Collagen is extracted from bovine (cow), poultry (chicken), porcine (pig), marine (fish), ovine (sheep) tissues as well as plant sources [1, 2]. The most plentiful source of collagen is bovine tissues such as the bone, skin, or tendons, thus bovine collagen is most frequently used for supplements . There are different extraction techniques that help isolate collagen peptides that contain a mixture of oligopeptides (2- to 20-amino acid chains), tripeptides (3-amino acid chains), and dipeptides (2-amino acid chains).
Thermal (heat) extraction is a common method for producing collagen supplements that uses thermal treatment in combination with high pressure . This process includes immersing native collagen in water at temperatures between 100 and 374 °C and at a pressure of less than 22 MPa [13, 14]. In addition, thermal extraction in combination with a high-filtration mesh may be used to isolate collagen peptides .
Heat that is sustained at recommended temperatures does not damage collagen, as the amino acid chains maintain their integrity at temperatures up to about 400°C by unfolding and folding in response to temperature changes. However, extremely high temperatures cause collagen peptide degradation that is irreversible. Furthermore, the combination of high heat exposure and grinding techniques in some collagen peptide production forms may damage peptide bonds and disorganize the protein structure [15, 16]. This disrupts digestive enzyme-directed digestion after powdered collagen peptide supplements are consumed.
Additional extraction methods such as pressurized heat and high-intensity ultrasound are currently under investigation to further provide options for collagen peptide production.
What are the Best Practices Now?
The combination of enzyme digestion and thermal treatment appears to be the most common extraction technique for different sources of collagen (e.g., bovine, marine, poultry, porcine). Special precautions are usually taken to ensure that high temperatures do not damage the amino acid bonds in native collagen.
Native collagen has a triple-fiber structure with the appearance of a tightly woven rope. This form of collagen also consists of large molecules that are hard to digest. To reap the benefits of collagen in supplement form, it is essential to consume collagen in small particle sizes that are produced through extraction. Pre-extraction conditions (e.g., fresh versus frozen) and the extraction source (e.g., bone versus skin) are the main factors that influence the characteristics of the extracted collagen peptides such as molecule size, amino acid composition, structure, and stability [17, 18].
Furthermore, the collagen peptide extraction procedure triggers a process called denaturation, in which the bonds that hold the amino acids in collagen fibers together in a tight, rope-like configuration are broken or degraded. After denaturation begins, the triple-fiber structure of native collagen changes to a random circular form due to the breakdown of amino acid bonds. This produces large amounts of peptides in easily digestible sizes. However, the amount of time collagen is processed before the mixture is neutralized influences functional properties such as invader-targeting activity, antioxidant strength, and ease of absorption following the extraction procedure.
In comparison to native collagen, extracted collagen peptides are highly dissolvable in water, rapidly digested, absorbed, and distributed throughout the body following consumption, and offer cost-effective extraction processes due to their simple structure [1, 19, 20]. Collagen peptides also often can have a neutral odor, are colorless, and have a low incidence of allergic reactions . Furthermore, collagen peptides offer a higher therapeutic use than native collagen as a result of these properties.
These are the main reasons why collagen peptides are the favorable choice for collagen-based products. S&H Collagen Protein Bars contain bovine collagen peptides that are gently extracted to ensure potency and noticeable benefits when they are consumed regularly.
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