Extraction methods for pure collagen extracts

The goal of collagen extraction and purification is to make the yield and purity of collagen extraction as high as possible and to make the extracted pure collagen extract meet the requirements of different fields. So far, there are four main extraction methods for pure collagen extracts as follows: acid method, alkaline method, salt method, and enzyme method. In the actual extraction process, different extraction methods are often combined to achieve a better extraction effect.

Here is the content list:

• Acid extraction

• Alkali extraction

• Salt method extraction

• Enzymatic extraction

Acid extraction

Acid extraction mainly uses a low ionic concentration of acidic conditions to impregnate the raw materials, thus breaking the intermolecular salt bonds and Schiff bases, while causing fiber swelling and dissolution. The main acids used as solvents are hydrochloric acid or sulfite, phosphoric acid, sulfuric acid, acetic acid, citric acid, and formic acid. The acid method is a relatively common and effective method for extracting pure collagen extracts Collagen extracted by the acid method retains its three-stranded helical structure to the greatest extent. This method is fast and the molecular weight of pure collagen extract is continuous, which is suitable for the preparation of medical biomaterials and raw materials, but the product yield is low, the equipment is corroded and the pollution is heavy.

Alkali extraction

The common treatment agents used for collagen extraction by the alkali method are lime, sodium hydroxide, sodium carbonate, etc. For example, Holzer et al. used a 1 % to 1.5 % lime water soaking method to extract pure collagen extract. Since it tends to cause peptide bond hydrolysis, the molecular weight of the obtained hydrolysis product is relatively low. Therefore, this method is not desirable if we want to retain the three-stranded helical structure of collagen.

Salt method extraction

The neutral salts used for the extraction of pure collagen extract by the salt method are hydrochloric acid-tris-hydroxymethyl aminomethane (Tris-HC1), sodium chloride, citrate, etc. Under neutral conditions, collagen dissolves when the concentration of salt reaches a certain amount. And different types of collagens can be precipitated by salting the pure collagen extract with different concentrations of sodium chloride.

Enzymatic extraction

Enzymatic extraction is the use of protease to dissolve collagen, the hydrolysis conditions are mild, the reaction rate is fast, the pure collagen extract still has the complete three-stranded helix structure, the protein purity is high, the physical and chemical properties are stable, and there is no environmental pollution. The common proteases used for enzymatic extraction are pepsin, trypsin, or complex enzymes. The process can be selected as a one-step method, i.e. direct extraction using enzyme solution. Two-step method, i.e., initial extraction with acid or base followed by enzyme extraction.

The pure collagen extract from Guangdong Victory Biotech Co., Ltd was highly concentrated, maintained bioactive collagen, and used a special manufacturing process to maintain the integrity of the triple helix structure.