Introduction of Cereal Enzymes
Cereal enzymes are specific biocatalysts for different kinds of cereal grains, i.e. wheat, corn, barley, oat, and rice. Cereal enzymes catalyze several biochemical transformations which in turn improve the quality and nutritional value of cereal products. There are several cereal enzymes such as amylase, protease, xylanase, cellulase, and lipase. These breakdown starch, proteins, fiber, and fats. Cereal enzymes are important in processing bread, biscuits, breakfast cereals, pasta, and baked products.
All the aforementioned products require the enzyme activity in order to improve the properties of the dough, the texture of the baked product, the volume of the product, and the shelf life. Cereal enzymes are very important in the modern food industry because of consumer demands for clean-label and high quality food products.
Cereal enzymes are becoming very popular because of food technologies and the modern ways of processing food. These enzymes make food production more consistent and also less time consuming and more economical because of less wasted ingredients. The goal of modern food production is to make more sustainable food and lessen the use of chemical additives. For this reason, cereal enzymes are becoming popular for more economical food production to industrial bakeries and cereal producers because of improved processing of grains and nutrients.
Cereal enzymes can be used to improve the nutritional content and digestibility of products made from cereals. These enzymes act on the macromolecules of cereals, making the nutrients more accessible and even more pleasant to eat. Currently, new uses of these enzymes are being discovered in many areas including baking, brewing, feeding animals, and making functional foods. Current advances in enzyme technology will allow cereal enzymes to improve and innovate even more, especially in the areas of developing safer, better, more nutritious, and higher quality cereals.
Types of Cereal Enzymes
Cereal enzymes improve the quality, digestibility, and even the shelf life of many cereal-based products. These enzymes are crucial to the baking, brewing, and even the animal feed industry. Cereal grains contain many macromolecules and components. Enzymes act selectively on these components. Because no enzyme performs all the functions, a mixture of many enzymes is required. Some of the commonly used enzymes are proteases, amylases, lipases, xylanases, cellulases, and phytases. Using the right type of enzyme helps cereal-based product manufacturers improve product quality and help save on production costs.
Amylase
Of all the cereal enzymes used in cereal processing, probably the most important is amylase. Starch is the major carbohydrate in cereal grains. Amylase breaks this down into smaller sugar units. Some of the smaller units formed are maltose and dextrin’s.
During fermentation, these sugars are utilized by yeast. The yeast in turn produces carbon dioxide, which helps the dough rise.
There are three main types of amylases used in processing cereals:
Alpha-amylase improves dough handling by reducing starch viscosity in a matter of minutes due to its ability to break bonds in starch at random locations.
Beta-amylase converts internal starch regions to maltose, a disaccharide, creating a source of fermentable sugar for yeast.
Glucoamylase is capable of producing glucose from starch almost entirely and finds a use in brewing and the production of starch hydrolysis syrups.
In cereals, amylase ensures a significant increase in dough fermentation and bread volume, a softer bread crumb, improved crust color, decreased staling, improved slicing quality, and prolonged product freshness. Amylase is used in almost all cereal-based products and malted beverages and is the primary enzyme of cereal processing technology because starch is the most abundant component of all cereal grains.
Protease
Protease hydrolyzes some peptide bonds in proteins. In gluten, it reduces the strength of dough and the difficulty in processing it.
In applications for baking, protease enzymes help form dough that is less time intensive in the mixing process, and is softer and more convenient to roll and shape. This is ideal for products such as biscuits, crackers, cookies, wafers, pizza bases, and flatbreads that require less gluten.
Protease enzymes promote uniformity of the end product and help relieve mechanical pressure on the dough during processing. In contrast to the manufacturing of bread, which requires a strong gluten structure, biscuit production benefits from a moderate weakening of gluten. Thus, the dosage of protease enzyme is crucial, as too much protease can render the dough too weak and greatly affect the end product quality.
Xylanase
Xylanase is one of the key cereal enzymes targeted toward arabinoxylans (AXs). These are complex hemicellulose polysaccharide building blocks in cereal cell walls. Due to their capacity to hold water, arabinoxylans can obstruct the process of gluten formation.
Xylanase acts on these bundles of hemicellulose and improves overall water management in the system, enhancing the stability of the dough, its elasticity, and its gas retention capacity. This also leads to improved loaf volume and softness of the crumb, finer crumb structure, and reduced stickiness of the dough, thus improving its machinability.
Xylanase is the enzyme of choice to be added to wheat and rye, and to whole and high fiber breakfast and baking products. Due to its beneficial effects on dough, and along with its compatibility with clean-label needs, it has replaced a number of synthetic dough conditioners.
Cellulase
Cellulase breaks down cellulose, the major structural polysaccharide of cereal bran and plant cell walls. Cellulose is also known as an anti-nutritional factor due to its indigestibility in humans. However, the ability of cellulase to alter plant fibers during processing makes cereal ingredients much easier to handle.
The use of cellulase during cereal processing leads to improved water absorption and a smoother dough with a finer crumb texture and a greater loaf volume. In whole grain products, the action of cellulase on the coarser fibers of the dough leads to a more pleasant mouthfeel and greater acceptance of the products.
Cellulase is also used to enhance fiber degradation and thus improve the nutritional value of brewing, juice clarification, and animal feeding.
Lipase
Lipase interacts with the lipid fraction of cereal flour and breaks down fats into their constituent parts of fatty acids and glycerol. During dough formation, fatty acids and glycerol interact with starch and proteins.
Lipase helps to enhance the stability of dough by fortifying gluten and helping to stabilize the air pockets formed during the mixing process. This leads to better retention of gas during baking, larger loaves, and a softer and more uniform crumb texture.
Lipase’s ability to replace the synthetic emulsifiers found in many baked goods is perhaps its greatest benefit. With a growing consumer preference for products with fewer synthetic ingredients, lipase is an ideal clean label substitution. It also helps to improve the product and prolong the period before staling occurs.
Lipase is found in a wide array of baked goods including bread, and also in cakes, buns, rolls, and other premium baked goods.
Glucose oxidase performs the oxidation of glucose to gluconic acid and, in the process, produces hydrogen peroxide. With the production of hydrogen peroxide, stronger disulfide bonds are formed.
The strengthening of bonds leads to an increase in the elasticity and stability of the dough. The improved retention of gas in the dough leads to a greater volume of bread and an improvement in the structure of the bread.
With the restriction and banning of the use of potassium bromate in many countries, the use of glucose oxidase as a substitute for the chemical oxidizing agents has increased. Its natural and effective use also lends itself well to clean label formulations for baked goods.
Glucose Oxidase
The enzymatic activity of glucose oxidase generates hydrogen peroxide and converts glucose to gluconic acid. Hydrogen peroxide aids in the formation of stronger disulfide bonds between gluten proteins.
The effect of this oxidation leads to an increase in the elasticity and stability of the dough during mixing and fermentation. The dough is then easier to handle, has an improved ability to hold gas, and yields bread with a higher volume and a finer crumb texture.
Glucose oxidase is preferred to chemical oxidizing agents, such as potassium bromate, which are used in baking and are banned or severely restricted in many countries. Glucose oxidase’s natural effectiveness allows for its use in clean-label formulations of baked goods.
Phytase
Phytase is an enzyme that hydrolyzes phytic acid, which is found in all cereals. Phytate complexes with and causes a reduction in the absorption of several minerals important to human health, such as calcium, iron, and zinc.
The action of phytase on phytic acid leads to an increase in the bioavailability of these minerals. This provides an improvement in the nutritional value of cereal-based products and enhances the post-ingestive absorption of these minerals.
Phytase is most useful in whole grain breads, breakfast cereals, and infant foods; it is also beneficial in animal feeds. In animal nutrition, phytase effectively replaces the use of inorganic phosphorus supplements and decreases the nitrogen load to the environment.
Hemicellulase
Hemicellulase refers to a group of enzymes that hydrolyze hemicellulose. Hemicellulose is another major component of the cell wall of cereals. In contrast to cellulose which is acted on by cellulase, hemicellulase hydrolyzes hemicellulose into smaller sugar units.
The enzyme helps improve flour hydration and dough flexibility. It helps retain gas and increases the volume of the loaf. It also helps the crumb be soft and improves the quality of baking. For baked products made with whole grains and high fiber, hemicellulase helps make the product softer and increases customer satisfaction.
Hemicellulase and xylanase are used together a lot because both act on cereal cell wall polysaccharides and have complementary enzyme activities.
Pentosanase
Pentosanase hydrolyzes pentosans, which are found throughout wheat and rye flour. Since pentosans are water-binding polysaccharides, excessive pentosans can interfere with gluten formation.
Pentosanase frees water within the pentosan, creating an opportunity for gluten to fully hydrate and reinforcing dough.
Pentosanase is especially useful for dough management, fermentation, and for increasing the volume of the loaf. It also improves crumb softness and consistency of the end product.
Pentosanase is especially useful for high fiber and whole wheat products and for rye bread because these all contain elevated amounts of pentosans.
Cereal Enzymes Treatment
Contemporary cereal processing relies on a variety of systems, each with a specific purpose. For example, one system may be designed to improve fermentation, while another may be used to complement xylanase and assist in the system’s dough management function. A third system may rely on the role of lipase to enhance the structure of the crumb, while phytase may be used in the same system to elevate the nutrient content of the end product.
Bakeries process a variety of products with distinct end goals. Each of these products requires a distinct combination of enzymes depending on the specific processing methods and moisture content.
Cereal enzymes perform specialized tasks during the processing of cereals which ultimately enhances the quality of the final cereal products. Important cereal enzymes include: Amylase, which breaks down starch into sugar; Protease, which alters the viscosity of gluten; Lipase, which strengthens the dough and emulsifiers and modifies the lipid proteins; and Glucose oxidase, which fortifies the gluten network.
The cereal enzymes mentioned above help food manufacturers process a variety of food products, including bakery and breakfast foods, cereals, pasta, brew, and animal feed in a more efficient manner. More importantly, the finished food products have superior quality and improved nutrition. As biotechnology develops, other cereal enzymes will perform more tasks in the food processing industry. These changes will help the food processing industry be more sustainable, while also meeting the consumers’ demands for high quality, clean-label foods.
Enzyme Treatment on Wheat Flour
Wheat flour enzyme treatment is a revolutionary development in the baking and flour milling industries. The method covers the addition of specific cereal enzymes to flour to enhance the profiles of the dough and the flour as well as to improve the efficiency of the processing and baking. The technique is also employed to improve the nutritional profile of the flour and the quality of the end products.
Cereal Enzymes are proteins that naturally occur in the body and that catalyze specific reactions. These enzymes do not appear in the final product of the reaction. Cereal Enzymes are much better than the artificial additives that alter the flour because they act on specific constituents and become denatured by heat in the baking process.
Wheat flour is made up of proteins, lipids, dietary fiber, a good amount of starch, and minerals, as well as some naturally present enzymes. The major component in flour is of course gluten, and that is what the cereal enzymes are meant to augment. Because of the consistent baking performance that is achieved by using enzymes, enzyme treated flour is widely used in the production of a whole host of baked goods.
Purpose of Enzyme Treatment
The major aim of using cereal enzymes to treat wheat flour is to enhance the functional characteristics of the flour. The ultimate effect of the treatment is a wide improvement on the quality of the bakery products. The products will have improved sensory characteristics such as flavor and crumb, and, in addition to the improved quality, the products will also have a longer shelf life. Cereal Enzymes treatment means savings for the manufacturers in time and costs. This is also because less flour is wasted and some of the chemical additives may be replaced.
Another key element is the backing of clean-label food manufacture. Cereal enzymes usage is in line with consumer trends and preferences. Modern consumers would rather have a food product with natural ingredients. Cereal enzymes would be the preferred choice out of all the other alternatives. During processing, enzymes do their work and become inactive post-baking. One of the examples of food manufacture using enzymes is baking.
It is well documented that enzymes interact with various components of wheat flour.
Starch
Starch is the predominant carbohydrate in wheat flour and serves as the primary energy source for the yeast during the flour fermentation process. Starch is converted by amylase enzymes to maltose and glucose, which in turn is utilized by yeast to produce the gas, carbon dioxide. Starch fermentation leaves the dough in a soft and porous structure.
Gluten Proteins
Superimposed on the structure of gluten are gliadin and glutenin proteins. These proteins provide dough with the required elasticity and strength. The action of protease and glucose oxidase on gluten differs. While protease acts on gluten to relax it, glucose oxidase works on it to strengthen.
Dietary Fiber
Wheat flour is home to arabinoxylans, cellulose, and hemicellulose. These fibers undergo partial hydrolysis through the action of xylanase and cellulase to enhance both the absorption of water and the handling of the dough.
Lipids
The action of lipase on the natural lipids of flour enhances the structure of the dough and yields a softer crumb.
Phytic Acid
The action of phytase on phytic acid releases the bound reserves of the essential nutrients.
Enzymes Used in Wheat Flour Treatment
Amylase
Amylase is the eminent cereal enzyme used in wheat flour treatment. It cleaves starch to fermentable sugars which serve as yeast nutrients. An increase in the sugars enhances the process of fermentation and increases the volume of the loaf
It contributes to the browning of crusts because, during the baking process, sugars involved in the Maillard reaction bind to the amino acids of the partially denatured proteins. It therefore helps in creating softer bread, with a better texture, and inhibits the firming of the bread crumb during storage, thereby improving the bread’s shelf life.
Protease
Protease breaks gluten proteins down into smaller peptides.
This decreases the strength of the dough while increasing its extensibility, thus making the dough easier to shape.
Protease is of great advantage during the production of biscuits, crackers, and wafers, where the desired dough is soft. However, excessive protease would diminish the integrity of the gluten and therefore, negatively affect the product.
Xylanase
Xylanase acts on arabinoxylans in bran and the cell walls of flour.
These are water-binding, dough strengthening fibers.
Xylanase acts to improve the softness and quality of the crumb of bread. It also enhances absorption capacity of the dough, and improves the stability and retention of the dough, and the volume of bread. It also reduces the stickiness of dough.
Lipase
Lipase works on the lipids of flour and enhances the interaction of proteins and starch.
With Lipase:
- Dough stability is increased
- Gas retention is improved
- The crumb is softer
- Loaf volume is increased
- Freshness is improved
- Synthetic emulsifier is replaced
Lipase is commonly used in making high-quality bread, where its effect is to improve texture.
Glucose Oxidase
The action of Glucose Oxidase is the oxidation of glucose to gluconic acid, with the concurrent formation of hydrogen peroxide.
The production of hydrogen peroxide favors the strengthening of gluten by formation of disulfide bonds. This serves to increase the elasticity of the dough, and improve its gas retention and the volume of the bread produced.
Cellulase
Advantages are:
- Better flour hydration
- Improved consistency in dough
- Greater loaf volume
- Softer whole grain products
- Better fiber utilization
Cellulase is especially beneficial in high-fiber and whole wheat baked products.
Phytase
Phytase breaks down phytic acid found naturally in wheat flour.
Phytic acid has an affinity for minerals and creates a barrier for their absorption in the human gut.
Phytase renders:
- Iron
- Zinc
- Calcium
- Nutritional value
- Better digestibility of
- Products
This enzyme is essential in whole grain products since phytic acid is concentrated in bran.
Technological Benefits of Cereal Enzymes Treatment
There are many technological benefits of enzyme treatment.
Dough is easier to mix, divide, and mold, and the process of dough manufacture is easier. Best of all, there is improved gluten development which increases the loaf volume.
Cereal enzymes are also beneficial for crust color, texture, and flavor. The bread is sliced easier, and is fresher. Enzyme treatment also slows starch retrogradation which increases the softness of bread.
From an industrial perspective, treatments with enzymes improve production efficiency by reducing mixing times, improving product consistency, reducing waste, and lowering manufacturing costs.
There are new highly stable and efficient designer cereal enzymes for use in wheat flour production. The future may also allow the use of multifunctional cereal enzymes blends that improve dough strength, nutritional quality, shelf life, and baking quality all at the same time.
The future also may allow the use of precision fermentation and enzyme engineering controlled by artificial intelligence to tailor the enzymes to our needs. We may also be able to increase the functionality of enzyme-treated wheat flour to produce more sustainable, less costly, and clean-label bake products.