Baking Enzymes

For decades, enzymes such as malt and fungal alpha-amylases have been used in bread-making. Rapid advances in biotechnology have made a number of exciting new enzymes available for the baking industry. The importance of enzymes is likely to increase as consumers demand more natural products free of chemical additives. For example, enzymes can be used to replace potassium bromate, a chemical additive that has been banned in a number of countries. The dough for white bread, rolls, buns and similar products consists of flour, water, yeast, salt and possibly other ingredients such as sugar and fat. Flour consists of gluten, starch, non-starch polysaccharides, lipids and trace amounts of minerals. As soon as the dough is made, the yeast starts to work on the fermentable sugars, transforming them into alcohol and carbon dioxide, which makes the dough rise. The main component of wheat flour is starch. Amylases can degrade starch and produce small dextrins for the yeast to act upon. There is also a special type of amylase that modifies starch during baking to give a significant anti-staling effect. Gluten is a combination of proteins that forms a large network during dough formation. This network holds the gas in during dough proofing and baking. The strength of this gluten network is therefore extremely important for the quality of all bread raised using yeast. Enzymes such as hemicellulases, xylanases, lipases, proteases (SEBake PP) and oxidases can directly or indirectly improve the strength of the gluten network and so improve the quality of the finished bread.

Amylase (SEBake X 50P) maximises the fermentation process to obtain an even crumb structure and a high loaf volume. Maltogenic amylase improves shelf life. Malt flour and malt extract can be used as enzyme supplements because malt is rich in alpha-amylases. Commercial malt preparations can differ widely in their enzyme activity, whereas an industrial enzyme is supplied with a standardized activity. The alpha-amylases degrade the damaged starch in wheat flour into small dextrins, which allows yeast to work continuously during dough fermentation, proofing and the early stage of baking. The result is improved bread volume and crumb texture. In addition, the small oligosaccharides and sugars such as glucose and maltose produced by these enzymes enhance the Maillard reactions responsible for the browning of the crust and the development of an attractive 'baked' flavour. Bread staling is responsible for significant financial loss for both consumers and bread producers. Staling is associated with a loss of freshness in terms of increased crumb firmness and decreased crumb elasticity. Staling is believed to be due to changes in starch structure during storage. When the starch granules revert from a soluble to an insoluble form, they lose their flexibility: the crumb becomes hard and brittle. For decades, emulsifiers have been used as anti-staling agents. However, they actually have a limited anti-staling effect and are subject to special labeling rules. Maltogenic amylase has the best anti-staling effect. AETL is launching maltogenic amylase shortly for baking industry.

Flour contains 2.5-3.5% non-starch polysaccharides, which are large polymers (mainly pentosans) that play an important role in bread quality due to their water absorption capability and interactions with gluten. Although the true mechanism of hemicellulase (SEBake HM), pentosanase or xylanase (SEBake XP) in bread-making has not been clearly demonstrated, it is well known that the addition of certain types of pentosanase or xylanase at the correct dosage can improve dough machinability, yielding a more flexible, easier-to-handle dough. Consequently, the dough is more stable and gives better ovenspring during baking, resulting in a larger volume and improved crumb texture. Normal wheat flour contains 1-1.5% lipids, both polar and non-polar. Some of these lipids, especially the non-polar lipids such as triglycerides, are bound with gluten, impeding its functionality. The addition of a functional lipase modifies the triglycerides, thereby modifying their interaction with gluten and resulting in a stronger gluten network. In turn, this ensures a more stable dough in case of over-fermentation, a larger loaf volume, and significantly improved crumb structure. Because of the more uniform and smaller crumb cells, the crumb texture is silkier and the crumb colour appears to be whiter. Chemical oxidants such as bromates, azodicarbonamide and ascorbic acid have been widely used to strengthen the gluten when making bread. As an alternative, oxidases such as glucose oxidase (SEBake GO) can partially replace the use of these chemical oxidants and achieve better bread quality.

Bread Improvers:

For decades, enzymes such as malt and fungal alpha-amylases have been used in bread-making. Rapid advances in biotechnology have made a number of exciting new enzymes available for the baking industry. The importance of enzymes is likely to increase as consumers demand more natural products free of chemical additives. For example, enzymes can be used to replace potassium bromate, a chemical additive that has been banned in a number of countries. The dough for white bread, rolls, buns and similar products consists of flour, water, yeast, salt and possibly other ingredients such as sugar and fat. Flour consists of gluten, starch, non-starch polysaccharides, lipids and trace amounts of minerals. As soon as the dough is made, the yeast starts to work on the fermentable sugars, transforming them into alcohol and carbon dioxide, which makes the dough rise. The main component of wheat flour is starch. Amylases can degrade starch and produce small dextrins for the yeast to act upon. There is also a special type of amylase that modifies starch during baking to give a significant anti-staling effect. Gluten is a combination of proteins that forms a large network during dough formation. This network holds the gas in during dough proofing and baking. The strength of this gluten network is therefore extremely important for the quality of all bread raised using yeast. Enzymes such as hemicellulases, xylanases, lipases, proteases (SEBake PP) and oxidases can directly or indirectly improve the strength of the gluten network and so improve the quality of the finished bread.

Amylase (SEBake X 50P) maximises the fermentation process to obtain an even crumb structure and a high loaf volume. Maltogenic amylase improves shelf life. Malt flour and malt extract can be used as enzyme supplements because malt is rich in alpha-amylases. Commercial malt preparations can differ widely in their enzyme activity, whereas an industrial enzyme is supplied with a standardized activity. The alpha-amylases degrade the damaged starch in wheat flour into small dextrins, which allows yeast to work continuously during dough fermentation, proofing and the early stage of baking. The result is improved bread volume and crumb texture. In addition, the small oligosaccharides and sugars such as glucose and maltose produced by these enzymes enhance the Maillard reactions responsible for the browning of the crust and the development of an attractive 'baked' flavour. Bread staling is responsible for significant financial loss for both consumers and bread producers. Staling is associated with a loss of freshness in terms of increased crumb firmness and decreased crumb elasticity. Staling is believed to be due to changes in starch structure during storage. When the starch granules revert from a soluble to an insoluble form, they lose their flexibility: the crumb becomes hard and brittle. For decades, emulsifiers have been used as anti-staling agents. However, they actually have a limited anti-staling effect and are subject to special labeling rules. Maltogenic amylase has the best anti-staling effect. AETL is launching maltogenic amylase shortly for baking industry.

Flour contains 2.5-3.5% non-starch polysaccharides, which are large polymers (mainly pentosans) that play an important role in bread quality due to their water absorption capability and interactions with gluten. Although the true mechanism of hemicellulase (SEBake HM), pentosanase or xylanase (SEBake XP) in bread-making has not been clearly demonstrated, it is well known that the addition of certain types of pentosanase or xylanase at the correct dosage can improve dough machinability, yielding a more flexible, easier-to-handle dough. Consequently, the dough is more stable and gives better ovenspring during baking, resulting in a larger volume and improved crumb texture. Normal wheat flour contains 1-1.5% lipids, both polar and non-polar. Some of these lipids, especially the non-polar lipids such as triglycerides, are bound with gluten, impeding its functionality. The addition of a functional lipase modifies the triglycerides, thereby modifying their interaction with gluten and resulting in a stronger gluten network. In turn, this ensures a more stable dough in case of over-fermentation, a larger loaf volume, and significantly improved crumb structure. Because of the more uniform and smaller crumb cells, the crumb texture is silkier and the crumb colour appears to be whiter. Chemical oxidants such as bromates, azodicarbonamide and ascorbic acid have been widely used to strengthen the gluten when making bread. As an alternative, oxidases such as glucose oxidase (SEBake GO) can partially replace the use of these chemical oxidants and achieve better bread quality.

Each of the enzymes mentioned above has its own specific substrate in wheat flour dough. For example, lipases work on the lipids, xylanase works on the pentosans, and amylases work on the starch. Because the interaction of these substrates in dough and bread is rather complex, the use of enzyme combinations can have synergistic effects that are not seen if only one enzyme is used - not even at high dosages. Quite often an overdose of enzymes will have a detrimental effect on either the dough or the bread. For instance, an overdose of fungal alpha-amylase or hemicellulase / xylanase may result in a dough that is too sticky to be handled by the baker or baking equipment. It is therefore beneficial for some types of bread formulation to use a combination of lower dosages of alpha-amylase and xylanase with low dosages of lipase or glucose oxidase to achieve optimum dough consistency, stability and bread quality.

AETL has launched SEBake SW Series - blended of various above mentioned enzymes as bread imporvers to get better crumb structure, good whiteness and better softness. AETL also offers individual enzymes as mentioned above.