Turning seafood by-products into ‘green gold’: [2] Earning billions from seafood waste and leftovers

Fish bones sold for USD 10 per kilogram

Bài liên quan

Turning seafood by-products into ‘green gold’: [1] Great potential

Tu Hai Seafood Co., Ltd. (Phuoc Thang Ward, Ho Chi Minh City), with more than 35 years of experience, specializes in producing and processing seafood for export to Japan and South Korea. Over 80% of its products are sand borer fish exported to the Japanese market. From Japan, Tu Hai’s sand borer fish are distributed globally, especially to European and American markets.

Tu Hai’s main product is fish fillets, so the heads and bones become by-products sold to companies making animal feed and aquaculture products. These by-products are sold at a very low price, only a few thousand dong per kilogram, and are prone to decomposition and spoilage, causing environmental pollution. This issue had long concerned Mr. Dao Quoc Tuan, the company’s General Director.

After much research, Mr. Tuan discovered that sand borer fish bones are rich in calcium. Tu Hai then studied the demand of Japanese customers and experimented with creating tasty dishes. With his sharp business insight, Mr. Tuan proposed the idea of exporting sand borer fish bones to Japanese partners and reached an agreement on a process to utilize these bones.

“After the meat is separated, the bones are cleaned, dried under the sun or with heat, and packed for export. In Japan, this ingredient is used to make delicacies such as crispy roasted fish bones, sesame-coated or batter-fried bones, becoming a popular drinking snack in Japanese restaurants. Customers can also buy them as takeaway products or in small packages for tourists. These dishes are not only appealing in flavor but also highly regarded for their nutritional value,” Mr. Tuan said.

Mr. Tuan also shared that the demand for dried sand borer fish bones has steadily increased over the years, with some years seeing demand outstrip supply. The average selling price is around USD 10 per kilogram, generating export revenues of USD 400,000–500,000 per year (approximately VND 10–12 billion per year) for the company.

From being a waste product, sand borer fish bones have not only increased the value of the seafood production chain but also contributed to a green, sustainable agriculture aligned with the circular economy trend, while enhancing Tu Hai’s international market reputation.

Turning seafood by-products into high-value products

The Southern Sub-Institute of Fisheries Research has also conducted studies to produce canned crab paste and chitosan from crab by-products. The capture and processing industry in Ba Ria - Vung Tau used to report an average annual catch of about 360,000 tons, of which crabs accounted for about 19,500 tons per year.

Crabs are classified by size, with larger crabs used for domestic consumption and processing for export. Smaller crabs (miscellaneous crabs) are sold at a low value, and only a small amount is processed into seasoned, crispy fried crabs. Alongside the main export crab products, a large volume of by-products is discharged into the environment, mainly crab shells, which are estimated to account for about 20% of the total crab catch.

Crab meat contains many different groups of vitamins, especially B vitamins. It also provides a significant amount of Omega-3 fatty acids, which are beneficial for the brain. Miscellaneous crabs contain very low levels of mercury (compared to other common marine fish), and their shells are mainly composed of chitin and chitosan, high-value materials used in medicine, chemistry, the food industry, and agriculture.

After harvesting, the crabs are washed and shelled. The shelled crabs are then processed into crab paste, canned ,and sterilized, resulting in a delicious product that can be consumed directly or used in dishes such as bun rieu (Vietnamese crab noodle soup) or hot pot.

The shells and leftover parts from canned crab paste production are collected to make chitosan, enhancing economic efficiency. The shells are cleaned to remove impurities, dried, and ground into powder. This powder undergoes mineral and protein extraction using a DES solvent, filtered to collect the residue, which is washed until reaching a neutral pH. It is then decolorized and dried until the weight stabilizes, resulting in chitosan powder.

Chitosan powder is used as a raw material in the medical, chemical, and food industries to produce food wrap films, synthetic plastics, and more. It sells for USD 400–500 per kilogram, or up to USD 1,000 per kilogram, when used in medical applications such as bandages and artificial skin regeneration.

Many companies nationwide have pursued similar initiatives. For example, Vinh Hoan Corp has produced collagen from pangasius fish skin, earning more than VND 600 billion in 2023. Sao Mai Group exports high-end fish oil and fish meal to Japan and South Korea. NTSF Seafoods has developed biodegradable biofilms made from shrimp shells, a promising plastic alternative.

According to projections, by 2030, Vietnam could produce 490,000 tons of food from shrimp heads, 100,000 tons from pangasius fish trimmings and stomachs, and 150,000 tons from pangasius fat. The potential for producing animal feed includes 146,000 tons from shrimp shells and 900,000 tons per year from fish heads, bones, and organs. The potential for processing into medical, pharmaceutical, cosmetic, and other industrial products includes 147,000 tons from shrimp heads and shells, and 80,000 tons from fish skin and swim bladders.

* USD 1 = VND 26,145. Source: Vietcombank.