Temperature effects on plasmalogen profile and quality characteristics in Pacific oyster (Crassostrea gigas) during depuration.

The quality of Pacific oyster (Crassostrea gigas) can be affected by many factors during depuration, in which temperature is the major element. In this study, we aim to determine the quality and plasmalogen changes in C. gigas depurated at different temperatures. The quality was significantly affected by temperature, represented by varying survival rate, glycogen content, total antioxidant capacity, alkaline phosphatase activity between control and stressed groups. Targeted MS analysis demonstrated that plasmalogen profile was significantly changed during depuration with PUFA-containing plasmalogen species being most affected by temperature. Proteomics analysis and gene expression assay further verified that plasmalogen metabolism is regulated by temperature, specifically, the plasmalogen synthesis enzyme EPT1 was significantly downregulated by high temperature and four plasmalogen-related genes (GPDH, PEDS, Pex11, and PLD1) were transcriptionally regulated. The positive correlations between the plasmalogen level and quality characteristics suggested plasmalogen could be regarded as a quality indicator of oysters during depuration.

Preliminary Purification and Partial Characterization of a Functional Bacteriocin of Lacticaseibacillus paracasei Zhang and Mining for its Gene Cluster.

Bacteriocins produced by lactic acid bacteria (LAB) have good potential for use as food biopreservatives. Lacticaseibacillus paracasei Zhang (L. paracasei Zhang) is both a food use and a probiotic bacterium. This study aimed to purify and preliminary characterize the active antibacterial metabolite of L. paracasei Zhang. The cell-free supernatant of L. paracasei Zhang was collected and purified by ultrafiltration and gel filtration chromatography. The 1-3 kDa active fraction could inhibit the growth of Staphylococcus aureus but not Escherichia coli. Further antibacterial activity assays revealed its capacity to suppress various foodborne and human opportunistic pathogens (including Staphylococcus aureus, Pseudomonas fluorescens, Pseudomonas aeruginosa, Listeria monocytogenes, and Bacillus cereus), but not fungi. The antibacterial activity showed good tolerance to heat (40 to 100 °C), acid-base (pH 2-3 and pH 6-10), and digestions by a number of industrial and animal/human enzymes (such as trypsin, pepsin, α-amylase, and protease K, except papain); these desired properties make it a suitable biopreservative to be used in harsh and complex industrial production processes. The high papain sensitivity suggested a proteinaceous/peptide nature of the bioactivity. Moreover, our genomic data mining for bacteriocin through BAGEL4 revealed an area of interest encoding a complete set of putative genes required for bacteriocin production. In conclusion, our study showed that L. paracasei Zhang can produce extracellular functional antibacterial metabolite, likely a class II bacteriocin. Our preliminary extraction and characterization of the active metabolite demonstrated that it has good potential to be used as a biopreservative or an agent for suppressing gastrointestinal infections.

Both viable Bifidobacterium longum subsp. infantis B8762 and heat-killed cells alleviate the intestinal inflammation of DSS-induced IBD rats.

In view of the safety concerns of probiotics, more and more attention is paid to the beneficial effects of dead probiotics cells. Herein, we investigated and compared the alleviation effects of viable Bifidobacterium longum subsp. infantis B8762 (B. infantis B8762) and its heat-killed cells on dextran sodium sulfate (DSS)-induced inflammatory bowel disease (IBD) rats. Four groups of rats (n = 12 per group) were included: normal control, DSS-induced colitis rats without bacterial administration (DSS), DSS-induced colitis rats with viable B. infantis B8762 administration (VB8762), and DSS-induced colitis rats with dead B. infantis B8762 administration (DB8762). Our results showed that both VB8762 and DB8762 administration exerted significant protective effects on DSS-induced IBD rats, as evidenced by a reduction in mortality, disease activity index score, body weight loss, as well as decreased histology score, which were companied by a significant decrease in serum pro-inflammatory factors compared with DSS group, and a stronger effect on modulating the fecal microbiota alpha-diversity and beta-diversity compared with DSS group. Additionally, the fecal metabolome results showed that both VB8762 and DB8762 interventions indeed altered the fecal metabolome profile and related metabolic pathways of DSS-induced IBD rats. Therefore, given the alleviation effects on colitis, the DB8762 can be confirmed to be a postbiotic. Overall, our findings suggested that VB8762 and DB8762 had similar ability to alleviate IBD although with some differences. Due to the minimal safety concern of postbiotics, we propose that the postbiotic DB8762 could be a promising alternative to probiotics to be applied in the prevention and treatment of IBDs.IMPORTANCEInflammatory bowel disease (IBD) has emerged as a global disease because of the worldwide spread of western diets and lifestyles during industrialization. Up to now, many probiotic strains are used as a modulator of gut microbiota or an enhancer of gut barrier to alleviate or cure IBD. However, there are still many issues of using probiotics, which were needed to be concerned about, for instance, safety issues in certain groups like neonates and vulnerable populations, and the functional differences between viable and dead microorganisms. Therefore, it is of interest to investigate the beneficial effects of dead probiotics cells. The present study proved that both viable Bifidobacterium longum subsp. infantis B8762 and heat-killed cells could alleviate dextran sodium sulfate-induced colitis in rats. The findings help to support that some heat-killed probiotics cells can also exert relevant biological functions and can be used as a postbiotic.

The inhibition mechanism of PostbioYDFF-3 on quality deterioration of refrigerated grass carp fillets from the perspective of endogenous enzyme and microorganisms changes.

The protective mode of PostbioYDFF-3 (referred to as postbiotics) on the quality stability of refrigerated fillets was explored from the aspects of endogenous enzyme activity and the abundance of spoilage microorganisms. Compared to the control group, the samples soaked in postbiotics showed significant reductions in TVC, TVB-N and TBARS values by 39.6%, 58.6% and 25.5% on day 5, respectively. In addition, the color changes, biogenic amine accumulation and texture softening of the fish fillets soaked in postbiotics were effectively suppressed. Furthermore, the activity of endogenous enzyme activities was detected. The calpain activities were significantly inhibited (p < 0.05) after soaking in postbiotics, which declined by 23%. Meanwhile, high throughput sequencing analysis further indicated that the growth of spoilage microorganism such as Acinetobacter and Pseudomonas were suppressed. Overall, the PostbioYDFF-3 was suitable for preserving fish meat.

Antibacterial and antibiofilm activities of protocatechualdehyde and its synergy with ampicillin against methicillin-resistant Staphylococcus aureus.

Protocatechualdehyde (PA) is a phenolic acid present in many plants and has many biological activities. Herein, the antagonistic effects and the action mechanism of PA against methicillin-resistant Staphylococcus aureus (MRSA) were studied. The results showed that PA had both significant antibacterial and anti-biofilm activities against MRSA. Additionally, PA had synergy with ampicillin against MRSA. It was elucidated that PA was prominent in destroying cell membranes, increasing cell membrane permeability and intracellular ROS production, thus leading to bacterial cell damage. Transcriptome analysis showed that PA disrupts many physiological pathways, including increasing cell membrane permeability, inhibiting biofilm formation, decreasing resistance to antimicrobial agents, and impairing DNA replication. Finally, the antimicrobial preservation test showed that PA could inhibit the growth of MRSA and prevent the corruption of beef. In summary, PA is an effective natural antibacterial substance and has a good application potential in food preservation, even in tackling antibiotic resistance problems.

Changes in Flavor-Related Biomarkers in Pacific Oysters (Crassostrea gigas) Following Microplastic Exposure.

Microplastics have been an emerging threat to filtering species and the ingestion and impacts of microplastics on oysters are a cause for concern. However, much remains unknown about the effects of microplastics on flavor-related biomarkers in oysters. Herein, a laboratory microplastic exposure with concentrations of 1, 10, and 100 mg/L for 15 days was performed to investigate the impacts of microplastics on the flavor parameters of oysters. Exposure to microplastics changed the odor characteristics of oysters. Microplastic exposure had minor effects on the fatty acid composition; however, significant alterations in free amino acids and nucleotides were observed under the 1 and 10 mg/L exposure groups, respectively. The overall results indicated 10 mg/L of microplastic exposure significantly increased the equivalent umami value of oysters. These findings stressed the effects of microplastics on oysters and would be an important reference for the assessment of the potential risks associated with microplastics in marine edible species.

The influence of γ-PGA on the quality of cooked frozen crayfish during temperature fluctuations.

The purpose of this study was to compare the influences of gamma-poly glutamic acid (γ-PGA) (1, 2, 3, and 4 %) to see which could outperform conventional cryoprotectant mixture (4 % sorbitol + 4 % sucrose) on cooked crayfish properties, such as physicochemical, textural qualities, oxidation reaction, water distributions, and microstructure integrity, during different freeze-thaw cycles. Crayfish quality characteristics improved significantly as γ-PGA concentration increased compared to control samples.Adding γ-PGA 4 % reduced the carbonyl content from 4.20 to 3.00 nmol/ mg protein during fluctuation-1 (F1), and from 4.15 to 2.80 nmol/ mg protein during fluctuation-2 (F2) compared to control samples. Furthermore, it increased the total sulfhydryl content from 4.15 and 4.76 to 6.19 and 6.47 mol/105 g protein during F1 and F2 and after five freeze-thaw cycles (FTC). This suggests that this concentration was more effective at controlling protein changes than other concentrations. γ-PGA generally enhanced the water-holding capacity by preventing protein denaturation and limiting ice crystal recrystallization. As a result, microstructure stability was evident, texture degradation was avoided, and the crayfish's color was preserved.

In-Depth Analysis of the Mechanism of Astaxanthin Succinate Diester in Reducing Ulcerative Colitis in C57BL/6J Mice Based on Microbiota Informatics.

This paper aims to explore the effect and mechanism of water-soluble astaxanthin succinate diester (Asta-SD) on ulcerative colitis (UC) induced by dextran sodium sulfate in zebrafish and C57BL/6J mice. Asta-SD was synthesized with hydrophilic fatty acid succinic anhydride and the hydroxyl groups at the ends of F-Asta were synthesized by esterifying. Through the construction of a zebrafish intestinal inflammation model, it was found that Asta-SD could effectively reduce the levels of ROS and increase the number of healthy intestinal lysosomes in zebrafish. After continuous gavage of Asta-SD for seven days, the body weight, disease activity index, colonic length, colonic histopathology, expression of inflammatory factors, and intestinal flora of the mice were measured. The results showed that Asta-SD could significantly alleviate weight loss and colonic shrinkage, as well as reducing pro-inflammatory cytokines and recess injury in UC mice. The 16S rRNA gene sequencing showed that Asta-SD significantly increased the beneficial bacteria (Lactobacillus, Anaerotruncus) and decreased the relative abundance of pathogenic bacteria, effectively maintaining intestinal microbiota homeostasis in mice. Based on Pearson analysis, Bacteroides, Parabacteroides, and Butyrimionas were expected to be associated with the significant difference in the expression of inflammatory factors between the UC and the corresponding host. Thus, Asta-SD significantly improves UC and maintains intestinal microbiota homeostasis.

A Europium Nanosphere-Based Time-Resolved Fluorescent Immunochromatographic Assay for the Rapid Screening of 4,4'-Dinitrocarbanilide: Aiming at Improving Strip Method Performance.

Considering that the strip method is simple and convenient for users, a Europium nanosphere-based time-resolved fluorescent immunochromatographic assay (TRFICA) for the rapid screening of 4,4'-dinitrocarbanilide (DNC) was developed to improve the performance of strip assays. After optimization, TRFICA showed IC50, the limit of detection, and cut-off values of 0.4, 0.07, and 5.0 ng mL-1, respectively. No significant cross-reactivity (CR < 0.1%) with 15 DNC analogs was observed in the developed method. TRFICA was validated for DNC detection in spiked chicken homogenates, and recoveries ranged from 77.3% to 92.7%, with coefficients of variation of <14.9%. Moreover, the time needed for the detection procedure, including the sample pre-treatment, was less than 30 min for TRFICA, which had never been achieved before in other immunoassays. The newly developed strip test is a rapid, sensitive, quantitative, and cost-effective on-site screening technique for DNC analysis in chicken muscle.

Effects of liquid nitrogen freezing at different temperatures on the quality and flavor of Pacific oyster (Crassostrea gigas).

This study aimed to evaluate the effects of different liquid nitrogen freezing (LNF) temperatures (-20, -40, -60, -80, and -100 °C) on the water holding capacity, texture, microstructure, and flavor of Crassostrea gigas (C. gigas). The results showed that -40 °C LNF, -60 °C LNF, and -80 °C LNF improved the water holding capacity of C. gigas (P < 0.05); -60 °C LNF and -80 °C LNF could effectively maintain the hardness of the body trunk and adductor muscles. Compared with -20 °C refrigerator freezing (RF), the LNF group could form smaller ice crystals and thus reduce the damage to the muscle cell structure damage, especially LNF at -80 °C. Gas chromatography-ion mobility spectrometry (GC-IMS) and e-nose results indicated that -80 °C LNF maintained the flavor profile of few aldehydes and alcohols compared to other freezing groups. Therefore, -80 °C LNF effectively improved the quality and maintain the flavor characteristics of frozen C. gigas.

An overview of microplastics in oysters: Analysis, hazards, and depuration.

Microplastic pollution has become an emergent global environmental issue because of its ubiquitous nature and everlasting ecological impacts. In marine ecosystems, microplastics can serve as carriers to absorb various contaminants and the ingestion of microplastics in oysters is of concern because they can induce several adverse effects. The analytical process of microplastics in oysters commonly consists of separation, quantification, and identification. Quantification of microplastics is difficult since information regarding the analytical methods is incoherent, therefore, standard microplastic analytical methods for shellfish should be established in the future. The depuration process can be used to reduce the level of microplastics in oysters to ensure safe consumption of oysters and longer depuration time facilitates improved depuration efficacy. In summary, this review aims to help better understand microplastic pollution in oysters and provide useful suggestions and guidance for future research.

The Interaction in Electrolyte Additives Accelerates Ion Transport to Achieve High-Energy Non-Aqueous Lithium Metal Batteries.

Electrolyte engineering is a feasible strategy to realize high energy density lithium metal batteries. However, stabilizing both lithium metal anodes and nickel-rich layered cathodes is extremely challenging. To break through this bottleneck, a dual-additives electrolyte containing fluoroethylene carbonate (10 vol.%) and 1-methoxy-2-propylamine (1 vol.%) in conventional LiPF6 -containing carbonate-based electrolyte is reported. The two additives can polymerize and thus generate dense and uniform LiF and Li3 N-containing interphases on both electrodes' surfaces. Such robust ionic conductive interphases not only prevent lithium dendrite formation in lithium metal anode but also suppress stress-corrosion cracking and phase transformation in nickel-rich layered cathode. The advanced electrolyte enables Li||LiNi0.8 Co0.1 Mn0.1 O2 stably cycle for 80 cycles at 60 mA g-1 with a specific discharge capacity retention of 91.2% under harsh conditions.

Flexible solar cells based on foldable silicon wafers with blunted edges.

Flexible solar cells have a lot of market potential for application in photovoltaics integrated into buildings and wearable electronics because they are lightweight, shockproof and self-powered. Silicon solar cells have been successfully used in large power plants. However, despite the efforts made for more than 50 years, there has been no notable progress in the development of flexible silicon solar cells because of their rigidity1-4. Here we provide a strategy for fabricating large-scale, foldable silicon wafers and manufacturing flexible solar cells. A textured crystalline silicon wafer always starts to crack at the sharp channels between surface pyramids in the marginal region of the wafer. This fact enabled us to improve the flexibility of silicon wafers by blunting the pyramidal structure in the marginal regions. This edge-blunting technique enables commercial production of large-scale (>240 cm2), high-efficiency (>24%) silicon solar cells that can be rolled similarly to a sheet of paper. The cells retain 100% of their power conversion efficiency after 1,000 side-to-side bending cycles. After being assembled into large (>10,000 cm2) flexible modules, these cells retain 99.62% of their power after thermal cycling between -70 °C and 85 °C for 120 h. Furthermore, they retain 96.03% of their power after 20 min of exposure to air flow when attached to a soft gasbag, which models wind blowing during a violent storm.

Nitrogen-doped carbon dots/Fe3+-based fluorescent probe for the "off-on" sensing of As(V) in seafood.

To better satisfy the application of rapid detection methods in the detection of As(V) in complex food substrates, we developed an "off-on" fluorescence assay to detect As(V) based on the competition between the electron transfer effect of nitrogen-doped carbon dots (N-CDs)/Fe3+ and the complexation reaction of As(V)/Fe3+, using N-CDs/Fe3+ as a fluorescence probe. Solid-phase extraction (SPE) was used to eliminate matrix interference during sample pretreatment. The detection limit was 7.6 ng g-1, with a linear range of 10-100 ng g-1. The method was further used to determine As(V) in different seafood products including snapper, shrimp, clams, and kelp. At the same time, the recovery of the method was validated by high-performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICP/MS), indicating that the developed method had good recoveries from 86% to 117% and met the needs for accurate determination of As(V). This approach has shown excellent application potential in the field of As(V) detection in various seafood products.

Application of multi-omics combined with bioinformatics techniques to assess salinity stress response and tolerance mechanisms of Pacific oyster (Crassostrea gigas) during depuration.

Depuration is a vital stage to ensure the safety of oyster consumption, and salinity had a great impact on the environmental adaptability of oysters, but the underlying molecular mechanism was poorly understood during depuration stage. Here, Crassostrea gigas was depurated for 72 h at different salinity (26, 29, 32, 35, 38 g/L, corresponding to ±20%, ±10% salinity fluctuation away from oyster's production area) and then analyzed by using transcriptome, proteome, and metabolome combined with bioinformatics techniques. The transcriptome showed that the salinity stress led to 3185 differentially expressed genes and mainly enriched in amino acid metabolism, carbohydrate metabolism, lipid metabolism, etc. A total of 464 differentially expressed proteins were screened by the proteome, and the number of up-regulated expression proteins was less than the down-regulated, indicating that the salinity stress would affect the regulation of metabolism and immunity in oysters. 248 metabolites significantly changed in response to depuration salinity stress in oysters, including phosphate organic acids and their derivatives, lipids, etc. The results of integrated omics analysis indicated that the depuration salinity stress induced abnormal metabolism of the citrate cycle (TCA cycle), lipid metabolism, glycolysis, nucleotide metabolism, ribosome, ATP-binding cassette (ABC) transport pathway, etc. By contrast with Pro-depuration, more radical responses were observed in the S38 group. Based on the results, we suggested that the 10% salinity fluctuation was suitable for oyster depuration and the combination of multi-omics analysis could provide a new perspective for the analysis of the mechanism changes.

Understanding fatty acid composition and lipid profile of rapeseed oil in response to nitrogen management strategies.

The fatty acid composition of rapeseed seeds plays an important role in oil quality for human nutrition and a healthy diet. A deeper understanding of fatty acid composition and lipid profiles in response to different nitrogen managements is critical for producing healthier rapeseed oil for the human diet. The fatty acid composition and lipid profiles were characterized through targeted GC-MS and lipidomics analysis (UPLC-MS) in this study. The results showed that nitrogen management significantly altered the fatty acid composition, thereby influencing oil quality when it is used to maximize the seed yield of rapeseed. Several fatty acid components (particularly oleic acid, linoleic acid, and linolenic acid) decreased significantly with increasing N application rate. A total of 1212 differential lipids in response to different N levels in the two varieties were clearly identified, that can be categorized into five classes, including 815 glycerolipids (GLs), 195 glycerophospholipids (GPs), 155 sphingolipids (SPs), 32 sterols (STs), and 15 fatty acyls (FAs). These differential lipids are likely to participate in lipid metabolism and signal transduction. Co-expression lipid modules were determined, and the key lipids, such as triglyceride (20:0/16:0/16:0; 18:0/18:1/18:3; 8:0/11:3/18:1), were found to be strongly related to several predominant fatty acids such as oleic acid and linoleic acid. The results further imply that some identified lipids are involved with lipid metabolism and could affect the fatty acid composition, which provide a theoretical guidance for increasing seed oil in Brassica napus.

Integration of Metallic Nanomaterials and Recognition Elements for the Specifically Monitoring of Pesticides in Electrochemical Sensing.

Although all countries have been controlling the excessive use of pesticides, incidents of pesticide residues still existed. Electrochemical biosensors are extensively applied detection techniques to monitor pesticides with the help of different types of biorecognition components mainly including, antibodies, aptamers, enzymes (i.e., acetylcholinesterase, organophosphorus hydrolase, etc.), and synthetic molecularly imprinted polymers. Besides, the electrode materials mainly affected the sensitivity of electrochemical biosensors. Metallic nanomaterials with various structures and excellent electrical conductivity were desirable choice to construct electrochemical platforms to achieve the detection with high sensitivity and good specificity toward the target. This work reviewed the developed metallic materials including monometallic nanoparticles, bimetallic nanomaterials, metal atoms, metal oxides, metal molybdates, metal-organic frameworks, MXene, etc. Integration of recognition elements endowed the electrode materials with higher specificity toward the target pesticide. Besides, future challenges of metallic nanomaterials-based electrochemical biosensors for the detection of pesticides are also discussed and described.

In situ performance and stability tests of large-area flexible polymer solar cells in the 35-km stratospheric environment.

Flexible organic solar cells (FOSCs) are one of the most promising power sources for aerospace aircraft due to their attractive advantages with high power-per-weight ratio and excellent mechanical flexibility. Understanding the performance and stability of high-performance FOSCs is essential for the further development of FOSCs for aerospace applications. In this paper, after systematic investigations on the performance of the state-of-the-art high-performance solar cells under thermal cycle and intensive UV irradiation conditions, in situ performance and stability tests of the solar cells in the 35 km stratospheric environment were carried out through a high-altitude balloon uploading. The encapsulated FOSCs with an area of 0.64 cm2 gave the highest power density of 15.26 mW/cm2 and an efficiency over 11%, corresponding to a power-per-weight ratio of over 3.32 kW/kg. More importantly, the cells showed stable power output during the 3-h continuous flight at 35 km and only 10% performance decay after return to the lab, suggesting promising stability of the FOSCs in the stratospheric environment.

Effects of cooling rates during depuration on the quality of Pacific oysters (Crassostrea gigas) at anhydrous preservation stage.

The Pacific oyster could be affected by several pressure sources during cold chain logistics, which reduce the quality of oyster, and even improve its mortality. For improving the quality of oyster, the effects of depuration process at different cooling rates (1, 3, 7, 11 and 16 °C/h) on selected Pacific oyster were studied. The results indicated that extreme fluctuations in the depuration temperatures could affect the survival rates and qualities of oysters. The oysters exhibited low survival rates, glycogen contents and pH values at an increased cooling rate. Their contents in the 1 °C/h group after 3 d preservation were 100 %, 16.30 ± 1.64 mg/100 g and 6.72 ± 0.01, respectively, while there were 71 %, 7.72 ± 0.88 mg/100 g and 6.53 ± 0.01 in the 16 °C/h group after 3 d preservation, respectively. Furthermore, the ATP-related compounds were affected by the different cooling rates. AMP and IMP were the main ATP-related compounds, and their contents in the 1 °C/h group after 3 d preservation were 37.21 ± 1.10 mg/100 g and 29.47 ± 1.10 mg/100 g, respectively, while there were 32.07 ± 1.10 mg/100 g and 13.16 ± 1.60 mg/100 g in the 16 °C/h group after 3 d preservation, respectively. The proportions of the total umami, as well as the sweet amino acids also decreased, the proportions of the umami amino acids and sweet amino acids in the total amino acids, were 31.37%-38.80%, and their proportions in 1 °C/h group were higher than that in 16 °C/h group. Conversely, the fatty acid content of each group exhibited significant differences. Combined with the above results, the oyster maintained a high survival rate and higher quality at a cooling rate of 1 °C/h during depuration.

A chemometric study on the identification of 5-methylfurfural and 2-acetylfuran as particular volatile compounds of oxidized fish oil based on SHS-GC-IMS.

Fish oil develops particular off-odors, mainly fishy odor, from the oxidation of its characteristic fatty acids, docosahexaenoic (DHA) and eicosapentaenoic (EPA). Anchovy oil (AO) was taken as representative of fish oils. This was compared to three vegetable oils with different fatty acid compositions, i.e. camellia, sunflower and linseed oil, and differential volatile compounds were identified by static-headspace gas-chromatography ion-mobility-spectrometry (SHS-GC-IMS) and orthogonal partial-least-squares discriminant analysis (OPLS-DA) during oxidation at 60 °C. Three groups of differential volatile compounds detected at higher concentrations in the AO were screened out and two compounds, identified as 5-methylfurfural and 2-acetylfuran, were characteristic to the AO and not found in the vegetable oils. They were formed from both EPA and DHA, only present in the AO, and their formation mechanisms were proposed. The contents of 5-methylfurfural and 2-acetylfuran increased linearly with the oxidation time and consequently they could be used as oxidative markers of fish oils.