➤ In 2024, more than 295 million people worldwide still faced severe hunger.
➤ In 2023, approximately 600 million people globally suffered from foodborne diseases annually.
➤ Children under the age of five account for 40% of the cases, leading to about 125,000 child fatalities each year.
As an essential component of the human diet, aquatic products are celebrated for their substantial nutritional value, distinctive flavor, and variety.
➤ In 2019, seafoods topped global consumption charts, surpassing all other meat types.
➤ In 2022, global fisheries and aquaculture production amounted to 185.4 million tons.
➤ By 2030, it is estimated that the global annual production of aquatic animals will reach 205 million tons, a fivefold increase over the 1960 level.
In 2019, more aquatic foods were consumed globally than chicken, pork, beef or sheep.
More than three billion people worldwide depend on aquatic products for at least one-fifth of their animal protein intake. China stands as the world's largest producer of aquatic products, accounting for approximately 70% of global aquaculture output. In 2024, China's total production of aquatic products amounted to 73.66 million tons, representing a 3.5% increase from the previous year. This growth underscores the vital role of aquatic products in the diets of Chinese residents.
The spoilage of aquatic products poses a significant challenge that urgently needs to be addressed in the field of food safety.
Aquatic products are known for their short shelf life and highly perishable property, with rapid
quality deteriorating after harvest. Research suggests that the annual loss and
waste of aquatic products amount to 15% (23.8 million tons in 2021), with 30%-35% of this loss
occurring during transportation and processing. Spoilage is identified as a major contributing
factor to this issue. Moreover, spoiled aquatic products accumulate histamine toxins and harbor
pathogenic bacteria, potentially leading to various foodborne diseases. In 2023, aquatic products
were responsible for 379 foodborne outbreaks in Chinese mainland, affecting 2,061 individuals.
We urgently need a safer, more efficient, and environmentally friendly biological preservation technology!
Currently, the preservation of aquatic products mainly relies on two methods:
chemical preservatives and cold chain systems. Chemical preservatives, including sulfites,
are associated with carcinogenic risks and potential harm to human health. Meanwhile, the
fossil fuel-dependent cold chain systems are a major source of carbon emissions and plastic
pollution, thereby causing substantial environmental damage. The production of one ton of
aquatic products directly generates 319.71 kg of CO2. Furthermore, current cold chain systems
are responsible for 402 billion kg of CO2 emissions globally.
Contrary to their seemingly useless appearance, crab and shrimp shells
possess immense potential, acting as a natural preservative!
Globally, the massive waste of crab and shrimp shell resources represents a significant problem.
In 2022, China produced over 50 million tons of marine crabs and shrimp, resulting in
approximately 10 million tons of crab and shrimp shell. Notably, some aquaculture practitioners
directly discard these shells in nearshore areas.
The primary component of crab and shrimp shells is chitin, which ranks as the world's second largest natural biomass resource with an annual biosynthetic capacity of approximately 10 billion tons. Through deacetylation and further chemical processing, chitin can be converted into chitosan, which can be further transformed into chitooligosaccharides, a broad-spectrum and highly effective antibacterial agent.
Chemical methods for degrading chitosan typically utilize acids or oxidizing agents. However, these approaches often lead to excessive hydrolysis, yielding poorly controlled product structures and contributing to sewage pollution. Physical methods, such as microwave radiation, ultrasonic fragmentation, or turbulent cavitation, are employed but encounter challenges including high equipment demands and difficulties in accurately controlling the degradation process.
