Enzymes are used to reduce mix times, increase oxidation and improve machinability in baked goods.

Enzyme


What is an Enzyme?

An enzyme is a protein catalyst that facilitates chemical changes in biological systems. Various categories of enzymes are used in baked goods, beverages, dairy, beer, glucose syrups, starch and other food products.1

In bakery systems, they can act as:

  • Dough conditioners
  • Fermentation enhancers
  • Anti-staling agents

This enables bakers to eliminate undesirable additives and to produce clean label baked goods.

A 3D structure of the enzyme Human salivary amylase.

A 3D structure of Human salivary amylase.

A 3D structure of the enzyme Aqualysin (protease).

A 3D structure of Aqualysin (protease).

Origin

Enzymes are naturally present in many living organisms such as animals, plants, bacteria and fungi. There, they participate in metabolic processes. They can be found in food materials such as cereal flours, fruits and vegetables.1

Commercial Production

Commercially, enzymes are produced by fermentation using food-grade microorganisms such as bacteria and fungi. They are produced as by-products of molasses or other carbon-source fermentation. Enzymes can be produced for specific activities and uses by downstream purification, conditioning and standardization.1

Function

Similar to other enzymes, ones used in bakery products can facilitate chemical reactions without undergoing any change in their molecular structure. They can be utilized continuously as long as they are not denatured, by heat for example. Also, there needs to be enough substrate in the flour. Examples of substrates are proteins, fats, sugars, starch or non-starch polysaccharides (cellulose, glucans, arabinoxylans).1,2

Primary uses in bakery products:3,4

  1. Fermentation aides (improvers)
  2. Mix reducers
  3. Modifiers of dough handling properties
  4. Dough strengtheners
  5. Crumb softeners (anti-staling agents)

Types of enzymes and their function in bakery products:1,3,4

IUPAC/IUB classification Type Chemical bond cleaved

Reaction catalysis/hydrolysis

Specific function
Hydrolases Protease Protein – peptide bond
  • Reduction of mixing time
  • Modification of dough handling properties
  • Pan flow improver
  • Improvement of dough machinability
  • Water redistribution in dough
Lipase Fats – Ester (alcohol-fatty acid) bond
  • Production of emulsifiers (mono- and di-glycerides) from fats (emulsifiers)
  • Stabilization of gas cells in batter and dough
  • Improve batter aeration
  • Crumb softening (anti-staling).
Amylases Starch – glycosidic bond
  • Fermentation improvers
  • Production of maltose, glucose from starch (yeast food)
  • Anti-staling agents
Cellulase Cellulose- glycosidic bond
  • Redistribution of water in dough
  • Improve gluten matrix cohesiveness (better gas retention)
  • Modification of dough consistency and handling properties
Xylanase / Pentosanase / Hemicellulase Arabinoxylans – glycosidic bond
Maltase, invertase Disaccharides, maltose and sucrose – glycosidic bond
  • Fermentation improvers
  • Production of monosaccharides (yeast food)
  • Improvement of crust color through browning reactions
Asparaginase Proteins – amide (carbon-nitrogen) bond
  • Reduction of acrylamide in thermally processed foods
Oxidoreductases Glucose oxidase Glucose – oxidation into gluconic acid and hydrogen peroxide
  • Dough strengthening
  • Aggregation of gluten-forming proteins through oxidation of sulfhydryl (–SH) groups to disulphide (S–S) bond
  • Mixing tolerance improvement
  • Enhanced dough gas retention capacity.
Hexose oxidase Oxidation of hexose sugars (less specific) by atmospheric oxygen into gluconic acid and hydrogen peroxide
Lipoxygenase Fatty acids – oxidation to produce peroxides
  • Similar functionality to that of glucose/hexose oxidase
  • Bleaching effect (destruction of flour carotenoid pigments).
Transferases Transglutaminase Acyl-transfer reaction between carboxamide group of peptide-bound glutamine residues and a

variety of primary amines

  • Similar functionality to glucose/hexose oxidase although using different mechanism (introduction of covalent cross-links between glutamine and lysine).

Application

Bakery enzymes are micro ingredients usually added at levels of 0.005–0.01% (50–100 ppm based on flour weight). How much depends on the formulation and process needs. They require special conditions for optimum activity and performance, namely:1,2

  • Acidity (pH): Most bakery varieties perform well within the pH range of 4.0–7.5.
  • Temperature: Chemical reaction rates double for every 18°F (10°C) increase in temperature. Optimal temperature for most commercial ones is 95–140°F/35–60°C.
  • Contact time between enzyme and substrate: Enzymes need time to act on the substrate.
  • Aqueous dispersion medium to support chemical reactions.
  • Amount of substrate: they work better when excess of substrate is available.
  • Adequate enzyme dosage

FDA Regulation

Enzymes used in the bakery industry are GRAS (Generally Recognized as Safe) food additives in the US. The FDA regulates their source or origin (food-compatible) and establishes limits to their use (if applicable) based on GMP.5

References

  1. Mathewson, P.R. Enzymes, 2nd edition, Eagan Press Handbook Series, AACC International, Inc., 1998, pp. 1–105.
  2. Kuddus, M. “Introduction to Food Enzymes.” Enzymes in Food Biotechnology. Production, Applications, and Future Prospects, Academic Press, Elsevier Inc., 2019, pp. 1–18.
  3. Van Oort, M. “Enzymes in Bread Making.” Enzymes in Food Technology, 2nd edition, Blackwell Publishing Ltd, 2010, pp. 103–143.
  4. Rosell, C.M., and Dura, A. “Enzymes in Bakeries.” Enzymes in Food and Beverage Processing, CRC Press, Taylor & Francis Group, LLC, 2016, pp. 171–195.
  5. Smith, J. “Enzymes.” Food Additives Data Book, 2nd edition, Blackwell Publishing Ltd., 2011, pp. 366–454.