Every day, 8 tons of pangasius skin are discarded in Vietnam and are considered waste products sold at dirt cheap prices. Scientists have developed technology to separate collagen from waste to help increase the value of the seafood industry.
According to statistics, in 2019 Vietnam exported 1.3 million tons of pangasius with a value of 2 billion USD. However, only 30% of the fish’s body weight is used, while the remaining 70% of the head, skin, and bones become by-products. On average, each pangasius factory releases 5 to 8 tons of fish skin and is often thrown away, causing environmental pollution.
However, pangasius skin contains up to 50% dry matter content such as collagen out of a total of 69% protein. Faced with that reality, Associate Professor, Dr. Phan Dinh Tuan and his research team at Ho Chi Minh City University of Technology conducted a method to extract collagen from discarded pangasius skin, in order to add value to the seafood industry.
“Game-changing” technology
According to reports from many organizations, the global collagen market demand in 2019 is estimated at 920 tons and the collagen market size is expected to reach 7.5 billion USD by 2027, with a compound annual growth rate of 6 .4% in the period from now to 2027.
Vietnamese scientists have seen great potential in separating collagen from pangasius skin, and have learned and deployed many methods since the 2000s, but most of them still have many disadvantages and are not really effective. The old way left the output product with up to 5% fat, while the market requirement was less than 0.5%.
Associate Professor, Dr. Phan Dinh Tuan and his colleagues “changed the game” with pangasius skin extraction technology. The group realized that reducing the amount of fat also unintentionally reduced the amount of collagen after extraction, so the group focused on improving the step of processing fish skin before extraction.
Researchers soaked fish skin in 3 types of solvents NaOH, LASTa and ethanol at a ratio of 1/10 and a temperature of only 4 degrees Celsius, to remove fat, bleach color and deodorize fishy odors. This step causes the fish’s skin to swell, protein and lipid bonds are broken, leading to the fat separating from the skin. Meanwhile, LASNa prevents fat from sticking back after defrosting.
However, when the lipids are separated, the protein also reduces the concentration of the skin, so the team stops soaking at a certain stage and then separates the remaining fat at a later stage. In the next step, Associate Professor Tuan and his colleagues will extract collagen by combining acetic acid with pepsin enzyme at temperatures from 3°C to 17°C for 24 hours. Finally, NaCL was added and then centrifuged to separate the crude collagen.
From model to practice
Raw collagen products are subjected to freeze drying under specific conditions, helping to produce finished products with high molecular weight, colorless, odorless and very low fat content, suitable for use as raw materials for production. cosmetics, food and pharmaceuticals.
In addition, when stored at temperatures below 39.5°C, collagen is not structurally denatured, so it is easy to preserve. This method achieves an extraction efficiency of up to 84.81%, helping to avoid wasting input materials, helping to increase the value of pangasius in general and products processed from pangasius in particular.
Research conducted by Associate Professor Tuan’s group, in addition to helping to effectively use discarded waste products, also helps determine the influence rules of three factors (acetic acid concentration, pepsin enzyme content and solvent/skin ratio). fish) on collagen extraction efficiency.
From this conclusion, the team can apply the technology to many other products such as basa fish due to the close correlation between model and experiment. The method of extracting and purifying collagen from pangasius skin by Associate Professor Dr. Phan Dinh Tuan and colleagues at Ho Chi Minh City University of Technology – National University has been granted a patent by the Intellectual Property Office. Useful solution number 2-0001753.
