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This study aimed to evaluate the effects of salinity on the proximate composition and fatty acid profile of the Nile tilapia fillet when reared in a biofloc system. Juveniles (200 ± 10 g) were reared at salinities of 2, 8, 15 and 22 PSU for 56 days. At the end of the experiment, the proximate composition and the fatty acid profile were evaluated in the fillets. No significant differences were observed for crude protein, ether extract, dry matter and ash levels. However, saturated (SFA) and monounsaturated (MUFA) fatty acids were higher in tilapia reared at 2 PSU compared to other salinities (8, 15, and 22 PSU). The polyunsaturated fatty acids (PUFA) contents did not vary among fish reared at salinities of 2, 8, and 15 PSU but were significantly lowest in tilapia reared at 22 PSU. The overall results suggest that the different salinities do not significantly affect the proximate composition of the Nile tilapia file reared in a biofloc system. On the other hand, the fatty acid composition was influenced by salinity, as a reduction in PUFA content was observed at the highest tested salinity (22 PSU) and an increase in SFA and MUFA contents were recorded at the lowest tested salinity (2 PSU). [ABSTRACT FROM AUTHOR]

Climate warming causes shorter winters and changes in ice and snow cover in subarctic lakes, highlighting the need to better understand under-ice ecosystem functioning. The plankton community in a subarctic, oligotrophic lake was studied throughout the ice-covered season, focusing on lipid dynamics and life history traits in two actively overwintering copepods, Cyclops scutifer and Eudiaptomus graciloides. Whereas C. scutifer was overwintering in C-IV to C-V stage, E. graciloides reproduced under ice cover. Both species had accumulated lipids prior to ice-on and showed a substantial decrease in total lipid content throughout the ice-covered period: E. graciloides (60%–38% dw) and C. scutifer (73%–33% dw). Polyunsaturated fatty acids of algal origin were highest in E. graciloides and declined strongly in both species. Stearidonic acid (18:4n-3) content in E. graciloides was particularly high and decreased rapidly during the study period by 50%, probably due to reproduction. The copepods differed in feeding behavior, with the omnivore C. scutifer continuing to accumulate lipids until January, whereas the herbivorous E. graciloides accumulated lipids from under-ice primary production during the last months of ice-cover. Our findings emphasize the importance of lipid accumulation and utilization for actively overwintering copepods irrespective of the timing of their reproduction. [ABSTRACT FROM AUTHOR]

The quality of fat in infant milk is determined by the fatty acid profile and selected indices describing nutritional value. The aim of this study was to analyze the fatty acid profile and lipid quality indices of infant formulas and compare these data with breast milk. The study material included seven types of cow's milk-based follow-on infant formulas and samples of mature breast milk. The determination of fatty acids was performed using the gas chromatography (GC) technique. Lipid quality indices were calculated based on the relevant equations. Infant formulas contained more medium-chain fatty acids (MCFAs) and oleic acid. Moreover, they contained more than 30% more linoleic acid and more than twice as much α-linolenic acid and docosahexaenoic acid. In contrast, significant amounts of trans fatty acids (TFAs) were noted in breast milk, while infant formulas contained trace amounts. Infant formulas were characterized by a lower AI (Index of Atherogenicity) (0.49–0.98) and TI (Index of Thrombogenicity) (0.48–0.60) and a higher H/H (hypocholesterolemic/hypercholesterolemic) ratio (1.93–2.30) compared with breast milk (1.47, 1.60, and 1.21, respectively). The composition of infant formulas depended on the type of fat added at the production stage and differed significantly from breast milk, particularly in terms of polyunsaturated fatty acids and lipid quality indices. [ABSTRACT FROM AUTHOR]

Microalgae can convert carbon dioxide into organic matter through photosynthesis. Thus, they are considered as an environment-friendly and efficient cell chassis for biologically active metabolites. Microalgal lipids are a class of organic compounds that can be used as raw materials for food, feed, cosmetics, healthcare products, bioenergy, etc., with tremendous potential for commercialization. In this review, we summarized the commercial lipid products from eukaryotic microalgae, and updated the mechanisms of lipid synthesis in microalgae. Moreover, we reviewed the enhancement of lipids, triglycerides, polyunsaturated fatty acids, pigments, and terpenes in microalgae via environmental induction and/or metabolic engineering in the past five years. Collectively, we provided a comprehensive overview of the products, biosynthesis, induced strategies and genetic engineering in microalgal lipids. Meanwhile, the outlook has been presented for the development of microalgal lipids industries, emphasizing the significance of the accurate analysis of lipid bioactivity, as well as the high-throughput screening of microalgae with specific lipids. [ABSTRACT FROM AUTHOR]

The use of high-value fatty acids (FA), omega-3 (n-3), and omega-6 (n-6) from seaweed could relieve the pressure from natural wild fish sources and reduce overfishing worldwide. This research is designed to explore how the harvest season (winter, spring, and summer) and culture period influence the biomass production yield, lipid content, and FA composition in the green seaweed Ulva sp. The studied seaweed was grown in plastic sleeves with flowthrough seawater in Mikhmoret (East Mediterranean, Israel) from July 2019 to December 2020. The Ulva species was identified as Ulva lactuca Linnaeus by DNA barcoding using rbcL, ITS, and tufA markers. No detectable genetic variability in U. lactuca samples was found throughout the research period. A quantitative examination of the lipid and FA content in U. lactuca in different harvest seasons revealed that the maximum content of lipids was in the summer, and that of polyunsaturated fatty acids (PUFAs) was in the winter. The PUFA profile included eicosapentaenoic acid, docosapentaenoic acid, docosahexaenoic acid, n-3, and n-6, where the n-6/n-3 ratio was comparable with the desired range for a balanced nutritional diet. [ABSTRACT FROM AUTHOR]

Lipids are a large group of natural compounds, together with proteins and carbohydrates, and are essential for various processes in the body. After death, the organism's tissues undergo a series of reactions that generate changes in some molecules, including lipids. This means that determining the lipid change profile can be beneficial in estimating the postmortem interval (PMI). These changes can also help determine burial sites and advance the localization of graves. The aim was to explore and analyze the decomposition process of corpses, focusing on the transformation of lipids, especially triglycerides (TGs) and fatty acids (FAs), and the possible application of these compounds as markers to estimate PMI and detect burial sites. A systematic review of 24 scientific articles from the last 23 years (2000–2023) was conducted. The results show that membrane glycerophospholipids (such as phosphatidylcholine and phosphatidylglycerol, among others) are the most studied, and the most promising results are obtained, with decreasing patterns as PMI varies. Fatty acids (FAs) are also identified as potential biomarkers owing to the variations in their postmortem concentration. An increase in saturated fatty acids (SFAs), such as stearic acid and palmitic acid, and a decrease in unsaturated fatty acids (UFAs), such as oleic acid and linoleic acid, were observed. The importance of intrinsic and extrinsic factors in decomposition is also observed. Finally, as for the burial sites, the presence of fatty acids and some sterols in burial areas of animal and human remains can be verified. In conclusion, glycerophospholipids and fatty acids are good markers for estimating PMI. It has been observed that there are still no equations for estimating the PMI that can be applied to forensic practice, as intrinsic and extrinsic factors are seen to play a vital role in the decomposition process. As for determining burial sites, the importance of soil and textile samples has been demonstrated, showing a direct relationship between saturated fatty acids, hydroxy fatty acids, and some sterols with decomposing remains. [ABSTRACT FROM AUTHOR]

The lipid profiles of the oyster Crassostrea gigas cultured in Khanh Hoa coast at three locations and harvested in different months throughout the year were compared. Seasonal and locational changes in total lipid (TL) content, phospholipid content, free fatty acid content, fatty acid (FA) composition, and thrombogenicity index were found. The total lipid content and n-3/n-6 ratio in oysters from Ninh Hoa were higher compared to those from Cam Lam and Van Ninh. For oyster from all three farming areas, the total lipid content was the lowest during the two spawning seasons (May and September). Lipids from C. gigas were separated into neutral and polar lipid fractions using silica gel column chromatography. The amount of neutral lipids recovered from the oyster muscle was significantly higher than that of the polar lipids. The FA composition showed that C. gigas was abundant in saturated fatty acids (30.89-39.16 g/100 g TL), followed by polyunsaturated fatty acids (28.13-35.88 g/100 g TL), and monounsaturated fatty acids (19.32-23.75 g/100 g TL). The dominant polyunsaturated fatty acids of oysters from the three farming areas were eicosapentaenoic acid (9.09-13.77 g/100 g TL) and docosahexaenoic acid (6.71-16.47 g/100 g TL). Based on the present findings, it can be concluded that the Pacific oyster C. gigas cultured in Khanh Hoa, Vietnam is a promising source of highly nutritious exploitable lipids. [ABSTRACT FROM AUTHOR]

The aim of this study was to assess the changes occurring as a result of boiling (100°C, 1 h) small brown snail (Cornu aspersum aspersum) meat in relation to its proximate composition, calcium, phosphorus and cholesterol content, as well as the profile of fatty acids and nutritional quality indices of the lipids. This species of snail was selected for research because it is currently of the greatest economic importance among edible terrestrial snails. It was hypothesized that the cooking effect may be different for foot and visceral sac. Samples for the research were collected from 6 populations bred on experimental fields of the National Research Institute of Animal Production in balice (Poland). The foot and the visceral sac, the edible parts of the snail species under investigation, were analysed separately, raw and boiled in water. The results were then compared to analogous studies carried out by other authors on beef, pork and poultry. It was found that in the visceral sac of Cornu aspersum aspersum the shares of dry matter, crude protein, fat, ash, calcium and phosphorus were greater than those in the foot (P<0.05), both in the raw and boiled material, whereas the cholesterol content was higher in the foot (P<0.05). Generally, especially in the foot, the heat treatment elevated the levels of the afore-mentioned quantities, yet the increases were not always statistically significant. Boiling the snail meat caused moderate changes in the fatty acid composition. The profile of the fatty acids and the nutritional quality indices of the foot fat were more advantageous than those in the visceral sac. In both parts of the snail carcass, the polyunsaturated fatty acids/saturated fatty acids (PUFA/SFA) ratio substantially exceeded the minimum value of 0.45 recommended by the British Department of Health. However, the n-6/n-3 ratio was too high, exceeding the maximum recommended level of 4.0 twofold and as much as threefold in the case of the foot and the visceral sac, respectively. In the foot, due to boiling, an increase of the share of sfa and monounsaturated fatty acids (MUFA) was observed, while PUFA, n-6 and n-3 decreased. In the visceral sac, the changes were less pronounced with a slight decrease of the share of sfa and PUFA, and an increase of MUFA. Therefore, in the foot, boiling worsened the PUFA/SFA ratio, the nutritive value index (NVI = (C18:0 + C18:1) / C16:0) and dietary fatty acids having a desirable neutral and hypocholesterolemic effect in humans (DFA = Σ MUFA + Σ PUFA + C18:0), but in the visceral sac these indices practically did not change. On the whole, the trends of the changes in terms of chemical composition due to boiling found in the small brown snail meat are similar to those after heat treatment of meat from popular farm animals, but the ranges of the changes differ. [ABSTRACT FROM AUTHOR]

The biological activity of an oil not only depends on its fatty acid composition but also the lipid composition and trace components. In this paper, to select the optimal mushroom oil, the component compositions (fatty acids, lipids, polyphenols, flavones, tocopherols, and unsaponifiable matters) and antioxidant activities in vitro of four mushroom oils (Agrocybe cylindracea, two Lentinula edodes, and Volvariella volvacea) were investigated and compared. The results showed that the four tested oils had the same fatty acid composition in different amounts, but the lipid component, minor components, and free radical scavenging activity in the tested oils varied widely depending on the type of mushroom. Overall, Volvariella volvacea oil was considered superior to the other three tested oils, as it had the largest contents of polar lipids, diglycerides, polyunsaturated fatty acids (74.38%), unsaponifiable matter (319.09 mg/kg), total phenols (124.08 mg/100 g), tocopherols (139.86 mg/100 g), as well as the highest ABTS and FRAP values (349.45 and 3801.70 μmol Trolox/100 g). This finding suggests that Volvariella volvacea oil is a promising resource that should be further researched. [ABSTRACT FROM AUTHOR]

Background: Amphora coffeaeformis, a unicellular diatom, can significantly accumulate lipids under nitrogen (N) limitation. However, the molecular mechanism underlying lipid accumulation in A. coffeaeformis remains unknown and its application development is lagging. Results: This work analyzed the lipid composition of A. coffeaeformis under N deprivation and investigated its mechanism underlying lipid accumulation using RNA-seq. The results showed that the total lipid content of A. coffeaeformis increased from 28.22 to 44.05% after 5 days of N deprivation, while the neutral lipid triacylglycerol (TAG) content increased from 10.41 to 25.21%. The transcriptional profile showed that N deprivation induced wide-ranging reprogramming of regulation and that most physiological activities were repressed, while the upregulation of glycerol-3-phosphate acyltransferase directly determined TAG accumulation. Moreover, we explored the effect of A. coffeaeformis as a food additive on the lipid composition of crucian carp. The results showed that the contents of unsaturated fatty acids in the meat of fish supplemented with A. coffeaeformis were significantly increased, indicating its potential application in animal nutrition for improving meat quality indicators. Conclusion: The findings shed light on the molecular mechanisms of neutral lipid accumulation and revealed the key genes involved in lipid metabolism in A. coffeaeformis. Moreover, we also confirmed that A. coffeaeformis can be used as feed additive for improving the lipid composition of crucian carp meat, which provided evidence for the biotechnology application of this high-oil microalgae. [ABSTRACT FROM AUTHOR]

One persistent puzzle in the life sciences is the asymmetric lipid composition of the cellular plasma membrane: while the exoplasmic leaflet is enriched in lipids carrying predominantly saturated fatty acids, the cytoplasmic leaflet hosts preferentially lipids with (poly‐)unsaturated fatty acids. Given the high energy requirements necessary for cells to maintain this asymmetry, the question naturally arises regarding its inherent benefits. In this paper, we propose asymmetry to represent a potential solution for harmonizing two conflicting requirements for the plasma membrane: first, the need to build a barrier for the uncontrolled influx or efflux of substances; and second, the need to form a fluid and dynamic two‐dimensional substrate for signaling processes. We hence view here the plasma membrane as a composite material, where the exoplasmic leaflet is mainly responsible for the functional integrity of the barrier and the cytoplasmic leaflet for fluidity. We reinforce the validity of the proposed mechanism by presenting quantitative data from the literature, along with multiple examples that bolster our model. [ABSTRACT FROM AUTHOR]

The nutrient and fatty acid composition of the muscle tissues in the dorsal (D), ventral (V), and caudal (C) regions of the pike perch were determined in this study. Pike perch had 19.63% protein, 0.92% lipid, 78.36% moisture, and 1.04% ash. The whole muscle (WM) (0.92%) of pike perch had the highest lipid content, followed by C (0.82%), V (0.73%), and D regions (0.69%). The results of the study revealed that total polyunsaturated fatty acid (PUFA) (32.37%-37.05%) values were higher than those of total saturated fatty acids (SFA) (29.96%-31.76%) and monounsaturated fatty acid (MUFA) (17.26%-20.81%) in all whole muscle (WM) and different regions (D, V, and C) of the pike perch. The highest SFA, MUFA, and PUFA amounts were in D, WM, and D regions, respectively. In all groups, the amount of Docosahexaenoic acid (DHA) (12.97-15.43%) was higher than Eicosapentaenoic acid (EPA) (5.66-6.97%). While there was no difference between regions in terms of EPA value, the difference between regions in terms of DHA values was found to be important (p <0.05). The highest EPA and DHA values were detected in the D region. Atherogenicity index (AI) (0.47-0.48), thrombogenicity index (TI) (0.33-0.35), hypocholesterolemic/hypercholesterolemic ratio (H/H) (2.01-2.07) and n-6/n-3 (0.47-0.51) ratios were at recommended levels in all regions (WM, D, V, and C) and there was no regional difference (p > 0.05). The results showed that the fatty acid composition of the pike perch varies according to different body regions, it is rich in nutrient content and has the recommended level of AI, TI, H/H, and n-6/n-3 ratios. It can be concluded that pike perch has beneficial health effects on human nutrition. [ABSTRACT FROM AUTHOR]

Lipids are essential in feeds for rearing marine fish. Inadequate handling and storage of feeds can cause lipid oxidation, increasing toxic compounds while decreasing the nutrition quality of feeds and negatively affecting both the physiology and rearing performance of fish. Here, the effect of increasing oxidized lipids intake was assessed on rearing performance and health of juvenile L. guttatus. Experimental feeds (EF) were manufactured with different levels of total peroxides (PV, 26–107 meqO2 × kg−1) and anisidine value (AV, 74–154). A total of 270 fish (18 fish by tank, three replicates by treatment) with an initial average weight of 6.5 ± 1 g were reared in 3 m3 tanks for 45 days. Survival and growth rate decreased with increasing PV and AV, particularly in fish fed with higher values of oxidized lipids. Viscerosomatic index was positively correlated with increase of oxidized lipids in EF, probably caused by increasing food retention into the gut. Glucose in plasma was inversely correlated with PV and AV in EF and together with the damage observed (i.e., inflammatory nodules, necrosis, and higher hepatosomatic index) suggests a decrease of liver metabolism. The increases of PV and AV on feeds were positively correlated with levels of triacylglycerides and total cholesterol in plasma, indicating an alteration in lipid metabolism. The total protein content in plasma and hematocrit was not different among treatments; in contrast, hemoglobin content decreased compared with control, suggesting an increase in the fragility of blood cells and oxygen transport capacity. Highly unsaturated fatty acid (HUFA) composition in the brain and liver was not different between treatments, but PV and AV were inversely correlated with docosahexaenoic acid (DHA) levels in neutral lipids and eicosapentaenoic acid (EPA) and arachidonic acid (ARA) levels in polar lipids in liver tissue, suggesting a specific demand to counteract cell damage caused by the accumulation of oxidized lipids. The content of HUFA in total lipids from muscle suggests this is an important storage tissue, whereas EPA level decreased with oxidized lipids in the diet. The results showed that increasing oxidized lipids on the diet compromise the health condition and rearing performance of juvenile rose snapper L. guttatus. [ABSTRACT FROM AUTHOR]

This review provides an outline of some of the challenges facing nutritionists in the Australian aquaculture industry. It commences with a brief description of how aquaculture nutrition differs from that for terrestrial livestock – the challenges of providing nutrition in aqueous environments, the diversity of species and the high trophic level of most. Specific challenges of aquaculture nutrition are then discussed in further detail, including the difficulty of measuring feed intake and digestibility, the limited ability to use carbohydrates for carnivores, and the specific requirements of species for lipids, including cholesterol, phospholipids, long-chain polyunsaturated fatty acids and carotenoids. The review then examines how environmental, social and governance concerns are leading to new trends in nutrition for the Australian industry. This includes topics such as the replacement of wild-caught fish meal and fish oil, in terms of both sources of omega-3 lipids and protein. For the former, possible solutions include greater use of seafood trimming, algal oil, and GMO-derived products. For the latter, solutions can include use of livestock render, plant protein meals, fermented products, and insects. Nutrient discharge is also a concern for the industry and nutritionist can assist by improving digestibility and nutrient retention from feeds. Finally, the carbon footprint of aquaculture is leading to new directions for industry and, in turn, for the field of aquaculture nutrition. Aquaculture feed formulations are being re-imagined. Not only do formulations have to meet the rigid nutrient requirements of the high trophic species cultured, but they will also have to adhere to increasing expectations of sustainable farming, animal health and welfare, and seafood quality. Environmental, social and governance concerns are steering the aquaculture industry in new directions and influencing nutrition research. This review provides an outline of some of the challenges facing nutritionists, which are leading to new trends for feeding Australian aquaculture. [ABSTRACT FROM AUTHOR]

Lipids from marine organisms are a source of molecules of high nutritional significance, like polyunsaturated fatty acids (PUFAs) and antioxidants. The incorporation of these molecules into the human body is possible mainly through the intake of fish and fish oil-based food. This review covers some of the health benefits and biochemical aspects of nutritional lipids, the available marine resources for the production of PUFAs and antioxidants, and the most used methods for the extraction and identification of these natural lipid molecules in the lab and in the industry. Emphasis is put on the use of residual biomass from fisheries to obtain these interesting products and the consequent improvement of the sustainability of the fish industry. [ABSTRACT FROM AUTHOR]

Biological membranes, primarily composed of lipids, envelop each living cell. The intricate composition and organization of membrane lipids, including the variety of fatty acids they encompass, serve a dynamic role in sustaining cellular structural integrity and functionality. Typically, modifications in lipid composition coincide with consequential alterations in universally significant signaling pathways. Exploring the various fatty acids, which serve as the foundational building blocks of membrane lipids, provides crucial insights into the underlying mechanisms governing a myriad of cellular processes, such as membrane fluidity, protein trafficking, signal transduction, intercellular communication, and the etiology of certain metabolic disorders. Furthermore, comprehending how alterations in the lipid composition, especially concerning the fatty acid profile, either contribute to or prevent the onset of pathological conditions stands as a compelling area of research. Hence, this review aims to meticulously introduce the intricacies of membrane lipids and their constituent fatty acids in a healthy organism, thereby illuminating their remarkable diversity and profound influence on cellular function. Furthermore, this review aspires to highlight some potential therapeutic targets for various pathological conditions that may be ameliorated through dietary fatty acid supplements. The initial section of this review expounds on the eukaryotic biomembranes and their complex lipids. Subsequent sections provide insights into the synthesis, membrane incorporation, and distribution of fatty acids across various fractions of membrane lipids. The last section highlights the functional significance of membrane-associated fatty acids and their innate capacity to shape the various cellular physiological responses. [ABSTRACT FROM AUTHOR]

Simple Summary: Probiotics can be used in pigs fattening as a partial or full alternative to antibiotic growth promoters. Their composition and the dosage used in the feed must not impair the nutritional value of the meat raw materials obtained from them. The use of the probiotic preparation Bokashi (containing specific strains of Lactobacillus and Saccharomyces cerevisiae yeast) as a feed additive in fattening pigs resulted in significant changes in meat and backfat fatty acid profiles and the lipid indexes calculated from them. The changes in the fatty acid profile of backfat appeared to be more beneficial to consumer health due to the increased proportion of polyunsaturated fatty acids (PUFA). From a technological point of view, there is a more favorable Saturation Index (SI) value in backfat. The study aimed to assess the effect of supplementation of pig diet with the Bokashi probiotic on the fatty acid profile of longissimus lumborum (LL) muscles and backfat. The research involved 120 hybrid pigs deriving from Naïma sows and P-76 boars. The experimental group's pigs received probiotics in their feed (containing Saccharomyces cerevisiae, Lactobacillus casei, and Lactobacillus plantarum). To analyze the fatty acid profile in intramuscular fat (IMF) of LL and backfat, 24 pig carcasses from the control group and 26 from the probiotic-supplemented group were randomly selected. Probiotic supplementation increased the Atherogenic Index, reduced the proportion of C20:4, and increased C12:0 and C18:2 n-6 in IMF LL, without affecting ΣSFA, ΣMUFA, and ΣPUFA. In backfat, probiotic supplementation decreased C18:1 and C18:2 n-6 proportion and increased C18:3 n-3, C20:3 n-6, and C20:4 n-6. These changes resulted in significantly higher ΣMUFA, ΣPUFA, PUFA Σn-3/Σn-6, and lower Saturation Index (SI). From a consumer health and technological point of view, probiotic supplementation improved the lipid profile of backfat to a greater extent than LL muscle. Bokashi, at a dose of 3 g/kg of feed in the last stage of pig production, had no significant effect on the fatty acid profile of the meat. [ABSTRACT FROM AUTHOR]

SUMMARY: Zooxanthella nutricula is a photosynthetic dinoflagellate symbiont of polycystine radiolarians. As such, it is hypothesized to provide fixed organic carbon, including in the form of acylglycerolipids and sterols, to its non‐photosynthetic host. We have previously characterized the sterols of Z. nutricula that may be transferred to its host and, in the present study, have turned our attention to three classes of fatty acid‐containing lipids, chloroplast‐associated galactolipids, betaine lipids, which are non‐phosphorylated phospholipid analogs present in many eukaryotes, and triglycerides. Zooxanthella nutricula was observed using positive‐ion electrospray/mass spectrometry (ESI/MS) and ESI/MS/MS to produce the galactolipids mono‐ and digalactosyldiacylglycerol (MGDG and DGDG, respectively) enriched in octadecapentaenoic (18:5(n‐3)) and octadecatetraenoic (18:4(n‐3)) acid to place it within a group of peridinin‐containing dinoflagellates in a C18/C18 (sn‐1/sn‐2 fatty acid regiochemistry) cluster, as opposed to another cluster with C20/C18 MGDG and DGDG, where the C20 fatty acid is eicosapentaenoic acid (20:5(n‐3)) and the C18 fatty acid is either 18:5(n‐3) or 18:4(n‐3). Zooxanthella nutricula was also observed to produce 38:10 (total number of fatty acid carbons:total number of double bonds), 38:6, and 44:7 diacylglycerylcarboxyhydroxymethylcholine (DGCC) as the sole type of betaine lipid. Although it is more difficult to determine which fatty acids are present in the sn‐1 and sn‐2 positions on the glycerol backbone of DGCC using ESI/MS/MS, gas chromatography/mass spectrometry (GC/MS)‐based examination indicated the putatively DGCC‐associated polyunsaturated fatty acid (PUFA) docosahexaenoic acid (22:6(n‐3)). Coupled with the C18 PUFAs of MGDG and DGDG, and fatty acids associated with triglycerides (also examined via GC/MS), Z. nutricula could serve as a rich source of PUFAs for its radiolarian host. These data demonstrate that Z. nutricula produces a similar set of PUFA‐containing lipids as Symbiodinium microadriaticum, a photosynthetic dinoflagellate symbiont of cnidarians, indicating a metabolic commonality in these phylogenetically discrete dinoflagellate symbionts with unrelated host organisms. [ABSTRACT FROM AUTHOR]

Ultraviolet B (UVB) radiation induces oxidative stress in skin cells, generating reactive oxygen species (ROS) and perturbing enzyme-mediated metabolism. This disruption is evidenced with elevated concentrations of metabolites that play important roles in the modulation of redox homeostasis and inflammatory responses. Thus, this research sought to determine the impacts of the lipid extract derived from the Nannochloropsis oceanica microalgae on phospholipid metabolic processes in keratinocytes subjected to UVB exposure. UVB-irradiated keratinocytes were treated with the microalgae extract. Subsequently, analyses were performed on cell lysates to ascertain the levels of phospholipid/free fatty acids (GC-FID), lipid peroxidation byproducts (GC-MS), and endocannabinoids/eicosanoids (LC-MS), as well as to measure the enzymatic activities linked with phospholipid metabolism, receptor expression, and total antioxidant status (spectrophotometric methods). The extract from N. oceanica microalgae, by diminishing the activities of enzymes involved in the synthesis of endocannabinoids and eicosanoids (PLA2/COX1/2/LOX), augmented the concentrations of anti-inflammatory and antioxidant polyunsaturated fatty acids (PUFAs), namely DHA and EPA. These concentrations are typically diminished due to UVB irradiation. As a consequence, there was a marked reduction in the levels of pro-inflammatory arachidonic acid (AA) and associated pro-inflammatory eicosanoids and endocannabinoids, as well as the expression of CB1/TRPV1 receptors. The microalgal extract also mitigated the increase in lipid peroxidation byproducts, specifically MDA in non-irradiated samples and 10-F4t-NeuroP in both control and post-UVB exposure. These findings indicate that the lipid extract derived from N. oceanica, by mitigating the deleterious impacts of UVB radiation on keratinocyte phospholipids, assumed a pivotal role in reinstating intracellular metabolic equilibrium. [ABSTRACT FROM AUTHOR]

The effect of sugarcane molasses on lipid content and fatty acids methyl ester (FAME) profile by Chromochloris zofingiensis is investigated in this work. For this purpose, the strain has been cultivated under mixotrophic conditions in a medium amended with specific concentrations of molasses (0.5 g/L, 1 g/L, and 2 g/L) able to sustain microalgae growth. Better biomass concentration, lipid content, and lipid productivity (1.6 g/L, 38% wt, and 286 mg/L/day) than the control (1.32 g/L, 16% wt, and 139 mg/L/day) were obtained with 2 g/L of molasses. The highest value of the total lipid content (42% wt) was reached with 1 g/L of molasses. FAME profile revealed a 97% composition in C16-C18 with no statistically meaningful differences among the three concentrations of molasses tested. The most represented fatty acids were C18:1 oleic (> 38% wt), C18:2 linoleic (> 21% wt), and C16:0 palmitic (> 14% wt). When using 2 g/L of molasses unsaturated fatty acids reached the highest portion (77%) than the control (61%). Specifically, all FAMEs have been quantitatively and qualitatively analyzed in order to improve biodiesel properties. The main characteristics of biodiesel obtainable from the algal lipids appeared in compliance with ASTM standards for unblended biodiesel and fulfilled European regulations (EN 14,214 and EN 590) for the quality of biodiesel. Owing the compliance of the corresponding biodiesel characteristics with international standards, a profitable biodiesel can be obtained under mixotrophic conditions triggered by the use of a food industry waste. Highlights: Sugarcane molasses can be used by Chromochloris zofingiensis to produce lipids. Molasses enhanced better cell growth than control medium. Molasses triggered biomass and lipid productivity better than control medium. Internal cell metabolism was modified by molasses to improve lipid production. Saturation and unsaturation levels in FAMEs were directly influenced by molasses. [ABSTRACT FROM AUTHOR]

The study aimed to apply gamma radiation as a cell pretreatment method for lipid extraction and for obtaining astaxanthin from residual biomass of Haematococcus pluvialis. Factor 1 of the two-factor experimental design was represented by cell pretreatment methods: biomass with chloroform:methanol under ultrasound (BCMU), biomass with chloroform:methanol under γ radiation (BCMR), dry biomass under γ radiation (DBR), and control (without pretreatment). Factor 2 considered the vegetative and cystic phases. Cultivation was performed in a mixotrophic system, and biomass was collected in both phases, centrifuged, lyophilized, and submitted to cell pretreatment and lipid extraction. Lipid content and FAMEs were evaluated comparing pretreatment methods and life cycle phases. Total lipid content was higher with the BCMR method in the vegetative (18% DW) and cystic (14% DW) phases. Gamma radiation combined with organic solvent was more efficient for increasing lipid yield, and DBR had a lipid yield similar to BCMU. FAME content differed between phases and pretreatments for most fatty acids, mainly C16:0, C16:1, C18:1n9c, C18:2n6c, C18:2n6t, and C18:3n3. The predominance of saturated or low unsaturated fatty acids makes H. pluvialis, in both phases, suitable for biofuel production. The preservation of astaxanthin from residual cystic biomass was observed when submitted to the DBR method, with a concentration similar to the raw biomass (1.5% DW). Gamma radiation in dry biomass has an antioxidant effect. Therefore, the lipid extraction method preceded by gamma irradiation was efficient for vegetative and cystic cells of H. pluvialis and contributed to the preservation of astaxanthin from residual cystic biomass. [ABSTRACT FROM AUTHOR]

Context: Plasma fatty acid profiles provide evidence of short-term feeding, while red blood cells (RBC) indicate longer-term feeding effects. Information on the rate of change in fatty acid profiles of sheep blood over time after alterations in diet is lacking. This study monitored the short- and longer-term effects of feeding grain-based diets to lambs on changes to omega-3 polyunsaturated fatty acids (PUFA) in blood fractions over 21 days. The data provide a guide to managing omega-3 PUFA availability for adequate tissue accretion of these fatty acids. Aims: To determine the rate of depletion over 21 days of omega-3 PUFA in the blood fractions of sheep fed on grain-based diets. Methods: Blood samples were taken from ewes taken off pasture and fed grain-based diets for 21 days. Fatty acid profiles in the blood plasma and RBC were used to monitor the rate of depletion of omega-3 PUFA. Key results: Immediate changes in plasma omega-3 PUFA concentrations occurred from the first day of grain feeding. The omega-3 PUFA content declined continuously on all five grains, but with substantial differences among them. RBC omega-3 PUFA contents displayed great variation across individual sheep but depletion was not significant. Conclusions: Plasma omega-3 PUFA depletion immediately on grain feeding indicated a lower availability for tissue accretion in growing sheep following short-term changes in diet. The lack of change in RBC omega-3 PUFA concentrations over 21 days indicated a differential accumulation of these fatty acids in this lipid depot compared with plasma, and changes in other tissues should also be examined. Implications: The effect of these short- and long-term changes on LC n -3PUFA accumulation in meat and reproductive tissues warrants further investigation. Omega-3 fatty acids can have important health implications and are associated with altered reproductive efficiency in sheep. The rate of depletion of omega-3 with different grain types was previously unknown; however, results from the current study showed that depletion is similar with oats, wheat, lupins and barley, although some changes in red blood cells were not as great for barley compared with other grains. The effect of these changes on fatty acid concentrations in meat and reproductive outcomes should be investigated further. [ABSTRACT FROM AUTHOR]

Emerging evidence suggests that fatty acids (FAs) and their lipid mediator derivatives can induce both beneficial and detrimental effects on inflammatory processes and joint degradation in osteoarthritis (OA) and autoimmune-driven rheumatoid arthritis (RA). The present study characterized the detailed FA signatures of synovial membranes collected during knee replacement surgery of age- and gender-matched OA and RA patients (n = 8/diagnosis). The FA composition of total lipids was determined by gas chromatography and analyzed with univariate and multivariate methods supplemented with hierarchical clustering (HC), random forest (RF)-based classification of FA signatures, and FA metabolism pathway analysis. RA synovium lipids were characterized by reduced proportions of shorter-chain saturated FAs (SFAs) and elevated percentages of longer-chain SFAs and monounsaturated FAs, alkenyl chains, and C20 n-6 polyunsaturated FAs compared to OA synovium lipids. In HC, FAs and FA-derived variables clustered into distinct groups, which preserved the discriminatory power of the individual variables in predicting the RA and OA inflammatory states. In RF classification, SFAs and 20:3n-6 were among the most important FAs distinguishing RA and OA. Pathway analysis suggested that elongation reactions of particular long-chain FAs would have increased relevance in RA. The present study was able to determine the individual FAs, FA groups, and pathways that distinguished the more inflammatory RA from OA. The findings suggest modifications of FA elongation and metabolism of 20:4n-6, glycerophospholipids, sphingolipids, and plasmalogens in the chronically inflamed RA synovium. These FA alterations could have implications in lipid mediator synthesis and potential as novel diagnostic and therapeutic tools. [ABSTRACT FROM AUTHOR]

Skeletal muscle (SkM) lipid composition plays an essential role in physiological muscle maintenance and exercise performance. Thyroid hormones (THs) regulate muscle formation and fuel energy utilization by modulating carbohydrates and lipid and protein metabolism. The best-known effects of THs in SkM include the promotion of mitochondrial biogenesis, the fiber-type switch from oxidative to glycolytic fibers, and enhanced angiogenesis. To assess the role of THs on the lipidic composition of SkM fibers, we performed lipidomic analyses of SkM cells and tissues, glucose tolerance experiments, and exercise performance tests. Our data demonstrated that TH treatment induces remodeling of the lipid profile and changes the proportion of fatty acids in SkM. In brief, THs significantly reduced the ratio of stearic/oleic acid in the muscle similar to what is induced by physical activity. The increased proportion of unsaturated fatty acids was linked to an improvement in insulin sensitivity and endurance exercise. These findings point to THs as critical endocrine factors affecting exercise performance and indicate that homeostatic maintenance of TH signals, by improving cell permeability and receptor stability at the cell membrane, is crucial for muscle physiology. [ABSTRACT FROM AUTHOR]

We synthesized a novel, structured lipid containing caprylic acid at its sn‐1,3 position and docosahexaenoic acid at its sn‐2 position (1,3C‐2D‐TAG) by using a two‐step enzymatic method and then investigated the relationship between the types of fatty acids in the structured lipid and their physiological functions. Furthermore, we compared the effects of similarly structured lipids on postprandial lipid metabolism and obesity protection. The results revealed that the novel structured lipid synthesized using the enzymatic method not only exhibited better physical properties than traditional oils but also had high oxidation stability and crystallization degree. In terms of physiological function, the low‐dose 1,3C‐2D‐TAG group exhibited higher cholesterol and triglyceride levels, lower kidney weight or body weight, and higher serum aspartate aminotransferase and blood urea nitrogen levels than control group, whereas the high‐dose 1,3C‐2D‐TAG group exhibited higher triglyceride levels. Moreover, the medium‐dose 1,3C‐2D‐TAG group had remarkably higher high‐density lipoprotein cholesterol levels and lower low‐density lipoprotein cholesterol levels than the high‐lipid, control, and 1,2,3C‐TAG groups; however, the cholesterol and triglyceride levels and kidney and liver functions did not differ significantly among these groups. The study results suggest that 1,3C‐2D‐TAG can not only facilitate the effective utilization of the energy supplied by medium‐chain fatty acids but also help overcome difficulties in the absorption of long‐chain polyunsaturated fatty acids. [ABSTRACT FROM AUTHOR]

This article examines the lipid composition of Pulmonaria obscura, a plant in the Boraginaceae family. The study focuses on the fatty acid composition of the lipids and their potential biological activity. The results indicate that the leaves contain various fatty acids, including omega-3 and omega-6 polyunsaturated fatty acids, which have positive effects on metabolic processes. The findings suggest that Pulmonaria obscura could be a valuable source of renewable raw material with multiple uses. The study was conducted as part of specific research tasks. [Extracted from the article]

It is hypothesized that plasma proportion of selected fatty acids (FAs) and dietary habits are linked with the risk of cardiovascular disease (CVD) in postmenopausal women. Therefore, this study was designed to determine the association of plasma FA composition and markers of dietary habits with an atherogenic index of plasma (AIP), a predictor of CVD risk in postmenopausal women. In total, 87 postmenopausal women with an average age of 57 ± 7 years were recruited and their dietary intake, anthropometric and biochemical parameters, and FA status in total plasma lipid proportions were determined, showing that 65.5% of the participants had a high risk of CVD according to their AIP value. After adjusting for some confounders (age, body mass index, and physical activity level), the risk of CVD was only positively associated with the frequency of consumption of animal fat spreads (butter and lard) of terrestrial origin. Regarding the FA profile, CVD risk was positively associated with the percentages of vaccenic acid, dihomo-γ-linolenic acid, and monounsaturated fatty acids (MUFA; mainly n-7) in total FA, as well as the MUFA/SFA ratio in total plasma and stearoyl-CoA desaturase-16 activity (16:1/16:0 ratio). In contrast, the risk of CVD was negatively associated with percentages of α-linolenic acid, total polyunsaturated fatty acids (PUFA), and PUFA/MUFA ratio in total plasma lipid, and the estimated activity of Δ5-desaturase (20:4/20:3 n-6 ratio). These results support the current recommendations to decrease the frequency of animal fat spread intake because it is associated with a reduced CVD risk based on AIP in postmenopausal women. In accordance with these plasma percentages of ALA, vaccenic acid, dihomo-γ-linolenic acid, PUFA, PUFA/MUFA ratio, and 16:1/16:0 ratio may be important parameters in CVD risk assessment. We aimed to explore the association between the risk of cardiovascular disease (CVD) and dietary habits as well as plasma fatty acid (FA) levels in postmenopausal women (PW). Dietary intake, anthropometric, biochemical parameters, and FA levels in plasma lipids were determined. The atherogenic index of plasma was calculated to predict CVD risks. Some plasma fatty acid in plasma may be important markers in assessing CVD risk. Limitation of animal fat spreads in diet may lower risk of CVD in PW. [Display omitted] [ABSTRACT FROM AUTHOR]

This paper investigates the fatty acid profiles of fish oil extracted from by-products of cultured Black Sea salmon, Oncorhynchus mykiss, using conventional [conventional fish oil (CFO)] and dry freezing oil [dry freezer oil (DFO)] techniques. In the CFO and DFO groups, monounsaturated fatty acid + polyunsaturated fatty acid (PUFA) comprised 74.00% and 72.68% of the total fatty acids, respectively. The highest PUFA was linoleic acid (CFO=14.22%, DFO=13.15%) with Docosahexaenoic acid (DHA, C22:6n3) being the second most concentrated fatty acid for PUFA in the CFO (8.12%) and DFO (8.02%) groups, followed by eicosapentaenoic acid (EPA, C20:5n3) (CFO=4.39%, DFO=2.87%). Similarly, the difference between groups in omega-3 was statistically significant (p<0.05) and the CFO ratio was higher in the DFO. The PI, AI, TI, h/H, and UI percentages in the CFO group were 0.99, 0.37, 0.26, 2.98, and 1.73%, respectively, while in the DFO group they were 0.80, 0.35, 0.31, 2.83, and 1.61%, respectively. The findings of this study conclude that the oils obtained from Black Sea salmon by-products are rich in omega-3 fatty acids and have good lipid quality indexes. [ABSTRACT FROM AUTHOR]

Using emulsifiers in poultry diets may increase digestibility of alternative lipid sources and enrich poultry egg yolks altering their fatty acid composition. This study aimed to evaluate performance, nutrient digestibility, egg quality, egg quality according to their storage period, and the fatty acid profile of Japanese quail egg yolk (Coturnix coturnix japônica). The design was completely randomized, in which 270 female quails were allocated in a 3x2 factorial diet arrangement: three lipid sources (soybean oil, poultry fat, and beef tallow), supplemented or not with an emulsifier, following two nutritional strategies – a diet formulated to meet the nutritional requirements proposed by INRA and a diet formulated with a reduction of 96 Kcal/kg of feed and added emulsifier. The effects of interactions between the lipid sources and the emulsifier were studied, their isolated effects when interactions were absent and the effect of storage time, and their interactions with the factors evaluated for egg quality variables. Feed intake was greater when beef tallow was added to the diets, while feed conversion was worse for birds fed diets with soybean oil and the emulsifier. Quails fed the diet with the emulsifier and soybean oil produced better quality eggs represented by the higher Haugh unit. Diets with beef tallow and poultry fat provided a higher percentage of palmitic and unsaturated fatty acids in the quail egg yolk. Alternative lipid sources such as beef tallow and poultry fat can be used as a substitute for soybean oil with added emulsifiers in diets for egg-laying quails without impairing performance and egg quality. The use of emulsifiers with alternative lipid sources to soybean oil can be considered a nutritional strategy in laying quail diets, but the reduction of energy in the diet must be adequate for the species. [ABSTRACT FROM AUTHOR]

Kefalotyri cheese made in December and April using milk from sheep grazing on pastures was aerobically kept, in the dark or under fluorescent light, for 40 days at 4°C. Unsaturated fatty acids, which were higher in April than in December cheese, were significantly (P < 0.05) decreased in all cheese samples under both storage conditions. According to lipid hydroperoxides, malondialdehyde and carbonyls changes, grated cheese samples stored under fluorescent light showed a higher protein and lipid oxidation as compared to samples stored in the dark. Sensory and colour characteristics were better for cheeses stored in the dark than those under fluorescent light. [ABSTRACT FROM AUTHOR]

Simple Summary: Insects are an important source of protein but insect fat increasingly slides into focus due to its high content of unsaturated fatty acids. Tenebrio molitor larvae were reared on several substrates with different nutritional contents to influence the fat and fatty acid contents of the larvae. The fat and fatty acid composition of the mealworm larvae were then analyzed in order to determine if a nutritional change could be detected using near-infrared reflectance spectroscopy. This is a rapid and non-destructive method for the online analysis of chemical composition. In this study, the diet used for rearing had a significant effect on the larval fat content and fatty acid composition as well as the absorbance of the near-infrared spectra and the larval growth rate and weight gain, i.e., a high fat content substrate reduced weight gain and larval growth. The most prevalent fatty acids identified and quantified were palmitic, oleic, and linoleic acid, showing a correlation between larval content and rearing diets containing high fatty acid amounts. A high dietary content of lauric acid, myristic acid, and α-linolenic acid resulted in a high content of these fatty acids in mealworm larvae. The fat and fatty acid content could be predicted accurately using near-infrared reflectance spectroscopy and were highly influenced by several diets having different proximate compositions. Several studies have shown that mealworms (Tenebrio molitor L.) could provide animals and humans with valuable nutrients. Tenebrio molitor larvae were studied to determine whether their rearing diets affected their fat and fatty acid content and to ascertain if it is possible to detect the changes in the larval fat composition using near-infrared reflectance spectroscopy (NIRS). For this reason, a standard control diet (100% wheat bran) and an experimental diet, consisting of wheat bran and the supplementation of a different substrate (coconut flour, flaxseed flour, pea protein flour, rose hip hulls, grape pomace, or hemp protein flour) were used. The results showed lesser weight gain and slower growth rates for larvae raised on diets with a high fat content. A total of eight fatty acids were identified and quantified, where palmitic, oleic, and linoleic acids were the most prevalent and showed a correlation between larval content and their content in the rearing diets. There was a high content of lauric acid (3.2–4.6%), myristic acid (11.4–12.9%), and α-linolenic acid 8.4–13.0%) in mealworm larvae as a result of the high dietary content of these fatty acids. NIR spectra were also influenced by the fat and fatty acid composition, as larval absorbance values differed greatly. The coefficient of the determination of prediction (R2P) was over 0.97, with an RPD value of 8.3 for the fat content, which indicates the high predictive accuracy of the NIR model. Furthermore, it was possible to develop calibration models with great predictive efficiency (R2P = 0.81–0.95, RPD = 2.6–5.6) for all fatty acids, except palmitoleic and stearic acids which had a low predictive power (R2P < 0.5, RPD < 2.0). The detection of fat and fatty acids using NIRS can help insect producers to quickly and easily analyze the nutritional composition of mealworm larvae during the rearing process. [ABSTRACT FROM AUTHOR]

This study investigated the effect of five in-house cooking methods (grilling, oven-cooking, frying, microwaving, and boiling) on lipid content and fatty acid composition in red mullet (Mullus barbatus). Moreover, the nutritional quality of the lipid fraction was evaluated by determining a number of lipid nutritional quality indices (LNQI). Moisture content of red mullet decreased after cooking, with the exception of boiled fish, while the lipid content significantly increased after microwave treatment and frying. After the latter, a ten-fold increase in lipid content was noted compared to fresh fish (from 2.1 to 21.1 g/100 g wet matter). All cooking methods caused significant changes in the fatty acid (FA) profile of M. barbatus. The content of saturated fatty acids (SFAs) varied significantly between raw and cooked fish with the lowest values determined for fried sample. Monounsaturated fatty acid (MUFA) content increased after oven cooking and frying, while polyunsaturated fatty acid (PUFA) content showed an opposite trend. The eicosapentaenoic acid (EPA) and docosahexaenoic (DHA) were the dominant fatty acids among n3 acids in all samples. EPA+DHA contribution in total FAs was significantly lower in the samples after oven cooking (19.6% total FAs) and frying (4.99% total FAs) than in the raw (25.5% of total FAs) fish. The n3/n6 ratio (range 1.25-3.65) decreased significantly after cooking; however, it remained above the recommended values for a healthy human nutrition (1:5). The PUFA/SFA ratio was between 0.69 in fried and 1.02 in boiled fish, both being greater than those recommended by the WHO/FAO [2003]. Atherogenicity index value decreased significantly after the cooking particularly in fried fish. The polyene index (PI), as a measure of PUFA damage, was in the range of 0.42-1.18. Although all cooking methods affected the FA profile, based on LNQI, it can be concluded that barbecue-grilling and boiling were the best cooking methods for healthy eating, due to their lowest effect on essential FAs. [ABSTRACT FROM AUTHOR]

Aim. The purpose of the work was to study the nutritional value of siberian sturgeon caviar Acipenser baerii, grown in aquaculture conditions in the Dnieper reservoirs of Ukraine, and to compare its quality indicators with this product produced abroad. Methods: There are identified organoleptic properties of siberian sturgeon caviar, and its energetic value, composition of amino acids in albumens and content of fatty acids in lipids of the product. The data obtained in the research were compared with the same indices of quality of caviar of sturgeons bred abroad. Results. The organoleptic properties of siberian sturgeon caviar bred in Ukraine (appearance, color, consistency, taste and aroma) conformed to its standardized indices of quality. The caviar contained all eight essential amino acids and belonged to category of products rich by albumen (21.54±2.13%), and fats eicosapentaenoic and docosahexaenoic ω-3 acids (3.46 % and 11.2 %, respectively) (13.20±0.93%). The big content of fat, especially of polyunsaturated fatty acids and ω-3 acids (the eicosapentaenoic and docosahexaenoic ones — 3.46 % and 11.2 %, respectively) is one more factor, which enables to identify the siberian sturgeon caviar as the product of high biological value. It was shown that the caviar of siberian sturgeon produced in Ukraine is in close coincidence with those that were produced in other countries. Conclusions. The totality of studied characteristics of caviar of siberian sturgeon produced in Ukraine witnesses its high nutritional value. Therefore, this product may be recommended in prophylactics of numerous illnesses and strengthening of state of health. [ABSTRACT FROM AUTHOR]

This review focuses on an understanding of lipid distribution and deposition dynamics in Atlantic salmon and explores the extent to which these can be predicted through multi-dimensional modeling. The methodology used to measure lipids can have an impact on their assessment and considerable work has been done to standardize and develop robust rapid assessment measures. The distribution of lipids in salmon fillets is spatially variable, with levels consistently highest in the belly region and lowest in the tail section. The level of lipids in the whole-body, fillet and Norwegian Quality Cut (NQC) of Atlantic salmon increases with fish size but plateaus as size increases. Lipid levels are predictable based on fish size data although there are various other factors that influence lipid deposition in the fillet. The relationship between these factors and the deposition of n-3 LC-PUFA is mathematically complex but does lend itself to multidimensional modeling. Effects are strongly influenced by dietary fatty acid composition and for the most part a "parity" exists between levels of certain fatty acids in the diet and what ends up in the body tissues. This parity results in a "dilution effect" that generally explains the relationship between diet and whole-body fatty acid levels. Some specific fatty acids demonstrate traits of selective retention in Atlantic salmon muscle tissue. Notably, docosahexaenoic acid is preferentially retained compared to other fatty acids. Which is explained by the understanding that not all fatty acids dilute at the same rate and biologically active fatty acids, like EPA, are essential for mediating inflammatory responses and have a critical role to play in biosynthesis. There are various influential dietary factors in addition to the level of specific fatty acids in the diet, that affect the level of deposition of n-3 LC-PUFA in the muscle. [ABSTRACT FROM AUTHOR]

We evaluated whether linseed oil (LO) modulates the effects of a high-carbohydrate diet (HCD) on liver inflammation, fatty acid (FA) accumulation, and lipid distribution in periportal and perivenous hepatocytes. The control group (control high-carbohydrate diet [HCD-C]) received an HCD with lard and soybean oil as the lipid source. The L10 and L100 groups received the HCD with 10% and 100% of LO as the lipid source, respectively. The animals were killed by decapitation before (day 0) and after receiving the diets. Liver FA composition, inflammation, and fibrogenesis gene expression were evaluated. Also, the percentage of lipid-occupied area in periportal end perivenous hepatocytes were measured. The L100 group exhibited a higher (P < .05) liver amount of omega-3 polyunsaturated FA (n-3 PUFA) and lower (P < .05) amounts of saturated FA (SFA), monounsaturated FA (MUFA), and omega-6 polyunsaturated FA (n-6 PUFA) compared with L10 or HCD-C mice. On day 56, interleukin 10 and type IV collagen gene expression were significantly upregulated and downregulated, respectively in L100. Also, the L100 group showed lower (P < .05) FA accumulation (i.e., total FA, SFA, MUFA, and n-6 PUFA). Also, L10 and L100 presented lower (P < .05) percentage of high lipid-containing portion in periportal and perivenous hepatocytes. We concluded that LO attenuation of liver inflammation promoted by an HCD is associated with increased liver n-3 PUFA levels, so modulating FA composition, deposition, and distribution in periportal and perivenous hepatocytes. [ABSTRACT FROM AUTHOR]

Supplementation of omega-3 fatty acids is considered a valuable strategy to supply the low intake of these fatty acids. Thus, the safety of the supplements is an important milestone. Because of that, we analyzed 20 unflavored supplements sold in the French market for fatty acid and triglyceride composition, for EPA and DHA, and for tocol content, as well as for oxidative status. This study found that only 2.5% of the supplements did not meet their label claims for omega-3 content. TAG analysis showed high variability among the triglyceride distribution, and the same trend was also noticed for the tocol content; in fact, a high variability of the distribution of the six tocols (four tocopherols and two tocotrienols) was found among the samples. Of the tested products, all of them complied with peroxide value, p-anisidine value, and Totox values established by the Global Organization for EPA and DHA Omega-3s (GOED) and were not oxidized. [ABSTRACT FROM AUTHOR]

1. The following study determined whether the effects of the combined addition of zinc amino acid complex (ZA) and selenomethionine (SM) was superior to their single addition in controlling the oxidative stress induced by dietary oxidised fat in laying hens. 2. Two hundred and forty 32-week-old laying hens were divided into the following dietary treatments (each consisting of six replicates of eight birds): 1) a fresh soy oil (FSO) diet; 2) an oxidised soy oil (OSO) diet; 3) an OSO diet plus 20 mg zinc as ZA/kg (OSO+ZA); 4) an OSO diet plus 0.2 mg selenium as SM/kg (OSO+SM); and 5) an OSO diet plus ZA and SM (OSO+ZA+SM). 3. After 10 weeks of feeding hens, feed intake, egg production, and egg mass in the OSO+ZA+SM group were similar to the FSO group but better (P < 0.05) than those in the OSO group. Shell thickness and shell breaking strength were significantly improved by the OSO+ZA and OSO+ZA+SM treatments. 4. Increases in the yolk concentrations of palmitic acid and total saturated fatty acids (SFA), and decreases in yolk linoleic acid, n-6 polyunsaturated fatty acids (PUFA), total PUFA, and PUFA/SFA ratio were induced by dietary oxidised fat which were normalised (P < 0.05) by OSO+SM and OSO+ZA+SM. 5. An increase (P < 0.05) in malondialdehyde and a decrease in 2,2-diphenyl-picrylhydrazyl radical scavenging activity in the yolk, induced by dietary oxidised fat, was significantly improved by all dietary supplementations, but only birds fed the OSO+ZA+SM diet exhibited similar values to those fed FSO. 6. In conclusion, the simultaneous inclusion of organic zinc plus selenium in the oxidised fat diets was beneficial for improving egg-laying performance, yolk fatty acid profile, and oxidative stability, but not for internal egg quality, compared with either zinc or selenium alone in laying hens. [ABSTRACT FROM AUTHOR]

In the field of lipid research, bioorthogonal chemistry has made the study of lipid uptake and processing in living systems possible, whilst minimising biological properties arising from detectable pendant groups. To allow the study of unsaturated free fatty acids in live cells, we here report the use of sterculic acid, a 1,2‐cyclopropene‐containing oleic acid analogue, as a bioorthogonal probe. We show that this lipid can be readily taken up by dendritic cells without toxic side effects, and that it can subsequently be visualised using an inverse electron‐demand Diels–Alder reaction with quenched tetrazine‐fluorophore conjugates. In addition, the lipid can be used to identify changes in protein oleoylation after immune cell activation. Finally, this reaction can be integrated into a multiplexed bioorthogonal reaction workflow by combining it with two sequential copper‐catalysed Huisgen ligation reactions. This allows for the study of multiple biomolecules in the cell simultaneously by multimodal confocal imaging. [ABSTRACT FROM AUTHOR]

In the field of lipid research, bioorthogonal chemistry has made the study of lipid uptake and processing in living systems possible, whilst minimising biological properties arising from detectable pendant groups. To allow the study of unsaturated free fatty acids in live cells, we here report the use of sterculic acid, a 1,2‐cyclopropene‐containing oleic acid analogue, as a bioorthogonal probe. We show that this lipid can be readily taken up by dendritic cells without toxic side effects, and that it can subsequently be visualised using an inverse electron‐demand Diels–Alder reaction with quenched tetrazine‐fluorophore conjugates. In addition, the lipid can be used to identify changes in protein oleoylation after immune cell activation. Finally, this reaction can be integrated into a multiplexed bioorthogonal reaction workflow by combining it with two sequential copper‐catalysed Huisgen ligation reactions. This allows for the study of multiple biomolecules in the cell simultaneously by multimodal confocal imaging. [ABSTRACT FROM AUTHOR]

Objective: Clinical heterogeneity in major depressive disorder likely reflects the range of etiology and contributing factors in the disorder, such as genetic risk. Identification of more refined subgroups based on biomarkers such as white matter integrity and lipid-related metabolites could facilitate precision medicine in major depressive disorder. Methods: A total of 148 participants (15 genetic high-risk participants, 57 patients with first-episode major depressive disorder and 76 healthy controls) underwent diffusion tensor imaging and plasma lipid profiling. Alterations in white matter integrity and lipid metabolites were identified in genetic high-risk participants and patients with first-episode major depressive disorder. Then, shared alterations between genetic high-risk and first-episode major depressive disorder were used to develop an imaging x metabolite diagnostic panel for genetically based major depressive disorder via factor analysis and logistic regression. A fivefold cross-validation test was performed to evaluate the diagnostic panel. Results: Alterations of white matter integrity in corona radiata, superior longitudinal fasciculus and the body of corpus callosum and dysregulated unsaturated fatty acid metabolism were identified in both genetic high-risk participants and patients with first-episode major depressive disorder. An imaging x metabolite diagnostic panel, consisting of measures for white matter integrity and unsaturated fatty acid metabolism, was identified that achieved an area under the receiver operating characteristic curve of 0.86 and had a significantly higher diagnostic performance than that using either measure alone. And cross-validation confirmed the adequate reliability and accuracy of the diagnostic panel. Conclusion: Combining white matter integrity in corpus callosum, superior longitudinal fasciculus and corona radiata, and unsaturated fatty acid profile may improve the identification of genetically based endophenotypes in major depressive disorder to advance precision medicine strategies. [ABSTRACT FROM AUTHOR]

Halocynthia aurantium is a marine organism that has been considered a promising source for bio-functional materials. Total lipids were extracted from H. aurantium tunic, and then they were separated into neutral lipids, glycolipids, and phospholipids. In the present study, fatty acid profiles of three lipids and their anti-inflammatory effects in RAW264.7 cells were investigated. Among the lipid classes, phospholipids showed the diversity of fatty acid constituents, compared with the glycolipids and neutral lipids. Three lipids contain different contents of fatty acids depending on the kinds of lipids. The most contents were saturated fatty acids (SFAs, 53–69% of the fatty acids) and monounsaturated fatty acids (MUFAs, 15–17% of fatty acids) and polyunsaturated fatty acids (PUFAs, 14–32% of fatty acids) are followed. H. aurantium lipids not only dose-dependently inhibited nitric oxide production but also reduced the expression of inflammatory cytokine genes such as TNF-α, IL-1β, and IL-6 in LPS-stimulated macrophages. It was also demonstrated that the expression of COX-2 was dose-dependently suppressed. Moreover, H. aurantium lipids decreased phosphorylation of NF-κB p-65, p38, ERK1/2, and JNK, suggesting that three lipids from H. aurantium tunic provide anti-inflammatory effects through NF-κB and MAPK signaling. These results indicate that H. aurantium is a potential source for anti-inflammation. [ABSTRACT FROM AUTHOR]

Studies on the influence of salinity on microalgal lipids have focused mainly on chlorophyte species and knowledge about photosynthetic secondary endosymbionts is limited. Haptophytes exemplify this situation and represent an interesting model to advance knowledge about the high phylogenetic variability of microalgae in their response to salinity. The estuarine Pavlovophyceae Diacronema vlkianum underwent particular lipid class and fatty acid changes under the effect of salinity. Variability due to salinity was higher in the fatty acid profile compared with that of the lipid class profile. Triacylglycerols decreased with salinity in actively growing cells and increased only when salinity rose to 50 and cell growth ceased. Hypersalinity caused a slight, although significant, sulpholipid decrease and a 4-fold increase in phosphatidylglycerol, suggesting a key role for this phospholipid in salt tolerance. Conversely, the betaine lipid diacylglycerol hydroxymethyl-N,N,N-trimethyl-β-alanine was specifically decreased with high salinity. The fatty acids that decreased the most with salinity were 14:0, 16:1n-7, 20:4n-6, 20:5n-3 and 22:6n-3, while higher levels of 16:1n-9, 17:1, 18:2n-6 and 18:3n-3 were induced by high salinity. Despite fatty acid changes, the unsaturation index did not vary with salinity, but nutritional value of D. vlkianum decreased at a salinity of 50 due to a lower presence of 20-C polyunsaturated fatty acids. This pattern of lipid variation in D. vlkianum with salinity has not been described in any other microalgae. Although D. vlkianum grows within a wide salinity range, production of nutritional and functional lipids is more favourable at low salinity values. [ABSTRACT FROM AUTHOR]

Globally, the incidence rate and number of patients with nonalcoholic fatty liver disease are increasing, which has become one of the greatest threats to human health. However, there is still no effective therapy and medicine so far. Silphium perfoliatum L. is a perennial herb native to North America, which is used to improve physical fitness and treat liver and spleen related diseases in the traditional medicinal herbs of Indian tribes. This herb is rich in chlorogenic acids, which have the functions of reducing blood lipids, losing weight and protecting liver. However, the effect of these compounds on nonalcoholic fatty liver disease remains unclear. Clarify the therapeutic effects and mechanism of the extract (CY-10) rich in chlorogenic acid and its analogues from Silphium perfoliatum L. on non-alcoholic fatty liver disease, and to determine the active compounds. A free fatty acid-induced steatosis model of HepG2 cells was established to evaluate the in vitro activity of CY-10 in promoting lipid metabolism. Further, a high-fat diet-induced NAFLD model in C57BL/6 mice was established to detect the effects of CY-10 on various physiological and biochemical indexes in mice, and to elucidate the in vivo effects of the extract on regulating lipid metabolism, anti-inflammation and hepatoprotection, and nontarget lipid metabolomics was performed to analyze differential metabolites of fatty acids in the liver. Subsequently, western blotting and immunohistochemistry were used to analyze the target of the extract and elucidate its mechanism of action. Finally, the active compounds in CY-10 were elucidated through in vitro activity screening. The results indicated that CY-10 significantly attenuated lipid droplet deposition in HepG2 cells. The results of in vivo experiments showed that CY-10 significantly reduce HFD-induced mouse body weight and organ index, improve biochemical indexes, oxidation levels and inflammatory responses in the liver and serum, thereby protecting the liver tissue. It can promote the metabolism of unsaturated fatty acids in the liver and reduce the generation of saturated fatty acids. Furthermore, it is clarified that CY-10 can promote lipid metabolism balance by regulating AMPK/FXR/SREPB-1c/PPAR-γ signal pathway. Ultimately, the main active compound was proved to be cryptochlorogenic acid, which has a strong promoting effect on the metabolism of fatty acids in cells. Impressively, the activities of CY-10 and cryptochlorogenic acid were stronger than simvastatin in vitro and in vivo. For the first time, it is clarified that the extract rich in chlorogenic acids and its analogues in Silphium perfoliatum L. have good therapeutic effects on non-alcoholic fatty liver disease. It is confirmed that cryptochlorogenic acid is the main active compound and has good potential for medicine. [Display omitted] • Chlorogenic acids CY-10 from Silphium perfoliatum L. has excellent therapeutic effect on NAFLD. • CY-10 improves lipid metabolism and inflammatory response, prevent liver damage. • CY-10 promotes lipid metabolism balance by regulating the AMPK/FXR signaling pathway. • Cryptochlorogenic acid may be the key ingredient of CY-10 regulating lipid metabolism. [ABSTRACT FROM AUTHOR]

[Display omitted] • The development of peanut oil volatile flavor requires oil to participate in thermal reaction. • Heating peanut oil to degrade the unsaturated fatty acids in the oil creates reducing aldehydes. • Linoleic acid is one of the precursors in the formation of the volatile flavor of peanut oil. • Develop a volatile flavor model capable of distinguishing different reactions. Lipid is an important precursor for volatile flavor formation, but it is not clear how to study the reactions involved in forming key volatile flavor compounds in peanut oil. In this paper, we innovatively established a flavor research model to investigate the contribution of different chemical reactions to the aroma compounds of peanut oil. The results showed that lipid participation in thermal reactions is necessary for forming major aroma compounds in hot-pressed peanut oil. Compared to the Maillard reaction, the lipid oxidation-Maillard reaction produces more compounds with 46 volatile substances identified. During the heating process, six new key substances were formed and the level of unsaturated fatty acids decreased by 7.28%. Among them, linoleic acid may be an important precursor for the formation of aroma components of hot-pressed peanut oil. Our study could provide theoretical guidance for understanding the volatile flavor mechanism of peanut oil and improving volatile flavor. [ABSTRACT FROM AUTHOR]

• Amylosucrase and pullulanase treatments of amylopectin produced linear α-glucans. • Linear α-glucans were prone to form V-type complexes with unsaturated fatty acid. • Digestibility of the complexes was controlled by their crystalline structure. • The formation of V-type structure improved the stability of unsaturated fatty acid. In this study, waxy corn starch (WCS) was modified by amylosucrase and pullulanase, producing linear starch chains with elongated length that favored the complexation with unsaturated fatty acids (uFAs). Compared to native WCS, the amylosucrase-modified WCS with an average chain length of 47.8 was easier to form V-type complexes with oleic acid, while increasing the degree of unsaturation impeded the formation of V-type complexes. The pullulanase treatment hydrolyzed the branching points of amylosucrase-modified WCS and the linear starch chains could forme V-type complexes with oleic acid, linoleic acid, and linolenic acid, with V-type crystallinity decreasing from 38.2 % to 20.1 %. V-type complexes had a lower thermal stability than the B-type starch crystallites, and their peak melting temperature ranged from 67.2 to 79.0 °C. The content of resistant starch in the complexes was in the range of 21.8 %-40.9 % and the formation of V-type complexes decreased the susceptibility of uFAs to oxygen. [ABSTRACT FROM AUTHOR]

Owing to its numerous physiological effects, Acer truncatum seed oil (ATO) is increasingly popular as a novel source of edible oil in China. To explore the characteristics of ATO accumulation, the potential biosynthetic mechanisms of the main fatty acids (FAs) were investigated during the six different developmental stages of A. truncatum seeds (i.e., S1 - S6). The results indicated that the ATO yields significantly increased from S1 to S5, and then decreased (S6), whereby the ratio of unsaturated fatty acids reached up to 82.63–90.65% of the total ATO content. The highest content of nervonic acid was observed at S6. Dynamic transcriptome data analyses revealed that 38,932 genes were actively transcribed in the five seed developmental stages (i.e., S1-S5), 103 of which were related to lipid metabolism. Combining with the gene expression and FA profiling, the potential metabolism of the main FA was further explored. Notably, changes in C18:1-CoA transformation were observed at the later periods of A. truncatum seed development (especially from S4 to S5), which might be the key factor limiting the accumulation of very long-chain fatty acids (VLCFAs). Additionally, 24 key functional genes related to lipid metabolism were highly correlated with VLCFA biosynthesis. Finally, 11 potential transcription factors from the bHLH, GRAS, bZIP, AP2/ERF, and MADS families exhibited highly positive correlations with these key functional genes in lipid metabolism, all of which might play important roles in regulating of VLCFA accumulation. • Characteristics of VLCFA accumulation were parsed during seed development. • Regulation of C18:1-CoA transfromation is the key steps in VLCFA accumulation. • Putative key genes and regulators were identified in VLCFA accumulation. [ABSTRACT FROM AUTHOR]

Due to their valuable nutritional content, several hemp-derived products from hempseeds have recently been placed in the market as food and food ingredients. In particular, the lipid composition of hempseeds has raised interest for their rich content in biologically active polyunsaturated fatty acids with an optimum ratio of omega-3 and omega-6 compounds. At present, however, the overall polar lipidome composition of hempseeds remains largely unknown. In the present work, an analytical platform was developed for the extraction, untargeted HRMS-based analysis, and detailed annotation of the lipid species. First, five one- and two-phase solid-liquid extraction protocols were tested and compared on a hempseed pool sample to select the method that allowed the overall highest efficiency as well as easy coupling with lipid derivatization by photochemical [2 + 2] cycloaddition with 6-azauracil. Underivatized lipids were annotated employing a data processing workflow on Compound Discoverer software that was specifically designed for polar lipidomics, whereas inspection of the MS/MS spectra of the derivatized lipids following the aza-Paternò-Büchi reaction allowed pinpointing the regiochemistry of carbon-carbon double bonds. A total of 184 lipids were annotated, i.e., 26 fatty acids and 158 phospholipids, including minor subclasses such as N-acylphosphatidylethanolamines. Once the platform was set up, the lipid extracts from nine hempseed samples from different hemp strains were characterized, with information on the regiochemistry of free and conjugated fatty acids. The overall analytical approach helped to fill a gap in the knowledge of the nutritional composition of hempseeds. [Display omitted] • One-phase lipid extraction more efficient than common two-phase extraction. • Methanol extraction was directly coupled with aza-Paternò-Büchi lipid derivatization. • 184 fatty acids and phospholipids were annotated in nine hempseed accessions. • Photochemical derivatization allowed pinpointing carbon-carbon double bonds. • Distinct regioisomeric compositions were determined in different accessions. [ABSTRACT FROM AUTHOR]

The positive corrective effect of fed flaxseed oil on the condition of the pancreas in acute L-arginine-induced pancreatitis was shown, the development of which was assessed by the number of necrotized acinar epitheliocytes in the head and tail of the pancreas and the activity of lipase and α-amylase in blood plasma. Feeding sunflower oil does not show a similar corrective effect. The normalizing effect of fed flaxseed oil on the state of the antioxidant defense system in rabbits in acute L-arginine-induced pancreatitis, on the content of thiobarbituric acid-positive products and the activity of superoxide dismutase, catalase and glutathione peroxidases in blood. Feeding sunflower oil leads to a deterioration of the oxidative-prooxidant balance. The ability of fed flaxseed oil to prevent disorders of content of non-esterified and esterified cholesterol in blood plasma, liver and skeletal muscle of rabbits in acute L-arginine-induced pancreatitis has been established. Feeding sunflower oil under the above conditions impairs the lipid composition of rabbit tissues. The positive effect of fed flaxseed oil on the ratio of anti-inflammatory polyunsaturated fatty acids of the ω-3 family to proinflammatory polyunsaturated fatty acids of the ω-6 family in the fatty acid spectrum of esterified cholesterol in blood plasma, liver and skeletal muscle of rabbits in acute L-arginine-induced pancreatitis. The result of the fed sunflower oil action on the studied indicators is quite the opposite. In acute L-arginine-induced pancreatitis, feeding flaxseed oil stimulates the conversion of cholesterol to bile acids, 25-OH-vitamin D3, testosterone, aldosterone and cortisol in rabbits. The stimulating ability of fed sunflower oil in this regard is less pronounced. [ABSTRACT FROM AUTHOR]

Purpose: Human milk (HM) composition is influenced by factors, like maternal diet and body stores, among other factors. For evaluating the influence of maternal fatty acid (FA) status on milk FA composition, the correlation between FA content in HM and in maternal plasma, erythrocytes, and adipose tissue was investigated. Methods: 223 European women who delivered at term, provided HM samples over first four months of lactation. Venous blood and adipose tissue (only from mothers who consented and underwent a C-section delivery) were sampled at delivery. FAs were assessed in plasma, erythrocytes, adipose tissue, and HM. Evolution of HM FAs over lactation and correlations between FA content in milk and tissues and between mother's blood and cord blood were established. Results: During lactation, arachidonic acid (ARA) and docosahexaenoic acid (DHA) significantly decreased, while linoleic acid (LA), alpha-linolenic acid (ALA), and eicosapentaenoic acid (EPA) remained stable. Positive correlations were observed between HM and adipose tissue for palmitic, stearic, oleic, and polyunsaturated fatty acids (PUFAs). Correlations were found between milk and plasma for oleic, LA, ARA, ALA, DHA, monounsaturated fatty acids (MUFAs), and PUFAs. No correlation was observed between erythrocytes and HM FAs. LA and ALA were more concentrated in maternal blood than in infant blood, contrary to ARA and DHA, supporting that biomagnification of LCPUFAs may have occurred during pregnancy. Conclusions: These data show that maternal adipose tissue rather than erythrocytes may serve as reservoir of PUFAs and LCPUFAs for human milk. Plasma also supplies PUFAs and LCPUFAs to maternal milk. If both, adipose tissue and plasma PUFAs, are reflection of dietary intake, it is necessary to provide PUFAs and LCPUFAs during pregnancy or even before conception and lactation to ensure availability for mothers and enough supply for the infant via HM. [ABSTRACT FROM AUTHOR]

Simple Summary: Expected climate change scenarios will have inevitable and important impacts on key foundation marine species such as seagrasses. This study was aimed to understand how the dwarf eelgrass Zostera noltii leaf lipid landscapes are altered under predicted ocean warming (+4 °C) and acidification (ΔpH 0.4) conditions. A severe reduction in the leaf total fatty acid (FA) content was observed in seagrasses individually exposed to hypercapnic or warming conditions, and this depletion was ameliorated under combined exposure to ocean warming and acidification conditions. The tested treatments also impacted the FA composition of all lipid classes, with warming exposure leading to decreases in polyunsaturated fatty acids (PUFAs). Galactolipid remodeling seems to have key roles in the physiological changes observed in seagrasses under these tested conditions, highlighting the higher impact of warming and that the proposed stress alleviation effect induced by increased water-dissolved CO2 availability. Neutral lipids were substantially increased under warming conditions, mainly with increases in C18 FA, impairing their use as substrates to maintain the osmotic balance of the cells. Nonetheless, the pace at which ocean warming is occurring can overcome the ameliorative capacity induced by higher CO2 availability, leaving seagrasses under severe heat stress beyond their lipid-remodeling capacity. Coastal seagrass meadows provide a variety of essential ecological and economic services, including nursery grounds, sediment stabilization, nutrient cycling, coastal protection, and blue carbon sequestration. However, these ecosystems are highly threatened by ongoing climatic change. This study was aimed to understand how the dwarf eelgrass Zostera noltii leaf lipid landscapes are altered under predicted ocean warming (+4 °C) and hypercapnic (ΔpH 0.4) conditions. Warming and hypercapnic conditions were found to induce a severe reduction in the leaf total fatty acid, though the combined treatment substantially alleviated this depletion. The lipid discrimination revealed a significant increase in the relative monogalactosyldiacylglycerol (MGDG) content in both hypercapnic and warming conditions, allied to plastidial membrane stabilization mechanisms. Hypercapnia also promoted enhanced phosphatidylglycerol (PG) leaf contents, a mechanism often associated with thylakoid reinvigoration. In addition to changing the proportion of storage, galacto- and phospholipids, the tested treatments also impacted the FA composition of all lipid classes, with warming exposure leading to decreases in polyunsaturated fatty acids (PUFAs); however, the combination of both stress conditions alleviated this effect. The observed galactolipid and phospholipid PUFA decreases are compatible with a homeoviscous adaptation, allowing for the maintenance of membrane stability by counteracting excessive membrane fluidity. Neutral lipid contents were substantially increased under warming conditions, especially in C18 fatty acids (C18), impairing their use as substrates for fatty acylated derivatives essential for maintaining the osmotic balance of cells. An analysis of the phospholipid and galactolipid fatty acid profiles as a whole revealed a higher degree of discrimination, highlighting the higher impact of warming and the proposed stress alleviation effect induced by increased water-dissolved CO2 availability. Still, it is essential to remember that the pace at which the ocean is warming can overcome the ameliorative capacity induced by higher CO2 availability, leaving seagrasses under severe heat stress beyond their lipid remodeling capacity. [ABSTRACT FROM AUTHOR]