Innovative protein sources from freshwater and marine environments - A comprehensive review

• Blue foods include fish, invertebrates, algae, and aquatic plants; • Over 70% of Earth's surface is ocean, offering sustainable cultivation and harvesting opportunities; • Blue foods' protein potential matches or exceeds that of traditional sources; • The food industry has explored protein extraction and analysis for various applications. Blue foods are a diverse and rich source of proteins and other valuable nutrients, comparable to or surpassing traditional protein sources such as eggs and soy. Additionally, these foods possess advantageous technological properties, including thickening, binding, foaming, antioxidant, emulsifying, adhesive, solubility, and gelling capabilities. They are noteworthy for their bioactive properties, such as immunomodulatory, antimicrobial, antioxidant, anti-inflammatory, and antilipidemic. These foods play a significant nutraceutical role and contribute to maintaining a healthy intestinal microbiota. Besides, blue foods offer environmental advantages, such as faster growth rates, reduced water consumption, and no competition for arable land compared to terrestrial food sources. These considerations are particularly relevant given projections indicating a significant global population increase and a greater demand for protein alternatives. This quest is justified by the necessity to mitigate pathologies and reduce the carbon footprint in alignment with sustainability principles. Within this context, this review article addresses scientific research conducted over the last five years, providing information on the primary protein sources in blue foods, methods for protein extraction, and their composition and nutritional aspects. Furthermore, the article discusses implications, future perspectives, and industrial applications in various segments, including the food industry, the development of food supplements, formulation of new products as protein alternatives, influence on rheology, and mechanisms to enhance the sensory aspects of final products.