Reduction In Polyunsaturated Fatty Acids Research Articles

Antioxidant and osteoinductive properties of organic selenium in microdiets for gilthead seabream (Sparus aurata) larvae

This study investigated the effect of yeast derived selenium (Se) dietary supplementation on larval performance, whole body mineral contents, lipid peroxidation, fatty acid profiles, expression of antioxidants and bone biomarkers genes, mineralization and skeletal anomalies in gilthead seabream (Sparus aurata) larvae. Five experimental microdiets containing 1.4, 6.1, 9.2, 12.0 and 14.0 mg Se/kg diets were fed to triplicate groups of larvae (total length: 7.26 ± 0.83 mm, 30 dph) for 21 days. Larval Se levels increased proportionally to the elevation of dietary Se. Those fed with dietary Se level at 6.1 mg/kg had a higher growth performance than those fed with non-supplemented diet (1.4 mg/kg), then reached a plateau from larvae fed with Se6.1 to Se14 diet although growth was not significantly affected by different diets. In addition, larval survival was not significantly affected. However, larvae fed the lowest Se levels showed a significant increase in lipid peroxidation, the downregulation of antioxidant genes, a reduction in polyunsaturated fatty acids (PUFA) contents and the highest incidence of skeletal anomalies. While increase up to 6.1–12 mg Se/kg, reduced oxidative stress, increased PUFA, vertebral mineralization, up-regulated antioxidant and bone metabolism related genes and contributing to reduce skeletal anomalies of larvae. However, further increase in dietary Se up to 14 mg/kg led to the lowest gpx, cat and alp expressions, in agreement with a lower mineralization. These findings suggest, dietary Se level at 6.1 mg/kg would be the minimum dietary Se level required in microdiets for gilthead seabream larvae. Thus, the study demonstrates the importance of dietary Se for bone metabolism and mineralization due to its antioxidant and osteo-inductive properties.

Effects of cholesterol removal treatment on the flavor and physicochemical properties of hot gel egg yolk

The aim of this study was to investigate effects of cholesterol removal treatment (CRT) on the flavor, taste, texture, color, and nutritional value of hot gel egg yolk (EY). The off-odor, volatile components and taste of EY treated with CRT were studied by electronic nose (E-nose), gas chromatography-mass spectrometry (GC–MS) and electronic tongue (E-tongue). The effect of CRT on the nutritional value of EY was studied by amino acid and fatty acid analysis. The CRT significantly reduced the content of hexanal, 2-amyl-furan, 1-octene-3-ol, styrene and heptanal in EY1-EY4, also decreased its bitter taste without affecting other taste and elasticity. In addition, the CRT did not affect the essential amino acids (EAA) content and L*, a* and b* values of EY1-EY4, but it led to the reduction in polyunsaturated fatty acids (PUFA) content. In general, the CRT is an effective way to reduce the off-odor of EY without affecting consumer acceptance.

Consumption of cashew nut induced anxiolytic-like behavior in dyslipidemic rats consuming a high fat diet

This study aimed to evaluate the effect of cashew nut consumption on anxiety-like behavior in dyslipidemic rats. The groups formed were: Control (CONT), Dyslipidemic (DL) and Dyslipidemic cashew nuts (DLCN). Tests to assess anxiety parameters were performed after the treatment period. Brain fatty acid profiles were analyzed. The animals in the DLCN group showed more rearing than DL, without differing from the CONT and less grooming than either the DL and CONT in the Open Field. In the Elevated Plus Maze, DLCN spent more time on the open arms and in the central area compared to the other groups. As for brain fatty acids, there was a reduction in polyunsaturated fatty acids for the DLCN compared to the other groups. The cashew nut, rich in fatty acids, phenolic and flavonoid compounds, reduced the anxiogenic-like behavior caused by dyslipidemia in rats without altering brain fatty acids.

Sources of variability in seagrass fatty acid profiles and the need of identifying reliable warming descriptors

Global warming is expected to have inexorable and profound effects on marine ecosystems, particularly in foundation species such as seagrasses. Identifying responses to warming and comparing populations across natural temperature gradients can inform how future warming will impact the structure and function of ecosystems. Here, we investigated how thermal environment, intra-shoot and spatial variability modulate biochemical responses of the Mediterranean seagrass Posidonia oceanica. Through a space-for-time substitution study, Fatty acid (FA) profiles on the second and fifth leaf of the shoots were quantified at eight sites in Sardinia along a natural sea surface temperature (SST) summer gradient (about 4 °C). Higher mean SST were related to a decrease in the leaf total fatty acid content (LTFA), a reduction in polyunsaturated fatty acids (PUFA), omega-3/omega-6 PUFA and PUFA/saturated fatty acids (SFA) ratios and an increase in SFA, monounsaturated fatty acids and carbon elongation index (CEI, C18:2 n-6/C16:2 n-6) ratio. Results also revealed that FA profiles were strongly influenced by leaf age, independently of SST and spatial variability within sites. Overall, this study evidenced that the sensitive response of P. oceanica FA profiles to intra-shoot and spatial variability must not be overlooked when considering their response to temperature changes.

Maximizing Nitrogen Removal and Lipid Production by Microalgae under Mixotrophic Growth Using Response Surface Methodology: Towards Enhanced Biodiesel Production

The present study aimed to optimize synthetic wastewater composition as a mixotrophic medium for enhanced growth and lipid accumulation coupled with high nitrogen removal by the green microalga Chlorella sp. Individual effects of the three main independent variables (nitrate concentration, seawater ratio, and glycerol supplementation) were tested initially, then response surface methodology (RSM) was subsequently performed to explore the optimum combined conditions. The highest lipid productivity of 37.60 mg/L day was recorded at 25% seawater. Glycerol supplementation enhanced both lipid content and biomass production, which resulted in the highest recorded lipid productivity of 42.61 mg/L day at 4 g/L glycerol. Central composite design followed by numerical optimization was further applied which suggested NaNO3 concentration at 101.5 mg/L, seawater ration of 23.8%, and glycerol supplementation of 0.25 g/L as the optimum conditions for dual maximum lipid productivity and nitrogen removal of 46.9 mg/L day and 98.0%, respectively. Under the optimized conditions, dry weight and lipid content increased by 31.9% and 20.3%, respectively, over the control, which resulted in increase in lipid productivity by 71.5%. In addition, optimization process resulted in pronounced changes in fatty acid proportions where saturated fatty acids increased by 7.4% in the optimized culture with simultaneous reduction of polyunsaturated fatty acids. The estimated biodiesel characteristics calculated from the fatty acid methyl ester (FAMEs) profile showed agreement with the international standards, while optimized cultures showed an 8.5% lower degree of unsaturation, which resulted in higher cetane numbers and lower iodine values. This study provides economical approach for optimization and efficient nutrient recycling through cultivation of Chlorella sp. for further enhanced biodiesel production.

Seasonal Acclimation Modulates the Impacts of Simulated Warming and Light Reduction on Temperate Seagrass Productivity and Biochemical Composition

Increases in seawater temperature and reduction in light quality have emerged as some of the most important threats to marine coastal communities including seagrass ecosystems. Temperate seagrasses, including Zostera marina, typically have pronounced seasonal cycles which modulate seagrass growth, physiology and reproductive effort. These marked temporal patterns can affect experimental seagrass responses to climate change effects depending on the seasons of the year in which the experiments are conducted. This study aimed at evaluating how seasonal acclimatization modulates productivity and biochemical responses of Zostera marina to experimental warming and irradiance reduction. Seagrass shoots were exposed to different temperatures (6, 12, 16, 20, and 24°C), combined with high (180 μmol photons m–2 s–1) and low (60 μmol photons m–2 s–1) light conditions across four seasons (spring: April, summer: July, and autumn: November 2015, and winter: January 2016). Plants exhibited similar temperature growth rates between 16 and 20°C; at 24°C, a drastic reduction in growth was observed; this was more accentuated in colder months and under low irradiance conditions. Higher leaf growth rates occurred in winter while the largest rhizomes were reached in experiments conducted in spring and summer. Increases in temperature induced a significant reduction in polyunsaturated fatty acids (PUFA), particularly omega-3 (n-3 PUFA). Our results highlight that temperate seagrass populations currently living under temperature limitation will be favored by future increases in sea surface temperature in terms of leaf and rhizome productivity. Together with results from this study on Z. marina from a temperate region, a wider review of the reported impacts of experimental warming indicates the likely reduction in some compounds of nutritional importance for higher trophic levels in seagrass leaves. Our results further demonstrate that data derived from laboratory-based studies investigating environmental stress on seagrass growth and acclimation, and their subsequent interpretation, are strongly influenced by seasonality and in situ conditions that precede any experimental exposure.

Reduction of Polyunsaturated Fatty Acids with Tumor Progression in a Lean Non-Alcoholic Steatohepatitis-Associated Hepatocellular Carcinoma Mouse Model.

Background and Aim: Non-alcoholic fatty liver disease (NAFLD) is the most common liver disease in Western countries. While obesity and diabetes are the hallmarks of NAFLD, it also develops in lean individuals in the absence of metabolic syndrome, with a prevalence of 7 percent in the U.S. and 25-30 percent in some Asian countries. NAFLD represents the spectrum of liver disease, starting with excess liver fat accumulation (NAFL) that can progress to nonalcoholic steatohepatitis (NASH), cirrhosis and ultimately hepatocellular carcinoma (HCC). To date, the pathogenesis of lean NASH-HCC is poorly understood and a mouse model is lacking. We aimed to develop a mouse model of lean NASH-HCC using a choline deficient and high trans-fat/sucrose/cholesterol diet to enable better understanding of its molecular pathogenesis.Methods: C57BL/6N mice were fed this diet starting at 4 weeks of age for 52 weeks and were compared to mice fed an isocaloric low fat control diet for the same duration. C57BL/6N mice were chosen instead of the C57BL/6J mice due to the high susceptibility of C57BL/6J mice to diet-induced obesity. The plasma and tumor fatty acid profile of these mice was also investigated.Results: Nearly 61% of the mice developed lean NASH-HCC. These mice showed reduction of plasma polyunsaturated fatty acids (PUFAs) (linolenic acids (α and γ, ω-3 and ω-6, respectively), eicosapentanoic acid (ω-3), docosahexanoic acid (ω-3), and linoleic acid (ω-6)) and increasing levels over time in mice with pre-malignant lesions.Conclusions: We developed a novel high penetrance diet-induced lean NASH-HCC mouse model. Plasma PUFA levels were reduced with tumor progression in parallel with reduced expression of genes controlling desaturase expression suggesting their potential use as biomarkers for lean NASH-HCC progression as well as chemopreventive molecules.

Research Note: Effect of packaging atmosphere on the fatty acid profile of intramuscular, subcutaneous fat, and odor of goose meat

The aim of the study was to investigate changes of the fatty acid profile in the intramuscular and subcutaneous fat as well as odor sensory evaluation of goose packaged under different conditions of modified atmosphere (vacuum and high-oxygen modified atmosphere of 80% O2 and 20% CO2 composition) and stored under refrigeration (4°C) for 11 D. Packaging in a high-oxygen modified atmosphere had a negative impact on goose meat quality due to the reduction of polyunsaturated fatty acids (PUFA), PUFA/saturated fatty acids (SFA) and the increase of SFA, which means a substantial loss of its nutritional value. Goose meat can be stored for 11 D without changes in the fatty acid profile, provided that a vacuum is used that limits oxygen exposure. At the end of storage, a better sensory evaluation of the odor intensity in the vacuum-packed samples was also observed in comparison to high oxygen modified atmosphere. Vacuum packaging turned out to be a better method for preserving fatty acid profile and the odor of goose meat during 11 D of storage.

A combination of vitamins C and E alleviates oxidized fish oil‐induced hepatopancreatic injury in juvenile Chinese mitten crabEriocheir sinensis

Dietary lipid oxidation is a lasting concern to aquafeed manufacturers and aquaculture farmers. Here, we determined if there was an association between oxidized fish oil (OFO) and hepatopancreatic injury in Chinese mitten crab, and evaluated the alleviating effects of a combination of vitamins C and E on hepatopancreatic injury. There were significant reductions in the body weight gain, hepatopancreatic index, and feed efficiency in crabs that received OFO. Diets with OFO also resulted in reduced crude fat contents in the hepatopancreas and muscle tissues, and alternations in the hepatopancreatic fatty acid compositions, especially a reduction in polyunsaturated fatty acids. Moreover, dietary OFO exposure reduced the antioxidant defense and non-specific immune response, caused hepatopancreatic injury, and even apparent whitening. An ultrastructural examination of the whitened hepatopancreas revealed that hepatopancreatic cells were injured at varying degrees following OFO exposure. The combination of vitamins C and E could efficiently maintain a constant fatty acid profile in the hepatopancreas exposed to OFO, thus alleviating OFO-induced hepatopancreatic injury. In addition, a biochemical analysis indicated that a combination of vitamins C and E not only improved the antioxidant status by mitigating the harmful effects of oxidized oil, but also modulated non-specific immune responses in the crab that received OFO. Overall, OFO-induced hepatopancreatic injury may be alleviated by a dietary combination of vitamins C and E, and the feeding of rancid forage fish or diets that contain highly oxidized oil is likely a cause of hepatopancreatic necrosis that is frequently observed in farmed crabs.

Effects of gamma radiation combined with cinnamon oil on qualities of smoked salmon slices inoculated with Shewanella putrefaciens.

Smoked salmon slices inoculated with Shewanella putrefaciens were untreated (CK) or treated with 2 kGy gamma radiation (G), 1% (v/v) cinnamon oil (C), or the combination of them (G+C), and then packaged and stored at 4°C for 10 days. Microbiological and physiochemical analyses were then carried out. All treatments showed a better effect on inhibiting the increase in total viable counts, total volatile basic nitrogen, and thiobarbituric acid‐reactive substances than CK, especially the treatment of G+C. In addition, the combination treatment also showed a best effect on retarding the reduction in polyunsaturated fatty acids of salmon samples in all treatments. These results indicated that treatments of gamma radiation and cinnamon oil on salmon samples, especially the combination treatment, can be used to maintain the quality of smoked salmon slices.

Effects of smoking on fatty acids composition of croaker (<i>Pseudotolithus senegalensis</i>)

Fish meat has become a component of a healthy diet, as it is considered a source of essential fatty acids. The effects of smoking on the fatty acids composition (FAC) of smoked croakers were determined. Smoked croakers were produced using improved smoking kiln by Nigerian Institute for Oceanography and Marine Research. The smoked croakers were packed in polythene bags and transported to Matis Research Laboratory, Iceland for analysis. The FAC were 91.44% of lipid and 91.51% of lipid for fresh and smoked croakers respectively. There was no significant difference (P>0.05) in the FAC as a result of smoking. However, the saturated fatty acids (SFA) and monounsaturated fatty acids (MUFA) increased significantly (P<0.05) with significant (P<0.05) reduction in polyunsaturated fatty acids (PUFA) as a result of smoking. There was also significant (P<0.05) reduction in the FAC of the smoked croakers analysed with skin to that of smoked croakers analysed without skin (skinless).The relationship of PUFA to SFA for fresh and smoked croakers were greater than 0.4 and the omega-6 to omega-3 ratios of both the fresh and smoked croaker were far less than one (1) thus constituting an excellent source of omega-3 fatty acids and a highly healthy food.Keywords: Croakers, smoked, fatty acids composition, with skin, skinless

Effects of Dietary Conjugated Linoleic Acid on Broiler Performance and Carcass Characteristics

The effects of three levels of conjugated linoleic acid dietary inclusion on the carcass characteristics and performance of broilers were evaluated. A total of 405 chickens were raised from 1 until 42 days of age, housed in a room with water and food ad libitum. The experimental design was completely randomized, with three treatments (0.0, 0.5 and 1% CLA) and nine replications (pen) to performance analysis, 18 replications (two birds per pen) to carcass composition, and five replications (left legs) to lipid profile. Performance was determined weekly and after 42 days, 18 birds per treatment were slaughtered to quantify breast and leg yield. Protein and fat was quantified in the leg and breast, as well as the detailed lipid profile of the leg. Data were analyzed by ANOVA and means compared by LS means. From 1 to 21 days chickens with 0% supplementation of CLA performed better compared to those receiving 0.5 and 1% CLA (P < 0.05), however, these differences were no longer significant from 21 to 42 days or for the overall study period (P > 0.05). Conjugated linoleic acid inclusion did not influence leg, breast and carcass yield, and leg and breast content of protein and fat. Both levels of CLA changed the leg lipid profile: there was an increased accumulation of CLA in meat, increased levels of saturated fatty acids and reduction of polyunsaturated fatty acids. Conjugated linoleic acid supplementation increased n-6:n-3 ratio. CLA supplementation in broiler feed is effective to produce meat enriched with its isomers and change lipid profile.

Using NMR to study changes in the characteristic constituents of stored rice

This study investigated constituent differences between stored and fresh rice using multidimensional solution-state nuclear magnetic resonance (NMR) spectroscopy. Fourier transform infrared (FTIR) spectroscopy and gas chromatography–mass spectrometry (GC-MS) was also used to determine constituent changes during storage.Signal variations in alkyl, alkoxy, acyl, hydroxyl, amine, and amino groups revealed hydrolysis of neutral fats and phospholipids to free fatty acids or lower esters. Signals from double bonds showed changes in unsaturated substances, such as glycerides and phospholipids, which correspond to a phenomenon exposed by GC-MS detection, that is, a reduction in polyunsaturated fatty acids occurs on storage. Moreover, the hydrolysis or oxidation of unstable lipids result in a conversion from fresh to aging rice with respect to the development of disagreeable flavors. Results from this study can both aid in our understanding and further the research into the progression and phenomenon of aging rice.

Physicochemical, oxidative and anti-oxidant stabilities of kenaf seed oil-in-water nanoemulsions under different storage temperatures

Kenaf seed oil-in-water nanoemulsions stabilised by sodium caseinate, Tween 20 and β-cyclodextrin complexes were produced using high pressure homogeniser. This formulation has been shown to possess good lipid digestion and increased bioaccessibility of tocopherols and total phenolic contents. However, its physicochemical and oxidative stability during storage was unknown. Therefore, the main objectives of this study were to evaluate the effects of three storage temperatures (4°C±2°C, 25°C±2°C and 40°C±2°C) on the physicochemical, oxidative and antioxidant stability of formulated kenaf seed oil-in-water nanoemulsions. The results showed that nanoemulsions stored at 4°C had maintained the highest stability with the highest zeta-potential value (−36.6mV), lowest changes of PDI and pH over 12 weeks of storage. It also presented the lowest reduction of polyunsaturated fatty acids (PUFA) over the course of storage period. In contrast, nanoemulsions that stored at 40°C exhibited lowest stability with the lowest zeta-potential (−27.3mV). Sediment was observed in 8 weeks of storage and it had the highest reduction of PUFA. Total phenolic contents in nanoemulsions that stored at 4°C and 25°C showed decreasing trend during the storage period, except for nanoemulsions that stored at 40°C showed a significant increase (p<0.05) in the first week of storage, but subsequently also displayed decreasing trend. The overall results showed that nanoemulsions that stored at 4°C and 25°C were stable for up to 8 weeks of storage. Nanoemulsions that stored under accelerated storage temperature of 40°C were stable for 1 week, which is equivalent to 28days at room temperature (RT) based on Arrhenius equation. The results of this study could provide better understanding of the storage stability of kenaf seed oil-in-water nanoemulsions under different storage temperatures. It could be served as a predictive model to estimate its shelf-life.

Type I Diacylglycerol Acyltransferase (MtDGAT1) from Macadamia tetraphylla: Cloning, Characterization, and Impact of Its Heterologous Expression on Triacylglycerol Composition in Yeast.

Acyltransferase enzymes have been reported as useful biotechnological tools in order to increase oil yield and modify fatty acid composition. Macadamia species are able to accumulate unusually high levels of palmitoleic acid that besides oleic acid amounts to over 80% of monounsaturated fatty acids in the seed oil. In this work, a gene encoding a type 1 acyl-CoA:diacylglycerol acyltransferase (DGAT1) was cloned from M. tetraphylla. DGAT activity of the protein encoded by MtDGAT1 was confirmed by heterologous expression in a yeast mutant. Fatty acid composition of triacylglycerols synthesized by MtDGAT1 was compared to that of DGAT1 enzymes from Arabidopsis and Echium, with the results suggesting a substrate preference for monounsaturated over polyunsaturated fatty acids. Characteristics of MtDGAT1 may contribute to biochemical mechanisms determining the particular fatty acid composition of Macadamia oil and also indicate the possibility of using this enzyme in biotechnological approaches where a reduction of polyunsaturated fatty acids in the oil is desired.

Soybean Aphid Infestation Induces Changes in Fatty Acid Metabolism in Soybean.

The soybean aphid (Aphis glycines Matsumura) is one of the most important insect pests of soybeans in the North-central region of the US. It has been hypothesized that aphids avoid effective defenses by inhibition of jasmonate-regulated plant responses. Given the role fatty acids play in jasmonate-induced plant defenses, we analyzed the fatty acid profile of soybean leaves and seeds from aphid-infested plants. Aphid infestation reduced levels of polyunsaturated fatty acids in leaves with a concomitant increase in palmitic acid. In seeds, a reduction in polyunsaturated fatty acids was associated with an increase in stearic acid and oleic acid. Soybean plants challenged with the brown stem rot fungus or with soybean cyst nematodes did not present changes in fatty acid levels in leaves or seeds, indicating that the changes induced by aphids are not a general response to pests. One of the polyunsaturated fatty acids, linolenic acid, is the precursor of jasmonate; thus, these changes in fatty acid metabolism may be examples of “metabolic hijacking” by the aphid to avoid the induction of effective defenses. Based on the changes in fatty acid levels observed in seeds and leaves, we hypothesize that aphids potentially induce interference in the fatty acid desaturation pathway, likely reducing FAD2 and FAD6 activity that leads to a reduction in polyunsaturated fatty acids. Our data support the idea that aphids block jasmonate-dependent defenses by reduction of the hormone precursor.

Alleviation of cadmium stress in Solanum lycopersicum L. by arbuscular mycorrhizal fungi via induction of acquired systemic tolerance

Experiments were conducted to evaluate cadmium (Cd) stress-induced changes in growth, antioxidants and lipid composition of Solanum lycopersicum with and without arbuscular mycorrhizal fungi (AMF). Cadmium stress (50μM) caused significant changes in the growth and physio-biochemical attributes studied. AMF mitigated the deleterious impact of Cd on the parameters studied. Cadmium stress increased malonaldehyde and hydrogen peroxide production but AMF reduced these parameters by mitigating oxidative stress. The activity of antioxidant enzymes enhanced under Cd treatment and AMF inoculation further enhanced their activity, thus strengthening the plant’s defense system. Proline and phenol content increased in Cd-treated as well as AMF-inoculated plants providing efficient protection against Cd stress. Cadmium treatment resulted in great alterations in the main lipid classes leading to a marked change in their composition. Cadmium stress caused a significant reduction in polyunsaturated fatty acids resulting in enhanced membrane leakage. The present study supports the use of AMF as a biological means to ameliorate Cd stress-induced changes in tomato.

Enhanced triacylglyceride extraction from microalgae using free nitrous acid pre-treatment

Abstract Triacylglyceride (TAG) recovery from algal biomass is primarily limited by the rigid algal cell envelope (cell wall and cell membrane). In this work, the effect of free nitrous acid (FNA) pre-treatment on TAG recovery from algal biomass with six different FNA concentrations is reported. Results show that at a range of low FNA concentrations (0.24–2.25 mg HNO2–N L−1) TAG recovery was strongly enhanced with increasing FNA concentration. An FNA concentration of around 2 mg HNO2–N L−1 resulted in a 3.3-fold increase in fatty acid recovery over untreated algae, but higher FNA concentrations (13.49 and 26.98 mg HNO2–N L−1) were detrimental to TAG recovery. Analysis of the fatty acid profile revealed that the higher FNA concentrations caused a reduction in polyunsaturated fatty acids. Also, the ratio of extracted fatty acids to total lipids was significantly reduced when high FNA concentration were applied, and only non-fatty acid lipids potentially benefited from more intense FNA pre-treatments.

Comparative antioxidant activity and 1H NMR profiling of Mediterranean fruit products

In this study the antioxidant activity of methanol extracts obtained from Mediterranean fruit products (prickly pear fruit jam and cream, myrtle berries jam, orange and mandarin-orange marmalades) was evaluated and compared in several in vitro models of oxidative stress. The compositional profile of methanol extracts (carbohydrates, organic acids, amino acids, and main phenolic compounds) was characterized by 1H NMR spectroscopy and the total phenol content was estimated by the Folin–Ciocalteu procedure. All extracts showed protective effect against thermal-cholesterol degradation, strictly correlated to total phenols. Extracts from prickly pear cream and myrtle berries jam preserved liposomes from Cu2+-induced oxidation, inhibiting the reduction of polyunsaturated fatty acids and the increase of malondialdehyde. Extracts from prickly pear cream and citrus marmalades significantly reduced the reactive oxygen species generation induced by tert-butylhydroperoxide in Caco-2 cell culture. The results of this work qualify all tested Mediterranean fruit preserves as a good source of biologically active components with considerable antioxidant potential.

Development of marker-free transgenic Jatrophaplants with increased levels of seed oleic acid

BackgroundJatropha curcas is recognized as a new energy crop due to the presence of the high amount of oil in its seeds that can be converted into biodiesel. The quality and performance of the biodiesel depends on the chemical composition of the fatty acids present in the oil. The fatty acids profile of the oil has a direct impact on ignition quality, heat of combustion and oxidative stability. An ideal biodiesel composition should have more monounsaturated fatty acids and less polyunsaturated acids. Jatropha seed oil contains 30% to 50% polyunsaturated fatty acids (mainly linoleic acid) which negatively impacts the oxidative stability and causes high rate of nitrogen oxides emission.ResultsThe enzyme 1-acyl-2-oleoyl-sn-glycero-3-phosphocholine delta 12-desaturase (FAD2) is the key enzyme responsible for the production of linoleic acid in plants. We identified three putative delta 12 fatty acid desaturase genes in Jatropha (JcFAD2s) through genome-wide analysis and downregulated the expression of one of these genes, JcFAD2-1, in a seed-specific manner by RNA interference technology. The resulting JcFAD2-1 RNA interference transgenic plants showed a dramatic increase of oleic acid (> 78%) and a corresponding reduction in polyunsaturated fatty acids (< 3%) in its seed oil. The control Jatropha had around 37% oleic acid and 41% polyunsaturated fatty acids. This indicates that FAD2-1 is the major enzyme responsible for converting oleic acid to linoleic acid in Jatropha. Due to the changes in the fatty acids profile, the oil of the JcFAD2-1 RNA interference seed was estimated to yield a cetane number as high as 60.2, which is similar to the required cetane number for conventional premium diesel fuels (60) in Europe. The presence of high seed oleic acid did not have a negative impact on other Jatropha agronomic traits based on our preliminary data of the original plants under greenhouse conditions. Further, we developed a marker-free system to generate the transgenic Jatropha that will help reduce public concerns for environmental issues surrounding genetically modified plants.ConclusionIn this study we produced seed-specific JcFAD2-1 RNA interference transgenic Jatropha without a selectable marker. We successfully increased the proportion of oleic acid versus linoleic in Jatropha through genetic engineering, enhancing the quality of its oil.