The wild harvest and aquaculture of Ulva spp. has deserved growing attention in Europe. However, the impact of geographical origin on the biochemical composition of different species and/or strains is yet to be described in detail. Hence, the present study aimed to detect the variability of the lipidome of different species and/or strains of Ulva originating from different geographic locations. We hypothesized that lipidomic signatures can be used to trace the geographic origin post-harvesting of these valuable green seaweeds. Ulva spp. was sampled from eight distinct ecosystems along the Atlantic Iberian coast and Ulva rigida was sourced from an aquaculture farm operating a land-based integrated production site. Results showed significant differences in the lipidomic profile displayed by Ulva spp. originating from different locations, namely, due to different levels of polyunsaturated betaine lipids and galactolipids; saturated betaine lipids and sulfolipids; and some phospholipid species. Overall, a set of 25 site-specific molecular lipid species provide a unique lipidomic signature for authentication and geographic origin certification of Ulva species. Present findings highlight the potential of lipidome plasticity as a proxy to fight fraudulent practices, but also to ensure quality control and prospect biomass for target bioactive compounds.

Fucus vesiculosus is an edible brown macroalga, with health benefits associated with its consumption and also a source of bioactive molecules. It is acknowledged that the biochemical composition of macroalgae changes when exposed to different environmental conditions occurring on different habitats, such as the water temperature, and light intensity. In the present study, the polar lipidome of Fucus vesiculosus was characterized for the first time using modern high-resolution HILIC-MS, and MS/MS approaches, to evaluate the phenotypic variability in two seasons of the year, e.g., winter and spring. A total of 187 molecular species were identified over eighteen classes of glycolipids, phospholipids and betaine lipids. Principal component analysis (PCA) multivariate statistical analysis and cluster analysis of polar lipid classes, polar lipid species and total fatty acids (FA) datasets, showed clustering according to the seasonal groups. While the lipid profile of Fucus vesiculosus harvested in the winter and spring yielded the same molecular species, the relative abundance of these species was significantly different. In the winter, changes were mainly due to the increased relative abundance of some molecular species of glycolipids and phospholipids, bearing octadeca(poly)enoic (18:3, 18:4) and eicosa(poly)enoic (20:4, 20:5) FA and betaine lipids species with short saturated FA (14:0) and polyunsaturated FA (PUFA). Importantly, glycolipids with n-3 PUFA and sulfolipids, have been reported to have important biological activities and therapeutic value. Overall, Fucus vesiculosus is a promising source of bioactive compounds that can be used as functional food or ingredients for human nutrition, feed, pharma, and cosmetic formulations. In this study, samples harvested in the winter season maximized yields of these bioactive components, when compared with samples harvested in the spring.

There is a growing trend to explore microalgae as an alternative resource for the food, feed, pharmaceutical, cosmetic and fuel industry. Moreover, the polar lipidome of microalgae is interesting because of the reports of bioactive polar lipids which could foster new applications for microalgae. In this work, we identified for the first time the Chlorococcum amblystomatis lipidome using hydrophilic interaction liquid chromatography-high resolution electrospray ionization- tandem mass spectrometry (HILIC-HR-ESI-MS/MS). The Chlorococcum amblystomatis strain had a lipid content of 20.77% and the fatty acid profile, determined by gas chromatography-mass spectrometry, has shown that this microalga contains high amounts of omega-3 polyunsaturated fatty acids (PUFAs). The lipidome identified included 245 molecular ions and 350 lipid species comprising 15 different classes of glycolipids (6), phospholipids (7) and betaine lipids (2). Of these, 157 lipid species and the main lipid species of each class were esterified with omega-3 PUFAs. The lipid extract has shown antioxidant activity and anti-inflammatory potential. Lipid extracts also had low values of atherogenic (0.54) and thrombogenic index (0.27). In conclusion, the lipid extracts of Chlorococcum amblystomatis have been found to be a source of lipids rich in omega-3 PUFAs for of great value for the food, feed, cosmetic, nutraceutical and pharmaceutical industries.

Macro- and microalgae are currently recognized sources of lipids with great nutritional quality and attractive bioactivities for human health promotion and disease prevention. Due to the lipidomic diversity observed among algae species, giving rise to different nutritional and functional characteristics, the mixture of macro- and microalgae has the potential to present important synergistic effects resulting from the complementarity among algae. The aim of this work was to characterize for the first time the lipidome of a blend of macro- and microalgae and evaluate the antioxidant capacity of its lipid fraction. Fatty acids were profiled by GC-MS, the polar lipidome was identified by high resolution LC-MS, and ABTS+• and DPPH• assays were used to assess the antioxidant potential. The most abundant fatty acids were oleic (18:1 n-9), α-linolenic (18:3 n-3), and linoleic (18:2 n-6) acids. The lipid extract presented a beneficial n-6/n-3 ratio (0.98) and low values of atherogenic (0.41) and thrombogenic indices (0.27). The polar lipidome revealed 462 lipid species distributed by glycolipids, phospholipids, and betaine lipids, including some species bearing PUFA and a few with reported bioactivities. The lipid extract also showed antioxidant activity. Overall, the results are promising for the valorization of this blend for food, nutraceutical, and biotechnological applications.

Brown seaweeds are known to present components with appealing bioactive properties eliciting great interest for industrial applications. However, their lipid content is generally disregarded beyond their fatty acid (FA) composition. This study thoroughly characterized the lipid profile of two brown seaweeds collected from Portuguese coast, the native Bifurcaria bifurcata and the invasive Sargassum muticum species, and bioprospecting for antioxidant activity. An integrated state-of-the-art approach including gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (HILIC-ESI-MS/MS), allowed a comprehensive picture of FA and polar lipid content. Polar lipid profile of B. bifurcata and S. muticum included 143 and 217 lipid species respectively, distributed between glycolipids, phospholipids, and betaine lipids. Some of the lipid species found have been assigned biological activity and contain of n-3 and n-6 FA. Sargassum muticum presented the highest n-3 FA content. Low concentrations of extracts of both seaweeds displayed antioxidant activity, with S. muticum presenting more promising results. These findings contribute to the nutritional and industrial exploitation of both seaweeds, highlighting their relevance as viable sources of bioactive and added-value compounds. Sargassum muticum presented interesting lipid composition and bioactivity, which may represent an accessible opportunity for the exploitation of this invasive seaweed, especially taking advantage of Sargassum blooms.

Polar lipids from microalgae have aroused greater interest as a natural source of omega-3 (n-3) polyunsaturated fatty acids (PUFA), an alternative to fish, but also as bioactive compounds with multiple applications. The present study aims to characterize the polar lipid profile of cultured microalga Emiliania huxleyi using hydrophilic interaction liquid chromatography coupled with high-resolution mass spectrometry (HILIC-MS) and fatty acids (FA) analysis by gas chromatography (GC-MS). The lipidome of E. huxleyi revealed the presence of distinct n-3 PUFA (40% of total FA), namely docosahexaenoic acid (22:6n-3) and stearidonic acid (18:4n-3), which give this microalga an increased commercial value as a source of n-3 PUFA present in the form of polar lipids. A total of 134 species of polar lipids were identified and some of these species, particularly glycolipids, have already been reported for their bioactive properties. Among betaine lipids, the diacylglyceryl carboxyhydroxymethylcholine (DGCC) class is the least reported in microalgae. For the first time, monomethylphosphatidylethanolamine (MMPE) has been found in the lipidome of E. huxleyi. Overall, this study highlights the potential of E. huxleyi as a sustainable source of high-value polar lipids that can be exploited for different applications, namely human and animal nutrition, cosmetics, and pharmaceuticals.

Olives (Olea europaea L.) are classic ingredients in the Mediterranean diet with well-known health benefits, but their lipid composition has not been fully addressed. In this work, we characterised triacylglycerol (TAG) and polar lipid profiles of the olive pulp while using a complementary methodological approach that was based on solid-phase extraction to recover the neutral lipid (NL) and the polar lipid-rich fractions. The TAG profile was analysed in the NL-fraction by C30 reversed-phase liquid chromatography (LC) and the polar lipid profile by normal-phase hydrophilic interaction liquid chromatography (HILIC), with both being coupled to electrospray ionization-mass spectrometry (ESI-MS) and ESI-MS/MS. This approach identified 71 TAG ions that were attributed to more than 350 molecular species, with fatty acyl chain lengths from C11:0 to C26:0, including different polyunsaturated acyl chains. The polar lipids included 107 molecular species that belonged to 11 lipid classes that comprised phospholipids, glyceroglycolipids, glycosphingolipids, and betaine lipids. In addition to polyunsaturated fatty acids, some of the phospholipids, glycolipids, and glycosphingolipids that were identified in the olive pulp have been described as biologically active molecules. Lipidomic phenotyping of the olive pulp has led to the discovery of compounds that will allow for a better assessment of its nutritional value and new applications of bioactive lipid components in this functional food.

The lipidome of the red seaweed Gracilaria sp., cultivated on land-based integrated multitrophic aquaculture (IMTA) system, was assessed for the first time using hydrophilic interaction liquid chromatography-mass spectrometry and tandem mass spectrometry (HILIC-MS and MS/MS). One hundred and forty-seven molecular species were identified in the lipidome of the Gracilaria genus and distributed between the glycolipids classes monogalactosyl diacylglyceride (MGDG), digalactosyl diacylglyceride (DGDG), sulfoquinovosyl monoacylglyceride (SQMG), sulfoquinovosyl diacylglyceride (SQDG), the phospholipids phosphatidylcholine (PC), lyso-PC, phosphatidylglycerol (PG), lyso-PG, phosphatidylinositol (PI), phosphatidylethanolamine (PE), phosphatic acid (PA), inositolphosphoceramide (IPC), and betaine lipids monoacylglyceryl- and diacylglyceryl-N,N,N-trimethyl homoserine (MGTS and DGTS). Antiproliferative and anti-inflammatory effects promoted by lipid extract of Gracilaria sp. were evaluated by monitoring cell viability in human cancer lines and by using murine macrophages, respectively. The lipid extract decreased cell viability of human T-47D breast cancer cells and of 5637 human bladder cancer cells (estimated half-maximal inhibitory concentration (IC50) of 12.2 μg/mL and 12.9 μg/mL, respectively) and inhibited the production of nitric oxide (NO) evoked by the Toll-like receptor 4 agonist lipopolysaccharide (LPS) on the macrophage cell line RAW 264.7 (35% inhibition at a concentration of 100 μg/mL). These findings contribute to increase the ranking in the value-chain of Gracilaria sp. biomass cultivated under controlled conditions on IMTA systems.

Palmaria palmata is an edible red macroalga widely used for human consumption and valued for its high protein value. Despite its low total lipid content, it is rich in eicosapentaenoic acid (EPA). This seaweed has been scarcely explored with regard to its lipid composition. The polar lipids of seaweeds are nowadays recognized as important phytochemicals contributing to their add value valorization and providing support for claims of potential health benefits. The present study aimed to disclose the polar lipid profile of P. palmata, farmed in an integrated multi-trophic aquaculture (IMTA) through modern lipidomic approaches using high-resolution LC-MS and MS/MS and to screen for the antioxidant properties of this red macroalga. A total of 143 molecular species of lipids were identified, belonging to several classes of polar lipids, such as glycolipids, phospholipids, and betaine lipids. It is noteworthy that the most abundant lipid species in each class were esterified with eicosapentaenoic acid (EPA), accounting for more than 50% of the lipid content. The polar lipid extract rich in EPA showed antioxidant activity with an inhibition concentration (IC) of IC30 = 171 ± 19.8 µg/mL for α,α-diphenyl-β-picrylhydrazyl radical (DPPH●) and IC50 = 26.2 ± 0.1 µg/mL for 2,20-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid radical cation (ABTS●+). Overall, this study highlights that P. palmata farmed in an IMTA framework can be a sustainable source of beneficial lipids with antioxidant activity. Moreover, this red macroalga can be exploited for future applications as a source of lipids rich in EPA for food and feed, nutraceuticals, and cosmetics.

Grateloupia turuturu Yamada, 1941, is a red seaweed widely used for food in Japan and Korea which was recorded on the Atlantic Coast of Europe about twenty years ago. This seaweed presents eicosapentaenoic acid (EPA) and other polyunsaturated fatty acids (PUFAs) in its lipid fraction, a feature that sparked the interest on its potential applications. In seaweeds, PUFAs are mostly esterified to polar lipids, emerging as healthy phytochemicals. However, to date, these biomolecules are still unknown for G. turuturu. The present work aimed to identify the polar lipid profile of G. turuturu, using modern lipidomics approaches based on high performance liquid chromatography coupled to high resolution mass spectrometry (LC-MS) and gas chromatography coupled to mass spectrometry (GC-MS). The health benefits of polar lipids were identified by health lipid indices and the assessment of antioxidant and anti-inflammatory activities. The polar lipids profile identified from G. turuturu included 205 lipid species distributed over glycolipids, phospholipids, betaine lipids and phosphosphingolipids, which featured a high number of lipid species with EPA and PUFAs. The nutritional value of G. turuturu has been shown by its protein content, fatty acyl composition and health lipid indices, thus confirming G. turuturu as an alternative source of protein and lipids. Some of the lipid species assigned were associated to biological activity, as polar lipid extracts showed antioxidant activity evidenced by free radical scavenging potential for the 2,2'-azino-bis-3-ethyl benzothiazoline-6-sulfonic acid (ABTS●+) radical (IC50 ca. 130.4 μg mL-1) and for the 2,2-diphenyl-1-picrylhydrazyl (DPPH●) radical (IC25 ca. 129.1 μg mL-1) and anti-inflammatory activity by inhibition of the COX-2 enzyme (IC50 ca. 33 µg mL-1). Both antioxidant and anti-inflammatory activities were detected using a low concentration of extracts. This integrative approach contributes to increase the knowledge of G. turuturu as a species capable of providing nutrients and bioactive molecules with potential applications in the nutraceutical, pharmaceutical and cosmeceutical industries.