The microalga Chlorella vulgaris is a popular food ingredient widely used in the industry, with an increasing market size and value. Currently, several edible strains of C. vulgaris with different organoleptic characteristics are commercialized to meet consumer needs. This study aimed to compare the fatty acid (FA) and lipid profile of four commercialized strains of C. vulgaris (C-Auto, C-Hetero, C-Honey, and C-White) using gas- and liquid-chromatography coupled to mass-spectrometry approaches, and to evaluate their antioxidant and anti-inflammatory properties. Results showed that C-Auto had a higher lipid content compared to the other strains and higher levels of omega-3 polyunsaturated FAs (PUFAs). However, the C-Hetero, C-Honey, and C-White strains had higher levels of omega-6 PUFAs. The lipidome signature was also different between strains, as C-Auto had a higher content of polar lipids esterified to omega-3 PUFAs, while C-White had a higher content of phospholipids with omega-6 PUFAs. C-Hetero and C-Honey showed a higher content of triacylglycerols. All extracts showed antioxidant and anti-inflammatory activity, highlighting C-Auto with greater potential. Overall, the four strains of C. vulgaris can be selectively chosen as a source of added-value lipids to be used as ingredients in food and nutraceutical applications for different market needs and nutritional requirements.

Olive oil is one of the most important agricultural products in Mediterranean areas, and currently the European Union is the largest producer. Due to technological innovations, Portugal has become one of the main olive oil producing countries over the last few years, accompanied by large amounts of olive oil pomace (OOP), the most representative residue of the olive oil extraction process. This is causing serious waste management problems since current management solutions also present environmental impacts. Here we explored the black soldier fly (Hermetia illucens) potential to biotransform OOP into valuable insect meals by feeding them OOP-based diets as substrates. Results show that despite survival rates not being affected by higher replacement (75% and 50%) levels of OOP, there was an increase in larval instar duration. Substrate reduction was significantly lower for higher replacement levels but was not affected up to the 50% replacement level. Feed conversion rate differed among all the treatments, increasing as the replacement level increased, while bioconversion rate, which also differed among all the treatments, decreased as replacement level increased. Differences in larval protein content were only seen at higher replacement levels (75%), with an increase in protein content for replacements of up to 25%. One of the most striking results was the change in fatty acid profile, which became more abundant in monounsaturated fatty acids (mostly oleic acid) as the olive pomace replacement levels increased in comparison with the control substrate, rich in saturated fatty acids (palmitic acid). These results show that BSF can be an effective OOP bioconversion agent, and resulting insect meals can be used as alternatives to currently available saturated fatty acid insect meals.

Dunaliella salina is a green microalga extensively explored for β-carotene production, while knowledge of its lipid composition is still limited and poorly investigated. Among lipids, polar lipids have been highlighted as bioactive phytochemicals with health-promoting properties. This research aimed to provide an in-depth lipidome profiling of D. salina using liquid and gas chromatography coupled with mass spectrometry. The lipid content was 6.8%, including phospholipids, glycolipids, betaine lipids, sphingolipids, triglycerides, diglycerides, and pigments. Among the total esterified fatty acids, 13.6% were 18:3 omega-3 and 14.7% were 18:1 omega-9. The lipid extract of D. salina showed anti-inflammatory activity by inhibiting cyclooxygenase-2 activity at 100 µg/mL, dose-dependent antioxidant scavenging activity, and antidiabetic activity by inhibiting α-glucosidase activity at 25 and 125 µg/mL. In conclusion, the lipid extract of D. salina has the potential to be used as a functional food ingredient or in the nutraceutical and cosmeceutical industries.

The microalgae Chlorella vulgaris and Tetraselmis chui are valued for their nutrient-rich content, including lipids and polyunsaturated fatty acids (PUFA). However, little is known about how storage and processing affect their lipid quality. This study aimed to assess the impact of domestic storage and cooking practices in dried biomass of C. vulgaris and T. chui. Four conditions were tested: control (newly opened package), light (storage at room temperature and daily light regimen for three weeks), frozen (storage in the freezer at −20 °C for three weeks), and heated (three cycles of 90 min at 100 °C). Lipid extracts were analyzed by GC-MS and LC-MS, and antioxidant activity through DPPH and ABTS radical scavenging assays. Tested storage conditions promoted a decrease in fatty acid content and in diacyl/lyso lipid species ratios of phospholipid (PC/LPC, PE/LPE) and betaine lipids (DGTS/MGTS). Lipid extracts from light treatment showed the lowest antioxidant activity in C. vulgaris (ABTS, IC40: 104.9; DPPH, IC20: 187.9 ± 15.0), while heat affected the antioxidant activity of T. chui (ABTS, IC40: 88.5 ± 2.8; DPPH, IC20 209.4 ± 10.9). These findings underscore the impact of managing storage and processing conditions to optimize the nutritional and functional benefits of C. vulgaris and T. chui in food and feed applications.

Aquafeed production is a fast-growing industry, seeking novel, cost-efficient raw materials to diversify traditional ingredients like fish meal and oil. Insects, particularly BSF larvae, convert by-products and waste into value-added biomass. In this study, by-products and co-products from two major fish-transforming industries in the Iberian Peninsula, i.e., tuna heads (THs) and codfish frames (CFs), hydrolysates of THs and CFs, and TH oils, were supplied to BSF larvae to improve their profile in n-3 fatty acids (FAs), namely EPA and DHA, and their protein/amino acid content. By testing the replacement levels of a control diet with by-products and co-products, we evaluated the amount of n-3 FA that could be added to BSF larval tissues. The results showed that high levels of a hydrolysed diet negatively impacted larval survival. In addition, parameters such as the moisture, protein content, and viscosity of the substrate affected bioconversion rates. Nevertheless, BSF fed with these diets contained high levels of lysine (5.8–8.4%, dry weight (DW)), methionine (1.5–2.4%, DW), and n-3 FA (14.4% DW: EPA 6.7% and DHA 7.1%). These findings suggest that BSF can effectively convert fish by-products into a nutrient-rich biomass for aquafeeds, supporting the diversification of raw material sources and promoting a circular bioeconomy.