Today's consumer expects sliced breads to keep their fresh texture for extended periods, a formulating need that today's enzymes answer.

Enzymes are the powerhouses behind the commercial production of many baked goods, oftentimes incognito. With current scientific advances, suppliers are able to offer highly specific functional enzymes that can replace non-label-friendly ingredients, yielding clean-label products with a reduced-carbon footprint.

“The use of enzymes in the production of baked goods greatly contributes to sustainability and a reduced footprint by reducing waste and off-spec products,” said Jan van Eijk, research director, baking ingredients, Lallemand Baking Solutions, Montreal, QC. “The most significant reduction in waste is accomplished by using shelf-life-­extending enzymes, such as maltogenic amylase, which keep bread fresh for a longer period of time, resulting in less stale bread being thrown away, more efficient distribution of bread, fewer line changeovers and more.”

Functional properties enable such savings. “Enzymes help ensure that less bread is discarded as waste,” said Soren Lund, regional marketing manager, Novozymes North America, Inc., Franklinton, NC. In doughs, they enable the starch structure to retain moisture better. “This means that the bread remains soft for a longer period of time,” he said. “This also means that industrial bakers do not have to distribute bread to the supermarket so often, so they can reduce their transportation costs.”

Compared with other performance products like emulsifiers, the usage level of enzymes is much lower for comparable results, according to Lutz Popper, PhD, head of R&D, SternEnzym GmbH & Co. KG, Ahrensburg, Germany. “This presents potential savings in logistics, transport, warehouse and production costs and, thus, in carbon footprint,” he said.

It’s clear this class of bakery additives brings a multitude of benefits to the bench. “Enzymes can be used by bakers for many functions, including helping with crust color, controlling fermentation, improving volume, making a softer crumb and slowing down the staling process,” observed Denis Wellington, president, BreadPartners Inc., Cinnaminson, NJ. “Before the introduction of modern enzyme technology, each of these functions would have required a separate ingredient, and each would have had to be included on the ingredient label.”

Lock-and-key system

To maximize the potential of commercial enzymes, bakers need to understand how they function and the types available for commercial use. Basically, enzymes bring reactants together so that the baker doesn’t have to rely on the natural pace of molecules’ chance meetings.

All enzymes are proteins. “They are made up of small amino acids strung together in a linear polymer,” said Defne Saral, global marketing manager, food enzymes, DuPont Nutrition & Health, Leiden, The Netherlands.

Enzymes are catalysts, not ingredients, and they are used at parts-per-million levels, according to Michael Beavan, director, technical services, bakery ingredients division, Watson Inc., West Haven, CT. “Enzymes align specific parts of the basic ingredients already present in the dough, principally flour,” he explained. “This allows them to react much faster than they would without the enzyme. The action changes the properties of those basic ingredients so that, for example, the gluten can hold more or less gas or the starch can hold more or less water.” This action can lead to better-handling dough, larger loaf volume or softer crumb structure.

For this to occur, a specific enzyme must complex with a specific substrate in a way often likened to a lock and key. After the desired reaction occurs, the enzyme is released, unchanged, along with the altered substrate. The enzyme continues to function in this manner again and again until deactivated, or denatured. Enzymes shut down when exposed to heat, as in the oven, or by a forced chemical alteration, such as a change in pH.

Sourcing reaction catalysts

Commercial enzymes can be separated into three core categories, according to Barry Clayton, senior vice-­president, AB Mauri North America, St. Louis. “There are the classical enzymes found in nature and suitable for use in ‘made with organic’ products,” he said. “Then there are nature-identical enzymes, where modern genetic manufacturing technology is used to deliver yield efficiencies and quality optimization. Lastly, there are engineered enzymes, which include full genetic modification technology.”

Enzymes are found everywhere. “Our scientists go out into nature and collect soil samples, sometimes from very exotic locations around the world, to find microorganisms with the capability of producing the desired enzymes,” Mr. Lund said. “Most people don’t know this, but one gram of soil contains more than 4,000 different microorganisms, each of which can produce hundreds or thousands of different enzymes.”

That’s a far cry from early enzyme choices. Describing malted grains and tropical fruit extracts as the original bakery enzyme providers, Mr. Beavan observed, “One problem with these sources is that they produce many enzymes, not all of which are desirable. The majority of enzymes used in bakeries today are produced by microbial fermentation, which can be controlled to produce highly specific individual enzymes.”

The microbial fermentation process resembles beer brewing; however, the products are not carbon dioxide, ethanol and flavor but distinct proteins instead, according to Dr. Popper. During enzyme manufacture, the spent microorganisms are removed by centrifugation and microfiltration along with any leftover nutrients required for their fermentation. These organisms produce a variety of enzymes to sustain their growth, enzymes now present in the clarified fermentation broth. “However, the target enzyme usually prevails and will be separated from the other proteins by ultrafiltration, absorption or precipitation,” he added.

With some industrially produced enzymes, a small number of amino acids are changed to improve enzyme performance, for example, at different temperatures, according to Ms. Saral. “Or the enzymes can be engineered to have enhanced pH stability or increased specificity of the catalyzed reaction,” she said.

During their manufacture, enzymes are standardized for activity by diluting them with a low-moisture carrier to give optimal stability. “For the baking industry, this is usually wheat flour or calcium sulfate,” Mr. van Eijk said. “Pure enzymes are too concentrated to be dosed in a bakery, so they are usually used in an enzyme-based dough conditioner that can more easily be dosed. The ­conditioner will contain one or more enzyme preparations and, sometimes, other ingredients intended for a certain application.”

Clean-label, fresh-keeping

“Modern-day enzymes have reduced or eliminated the need for many chemical emulsifiers or other additives that bakers have used for more than 50 years,” Mr. Wellington said. “Enzymes have become the industry’s go-to in efforts to clean up ingredient legends.”

The most important enzymes used for clean-label ­purposes are phospholipases that replace emulsifiers such as diacetyl tartaric acid esters of mono- and diglycerides (DATEM) or sodium stearoyl lactylate (SSL) and glucose oxidases to replace chemical-oxidizing agents such as azodicarbonamide (ADA), according to Mr. van Eijk.

Enzyme selection depends on many factors. “Specific criteria vary by application, with factors to consider ­including pH, viscosity, dough handling, stickiness, dough strengthening and more,” Mr. Clayton explained. “And of course, don’t forget cost-in-use value.”

Most enzymes are used in bread, either for flour standardization or as part of an improver. “They improve the machinability, the dough stability, the volume yield, the shape, the crust, the crumb structure and softness, and the shelf life of the crumb softness,” Dr. Popper said.

Shelf life extension — also termed fresh-keeping — has prompted many bakers to give enzymes a closer look. “The products that tend to benefit the most are those that require fresh-keeping and in particular those that also have a specific volume requirement,” Ms. Saral said. “Most traditional pan breads are expected to be soft and light in texture and are now also expected to have shelf lives of up to three weeks.

“Specific amylases, such as maltotetrahydrolases, are mainly responsible for the anti-staling effects although phospholipase enzymes and bacterial xylanases can provide some additional softness,” she continued. Amylases modify the amylopectin portion of wheat starch to greatly reduce its recrystallization, or retrogradation, over time, thus keeping baked goods softer for a longer time.

For improving volume, Ms. Saral pointed to hexose oxidase, glucose oxidase, xylanase and phospholipase, often in combination. Several mechanisms are involved. “Phospholipases modify naturally occurring lipids in the wheat flour, producing emulsifiers that strengthen the protein structure,” she said. “Xylanases specifically modify the arabinoxylan polysaccharides naturally present in flour.” This releases water that can be absorbed by gluten to produce stronger networks and greater volume.

“Hexose oxidase and glucose oxidase oxidize small amounts of sugars in the product, resulting in production of very small amounts of hydrogen peroxide,” Ms. Saral added. This helps cross-link gluten proteins, which also generates stronger networks and increased volume.

Exacting measures

Enzymes are selected according to the flour requirements and the application. With amylase, the falling number (FN) of the flour is an important parameter, according to Dr. Popper. “It is a measure for the intrinsic enzyme activity of the flour, with 300 to 400 seconds being normal,” he explained. “An FN below 300 suggests high intrinsic enzyme activity, whereas above 400, it’s low.”

Performance must hold up to expectations in selection. “We run extensive tests on all available enzymes to choose the most suitable for what we are trying to achieve.” Mr. Wellington reported. “The actual amount of enzyme used is critical in achieving the desired effect.

“Doubling the recommended amount will not deliver twice the performance,” he advised. “It’s the contrary. The dough will most likely become unworkable.”

Dough is a complicated system. When including enzymes, it is important to determine the desired reaction and where in the process it should take place. “For example, dough conditioners are designed to build strength as the dough progresses from the mixer to the oven,” Mr. Beavan said. This will increase dough strength to help the dough hold its shape and prevent collapse when it comes out of the oven.

“Crumb softener blends, although added into the mixer with other dough ingredients, exert the majority of their action when the starch begins to gelatinize during the first stages of baking,” he explained.

For bread-baking purposes, amylase should be added to flour with an FN above 400 to obtain a reasonable volume yield and acceptable crumb softness, Dr. Popper noted. “If you used that same flour in a wafer application, the addition of amylase should be avoided because it may cause excessive adhesion of the wafer sheets to the irons,” he said.

“For wafers, proteases are more useful because they avoid the formation of gluten lumps in the liquid batter,” Dr. Popper continued. “In bread applications, proteases would likely have a disastrous effect on dough stability. Only if the gluten is very strong, a small amount of a mild protease may improve baking.”

For hard biscuits and crackers, the use of proteases is quite common. “Proteases relax the protein, thus reducing the tension of the dough,” Dr. Popper said. “This improves the processing of the rather hard dough and prevents deformation of products, such as hairline cracks or blisters. In this function, they replace chemicals such as sodium metabisulfite.”

It’s a different story for cake. Enzyme activity can be inhibited if too much sugar and fat are present or under conditions of low water activity, according to Dr. Popper. Yet cake applications are where phospholipase shines for improving crumb, and osmo-tolerant amylase prolongs shelf life by keeping the crumb soft.

On the whole, enzymes are relatively easy to work with, observed Bradley Cain, vice-president, Cain Food Industries Inc., Dallas. “They are very stable and do not react with other ingredients before being hydrated,” he said. “We encourage bakers to store enzymes in a cool, dry place to ensure shelf life and activity.”

In times to come

What does the future hold? “Enzymes in the baking industry are still in their infancy, though we expect significant growth in time,” Mr. Clayton said. There’s a great deal of opportunity, with all parties involved, from the baker to the consumer benefiting.”

Biochemical technology has benefited enzyme performance greatly. “Modern techniques for producing enzymes have resulted in enzymes that are purer without undesirable side activities,” Mr. van Eijk noted. In many cases, these materials are more economical to use because of the improvements in enzyme production accomplished through modern biotechnology. The improved isolation and purification techniques, he noted, make modern enzymes “more specific with desirable action patterns, resulting in better tolerance toward overdosing.”

These methods include genetic manipulation, and Mr. Clayton added, “If modern technology gains full consumer acceptance, it is fair to say the sky is the limit. But if a vocal minority is allowed to dictate the conversation, there could be a tough road ahead.

“We believe in the consumers’ right to know,” he continued, “and as an industry, we will need to invest in education in order to move forward with new technologies. In the end, there is room for all levels of technology if they are managed, communicated and implemented with clarity and transparency.”

The potential is high, and as Mr. Lund noted, “When you consider that one single enzyme molecule contains more DNA sequence combinations than there are atoms in the universe, the possibilities truly are endless.”