Abstract
The growing demand for sustainable, functional ingredients in the food industry has driven interest in marine-derived biopolymers. Among marine sources, microalgae represent a promising yet underexplored reservoir of bioactive gel-forming compounds, particularly extracellular polysaccharides (EPSs), both sulfated and non-sulfated, as well as proteins that exhibit unique gelling, emulsifying, and stabilizing properties. This study focuses on microalgal species with demonstrated potential to produce viscoelastic, shear-thinning gels, making them suitable for applications in food stabilization, texture modification, and nutraceutical delivery. Recent advances in biotechnology and cultivation methods have improved access to high-value strains, which exhibit promising physicochemical properties for the development of novel food textures, structured formulations, and sustainable food packaging materials. Furthermore, these microalgae-derived gels offer additional health benefits, such as antioxidant and prebiotic activities, aligning with current trends toward functional foods containing prebiotic materials. Key challenges in large-scale production, including low EPS productivity, high processing costs, and lack of regulatory frameworks, are critically discussed. Despite these barriers, advances in cultivation technologies and biorefinery approaches offer new avenues for commercial application. Overall, microalgal gels hold significant promise as sustainable, multifunctional ingredients for clean-label food formulations.
1. Introducing Microalgae as a Sustainable Alternative for Food Applications and Gel-Forming Materials
The global population is projected to reach approximately 10 billion by 2050, posing a significant challenge to sustainable food production [1]. In response to this major concern, there is an increasing need for innovative and alternative bioresources. Microalgal biomass is emerging as a valuable resource, rich in both macro- and micro-nutrients. It contains key biopolymers such as polysaccharides, proteins, and lipids, as well as bioactive secondary metabolites like vitamins, carotenoids, phycobiliproteins, polyphenols, and chlorophylls [2]. These components are essential not only for food and nutraceutical applications but also for the development of biopolymers and gel-based materials in various industrial sectors. Likewise, in this new era, the pressing need for scalable, economically viable, and environmentally sustainable gel-forming agents can be met by valorizing algal biomass [3,4,5]. Gels derived from microalgae may offer a renewable and functional alternative to conventional, resource-intensive gelling materials. Moreover, these microalgae-based gels may support the increasing demand for high-quality food products, contributing to a more sustainable and resilient food system.
Today, the microalgae industry is highly dynamic, with numerous new companies entering the market each year. In Europe alone, over 150 companies of various sizes are actively producing microalgae products, predominantly focusing on Arthrospira platensis (commonly known as Spirulina) [6,7]. In the United States, the microalgae-based food market is projected to expand significantly, reaching an estimated value of USD 359.87 million by 2032. This growth is driven by major food industry conglomerates investing in research and development to innovate and commercialize microalgae-based food products [8].
Microalgae, including cyanobacteria, have a rich history as a nutritional resource, traditionally consumed for centuries in various regions around the world [9]. Beyond their nutritional value, they are also recognized for their abundant diversity and adaptability, thriving in diverse environments including marine, brackish, and freshwater systems, as well as terrestrial and subaerial habitats [10]. They encompass over 73,000 identified species, though estimates suggest up to 10 million, most of which are autotrophic, while some can grow heterotrophically. Key groups include Cyanobacteria (prokaryotes) and various eukaryotic lineages such as Bacillariophyta, Haptophyta, Ochrophyta, Euglenozoa, Chlorophyta, and Rhodophyta. Despite being distinct, cyanobacteria and microalgae are often grouped due to their shared role as photosynthetic microorganisms [11].
Microalgae like Arthrospira (Spirulina), Chlorella, and Aphanizomenon are widely used for human consumption due to their high protein and nutrient content, while Dunaliella and Haematococcus are valued for their antioxidant carotenoids. In the food industry, microalgae are incorporated into protein powders, functional drinks, supplements, natural colorants, and antioxidants, offering nutritional and health benefits [9,12]. Beyond human nutrition, microalgae are being increasingly explored and utilized in the circular economy [13,14,15] for their potential in biodiesel production [16], recycling of food industry wastewater through microalgal remediation [17], and as a sustainable source of biomaterials, reflecting their broad utility and commercial value [13,16,17,18].
Today, microalgae are recognized for much more than their traditional use as dietary supplements. Their ease of cultivation and ability to grow under controlled conditions make them an attractive and sustainable source of valuable products [4,19]. Additionally, microalgae and cyanobacteria are increasingly valued for their capacity to generate innovative materials, particularly in the field of hydrocolloids and gel-forming agents, expanding their application potential well beyond traditional uses [4,20,21,22,23].
Recent research demonstrates that polysaccharides and proteins derived from microalgae can be engineered into hydrogels, offering valuable functionalities as texturizers, stabilizers, and controlled-release systems in functional foods [4,5,24,25]. For example, microalgal species like Porphyridium and Nostoc yield hydrogels suited to biomedical uses [26], while protein-rich algae like Spirulina and Chlorella can be formulated into gels for food technology and therapeutic delivery [3]. These developments also contribute to sustainability goals by reducing reliance on synthetic and animal-derived gelling agents.
To align with the principles of a circular economy, there is a pressing need to adopt novel biorefinery approaches that balance economic viability, social acceptance, and environmental responsibility. This review explores the potential of gels derived from marine microalgae for food applications, focusing on diverse species capable of producing functional gel-forming agents, including polysaccharides and proteins. It examines the mechanisms of gel formation, evaluates the functional and technological properties of these gels, and assesses their current and potential applications in the food industry and beyond. Overall, microalgae-derived gels represent a promising and sustainable alternative to conventional gelling agents, offering significant potential for innovation in future food formulations.
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Terpou, A.; Dahiya, D.; Nigam, P.S. Prospects of Gels for Food Applications from Marine Sources: Exploring Microalgae. Gels 2025, 11, 569. https://doi.org/10.3390/gels11080569
Read also our introduction article on Marine Ingredients here:
