Sustainable Carotenoids in Aquafeeds: Unlocking Circular Economy Solutions Beyond Terrestrial Sources

Abstract

Carotenoids are natural pigments abundant in fruits and vegetables, playing a vital role in the aquaculture industry. Traditionally, aquafeed has relied on terrestrial plants for carotenoid supplementation, enhancing fish coloration while providing antioxidative benefits, boosting immunity, and serving as a vitamin A source. However, this reliance raises sustainability concerns as global food demand increases, making land-based sources less viable and cost-effective. Additionally, consumers and fish farmers are increasingly wary of synthetic additives, preferring natural alternatives. This review highlights the importance of exploring alternative natural sources of carotenoids to reduce pressure on terrestrial resources and minimise synthetic usage. Agricultural waste and byproducts from crustacean processing offer significant opportunities for sustainable carotenoid extraction. These food byproducts can be valorised effectively within a circular economy framework. Microalgae emerge as another promising source of carotenoids. They yield higher quantities compared to land crops and can be cultivated under controlled conditions year-round. The potential for innovative carotenoid types through microbial fermentation further enhances their attractiveness for aquaculture applications. The primary aim of this review is to identify and promote these alternative natural sources of carotenoid production in the aquafeed sector. It also examines the essential role of carotenoids in fish nutrition and health. By focusing on sustainable practices and alternative sourcing, this study seeks to support long-term strategies for carotenoid production in aquaculture feeds while aligning with consumer preferences for natural ingredients.