Emerging Trends in Sustainable Biological Resources and Bioeconomy for Food Production

Abstract

The mounting global population and the challenges posed by climate change underline the need for sustainable food production systems. This review synthesizes evidence for a dual-track bioeconomy, green (terrestrial plants and insects) and blue (aquatic algae), as complementary pathways toward sustainable nutrition. A comprehensive review of the extant literature, technical reports, and policy documents published between 2015 and 2025 was conducted, with a particular focus on environmental, nutritional, and techno-economic metrics. In addition, precision agriculture datasets, gene-editing breakthroughs, and circular biorefinery case studies were extracted and compared. As demonstrated in this study, the use of green resources, such as legumes, oilseeds, and edible insects, results in a significant reduction in greenhouse gas emissions, land use, and water footprints compared with conventional livestock production. In addition, these alternative protein sources offer substantial benefits in terms of bioactive lipids. Blue resources, centered on micro- and macroalgae, furnish additional proteins, long-chain polyunsaturated fatty acids, and antioxidant pigments and sequester carbon on non-arable or wastewater substrates. The transition to bio-based resources is facilitated by technological innovations, such as gene editing and advanced extraction methods, which promote the efficient valorization of agricultural residues. In conclusion, the study strongly suggests that policy support be expedited and that research into bioeconomy technologies be increased to ensure the sustainable meeting of future food demands.

1. Introduction

1.1. Context of the Global Problem

Global population growth is one of the most pressing challenges of the 21st century, with profound implications for the sustainability of biological resources and global food security. The world’s population has now surpassed 8 billion people and is expected to reach 9.7 billion by 2050, according to United Nations estimates [1]. This increase is putting unprecedented pressure on food production systems and the ecosystems that support them, threatening both the capacity of natural resources and the stability of the economies that depend on them [2]. The intensification of agricultural production to meet future food needs has led to an expansion of arable land and intensive use of soils, resulting in the degradation of ecosystems, loss of biodiversity, and depletion of water resources. Agriculture, which already accounts for about 70% of global freshwater use and a third of greenhouse gas emissions, urgently needs to shift to more sustainable models to avoid overshooting planetary boundaries [3,4].

Climate change is profoundly altering agricultural production systems around the world, directly affecting the availability of essential biological resources for human food [5]. As global temperatures continue to rise, rainfall patterns are becoming more erratic and extreme weather events such as droughts, floods, and heat waves are intensifying. These changes affect crop productivity, alter natural growing cycles, and degrade the ecosystems that support agriculture. In addition, biodiversity loss, exacerbated by climate change, threatens the stability of agricultural ecosystems and the ecological services they provide, such as pollination and natural pest control [6].

Transforming food production for a sustainable future requires both technological innovation and systemic reform. Key strategies include adopting precision agriculture to reduce resource waste, promoting mixed and intercropping systems to improve soil health and resilience, and scaling up soilless methods like hydroponics, aquaponics, and vertical farming for efficient year-round production. Enhancing post-harvest infrastructure—such as cold storage and rural logistics—can significantly cut food losses. These advancements must be supported by public policies that incentivize sustainable practices, invest in research, and protect smallholders. Additionally, reforming markets and supply chains to support local food systems and improve traceability is essential to ensure efficiency, equity, and environmental integrity in future food systems. Similarly, the transition to a circular bioeconomy, based on the efficient use of biological resources and the reduction of the environmental impact of agriculture, is emerging as a viable alternative to ensure food security in an uncertain future [7].

Sustainable biological resources offer strategic solutions to mitigate these pressures and support long-term human development. These resources—such as insect protein, algae, mycoproteins, and plant-based alternatives—can reduce dependence on resource-intensive systems like livestock farming, which require large amounts of water, feed, and land.

1.2. The Bioeconomy as a Tool to Achieve Sustainability

Given the scale and urgency of today’s global challenges—ranging from climate instability and biodiversity loss to food insecurity and resource depletion—it is increasingly clear that conventional economic and production models are insufficient to ensure long-term sustainability. These interconnected crises demand systemic change that aligns environmental stewardship with economic development. In this context, the bioeconomic approach emerges as a strategic solution. By leveraging renewable biological resources, circular systems, and innovation in biotechnology, the bioeconomy offers a pathway to meet growing societal needs while reducing environmental impact and regenerating natural systems [8].

Bioeconomy is an economic model based on the sustainable use of renewable biological resources—such as plants, animals, micro-organisms, and biomass—to produce food, energy, materials, and industrial products. This approach uses advances in biotechnology, bioengineering, and environmental sciences to generate economic value from biological processes, with the aim of reducing dependence on non-renewable resources such as fossil fuels and mitigating environmental impacts [9]. The bioeconomy is closely related to the food industry as it provides innovative solutions to the challenges of food production in a more sustainable and efficient way.

In relation to SDG 2, the bioeconomy can improve food security through the development of new agricultural technologies, such as climate-resilient crops and biofertilizers that regenerate soils, enabling more efficient and sustainable food production. In addition, the conversion of agricultural residues into bioproducts (such as biofuels or bioplastics) can diversify income sources in rural areas, contributing to local economic development and poverty reduction [10].

In relation to SDG 12, the bioeconomy promotes a circular economy in which waste is valorized and the environmental impact of production is minimized. For example, reusing agricultural by-products or food waste to produce biogas or compost not only reduces waste but also creates new opportunities to produce clean energy or improve soil quality. This efficient and sustainable approach helps reduce the consumption of non-renewable resources, reduces the environmental footprint of the food industry, and is directly aligned with responsible production and consumption goals [10].

The transition to a sustainable bioeconomy represents a fundamental shift in the way we use natural resources, moving away from reliance on fossil fuels to an approach based on biomass and other renewable biological resources. This shift is crucial because fossil fuels such as oil, coal, and natural gas are not only finite and non-renewable, but their intensive use has contributed significantly to climate change, pollution, and ecosystem degradation. In contrast, biomass—which includes plants, agricultural residues, algae, and other organic materials—is a renewable resource that can be regenerated through natural processes or sustainable agricultural practices, offering a greener and more efficient alternative.

1.3. Policies and Regulatory Frameworks

In recent years, there has been a significant push towards policies that promote sustainability and the bioeconomy in food production, both globally and locally. These policies aim to transform food systems towards more sustainable models, minimizing environmental impacts, promoting the efficient use of natural resources, and encouraging the circular economy and the development of biotechnologies [11].

The United Nations has set 17 SDGs, which include specific targets for transforming food systems towards sustainability. Of particular note are targets related to zero hunger (SDG 2), responsible production and consumption (SDG 12), and climate action (SDG 13), which promote the bioeconomy and reducing waste in food production. On the other hand, the Food and Agriculture Organization of the United Nations (FAO) promotes a sustainable bioeconomy model in the food sector through its Strategic Framework, which focuses on improving resource efficiency, reducing waste, and utilizing agricultural and food by-products. Finally, the United Nations Framework Convention on Climate Change (UNFCCC), through initiatives such as the Paris Agreement, promotes emission reductions in the agricultural sector and the transition to sustainable practices, including incentives for low-emission and climate-resilient agricultural systems.

In light of the aforementioned global challenges, this review is driven by three primary motivations. Firstly, the escalating imperative to ensure food security for a progressively expanding global population underscores the necessity to identify sustainable and scalable biological resources. Secondly, there is mounting environmental pressure to reduce the ecological footprint of conventional food systems, particularly livestock production, which necessitates a transition to alternative, low-impact protein sources. Thirdly, recent policy developments and international sustainability frameworks, including the United Nations Sustainable Development Goals, have increasingly emphasized the importance of the bioeconomy in achieving systemic reform. In response to these drivers, the present review focuses on emerging green (terrestrial) and blue (aquatic) biological resources and their role in fostering resilient, circular, and low-carbon food systems aligned with global sustainability objectives.

The objective of this review is to comprehensively examine emerging trends in the sustainable use of biological resources within the context of the green and blue bioeconomy as they relate to food production. Special emphasis is placed on novel food sources such as plant-based proteins, edible insects, algal bioactives, and microbial fermentation products, as well as on innovative approaches to valorizing agricultural residues. The review also aims to explore how these strategies align with global sustainability frameworks (particularly the Sustainable Development Goals) and contribute to enhancing food security, minimizing environmental impact, and promoting circular economy principles in the agri-food sector.

2. Methodology

The present narrative review was designed to provide a systematic yet integrative appraisal of emerging biological resources for a green-and-blue bioeconomy. Initially, the authors established the scope of the inquiry by delineating three evidence domains (environmental performance, nutritional quality, and techno-economic feasibility) and subsequently constrained the investigation to primary and gray literature published from January 2015 to March 2025, a period that coincided with a marked acceleration in the development of bio-based innovations. A comprehensive search strategy was implemented in Web of Science, Scopus, and PubMed, complemented by targeted retrieval of policy papers from FAO, EU Directorate-General RTD, and OECD databases, and of patent and market reports via Google Scholar and Espacenet. Search strings are to be composed of Boolean operators, with core concepts (e.g., bioeconomy OR circular economy) to be linked with resource-specific terms (plant proteins, edible insects, micro-/macro-algae, single-cell protein). Duplicates were removed in EndNote, and titles/abstracts were screened independently by two reviewers against three inclusion criteria: The primary focus of the research should be on food or feed applications. In addition, the provision of at least one quantitative environmental, nutritional, or economic indicator is essential. Finally, the research must be supported by a peer-reviewed source or one that is publicly verifiable. Due to the narrative format and heterogeneity of the indicators, it was not possible to conduct a formal risk-of-bias scoring or meta-analysis. This leaves the findings vulnerable to publication bias and selective reporting. Restricting the search to English-language studies published between 2015 and 2025 may have excluded earlier or non-English studies.

3. Green Bioeconomy Resources

Green non-conventional bioeconomy resources, particularly plant-based and insect-based alternatives, are gaining considerable attention due to their potential to address global sustainability challenges.

3.1. Plant-Based Resources

In the green bioeconomy, plant-based resources play a pivotal role in the shift towards sustainable and environmentally friendly food production systems. Plant-derived proteins and oils are receiving growing attention not only as nutritional components but also due to their bioactive properties, which offer significant health benefits. With increasing global concerns over food security, environmental sustainability, and human health, plant-based resources are viewed as an essential tool in addressing these interconnected challenges [12,13,14].

Plant-based resources are inherently renewable and exhibit a considerably lower environmental impact compared to animal-derived products. They demand significantly less water, land, and energy, while also generating fewer greenhouse gas emissions [12,13]. Legume crops possess significant potential for conservation agriculture, serving effectively as both active growing crops and crop residues [15]. For instance, legumes significantly contribute to soil fertility through a symbiotic interaction with rhizobia, microorganisms that convert atmospheric nitrogen into a biologically available form via biological nitrogen fixation (BNF). This mechanism enhances soil nitrogen content, benefitting both the host plant and surrounding crops, while concurrently decreasing reliance on synthetic nitrogen fertilizers, thus promoting more sustainable agricultural practices. They contribute high-quality organic matter to the soil [16], enhancing nutrient circulation and improving water retention [17]. Furthermore, these plant crops can be grown in a wide range of climates, ensuring the diversification of food production systems and enhancing food security [18]. The shift toward plant-based diets, combined with the bioeconomy’s focus on sustainability, is driving innovations in the ways plants are utilized for human consumption [19,20,21].

As mentioned earlier, the environmental footprint of plant-based resources is considerably smaller compared to animal-based products. A 2020 study by Poore and Nemecek demonstrated that shifting from animal-based to plant-based proteins in the United States could reduce individual food-related greenhouse gas emissions by up to 73% [13]. This is largely because plant cultivation requires fewer resources and leads to reduced deforestation and land degradation [12,13]. For instance, producing 1 kg of beef requires approximately 15,000 litters of water, whereas 1 kg of lentils only requires about 1200 litters [22]. In fact, it takes 2 to 15 kg of plant foods to produce just 1 kg of meat, highlighting the greater efficiency of grain-based diets [23].

Plant-based proteins and oils are often lower in saturated fats and cholesterol compared to animal-based alternatives, making them more suitable for maintaining cardiovascular health [24]. Moreover, plants are being investigated not only for their nutritive value and macronutrient content, such as proteins, carbohydrates, and fats, but also for their bioactive compounds, which have demonstrated potential in promoting health and preventing diseases with antioxidant, anti-inflammatory, and antimicrobial properties [14].

The growing awareness of the negative health effects of red and processed meat, along with concerns about the environmental impact of animal products, is driving the shift toward sustainable plant-based diets with reduced animal product consumption [20,25]. Plant-based proteins and oils are being incorporated into a variety of food products, from meat substitutes and dairy alternatives to snacks and nutritional supplements [23]. To date, various applications of pea protein within the food industry have been thoroughly researched. These include its use in encapsulating bioactive ingredients, creating edible films, producing extruded products, and substituting for cereal flours [26]. Plant-based meat alternatives, such as those made from soy, pea protein, or wheat gluten (seitan), have gained significant traction in the market [19,20,25,26]. The plant-based meat alternatives global market is projected to increase from USD 1.6 billion in 2019 to USD 3.5 billion by 2026 [25].

Functional foods are foods that offer potential health benefits beyond basic nutrition, contributing to overall well-being and potentially reducing the risk of certain diseases. Due to the previously mentioned health benefits, plant-based ingredients with bioactive properties are increasingly being incorporated into functional foods that are designed to provide health advantages beyond basic nutrition [27,28]. Examples of such benefits include plant oils like flaxseed oil and hemp oil, which are rich in omega-3 fatty acids that support heart health and cognitive function [29,30]. Additionally, plant-derived polyphenols, such as those found in green tea, are being integrated into foods and beverages for their potent antioxidant and anti-inflammatory properties and their effects against cancer and other diseases such as diabetes and neurological and cardiovascular diseases [31].

Within the food sector, plant-based resources align with the goals of the bioeconomy by offering a means of producing nutritious, affordable, and eco-friendly foods [12,13,22]. Furthermore, the development of plant-based products encourages innovation in agriculture and food technology, driving the creation of new supply chains and business models that support local economies and reduce dependency on imported commodities [20,21,25]. However, while shifting to plant-based agriculture is often linked to land conservation, this assumes optimal land conversion practices and overlooks regional variations in soil fertility, crop suitability, and socio-political constraints [32]. In certain contexts, livestock production may still offer advantages in terms of livelihoods, cultural significance, or the use of marginal lands unsuitable for crops. In addition, there is limited longitudinal and region-specific data on the long-term effects of large-scale dietary shifts on agricultural biodiversity, food system resilience, and rural economies. Second, more inter-disciplinary research is needed to assess how emerging plant-based innovations interact with social equity and food sovereignty frameworks [33].

3.2. Insect-Based Resources

The concept of sustainability is gaining increasing importance on a global scale. Consequently, it is imperative to identify alternative food sources to replace traditional ingredients that are less sustainable. One potential option could be to utilize proteins, lipids, and fibers derived from edible insects as food components, serving as substitutes for existing ones [34]. The practice of consuming insects as a regular dietary component has been documented in numerous regions across the globe for millennia [35]. This phenomenon is referred to as entomophagy. As van Huis et al. (2013) [35] demonstrate, the following insects are of interest in this study: beetles, caterpillars, bees, wasps, ants, grasshoppers, locusts, crickets, cicadas, leaf and planthoppers, scale insects and true bugs, termites, dragonflies, and flies [36].

Insects can provide many benefits for human health as they have a high nutritional value. In this sense, insects are rich in protein, healthy fats, calcium, iron, and zinc [35]. However, the resulting nutritional profile of insects depends on the species, development stage, diet, and processing [36]. There are some advantages associated with the use of insects as novel food. Insect farming is presented as a sustainable alternative to traditional livestock to meet the growing demand for protein products in the market and emerging nutritional needs [37]. Moreover, there is an environmental effect that the consumption of insects can have. In terms of food production, insects lead to lower emissions of greenhouse gases or ammonia than traditional farm animals; they do not require extensive land for their production, insects are more efficient in converting feed to protein as they are cold-blooded animals, and they can be fed with organic waste [35]. Therefore, insects are presented as a very good candidate for the future of sustainable food production [38,39]. The insects most commonly farmed for food and feed are the yellow mealworm (Tenebrio molitor L.), the house cricket (Acheta domesticus L.), the black soldier fly (Hermetia illucens L.), and the common housefly (Musca domestica L.) [40].

Insects are not only used as direct raw materials in the food industry, but they also have the potential to produce a wide range of high-value products. One of the most notable products is honey, which is produced by bees, with an estimated annual production of 1.2 million tons. Another significant product is carmine, a red dye derived from scale insects that is widely used in coloring food, textiles, and pharmaceuticals [35]. On a global level, the most consumed insects, 31%, are beetles (Coleoptera). They are followed by caterpillars (Lepidoptera), at 18%; bees, wasps, and ants (Hymenoptera), at 14%; grasshoppers, locusts, and crickets (Orthoptera), at 13%; and cicadas, leafhoppers, planthoppers, and scale insects (Hemiptera), at 10%. For the food industry, mealworms, which are the larvae of the mealworm beetle (Tenebrio molitor), are one of the favorite applicants [41]. In addition, Tenebrio molitor, Acheta domesticus, and Locusta migratoria are very versatile insects, as they can be used as complements of edibles such as potatoes, legumes, cereal-based products, pasta-based products, soups, nuts, oilseeds and chickpeas, meat analogues, and beverages [42].

While the use of insects as a food source has been practiced for centuries, insects are seen as a relatively new culinary trend in many Western countries. As a result, one important factor to consider when incorporating insects or their derivatives into food production is the applicable regulatory framework [43]. One potential solution involves extracting proteins and lipids from insects for use as ingredients in food products [34]. Although edible insects are often proposed as a potential alternative food source, it is crucial to recognize the associated allergy risks. Edible insects can trigger allergic reactions that could affect humans as they contain some proteins that are contemplated as allergens, such as arginine kinase, α-amylase, and tropomyosin [44]. Another important consideration is the possibility of cross-reactivity between allergens found in different insect species as well as the presence of chitin in the exoskeletons of some insects [45,46]. Chitin may pose nutritional challenges and can impact protein digestibility, although some enzymes in the human gastrointestinal tract have been shown to digest chitin [47,48]. However, appropriate techniques for preparing food can decrease the chance of cross-reactivity and allergy risks in food that contains insects. Methods like heat treatment and enzymatic breakdown are examples of these techniques [49].

When considering insects as a new source of food, it is important to understand and comply with the relevant legal guidelines and regulations [44]. For this reason, the production and marketing of insects as a food source in Europe is regulated by EU Reg 2015/2283 [50]. However, the legal classification of insects remains ambiguous, often fluctuating between being considered livestock, pests, or industrial inputs, which affects how they are regulated, subsidized, and integrated into national bioeconomy strategies. Despite their growing importance, insects exist in a legal gray area. Most jurisdictions lack comprehensive regulations addressing their farming, processing, welfare, and trade. In many cases, food and feed safety laws are not well-adapted to insect products, approval processes are slow, and welfare considerations are nearly absent [51]. Additionally, the use of insects in environmental services or biotechnology raises questions about biodiversity, invasive species, and intellectual property, which require legal oversight. To support a sustainable bioeconomy, legal systems must provide clear definitions, create insect-specific standards, and ensure regulatory consistency across sectors and borders.

Furthermore, while many studies tout insect farming as environmentally beneficial, the environmental impact of large-scale insect farming is still not fully understood. Key questions remain around energy use in climate-controlled rearing environments, the long-term ecological effects of diverting organic waste to insect feed, and the carbon footprint of processing insects into consumer-ready products. There is also ambiguity around consumer acceptance. Cultural preferences and psychological aversions (the “yuck factor”) in Western societies present significant barriers to the mainstream adoption of edible insects [35]. Despite technological advancements in integrating insect-based ingredients into familiar food forms, shifting consumer perceptions remains a challenge—one that is often underemphasized in technical or environmental assessments.

In summary, while there is widespread consensus about the potential of insects as sustainable and nutritious food sources, the field must address several contradictions and gaps related to nutritional variability, consumer behavior, safety and scalability.

4. Blue Bioeconomy Resources

The blue bioeconomy represents an innovative and sustainable approach to harnessing marine and aquatic biological resources with significant potential to address global food security challenges. In recent years, considerable attention has been focused on exploring the diverse applications of marine organisms, driven by their rich biodiversity and unique biochemical properties. This section of the review highlights emerging trends and recent advancements in two critical areas of the blue bioeconomy: algae and marine collagen.

Algal-Derived Resources

Algae are emerging as a promising alternative protein source due to their high nutritional value, rapid growth rate, and minimal environmental footprint. Both microalgae (such as Spirulina and Chlorella) and macroalgae (seaweeds) contain significant amounts of protein, essential amino acids, vitamins, and antioxidants. Unlike traditional crops, algae can be cultivated on non-arable land using saline or wastewater, making them highly sustainable. Their versatility in food applications—from supplements to meat alternatives—positions algae as a key player in the future of sustainable nutrition.

Marine algae, encompassing both microalgae and macroalgae, represent a heterogeneous group of photosynthetic organisms that are not taxonomically unified but are functionally critical to aquatic ecosystems and the global carbon cycle. These organisms reduce atmospheric CO₂ through oxygenic photosynthesis—predominantly via chlorophyll a—contributing to nearly 50% of global photosynthetic activity [52].

From a biotechnological perspective, both groups of algae offer distinct advantages and limitations that are critical to valorization pathways in the blue economy. Microalgae are characterized by high growth rates, metabolic plasticity (autotrophic, mixotrophic, or heterotrophic modes), and the ability to be cultivated under controlled conditions (e.g., photobioreactors), making them ideal for large-scale industrial use. They are widely exploited for the production of high-value compounds such as proteins, lipids, carotenoids, polyunsaturated fatty acids, and antioxidants, with applications in nutraceuticals, pharmaceuticals, cosmetics, aquaculture, and wastewater treatment [53]. Meanwhile, macroalgae play a key ecological role in coastal ecosystem stability, primary productivity, and habitat provision. They are traditionally used in food, agriculture, and hydrocolloids (e.g., agar, alginates, carrageenan) and are gaining momentum for biofuel, bioplastic, and bioactive compound production. However, macroalgal biomass—especially in the form of marine macroalgal waste (MMW) from blooms like Sargassum—can also pose environmental risks, including GHG emissions and disease vector proliferation. The valorization of algal biomass, particularly from waste streams, supports a circular bioeconomy by converting low-value or problematic residues into valuable bioproducts, though technical and economic challenges remain in optimizing scalability, biomass consistency, and extraction efficiency. Thus, understanding the physiological, ecological, and biotechnological differences between micro- and macroalgae is essential for leveraging their full potential in sustainable marine resource exploitation [54].

Algal proteins derived from microalgae such as Spirulina, Chlorella, and Nannochloropsis have attracted increasing attention as sustainable and nutritious alternatives to traditional animal-based proteins. These microalgal proteins are rich in essential amino acids, such as leucine, lysine, and phenylalanine, alongside valuable micronutrients like vitamins and minerals, making them suitable for human nutrition, pharmaceutical applications, and industrial formulations. Notably, species like Spirulina platensis and Chlorella vulgaris contain approximately 51–58% protein by dry weight, with high concentrations of essential amino acids such as leucine, lysine, and phenylalanine [55]. Nannochloropsis species, including N. oculata and N. gaditana, also demonstrate notable protein content, with values ranging from 35% to 71% of dry matter. These microalgae are particularly rich in glutamic acid and aspartic acid, contributing to their umami flavor profile [56,57,58]. Chlorella stands out not only for its high protein content but also for its versatility in cultivation, particularly in wastewater treatment systems, thus providing an environmentally responsible and economically viable approach to food security and sustainability [59]. The amino acid profile of algal proteins is comparable to that of traditional plant proteins, making them an appealing choice for various applications.

Beyond their nutritional value, algal proteins are gaining attention for their bioactive properties, which are particularly relevant in the pharmaceutical sector. Bioactive peptides derived from these proteins have shown potential antimicrobial, anti-inflammatory, and antioxidant activities, making them viable candidates for nutraceuticals and drug delivery systems [60]. These bioactive peptides can also be utilized in the development of supplements aimed at supporting immune function, reducing inflammation, and combating oxidative stress. Furthermore, algal proteins can serve as carriers or excipients in drug delivery formulations, thereby improving the bioavailability of active compounds.

A key aspect of algal protein utilization is its digestibility, which varies depending on the species and processing methods used. Digestibility is a critical factor influencing the bioavailability of these proteins, and several studies have explored this aspect. For instance, research shows that the crude protein digestibility of Nannochloropsis is about 54% in non-cell-disrupted forms, while Chlorella can reach up to 84% digestibility when cell disruption techniques are employed [61]. This variation highlights the importance of processing techniques to improve the digestibility and absorption of algal proteins. Additionally, cell-wall disruption is necessary to enhance the release of intracellular proteins and other bioactive compounds, ensuring that the proteins are bioavailable in human consumption.

The commercial utilization of algal proteins, however, faces several challenges. Production costs remain high due to the need for specialized cultivation systems, such as photobioreactors, and efficient protein extraction techniques. Furthermore, the variability in protein content among different species and cultivation conditions adds complexity to large-scale production. Despite these challenges, algal protein production offers significant environmental advantages over traditional animal farming, including a lower carbon footprint and the potential for carbon sequestration during cultivation. Furthermore, the use of waste streams for algal cultivation, as demonstrated with Chlorella, can contribute to a circular economy by recycling nutrients and minimizing waste [62].

Algal oils, especially those derived from marine microalgae, are valuable sources of long-chain polyunsaturated fatty acids (LC-PUFAs), primarily omega-3 fatty acids such as docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). These fatty acids are essential for human health, playing crucial roles in cardiovascular protection, neural development, visual acuity, and the modulation of inflammatory responses [63]. Among algae, microalgae are the predominant producers of these oils, whereas macroalgae tend to have a lower total lipid content and a different fatty acid composition, with fewer LC-PUFAs and more structural lipids [64].

Algal lipids are composed of various fatty acid types, including saturated fatty acids (SFAs), monounsaturated fatty acids (MUFAs), and polyunsaturated fatty acids (PUFAs), which can be further classified into omega-3 (e.g., DHA, EPA), omega-6 (e.g., linoleic acid), and omega-9 (e.g., oleic acid) families. Omega-3 fatty acids, particularly docosahexaenoic acid (DHA), are of significant interest due to their anti-inflammatory, neuroprotective, and cardiovascular benefits. Algal species such as Rugulopteryx okamurae have demonstrated high omega-3 content, with DHA levels comparable to or exceeding those found in traditional fish oils [65]. The distribution of these fatty acids within lipid classes—triacylglycerols (TAGs), phospholipids, and glycolipids—affects their nutritional and functional properties. DHA, for instance, is often concentrated at the sn-2 position in TAGs, which enhances its digestibility and absorption in the human gut [63].

This structural specificity contributes to the superior bioavailability of algal-derived omega-3s compared to synthetic or non-marine sources. Omega-6 fatty acids, while also crucial for human health, must be balanced with omega-3s to prevent pro-inflammatory effects, underscoring the importance of maintaining a proper ratio between these two essential fatty acids in the diet. Omega-9 fatty acids, found in some algal oils, support cardiovascular health and are increasingly utilized in skincare products for their emollient and anti-aging properties [66]. Together, these fatty acids, combined with eco-friendly cultivation practices, make algal oils a sustainable and nutritionally beneficial alternative to traditional sources of omega-3 fatty acids, offering valuable applications in food, nutraceuticals, and cosmetics.

Moreover, the extraction of algal oils can be performed using several methods, including cold pressing, organic solvent extraction, and more advanced techniques such as supercritical CO₂ extraction. Supercritical CO₂ is particularly advantageous for preserving thermolabile compounds and achieving high selectivity and purity without solvent residues, aligning with green chemistry principles. Moreover, emerging techniques like enzyme-assisted extraction and ultrasound- or microwave-assisted extraction have been developed to enhance yield and reduce energy inputs, although their scalability remains under investigation [67,68].

Algal oils are increasingly utilized in high-value sectors such as food, nutraceuticals, cosmetics, and the bioindustry due to their rich content of long-chain polyunsaturated fatty acids, particularly DHA and EPA. In the nutrition sector, they serve as plant-based alternatives to fish oil, used in supplements and fortified foods like infant formulas and dairy substitutes. In cosmetics, their antioxidant and moisturizing properties support applications targeting skin aging, inflammation, and barrier repair. Additionally, their high lipid productivity renders certain microalgal strains promising for industrial use, including the production of biofuels, bioplastics, and eco-friendly lubricants. Moreover, advanced encapsulation systems using prebiotic compounds such as inulin and chitosan have demonstrated the potential to enhance the oxidative stability, solubility, and functional properties of algal oils, positioning them as sustainable, eco-friendly functional ingredients for use in food and nutraceutical applications [69,70,71].

In conclusion, algal oils, particularly from microalgae, represent a promising and sustainable source of high-value lipids for nutritional, pharmaceutical, cosmetic, and industrial applications. Continued innovation and investment in algal research and bioprocessing technologies will be key to unlocking their full commercial potential in the context of the growing demand for clean-label and eco-friendly products.

5. Common Resources in Green and Blue Bioeconomy

5.1. Fermented Proteins

Microbial fermentation is a sustainable method of producing high-quality protein for food systems. Fermented proteins, also referred to as single-cell proteins (SCP), are defined as the protein-rich biomass derived from microbes such as filamentous fungi, yeast, and bacteria cultivated in controlled environments [72]. These microbes have the capacity to convert a variety of feedstocks, ranging from sugars to agricultural residues and even gases, into edible biomass, thereby presenting a promising alternative to conventional animal proteins. In the context of escalating global protein demand, SCP offers a strategy to “decouple” protein production from land and water constraints, thereby reducing the environmental impact of food production [73]. Fermentation-based protein production is typically rapid and efficient, yielding biomass in a matter of hours or days, in contrast to the months or years required for plant and animal proteins. This efficiency is reflected in a significant reduction in resource consumption and greenhouse gas emissions. For instance, the carbon footprint of fungal mycoprotein has been documented as being ten times lower than that of beef and four times lower than that of chicken [74]. Furthermore, its lifecycle greenhouse emissions per kilogram are even lower than those of soy or pea protein [75]. Such reductions in emissions and land use underscore the sustainability advantages of fermented microbial proteins over traditional protein sources.

Fermented proteins are known to offer favorable nutritional properties. Filamentous fungi have been found to produce biomass with 30–50% protein (dry weight) and an amino acid profile that adheres closely to the standards set out by the Food and Agriculture Organization (FAO), with notable richness in lysine and threonine [72]. Fungal mycoprotein, produced from Fusarium venenatum in continuous fermenters, has been shown to be high in protein and to naturally contain approximately 25% dietary fiber (largely β-glucans and chitin from cell walls), in addition to micronutrients such as B-vitamins, selenium, and zinc [76]. Indeed, the Quorn™ mycoprotein product has been consumed in over eight billion meals since its 1985 launch, attesting to its commercial success and consumer acceptance. A plethora of studies have indicated the potential health benefits of fungal protein, suggesting its functionality as a prebiotic fiber, its ability to assist in the regulation of blood cholesterol and glucose levels, and its capacity to support muscle protein synthesis. Yeast-derived proteins have similarly high protein content (often ~40–55%) and are rich in B-vitamins. Yeast biomass and extracts (e.g., nutritional yeast) are already used to fortify foods or impart savory flavors. Bacterial SCP has been found to contain elevated levels of protein (50–80%), exhibiting favorable amino acid profiles. However, the high nucleic acid content (RNA) of these samples frequently necessitates processing to avert the occurrence of purine overload [76]. It is noteworthy that certain bacterial fermentations yield valuable co-products. For instance, many bacteria and yeast synthesize vitamins or antioxidants along with protein, thereby enhancing the nutritional profile of biomass. It is evident that fermented microbial proteins have the capacity to supply essential amino acids that are comparable to those derived from traditional animal sources. This renders them a potentially viable option for both human nutrition and food security.

A significant motivator for the exploration of fermented proteins is their capacity to reduce the environmental impact. The cultivation of microbes in bioreactors necessitates a significantly reduced land area in comparison to the raising of crops or livestock. Furthermore, these bioreactors can be utilized in non-arable locations. It has been demonstrated that water requirements are reduced and that closed fermentation systems are capable of recycling nutrients in an efficient manner. Life-cycle assessments demonstrate that mycoprotein-based foods generate a significantly lower quantity of greenhouse emissions and utilize less water and land than meat equivalents [76]. Furthermore, the process of fermentation has the capacity to enhance the value of substrates that may be considered low-value, thereby contributing to the establishment of a circular bioeconomy. For instance, certain yeast and fungal species have been found to be capable of utilizing agricultural by-products or even wood hydrolysates as a nutrient source, thereby facilitating the conversion of waste materials into edible protein. Innovative approaches utilize methane-oxidizing bacteria or hydrogen-oxidizing bacteria, which feed on greenhouse gases (methane, CO₂) with renewable energy to produce protein-rich biomass, essentially “food from air” [73]. This suggests a future in which the supply of protein is increasingly decoupled from conventional agricultural practices. Furthermore, microbial protein production engenders a reduced level of pollutants (e.g., no manure or methane from enteric fermentation) and can be situated in close proximity to consumer markets, thereby reducing transportation-related emissions.

5.2. Natural Polyphenols and Antioxidants

Bioactive compounds are naturally occurring chemical constituents found in small quantities in plants and other natural sources. These compounds have the capacity to interact with biological systems, thereby producing health-promoting effects [77]. These compounds can be classified into different categories according to their chemical structure and functions, including phenolic compounds, terpenoids, alkaloids, carotenoids, and organosulfur compounds [78]. Their physiological activities encompass antioxidant, anti-inflammatory, and antimicrobial functions, among others, rendering them valuable for applications in functional foods, nutraceuticals, and pharmaceuticals [79,80,81].

Of these, phenolic compounds represent the most substantial and varied group of plant secondary metabolites, comprising over 10,000 known structures. Structurally, these compounds are characterized by one or more aromatic rings with one or more hydroxyl groups, ranging from simple phenols to complex polymers such as tannins and lignans [82]. Phenolic compounds are distributed widely in a variety of foodstuffs, including fruits, vegetables, grains, herbs, and beverages such as tea and wine. In plants, these compounds fulfill a number of physiological functions and play a significant role in defense against environmental and biological stressors. Moreover, their presence in foods has been demonstrated to contribute to organoleptic characteristics, including color, bitterness, and aroma [83,84].

In recent decades, phenolic compounds have attracted considerable attention due to their ability to exhibit a wide spectrum of biological effects, including antioxidant, anti-inflammatory, anticancer, antiviral, and immunomodulatory actions [77]. The central role of their antioxidant capacity in their health-promoting potential is evidenced by their ability to neutralize reactive oxygen species (ROS), thereby mitigating oxidative stress, a factor implicated in the onset of conditions such as cardiovascular diseases, cancer, diabetes, and neurodegenerative disorders. Beyond ROS scavenging, phenolic compounds have been demonstrated to modulate signaling pathways, induce apoptosis, arrest cellular proliferation, and potentially reverse epigenetic alterations associated with disease progression. Evidence has been posited to suggest a dual antioxidant and pro-oxidant behavior, which would be contingent on the cellular environment. This behavior could be a contributing factor to their chemopreventive effects. In addition, phenolic compounds have been demonstrated to support immune function by downregulating chronic inflammation and inhibiting angiogenesis in tumor development [82,85].

Polyphenols are present in a wide variety of plant-derived foods, though their concentrations and significance vary substantially among sources. On a global scale, the most significant contributors to polyphenol intake are commodities that are both rich in polyphenols and widely consumed, such as green and black tea, red wine, coffee, and cocoa [86]. Fruits and vegetables are commonly cited as sources of phenolic compounds; however, their overall contribution is often secondary, due to lower concentrations and variability in content. Nonetheless, specific fruits like berries, grapes, and pomegranates; and vegetables like onions, garlic, or spinach contain notable levels of flavonoids and phenolic acids [87]. Other important sources of structurally unique phenolic compounds with high antioxidant potential are different herbs and spices, nuts, oilseeds, extra virgin olive oil, and certain algae [88]. Additionally, polyphenols can be delivered through plant extracts used in dietary supplements, pharmaceuticals, and nutricosmetics, extending their relevance beyond conventional food matrices.

In recent years, the search for novel sources of phenolic compounds has intensified, driven by the growing demand for bioactive ingredients in the functional food and nutraceutical industries. Nowadays, researchers and industries alike have turned their attention to alternative and underutilized matrices, particularly those aligned with sustainability goals. In this context, agro-industrial by-products (fruit peels, seeds, pomace, and other processing residues) have emerged as promising raw materials rich in phenolic compounds [89]. These by-products often contain significant amounts of polyphenols, polysaccharides, organic acids, and other functional molecules, making them economically attractive and environmentally responsible options for ingredient development [79]. Residues from grape, apple, and pomegranate processing are rich in high-value phenolics such as anthocyanins and tannins [90,91]. Avocado peels contain important amounts of procyanidins, catechin, and phenolic acids [92]. Grape pomace, for example, retains about 70% of the polyphenols present in grapes and has shown strong antioxidant and antimicrobial activity [93]. Similarly, spent coffee grounds and palm oil effluents have emerged as viable sources of antioxidants when processed appropriately [94,95]. Other non-conventional sources include edible mushrooms, macroalgae [96], edible flowers [97], and dandelion seeds [98], which untapped polyphenolic profiles.

The efficient extraction of phenolic compounds from plant matrices is of crucial importance for their application in the food and health sectors. Conventional extraction methodologies, encompassing maceration, Soxhlet extraction and reflux, have been extensively utilized. Nevertheless, these techniques are frequently subject to criticism due to their extended processing times, substantial energy demands, and reliance on hazardous solvents [77]. These limitations have prompted the development of greener and more efficient extraction techniques that aim to increase extraction yield while minimizing environmental impact. Among emerging technologies, ultrasound-assisted extraction (UAE) has proven effective due to its ability to enhance mass transfer through cavitation, reducing both extraction time and solvent usage [79]. Microwave-assisted extraction (MAE) has been demonstrated to accelerate the rupture of cell walls and the solubilization of target compounds, thus offering a high yield in a reduced time frame [77]. Supercritical fluid extraction (SFE), particularly employing CO₂, is optimal for thermosensitive compounds and yields solvent-free extracts. The methodology has been successfully applied to matrices such as dandelion seeds and garlic [98,99]. Another promising method is the use of natural deep eutectic solvents (NADES), which are biodegradable and capable of solubilizing a wide range of phenolics due to their strong hydrogen-bonding networks [94]. Enzyme-assisted extraction (EAE) has been shown to be a particularly effective method for the breakdown of plant cell walls, with the purpose of releasing bound phenolics, particularly in fruit and vegetable by-products [93].

These innovative extraction technologies are in alignment with sustainability principles and allow for the valorization of food industry waste streams. When integrated with scalable industrial processes, they offer an environmentally friendly and economically viable route to producing high-quality phenolic-rich extracts for nutraceutical and functional food applications [89,100].

Notwithstanding the advantages inherent in phenolic compounds, their bioavailability is influenced by a multitude of factors, including chemical structure, molecular size, release in the food matrix, conjugation with other compounds, degree of polymerization, solubility, metabolism, and intestinal absorption [82,84]. In order to capitalize on the full therapeutic potential of phenolic compounds in the prevention and management of chronic diseases, it is essential to enhance their bioavailability. In order to address these challenges, a number of strategies have been developed.

• Chemical modification, encompassing a range of reactions such as methylation and glycosylation, is a fundamental aspect of biological research.
• Nanoparticle encapsulation is a method of protecting materials from degradation and enabling targeted release. Polyphenols have been found to be compatible with nanospheres, micelles, and liposomes, enhancing aqueous solubility and cellular uptake [99].
• Emulsion-based systems have been shown to provide controlled release and improved dispersion, making them useful in both the pharmaceutical and functional foods industries [101].
• The incorporation of the subject into polymeric carriers, including but not limited to chitosan, dendrimers, and cyclodextrins, has been demonstrated to enhance solubility and stability in aqueous environments [78].
• Solid dispersions (where polyphenols are dispersed in hydrophilic carriers) have been shown to enhance the dissolution rate and absorption in gastrointestinal fluids.
• Supercritical fluid technologies and nanoprecipitation offer precise control over particle size, thereby improving surface area and, consequently, dissolution rate.

The integration of agro-waste valorization with bioavailability enhancement represents a frontier approach. The combination of green extraction from food waste with advanced delivery technologies has the potential to yield high-value, sustainable ingredients, as reported previously in some studies [102].

6. Conclusions

This review has identified and analyzed key innovations in the sustainable utilization of biological resources within the food production sector, emphasizing their role in transitioning toward a green and blue bioeconomy. Among the most promising solutions are plant-based proteins, insect-derived ingredients, algal bioactives, microbial fermentation products, and upcycled dietary fibers. These resources offer substantial environmental and nutritional advantages, contributing to reduced greenhouse gas emissions, decreased reliance on conventional livestock, and enhanced food system resilience.

The sustainable biological resources examined in this review offer a wide range of practical applications across the food industry, with the potential to enhance nutritional value, reduce environmental impact, and support circular economy models. For instance, insect-derived flours, such as those derived from Tenebrio molitor or Acheta domesticus, are being incorporated into protein-rich snacks, pastas, and baked goods, thus offering a high-protein, low-impact alternative to conventional animal proteins. Algae-derived oils, which are rich in DHA and EPA, are currently used in infant formulas, dietary supplements, and functional beverages as plant-based omega-3 sources, thereby reducing reliance on fish-derived lipids. Moreover, the utilization of upcycled plant by-products, including but not limited to apple pomace, citrus peels, and grape skins, has seen a marked increase in recent times. These by-products find application in the enrichment of bakery products and cereals with dietary fiber and polyphenols. This dual benefit of the use of upcycled plant by-products is twofold: firstly, it serves to address issues of food waste, and secondly, it serves to enhance the functionality of the end product. These innovations are not only technologically feasible but are also gaining consumer acceptance and regulatory approval in various markets. The scaling up of such applications will require investment in infrastructure, targeted policy support, and further research into sensory optimization and consumer education. However, their current trajectories suggest a promising and actionable path toward more sustainable food systems.

However, despite their potential, several barriers to implementation remain. Regulatory frameworks for novel foods, particularly insect-based and microbial proteins, are still underdeveloped or inconsistent across regions. Consumer acceptance is another critical limitation, especially in Western markets, where cultural perceptions pose challenges to the adoption of insect-based and algae-derived ingredients. Technical obstacles, such as the high cost and scalability of algal protein production or the limited digestibility of some alternative proteins, also constrain widespread application. Moreover, economic viability is often dependent on policy incentives and infrastructure investments that are currently lacking in many regions.

To fully realize the benefits of sustainable biological innovations, it is imperative to address these limitations through coordinated efforts across policy, industry, and research. Future strategies should focus on harmonizing regulations, investing in consumer education, scaling up cost-effective technologies, and fostering cross-sectoral collaboration to build resilient, circular food systems. Only through such systemic efforts can these emerging resources transition from niche applications to transformative solutions for global food security and environmental sustainability.