| Antarctic krill (Euphausia superba) and its products have garnered increasing attention as valuable natural resources due to their rich nutritional profile, particularly in bioactive compounds such as protein and phospholipids. These components offer significant health benefits, including antioxidant and anti-inflammatory properties, which have attracted consumers seeking nutritional supplements and functional foods. However, the safety and quality of Antarctic krill products are of critical concern, especially in relation to the presence of elements like arsenic and fluoride, as well as the potential allergenic properties of krill proteins. This review provides a comprehensive analysis of the safety issues surrounding Antarctic krill and its products, addressing key concerns such as the presence of arsenic, fluoride, allergenic proteins, and strategies to mitigate these risks. One of the primary safety concerns of Antarctic krill is its potential to accumulate arsenic through its diet of plankton and algae. Various forms of arsenic exist in the natural environment, and the toxicity of arsenic depends on its specific chemical forms. Inorganic arsenic, particularly arsenite (As(III)) and arsenate (As(V)), is highly toxic, whereas organic arsenic compounds like arsenobetaine (AsB) are considered non-toxic or of low toxicity. Studies have shown that Antarctic krill contains arsenic primarily in the less harmful organic forms, with AsB accounting for a significant proportion of the total arsenic content. The levels of inorganic arsenic in Antarctic krill and its products are typically far below the regulatory limits set by food safety standards, such as the national standard of our country (GB 2762—2022), which stipulates that the maximum allowable inorganic arsenic content in aquatic products should not exceed 0.50 mg/kg. However, some krill oil samples have been found to exceed the specific standard of 0.1 mg/kg for inorganic arsenic in krill oil, highlighting the need for continued monitoring and control of arsenic levels in these products. Fluoride is another contaminant of concern in Antarctic krill. Fluoride naturally accumulates in marine organisms, particularly in the exoskeletons of crustaceans like krill. While fluoride is an essential micronutrient at low concentrations, excessive fluoride intake can lead to health issues such as skeletal fluorosis. Research has demonstrated that Antarctic krill and its products, especially krill meal and krill powder, contain elevated levels of fluoride due to the high fluoride content in the exoskeleton. The presence of fluoride limits the use of krill products in health supplements, and the removal of fluoride remains a technical challenge. Current strategies for defluorination include physical and chemical treatments such as enzymatic hydrolysis, calcium salt precipitation, and filtration, although further research is required to improve the efficacy of these methods without compromising the nutritional quality of the products. In addition, the allergenic potential of Antarctic krill is another significant safety issue. Krill contains proteins, such as tropomyosin, that are known allergens and can trigger immune responses in sensitive individuals, particularly those with shellfish allergies. Symptoms of krill protein allergies include skin reactions, respiratory issues, and gastrointestinal discomfort. Although there are no specific treatments for food allergies, several studies have explored ways to reduce the allergenicity of krill proteins. Techniques such as microwave treatment, ultra-high-pressure processing, protease digestion, and electron beam irradiation have shown promising results in reducing the allergenic potential of tropomyosin and other proteins. For instance, microwave and ultra-high-pressure treatments have been shown to reduce shrimp allergenicity, while protease digestion eliminates allergenic protein bands. Moreover, the Maillard reaction, commonly used in food processing, has been found to reduce the allergenicity of tropomyosin by altering its secondary structure. These findings offer potential solutions for making krill products safer for consumption by individuals with shellfish allergies. Given the growing demand for krill products in the food and nutraceutical markets, ensuring the safety and quality of these products is essential. Future research should focus on understanding the mechanisms of arsenic, fluoride, and allergenic protein toxicity, as well as developing more efficient methods for removing these harmful substances. Advances in processing technologies, such as improved defluorination techniques and novel methods for reducing protein allergenicity, are critical for enhancing the safety of krill products. In addition, regulatory frameworks need to be strengthened to ensure that krill products meet food safety standards. This includes the use of advanced detection technologies for monitoring contaminants such as arsenic and fluoride, as well as implementing strict labeling requirements for allergens. International cooperation is also vital for sharing research findings and regulatory experiences, which can lead to the establishment of unified safety standards for krill products. Public education is another important aspect of ensuring consumer safety. Raising awareness about the potential risks associated with krill consumption, including heavy metal contamination and allergenicity, can help consumers make informed decisions. Finally, ongoing policy development and the establishment of a comprehensive quality control system will be crucial for protecting consumer health and ensuring the sustainable development of the Antarctic krill industry. In conclusion, Antarctic krill holds immense potential as a sustainable and nutritious resource, but ensuring the safety of its products is paramount. Through continued research, technological advancements, regulatory oversight, and public education, the krill industry can address safety concerns while meeting the growing consumer demand for healthy and functional foods. |
