have a single activity and better activity in converting water-unextractable xylans into water-extractable. This results in a strengthening effect of the gluten development. As a consequence, the bread dough becomes more tolerant to process stress. The final breads have a regular volume and a finer crumb structure. At Puratos, we purify and produce different xylanases enzymes. We also use a specific type of xylanase in our S500 improver. This is a patented enzyme that ensures dough tolerance even at lower temperatures.
For freshness improvement, amylases are enzymatic preparations that are used more and more in packaged breads. Their main activity is hydrolysis of starch during baking. As a result, breads are staling slower over their shelf life. Often combinations of different freshness-improving amylases are required to balance crumb softness, crumb moistness and crumb resilience.
Lipases act on nonpolar lipids present in flour, resulting in a finer, whither, softer crumb. Phospholipases act on polar lipids, which helps make doughs more shock-tolerant and results in more voluminous and regular breads.
Oxidases are mainly used to enhance dough processing. The use of oxidases helps to achieve firmer and less sticky dough. The uses of oxidases are of particular interest in doughs with high hydration, such as rye bread applications.
The uses of proteases are limited to countries such as US and Japan where bread flour qualities are very high in protein. These flours might result in too bucky doughs. Proteases help in increasing the dough extensibility.
How does enzyme use fit with the trend today that favors “natural” ingredient choices?
Enzymes are obviously natural components obtained from living microorganisms and are naturally present in all food and living organisms. Their functionality is as a catalysis that regulates biological reactions. Enzymes are proteins that are inactivated during baking. They are digestible like any other protein present in food.
What advice do you give a baker/customer wanting to switch out of chemical additive ingredients and into enzyme-based materials? How can they get started with such conversions?
Enzymes are not “magic ingredients” that can replace all additives.
Enzymes regulate the functionality of all components for a better efficiency, allowing a reduction of the addition of some food additives. Generally speaking, enzymes catalyze (speed-up and regulate) several reactions during food processing. Each specific enzyme has one major influence linked to their substrate specificity and conditions of use. This means that, once in a dough, enzymes continue to perform their action as long as there is substrate available and the conditions (water, temperature, pH and so forth) are right. These condition constraints are of less importance in the case of chemical additive ingredients.
It is also important to know that only small amounts of enzymes are added in bread processing because excessive amounts would not provide a workable dough.
When using more enzyme based dough conditioners or bread improvers, bakers need more discipline in respect to processing times and conditions then when using chemical additive ingredients. Bakers who used to work with bromate-based dough conditioners will need to build in more discipline with respect to processing times and dough handling when converting to nonbromated, enzyme-based alternatives.
Puratos invests a lot of time and research into developing dough conditioners and enzymatic systems to ensure it provides peace of mind for their customers. In addition, the company also provides support in how to use them and at which dosage.
How should enzymes be stored and handled within the bakery setting?
There is no specific safety issue linked to the use of enzymes, and no intake allergy has ever been demonstrated with the use of enzymes in food processing.
Under very concentrated amounts, enzymes may cause respiratory sensitization in a dusty environment. Enzyme producers stabilize their products with a nondusting carrier. When diluted in a dough conditioner, these risks are considerably reduced. Stabilized enzyme preparations should be stored under regular dry and cool conditions.
What is Puratos’ most recent introduction of enzymes or enzyme-based products for use in baked foods? What function do they serve in which products?
The most recent development at Puratos is the introduction of a bacterial protease. This thermophyle protease is not active on the dough at a low temperature. This protease hydrolyzes gluten during the early baking stage of breads and yeast-raised donuts. The effect is a reduction of crumb chewiness, enabling a shortened bite of any yeast-raised item. This enzyme is being used in Puratos Intens and Soft’r Improvers to enhance short bite of all types of yeast-raised bakery items.