Proteins serve as integral components in the world of food science, contributing significantly to the texture, structure, and nutritional value of various products. They are considered the building blocks of life. Proteins are macromolecules composed of amino acids. In food, they play a crucial role in providing structure, texture, and nutritional content. The main proteins used in confectionery as ingredients are gelatin, soy, egg, wheat, milk, and whey, each bring unique attributes to the table, influencing the quality of confectionery products. Here is a brief description of each.

  • Gelatin: mixture of peptides and proteins derived from the partial hydrolysis of collagen. Composed mainly of amino acids like glycine, proline, and hydroxyproline.
  • Soy Protein: Rich in essential amino acids, soy protein contains a balanced profile crucial for human nutrition. Globulins, glycinin, and β-conglycinin are key components in its composition.
  • Egg Protein: Eggs boast a complete amino acid profile, essential for human health. Ovalbumin, ovotransferrin, and ovomucin are its predominant proteins.
  • Wheat Protein: Gluten, a complex mixture of gliadins and glutenins, imparts unique viscoelastic properties. Gliadins contribute to extensibility, while glutenins provide elasticity.
  • Milk Protein: Comprising caseins and whey proteins, milk protein offers a rich source of essential amino acids. It contains a blend of Alpha-s1, alpha-s2, beta, and kappa caseins, along with alpha-lactalbumin and beta-lactoglobulin in whey.
  • Whey Protein: A byproduct of cheese production, whey protein contains a high concentration of essential amino acids.In its composition Beta-lactoglobulin, alpha-lactalbumin, immunoglobulins, and lactoferrin are key components.

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Source and Processing

Soy Protein:

Source: Soybeans

Extraction: Soy protein isolate is obtained through a process involving soy flour, extraction with solvents, and precipitation.

Egg Protein:

Source: Eggs

Extraction: Separation of egg whites followed by spray drying yields egg white protein.

Wheat Protein:

Source: Wheat grains

Extraction: Milling wheat grains and subsequent separation of gluten from starch.

Milk Protein:

Source: Milk

Extraction: Precipitation of casein from milk, followed by spray drying for powder formation.

Whey Protein:

Source: Whey, a byproduct of cheese production

Extraction: Filtration, concentration, and drying processes yield whey protein isolate.


Source: Primarily sourced from animal connective tissues, often obtained from pigskin or bovine hides. Marine sources like fish scales are also utilized for specific applications.

Extraction: Collagen-rich tissues undergo a series of processing steps, including acid or alkaline treatment and extraction, to yield gelatin.

Main function in Confections

Proteins have many used in the Confectionery industry, some examples are listed below:

  • Flavor and color: Combined with reducing sugars and heat, proteins will go through Maillard reaction creating flavor and color compounds.
  • Texture Enhancement: Soy, egg, and wheat proteins contribute to the viscoelasticity of dough, providing structure to baked confections.
  • Emulsification: Egg proteins exhibit excellent emulsifying properties, enhancing the stability of fillings and coatings.
  • Foaming: Whey proteins, particularly beta-lactoglobulin, Egg albumen and wheat protein can contribute to the formation and stability of foams in confectionery products.
  • Gel Formation: Gelatin's ability to form thermoreversible gels is exploited in confectionery to produce gummies, marshmallows, and other gel-based treats.
  • Nutritional content: Milk is used to increase protein content in confections such as caramel and fudge.

Molecular structure

Proteins consist of a sequence of amino acids, and each protein source possesses a distinct amino acid fingerprint. The interactions among these amino acids, characterized by diverse chemical structures, result in the creation of the three-dimensional protein structure, known as conformation. Additionally, these interactions play a pivotal role in defining the specific functionality and reactions exhibited by the protein.


  • Molecular Weight: Proteins vary widely in molecular weight, ranging from a few thousand to several million Daltons. This characteristic will affect its biological and functional properties.
  • Charge: The presence of ionizable amino acid residues (acidic and basic) imparts a net charge to proteins. The overall charge of a protein depends on the pH of its surroundings, influencing its solubility and interactions with other molecules.
  • Solubility: The solubility of a protein is influenced by its amino acid composition, charge distribution, and the surrounding environment's pH and ionic strength. Changes in these factors can lead to protein precipitation or aggregation, understanding this is crucial to use them.
  • Hydrophobicity: Hydrophobic amino acid residues tend to cluster together in the interior of a protein, away from water. This hydrophobic core contributes to the protein's stability and folded structure.
  • Isoelectric Point (pI): The pH at which a protein carries no net electrical charge is its isoelectric point (pI). At this point, a protein is least soluble and may precipitate. Knowledge of the pI is crucial for various protein purification techniques.
  • Conformation and Folding: Proteins adopt specific three-dimensional structures (conformations) dictated by their amino acid sequence. The folding of proteins is critical for their function, and disruptions in folding can lead to loss of activity or aggregation.
  • Thermal Stability: Proteins have characteristic temperature ranges in which they remain stable. Outside these ranges, proteins may denature, losing their structure and functionality. Thermal stability is a key consideration in food processing and other applications.
  • Absorption of UV Light: Proteins absorb UV light at a wavelength of around 280 nm due to the presence of aromatic amino acids like tryptophan and tyrosine. This property is often used to quantify protein concentration.
  • Viscosity: The presence of proteins in a solution can affect its viscosity, especially in concentrated solutions or gels. This property is important during confectionary manufacturing. 
  • Buffering Capacity: Proteins can act as buffers, helping to maintain the pH of their surrounding environment. 


In United States of America, the primary regulations for food, are typically found in Title 21 of the Code of Federal Regulations (CFR). Specifically, Subchapter B of Title 21 covers food for human consumption. Regulations pertaining to specific proteins may be found in various parts of Title 21, depending on the source and application of the protein. For example, regulations related to egg products can be found in 21 CFR Part 160, and those for milk products are in 21 CFR Part 131.

If the proteins are used as food additives, relevant information may be present in 21 CFR Part 172. This part covers permitted food additives and their conditions of use.

For information on labeling requirements, including the declaration of protein sources, 21 CFR Part 101 is relevant. This part addresses the labeling of various food products.

Some proteins may have GRAS status, meaning they are considered safe for consumption. Information on GRAS substances can be found in 21 CFR Part 182.

FDA Guidance Documents:

Additionally, the FDA issues guidance documents that provide interpretations and recommendations. These documents may offer insights into best practices for using specific proteins in food products.

To obtain the most up-to-date and specific information, it is recommended to check the U.S. Food and Drug Administration (FDA) website or directly consult the latest version of the Code of Federal Regulations

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