# Emerging Trends in Sustainable Biological Resources and Bioeconomy for Food Production
## 4 Blue Bioeconomy Resources
### Algal-Derived Resources
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--triacylglycerol Sycerols (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].