Enzymes benefit flour millers and bakers

by Emily Wilson
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All wheat is not created equal. For instance, climate affects wheat quality, so wheat varieties vary from country to country.

The continental climate of the United States favors quality, while France's mild sea climate favors quantity.

"The climatological conditions are an extra trigger of wheat quality, in addition to different varieties," said Taygun Basaran, U.S. product manager for the Brussels-based Beldem Corp., at a recent meeting of the Central District of the Association of Operative Millers in Lake Ozark, Missouri, U.S.

Beldem, which has been working with the milling and baking industries for more than 25 years, produces enzymes designed specifically to meet bread-baking requirements.

With all the varieties of wheat grown around the world in such differing climates, the phenotypes and genotypes of wheat fluctuate from one year to another, affecting the baking quality of flour.

Enzymes, Basaran said, can help millers standardize the baking quality of flour from season to season, year to year, creating a better flour for their customers.

Basaran, who is based in Beldem's Pennsauken, New Jersey, U.S. office, said companies that manufacture and sell enzymes and other flour improvers typically analyze flour for their customers to bring it to an acceptable baking level. From this point, bakers can adjust their formulation with dough conditioners to suit their applications.

"Flour yield is inversely proportional to quality of flour, where the amount of wheat gluten is the limiting factor," Basaran explained. "Yield increases at the expense of wheat gluten, resulting in a decrease in baking quality. The trend of growers producing more and more wheat per acre is common around the world. This is why it is essential to compensate the loss in quality with other ingredients. Millers around the world, particularly in Europe, use a great amount of enzymes every year to maintain a certain baking quality level."

As all millers know, the best or most appropriate wheat is not always available at the acceptable price. Given that fact, millers optimize their process by adding traditional oxidizing agents and a-amylase to reach a certain baking quality.

"However, this does not standardize the quality of flour," Basaran said. "We suggest different enzymes to correct the flour, rather than the traditional oxidizing agents."

Enzymes offer many benefits that may not be reflected on flour or dough tests, Basaran said. For example, 10% protein content flour treated by enzymes could perform similar to 12% protein content in untreated flour, he said. In addition, enzymes need time to work and dough tests may not reveal their full benefits.

"Enzymes become active upon addition of water onto flour and find the necessary amount of reaction time during dough formation and baking," Basaran explained. "The duration of a farino-graph measurement is sometimes too short for enzymes to show their full functional potential."

Enzymes strongly act on dough functionality and bread by increasing bread volume, improving softness and/or enhancing shelf-life and dough tolerance.

"Enzyme preparations are powerful tools to make a better flour, but they need a careful approach and a good knowledge of baking," Basaran said. "They are used for flour correction and for improving bread. They are key ingredients added on top of the other classical oxidizers, such as ADA (azodicorbonamide) and ascorbic acid."

Some enzymes compensate for poor protein quality and/or low protein levels, Basaran said. These issues concern millers worldwide, he added. "It is possible to reduce addition of gluten at the bakery, yet achieve an equal or better baking quality at a lower cost," he explained. "Enzymes can provide strength to the dough, therefore they don't need to have that sort of cost associated with gluten. Enzymes are by far more cost effective than gluten."

Certain enzymes also can be used to reach higher bread volumes.

"Enzymes offer ways to differentiate one flour from its competition, therefore, providing the miller with a value-added product," Basaran said, noting the trend now in the United States is to create value-added products with the new enzyme technology. Enzymes are already widely used for that purpose in other regions of the world, including Europe, Middle East and Africa.

"The trend of wheat manufacturers is going towards producing higher quantities, thus lowering quality, which in turn means lowering protein content," he said. "Millers need to understand that enzymes can offer solutions to maintain constant quality for their customers."

ENZYME FUNCTION. Enzymes are proteins that are essential to all living organisms. Every living organism contains enzymes, Basaran said. "They act as biological catalysts to increase the rate of biotransformation in dough," he said.

Enzymes work very specifically; only one type of substance is recognized by one type of enzyme. Most enzymes break complex molecules down into their specific building blocks.

The amylase enzyme breaks down starch to glucose. Xylanase breaks down xylan to xylose, and protease breaks down proteins to amino acids.

Enzymes can be produced from three different sources: plants, animals and microorganisms. Microorganism sources are preferred, Basaran said, since they allow for stabilized production, standardized products and assure faster, more controlled production of enzymes than animals or plants.

A microorganism strain is placed into a test tube to start production. With the necessary nutrients and growing conditions, the microorganisms are transferred from a test tube to a larger container and finally to "fermenters" increasing in size.

After fermentation, the solution from the fermenter is filtered and enzymes are separated from the microorganisms. This liquid enzyme is then dried and placed into bags.

The first generation of enzymes was used in the 1950s, as a-amylase. The second generation created in the 1970s led to protease and xylanase. More recently, bacterial amylase, glucose oxidase and lipase have been developed. New enzymes or combinations of enzymes are continually being discovered, Basaran said.

The function of a-amylase, he explained, is to correct endogenous concentration, provide fermentable sugars for the yeast to increase the volume of the bread, to improve crumb structure, to decrease staling of bread, and to increase crust color.

Amylase is the name given to the enzyme that cuts the bonds in starch. Many different types of amylase enzymes exist, such as a-amylase, glucoamylase, pullullanase and b-amylase. Each type breaks down starch to its sugar components, but each attack at different points (or sites) on the starch molecule, he explained.

The xylanase enzyme is used to stabilize quality variation, to increase volume by improving water-binding and strengthening the gluten network, and to improve dough tolerance and machinability.

"Millers often use the enzyme glucose oxidase because the oxidation reaction will mainly strengthen the gluten matrix by oxidizing the sulphydryl groups that are positioned at the edges of the glutenin molecules," Basaran said. "This will have a positive effect on water absorption and will reinforce the dough."

The protease enzyme works to hydrolyze the gluten network and to soften dough for typical applications such as crackers and biscuits.

Basaran said enzyme companies can help millers analyze flour and offer enzyme solutions to specific problems. The key is to identify the goal, he said, whether it is providing extensibility or strength, increasing bread volume, gluten replacement, or producing cost effective flour blends.

Strong flours can sometimes have too short of a structure, Basaran said. Extra extensibility can be induced with enzymes, and an alveograph screening will help predict dough tolerance and the amount or type of enzymes needed.

"Define which enzyme activities will be relevant to the desired improvement or functional properties," he said. "Then optimize enzyme combinations in order to exploit cumulative and synergetic effects."