Low Oleic Acid Research Articles

Genotype by environment interaction influence on functional molecules (tocopherols and sterols) accumulation in sunflower oil

Tocopherol and sterol are non-dietary functional molecules in sunflower oil, which act as antioxidants, reduce cholesterol and improve immunity against diseases. The present study was designed to determine tocopherol and sterol contents in 13 high and two low oleic acid sunflower hybrids across two seasons (spring and autumn) and four locations under subtropical conditions of Pakistan with contrasting reproductive phase temperatures. The results showed that tocopherol and sterol contents varied across the seasons and locations. Autumn planting produced high tocopherol content. Moreover, locations under high temperature during reproductive phase negatively affected the sterol and tocopherol contents. High oleic acid hybrids yielded 38% higher tocopherol content than low oleic acid hybrids. High oleic acid hybrids produced higher sterol contents at all locations and seasons. Hybrids such as H4 and H5 are considered stable due to comparatively close values of tocopherol and sterol contents across the four locations when compared with standard checks and other hybrids during spring season as indicated from various stability parameters. Hybrids H8, H4 and H5 also manifested higher magnitude of heterosis for tocopherol and sterol contents that may be due to overdominance gene action. Breeding lines such as B.116.P, B.112.P and RH.365 were positive combiners for the investigated traits, thus likely carrying positive alleles for both tocopherol and sterol traits.

A Multimodal Drug-Diet-Immunotherapy Combination Restrains Melanoma Progression and Metastasis.

The genetic landscape of cancer cells can lead to specific metabolic dependencies for tumor growth. Dietary interventions represent an attractive strategy to restrict the availability of key nutrients to tumors. In this study, we identified that growth of a subset of melanoma was severely restricted by a rationally designed combination therapy of a stearoyl-CoA desaturase (SCD) inhibitor with an isocaloric low-oleic acid diet. Despite its importance in oncogenesis, SCD underwent monoallelic codeletion along with PTEN on chromosome 10q in approximately 47.5% of melanoma, and the other SCD allele was methylated, resulting in very low-SCD expression. Although this SCD-deficient subset was refractory to SCD inhibitors, the subset of PTEN wild-type melanoma that retained SCD was sensitive. As dietary oleic acid could potentially blunt the effect of SCD inhibitors, a low oleic acid custom diet was combined with an SCD inhibitor. The combination reduced monounsaturated fatty acids and increased saturated fatty acids, inducing robust apoptosis and growth suppression and inhibiting lung metastasis with minimal toxicity in preclinical mouse models of PTEN wild-type melanoma. When combined with anti-PD1 immunotherapy, the SCD inhibitor improved T-cell functionality and further constrained melanoma growth in mice. Collectively, these results suggest that optimizing SCD inhibitors with diets low in oleic acid may offer a viable and efficacious therapeutic approach for improving melanoma treatment. Significance: Blockade of endogenous production of fatty acids essential for melanoma combined with restriction of dietary intake blocks tumor growth and enhances response to immunotherapy, providing a rational drug-diet treatment regimen for melanoma.

BnGLO4 gene cloning and bioinformatics analysis in Brassica napus L

High oleic acid rapeseed oil offers superior nutritional and health benefits, but its mass production is limited due to poor resistance and slightly lower yield. Photosynthesis serves as the foundation of biological survival and closely correlates with crop resistance to stresses, yield, and quality. To identify photosynthesis-related genes, transcriptome sequencing was conducted on high oleic acid rapeseed Gaoyousuan No. 1 and low oleic acid rapeseed Xiangyou 15 resulting in the identification of a total of 9396 differentially expressed genes (4669 up-regulated and 4727 down-regulated). From these genes nine candidate genes were screened using GO and KEGG analysis with BnGLO4 being selected for cloning purposes. The BnGLO4 gene fragment has a length of 1161 bp with an ORF sequence of 1092 bp encoding a theoretical isoelectric point of pI 7.60; it encodes an unstable lipid-soluble protein localized in peroxisomes without transmembrane structural domains or signal peptides. Its amino acid sequence homology was highest with that of BnaA01G0355200ZS, BnaA01G0355600ZS, BnaA05G0410400ZS, BnaC01G0441800ZS, and Brassica rapa (XP_0091171 45.1), Brassica napus (CDY39100.1), Brassica cretica (KAF3533604.1) and Brassica oleracea var. oleracea (XP_0136106 44.1) belonging to the same cruciferous family.The BnGLO4 gene may be associated with responses to abiotic stresses such as salt, drought, and temperature extremes along with photosynthesis and growth in rapeseed plants. The expression levels of the GLO4 gene (BnaA01G0355200 ZS) were highest in filaments while being higher at each stage in seeds and siliques with the highest expression level at day 14 in seeds. Expression was significantly upregulated after 3 ​h of salt stress treatment, reaching a maximum at 12 ​h before slightly decreasing at 24 ​h. The findings of this study lay a foundation for further investigation on photosynthesis and stress response in high oleic rapeseed.

Dietary oleic acid contributes to the regulation of food intake through the synthesis of intestinal oleoylethanolamide.

Among the fatty acid ethanolamides (FAEs), oleoylethanolamide (OEA), linoleoylethanolamide (LEA), and palmitoylethanolamide (PEA) are reported to be involved in feeding regulation. In particular, OEA is well characterized as a satiety signal. Following food consumption, OEA is synthesized from oleic acid (OA) via an N-acyl phosphatidylethanolamine-specific phospholipase D-dependent pathway in the gastroenterocytes, and OEA induces satiety by recruiting sensory fibers. Thus, we hypothesized that dietary OA is an important satiety-inducing molecule. However, there has been no direct demonstration of the effect of dietary OA on satiety induction without the influence of the endogenous biosynthesis of OA from stearic acid (SA) or other FAEs. In this study, we used two experimental diets to test our hypothesis: (i) an OA diet (OAD; 38.4 mg of OA/g and 7.2 mg of SA/g) and (ii) a low OA diet (LOAD; 3.1 mg of OA/g and 42.4 mg of SA/g). Relative to mice fed the OAD, mice fed the LOAD for two weeks exhibited reduced levels of jejunal OEA but not jejunal LEA and PEA. The LOAD-fed mice showed an increase in food intake and body weight gain. Moreover, LOAD-induced increase in food intake was immediately observed after the switch from the OAD, whereas these effects were diminished by the switch back to the OAD. Furthermore, treatment with OA and OEA diminished the effects of LOAD on food intake. Collectively, these results show that dietary OA is a key factor in the reduction of food intake and increase in satiety mediated by OEA signaling.

Bioinformatics and Functional Analysis of High Oleic Acid-Related Gene GmSAM22 in Soybean [Glycine max (L.) Merr.

High yield, high quality, stable yield, adaptability to growth period, and modern mechanization are the basic requirements for crops in the 21st century. Soybean oleic acid is a natural unsaturated fatty acid with strong antioxidant properties and stability. Known as a safe fatty acid, it has the ability to successfully prevent cardiovascular and cerebrovascular disorders. Improving the fatty acid composition of soybean seeds, can not only speed up the breeding process of high-quality high-oil and high-oleic soybeans, but also have important significance in human health, and provide the possibility for the development of soybean oil as a new energy source. Hence, the aim of this study was to analyze the high oleic acid elated gene GmSAM22 in soybean. In this research the soybean oleic acid-related gene GmSAM22 was screened out by Genome-wide association analysis, a 662 bp fragment was acquired by specific PCR amplification, and the pMD18T cloning vector was linked by the use of a seamless cloning technique. Bioinformatics analysis of the signal peptide prediction, subcellular localization, protein hydrophobicity, transmembrane region analysis, a phosphorylation site, protein secondary and tertiary structure and protein interaction analysis of the protein encoded by the SAM22 gene was carried out. The plasmid of the gene editing vector is pBK041. The overexpression vector was transformed from pCAMBIA3301 as the base vector, and overexpression vector were designed. Positive plants were obtained by genetic transformation by the pollen tube channel method. Fluorescence quantitative PCR was performed on the T2 generation plants to detect the relative expression levels in different tissues. Southern Blot was used to detect the presence of hybridization signal. Screening genes BAR, 35S, and NOS in plants were identified by conventional PCR. 10 seeds with high and low oleic acid content were chosen for quantitative PCR identification, and finally, the concentration and morphology of soybean fatty acids were identified by near-far infrared spectroscopy. On 10 seeds with an upper and lower oleic acid content, a quantitative fluorescence analysis was done. In Southern blot hybridization, the SAM22 gene was integrated into the recipient soybean plant in hands of a sole copy. Fluorescence quantitative PCR appeared that the average relative expression of the SAM22 gene in roots, stems, leaves, and seeds was 1.70, 1.67, 3.83, and 4.41, respectively. Positive expression seeds had a 4.77% increase in oleic acid content. The level of oleic acid in the altered seeds was reduced by 4.13% when compared to CK, and it was discovered that the GmSAM22 gene could be a regulatory and secondary gene that promotes the conversion of stearic acid to oleic acid in soybean. There has not been a discussion of gene cloning or functional verification. The cloning and genetic transformation of the soybean SAM22 gene can effectively increase the content of oleic acid, which lays a foundation for the study of soybean with high oleic acid.

Selection indices for oil content and oil yield improvement in low and high oleic acid content populations in sunflower (Helianthus annuus L.)

A F2 population was partitioned into low oleic and high oleic acid content groups using a high oleic allele-specific marker.  These low and high oleic acid content groups and pooled groups were subjected to variability and association analyses.  The variability parameters were similar in both high oleic and low oleic populations.  Traits viz., plant height, head diameter, 100-seed weight, seed yield and oil content are considered as selection indices for improving oil yield.   These selection indices can be followed to improve oil yield in both high oleic and low oleic populations.   However, separate selection indices to improve oil content viz., volume weight, plant height and head diameter for high oleic acid populations and volume weight, days to flowering and 100-seed weight for a low oleic populations may be followed.   These results indicated that similar selection indices could not be adopted to improve a trait in all populations. Keywords: Sunflower, high oleic acid content, oil yield, variability, correlation.

Promising Novel Method of Acetylation Modification for Regulating Fatty Acid Metabolism in Brassica napus L.

Simple SummaryThe quality of rapeseed (Brassica napus) oil depends mainly on the degree of hydrocarbon chain saturation of fatty acids. In previous studies, seeds of the B. napus near-isogenic lines were used as raw materials by iTRAQ analysis at 20–35 days after pollination, and three differential proteins related to oleic acid metabolisms were found to be related to acetylation modification. Thus, we analyzed lysine acetylation using the same raw materials. The function of the corresponding genes of fatty acid metabolisms-related differential proteins was verified by identifying the overexpression of BnACP363K, BnACP363R, and BnACP363 in Arabidopsis thaliana. The results show that the acetylation modification of BnaACP3 may have a selective effect on oleic acid and slow down the conversion of oleic acid to linoleic acid. This is the first report of oleic acid synthesis regulation by acetylation. In this study, lysine acetylation analysis was conducted using two Brassica napus near-isogenic lines, HOCR and LOCR, containing high and low oleic acid contents, respectively, to explore this relationship. Proteins showing differences in quantitative information between the B. napus lines were identified in lysine acetylation analysis, and KEGG pathways were analyzed, yielding 45 enriched proteins, most of which are involved in carbon fixation in photosynthetic organisms, photosynthesis, ascorbate and aldarate metabolism, and glycolysis. Potential key genes related to fatty acid metabolisms were determined. To further explore the effect of acetylation modification on fatty acid metabolisms, the acyl-ACP3 related gene BnaACP363K was cloned, and a base mutation at No.63 was changed via overlapping primer PCR method. This study is the first to demonstrate that acetylation modification can regulate oleic acid metabolisms, which provides a promising approach for the study of the molecular mechanism of oleic acid in rapeseed.

Effects of Process Variables on Properties of CoFe2O4 Nanoparticles Prepared by Solvothermal Process

Controlling the morphology and magnetic properties of CoFe2O4 nanoparticles is crucial for the synthesis of compatible materials for different applications. CoFe2O4 nanoparticles were synthesized by a solvothermal method using cobalt nitrate, iron nitrate as precursors, and oleic acid as a surfactant. The formation of CoFe2O4 nanoparticles was systematically observed by adjusting synthesis process conditions including reaction temperature, reaction time, and oleic acid concentration. Nearly spherical, monodispersed CoFe2O4 nanoparticles were formed by changing the reaction time and reaction temperature. The oleic acid-coated CoFe2O4 nanoparticles inhibited the growth of particle size after 1 h and, therefore, the particle size of CoFe2O4 nanoparticles did not change significantly as the reaction time increased. Both without and with low oleic acid concentration, the large-sized cubic CoFe2O4 nanoparticles showing ferromagnetic behavior were synthesized, while the small-sized CoFe2O4 nanoparticles with superparamagnetic properties were obtained for the oleic acid concentration higher than 0.1 M. This study will become a basis for further research in the future to prepare the high-functional CoFe2O4 magnetic nanoparticles by a solvothermal process, which can be applied to bio-separation, biosensors, drug delivery, magnetic hyperthermia, etc.

Determination of allosteric and active sites responsible for catalytic activity of delta 12 fatty acid desaturase from Geotrichum candidum and Mortierella alpina by domain swapping

Cheese lacks essential fatty acids (EFAs). Delta 12 fatty acid desaturase (FADS12) is a critical enzyme required for EFA biosynthesis in fermentation of the predominant strains of cheese. Previously, we identified the FADS12 gene and characterized its function for the first time in Geotrichum candidum, a dominant strain used to manufacture soft cheese with white rind. In this study, we analyzed the molecular mechanism of FADS12 function by swapping domains from Mortierella alpina and G. candidum that had, respectively, high and low oleic acid conversion rates. The results revealed three regions that are essential to this process, including regions from the end of the second transmembrane domain to the beginning of the third transmembrane domain, from the end of the third transmembrane domain to the beginning of the fourth transmembrane domain, and from the 30-amino acid from the end of the sixth transmembrane domain to the C-terminal end region. Based on our domain swapping analyses, nine pairs of amino acids including H112, S118, H156, Q161, K301, R306, E307, A309 and S323 in MaFADS12 (K123, A129, N167, M172, T302, D307, I308, E310 and D324 in GcFADS12) were identified as having a significantly effect on FADS12 catalytic efficiency, and linoleic acid and its analogues (12,13-cyclopropenoid fatty acid) were found to inhibit the catalytic activity of FADS12 and related recombinant enzymes. Furthermore, the molecular mechanism of FADS12 inhibition was analyzed. The results revealed two allosteric domains, including one domain from the N-terminal region to the beginning of the first transmembrane domain and another from the 31st amino acid from the end of the sixth transmembrane domain to the C terminus. Y4 and F398 amino acid residues from MaFADS12 and eight pairs of amino acids including G56, L60, L344, G10, Q13, S24, K326 and L344 in MaFADS12 (while Y66, F70, F345, F20, Y23, Y34, F327 and F345 in GcFADS12) played a pivotal role in FADS12 inhibition. Finally, we found that both allosteric and active sites were responsible for the catalytic activity of FADS12 at various temperatures, pH, and times. This study offers a solid theoretical basis to develop preconditioning methods to increase the rate at which GcFADS12 converts oleic and linoleic acids to produce higher levels of EFAs in cheese.

India’s first high oleic safflower variety for commercial cultivation

Indian safflower varieties possess low oleic acid content (16-20%). Therefore, high oleic (>70%) safflower oil isimported from abroad to meet the domestic needs. ICAR-Indian Institute of Oilseeds Research developed India’s first high oleic safflower variety, ISF-1, which has been notified recently for all India cultivation. ISF-1 contains 76% oleic acid and 31% oil. It gives four-fold higher oleic acid yield (4.41 q/ha) than the leading variety, PBNS-12 (1.0 q/ha). Its performance with respect to oleic acid content and seed and oil yield in AICRP (Safflower) trials and in farmers’ fields across the country is presented in this paper.

Advances in Crop Improvement and Delivery Research for Nutritional Quality and Health Benefits of Groundnut (Arachis hypogaea L.).

Groundnut is an important global food and oil crop that underpins agriculture-dependent livelihood strategies meeting food, nutrition, and income security. Aflatoxins, pose a major challenge to increased competitiveness of groundnut limiting access to lucrative markets and affecting populations that consume it. Other drivers of low competitiveness include allergens and limited shelf life occasioned by low oleic acid profile in the oil. Thus grain off-takers such as consumers, domestic, and export markets as well as processors need solutions to increase profitability of the grain. There are some technological solutions to these challenges and this review paper highlights advances in crop improvement to enhance groundnut grain quality and nutrient profile for food, nutrition, and economic benefits. Significant advances have been made in setting the stage for marker-assisted allele pyramiding for different aflatoxin resistance mechanisms—in vitro seed colonization, pre-harvest aflatoxin contamination, and aflatoxin production—which, together with pre- and post-harvest management practices, will go a long way in mitigating the aflatoxin menace. A breakthrough in aflatoxin control is in sight with overexpression of antifungal plant defensins, and through host-induced gene silencing in the aflatoxin biosynthetic pathway. Similarly, genomic and biochemical approaches to allergen control are in good progress, with the identification of homologs of the allergen encoding genes and development of monoclonal antibody based ELISA protocol to screen for and quantify major allergens. Double mutation of the allotetraploid homeologous genes, FAD2A and FAD2B, has shown potential for achieving >75% oleic acid as demonstrated among introgression lines. Significant advances have been made in seed systems research to bridge the gap between trait discovery, deployment, and delivery through innovative partnerships and action learning.

Association Mapping Analysis of Fatty Acid Content in Different Ecotypic Rapeseed Using mrMLM.

Brassica napus L. is a widely cultivated oil crop and provides important resources of edible vegetable oil, and its quality is determined by fatty acid composition and content. To explain the genetic basis and identify more minor loci for fatty acid content, the multi-locus random-SNP-effect mixed linear model (mrMLM) was used to identify genomic regions associated with fatty acid content in a genetically diverse population of 435 rapeseed accessions, including 77 winter-type, 55 spring-type, and 303 semi-winter-type accessions grown in different environments. A total of 149 quantitative trait nucleotides (QTNs) were found to be associated with fatty acid content and composition, including 34 QTNs that overlapped with the previously reported loci, and 115 novel QTNs. Of these, 35 novel QTNs, located on chromosome A01, A02, A03, A05, A06, A09, A10, and C02, respectively, were repeatedly detected across different environments. Subsequently, we annotated 95 putative candidate genes by BlastP analysis using sequences from Arabidopsis thaliana homologs of the identified regions. The candidate genes included 34 environmentally-insensitive genes (e.g., CER4, DGK2, KCS17, KCS18, MYB4, and TT16) and 61 environment-sensitive genes (e.g., FAB1, FAD6, FAD7, KCR1, KCS9, KCS12, and TT1) as well as genes invloved in the fatty acid biosynthesis. Among these, BnaA08g08280D and BnaC03g60080D differed in genomic sequence between the high- and low-oleic acid lines, and might thus be the novel alleles regulating oleic acid content. Furthermore, RT-qPCR analysis of these genes showed differential expression levels during seed development. Our results highlight the practical and scientific value of mrMLM or QTN detection and the accuracy of linking specific QTNs to fatty acid content, and suggest a useful strategy to improve the fatty acid content of B. napus seeds by molecular marker-assisted breeding.

Variability and inheritance of the «oleic acid content» and «1000-achene weight» traits by F1 and F2 sunflower

Purpose and objectives. To establish features of the inheritance variability of oleic acid content in oil in F1 and F2 hybrids upon crossing genetic sources of high oil content with confectionery sunflower lines, to create new starting material with increased content of oleic acid and high 1000-seed weight.Material and methods. The study was conducted in the fields of scientific crop rotation of the Plant Production Institute named after V.Ya. Yuriev of NAAS in 2015–2017. The content of oleic acid in achene oil was analyzed in lines, F1 hybrids derived from crossing these lines and segregating F2 generation. Hybrids were obtained from diallel crossing ten lines: one of them was high oleic line VK-L-4; five confectionery lines and four lines - components of oil hybrids with usual content of oleic acid.Results and discussion. The article presents the results of a three-year analysis of the oleic acid content in seed oil. The studied lines were ranked according to this trait: low-oleic Kh51B (≤25%), high-oleic VK-L-4 (≤88.88%), the other lines were mid-oleic (25–35%). In the first generation, the increased content of oleic acid was stable in only three hybrid combinations: VK-L-4/Kh51B, VK-L-4/Kh2301V and Skx51A/VK-L-4 (56.77–64.11%). In these combinations, the oleic acid content in seed oil is inherited by intermediate type, and the degree of phenotypic dominance (hp) was 0.18, 0.07 and 0.10%, respectively, in 2016 and 0.30, 0.09 and 0.16%, respectively, in 2017.In the segregating F2 offspring, accessions of all the categories of the oleic acid content in seed oil were identified: low-oleic (20–34%), mid-oleic (35–55%), with an increased content of oleic acid (60–70%) and high-oleic (> 82% ). As to the 1000-achene weight, segregation in F2 was also observed, and the trait varied 26.0 to81.0 g. There was a significant negative correlation (r = -0.351 for accessions from hybrid combination VK-L-4/Kh51B and r = - 0.441 - from hybrid combination Skh51A/VK-L-4) between the oleic acid content in seed oil and 1000-achene weight.Conclusions. The study established that crossing two lines with low or medium oleic acid content in oil failed to generate hybrids with high or increased oleic acid content. The level of this trait did not exceed 33.84%. Combinations with high-oleic line VK-L-4 gave hybrids distinguished by an increased content of oleic acid (56.77–64.11%). The inheritance type for this trait in F1 hybrids was determined upon crossing two lines with usual oleic acid content or a line with usual oleic acid content and a high-oleic one. The content of oleic acid was inherited by dominance of low content or by intermediate inheritance. In F2 offspring, there were accessions of all the types of oleic acid content: from low-oleic (19.75%) to high-oleic (87.82%). F2 also segregated by 1000-achene weight, and the trait varied within 26.0-81.0 g. There was a significant negative correlation between these two traits, however, given low r=-0.441 and r=-0.351, it is possible to develop high-oleic confectionary lines from the studied breeding material.

ITRAQ-based quantitative proteomics analysis of an immature high-oleic acid near-isogenic line of rapeseed

High-oleic acid rapeseed is a new and promising rapeseed variety because it produces oil with high-quality health and nutrient properties. To identify differentially expressed proteins in a high-oleic acid rapeseed line, self-bred seeds (20 to 35 days after pollination) of a high- and a low-oleic acid rapeseed near-isogenic line (oleic acid contents of 81.4 and 56.2%, respectively) were used as raw materials for iTRAQ (isobaric tags for relative and absolute quantitation) analysis. In total, 24,755 peptides, 14,455 unique peptides, and 4726 proteins were identified. Among them, 137 differentially expressed proteins were assigned pathway annotations, accounting for 3.84% of the total proteins (3568). Three differentially expressed proteins, PSaB (gi|383930478), Lhcb6 (gi|50313237), and ALD (gi|15227981) were subjected to western blotting analyses. The results were consistent with the iTRAQ data, demonstrating the satisfactory quality of the iTRAQ experimental procedures and data. The transcript levels of 19 genes involved in fatty acid metabolism and photosynthesis were analyzed by qPCR. The transcript levels were consistent with the protein levels for 10 of these genes, but inconsistent for the other nine genes. Among the differentially expressed proteins were key enzymes in fatty acid biosynthesis and polyunsaturated fatty acid biosynthesis (acyl-CoA thioesterase, 3-ketoacyl-CoA reductase, omega 6 reductase, and acyl-CoA dehydrogenase), oleic acid biosynthesis (acyl-CoA thioesterase and omega 6 reductase), and seed lipid content (long-chain acyl-CoA synthetase). These results provide fundamental functional proteomics information for further breeding work on high-oleic acid rapeseed. This information will also be useful for research on the molecular mechanism of oleic acid synthesis.

Competition of Thermomyces lanuginosus lipase with its hydrolysis products at the oil–water interface

Lipase–catalyzed hydrolysis of triglycerides yields glycerol and free fatty-acids, provided that the enzyme is non-regioselective. For an Sn-1,3 regioselective enzyme, such as lipase from Thermomyces lanuginosus, the final product is no longer glycerol but Sn-2 monoglyceride instead. However, surface active molecules generated by lipolysis may have a detrimental effect on the interfacial biocatalysis since it is known that low molecular weight surfactants can displace proteins from interfaces. By using drop profile analysis tensiometry, we evaluated the interfacial properties of the lipase–generated molecules and their competitive effect on the adsorption behavior of the lipase and on the proceeding lipolysis. Our results show that even at concentration ratios of 8.64×10−4M (Sn-2 monoglyceride) to 2.5×10−7M (lipase), the final interfacial pressure values are very similar as for the system containing the lipase alone (i.e. ∼26 mN/m). This is a strong indication that monoglycerides, as the most interfacially active products generated during regioselective lipolysis, are expelled from the oil–water interface by the lipase. We attribute this effect to intermolecular lipase–lipase interactions, resulting in a low desorption probability of the lipase. For low oleic acid concentrations, the interfacial tension is solely determined by the lipase, while for higher concentrations, lipase and oleic acid both contribute to the tension values. We propose a hypothesis based on the preferential interaction of oleic acid molecules with hydrophobic sites on the lipase. The pH dependence of the adsorption rate and the interfacial activity of the lipase were also investigated.

Association of low oleic acid intake with diabetic retinopathy in type 2 diabetic patients: a case-control study.

BackgroundThe objective of this study was to describe the intake of macronutrient, especially fatty acids, and explore their possible effect on diabetic retinopathy (DR) in patients with type 2 diabetes mellitus.MethodsIn this case–control study, we included a total of 146 patients with DR and 148 without DR. The intake of macronutrient was evaluated using a validated food frequency questionnaire. We used logistic regression adjusted for sex, age, diabetes duration, energy intake, educational level, physical activity, waist circumference, systolic blood pressure, high-density lipoprotein cholesterol and diabetes treatment, to estimate odds ratio (ORs) of DR.ResultsPatients with DR had significantly lower intake of fibre, monounsaturated fatty acids (MUFA), and palmitic and oleic acid. Inverse associations were observed between MUFA and oleic acid intake in DR. Subjects with intermediate and high MUFA intake were less likely to have DR than those with lower MUFA intake, with ORs of 0.46 (95 % CI: 0.22–0.93) and 0.42 (95 % CI: 0.18–0.97), respectively. Similarly, intermediate and high oleic acid intake were associated with reduced DR frequency compared with low oleic acid intake, with OR values of 0.48 (95 % CI: 0.23–0.97) and 0.37 (95 % CI: 0.16–0.85), respectively. These associations were stronger in patients with a longer diabetes duration.ConclusionIn type 2 diabetes mellitus, MUFA and oleic acid intake were inversely associated with DR.

Differential expression of fatty acid desaturases in Mari and Shengeh olive cultivars during fruit development and ripening

To understand the molecular basis of the higher oleic/linoleic acid content in Mari and Koroneiki with respect to Shengeh and Arbequina olive cultivars, we have focused on analysis of fatty acids, as well as expression levels of OeSAD and three oleate desaturase genes during fruit development and ripening. The mesocarp oil content was determined using a Minispec NMR. Moreover, oleic and linoleic acid contents were recorded by GC. Quantitative real time PCR was used for gene expression analysis. Mari and Shengeh exhibited the highest and lowest levels of OeSAD gene expression, respectively, which corresponded fully to a change in the pattern of oleic acid and oil accumulation throughout mesocarp development. Regarding oleate desaturases, a decreasing pattern of OeFAD2‐1 and OeFAD6 transcripts accompanied by an increasing trend of OeFAD2‐2 expression during mesocarp development showed that, coinciding with oil accumulation, linoleic acid content is mainly determined by the OeFAD2‐2 gene. In conclusion, the higher oleic/linoleic ratio in Mari and Koroneiki cultivars compared to Shengeh and Arbequina was due to much higher expression levels of OeSAD and lower expression levels of OeFAD2‐2.Practical applications: Increasing the oleic to linoleic acid ratio has become one of the major goals for researchers in the area of plant lipid modification. To this end, understanding the mechanisms by which fatty acid composition is determined during olive fruit development and ripening would represent an important step toward the ultimate goal of regulating these processes in a directed and predictable manner.Relative expression of OeSAD gene (B) during mesocarp development and ripening of the high (Mari and Koroneiki) and low (Shengeh and Arbequina) oleic acid olive cultivars. The beginning of fruit ripening, corresponding to the appearance of pink‐purple color, is marked by an arrow. Different letterings show that the results significantly different at P < 0.05. The bars represent the SD of the mean (DAFB, days after full bloom).

Evaluation of Indigenous and Exotic Germplasm of Indian Mustard [Brassica juncea(L.) Czernj & Cosson] for Morpho-Physiological and Quality Characters

Sixty germplasm accessions from India (27), Australia (25) and China (8) along with 5 check varieties (Bio-902, Bio-772, PCR-7, Rohini and Varuna) of Indian mustard [Brassica juncea (L.) Czernj. & Cosson] were grown in an augmented block design with four blocks during rabi season of 2007–08 to assess magnitude and nature of variability for morpho-physiological and quality characters. Significant mean sum of squares due to genotypes indicated presence of substantial variability for all the morpho-physiological characters investigated except protein content. Seed yield/plant, secondary branches/plant, biological yield, 1000-seed weight, specific leaf weight at 50% and full flowering, leaf area index at full flowering and total dry matter at 50% flowering had high genetic variability and could be exploited through selection. The Chinese accessions were very late in maturity due to fact that they were selected under long day conditions and no seed could be harvested. Indian varieties such as GM-2, RGN-13, JM-3, VSL-5 and Australian accession JM-018 showed very low saturated fatty acids (<2%). Oleic acid content in the indigenous germplasm was low varying from 6.0–18.1% and all had high erucic acid in the range of 31.5% (Basanti)-52.5% (GM-2). The Australian accessions exhibited low erucic acid (< 2%) and high oleic acid (29.7–58.4%). Glucosinolate content in the indigenous germplasm ranged from 75–136.6 μ moles/g defatted seed meal. In the Australian accessions it was up to 30 μ moles/g defatted seed meal. Several potentials accessions were identified from exotic as well as indigenous germplasm for utilization in the breeding programme.

Partitioning of Oleic Acid into Phosphatidylcholine Membranes Is Amplified by Strain

Partitioning of fatty acids into phospholipid membranes is studied on giant unilamellar vesicles (GUVs) utilizing phase-contrast microscopy. With use of a micropipet, an individual GUV is transferred from a vesicle suspension in a mixed glucose/sucrose solution into an isomolar glycerol solution with a small amount of oleic acid added. Oleic acid molecules intercalate into the phospholipid membrane and thus increase the membrane area, while glycerol permeates into the vesicle interior and thus via osmotic inflation causes an increase of the vesicle volume. The conditions are chosen at which a vesicle swells as a sphere. At sufficiently low oleic acid concentrations, when the critical membrane strain is reached, the membrane bursts and part of vesicle content is ejected, upon which the membrane reseals and the swelling commences again. The radius of the vesicle before and after the burst is determined at different concentrations of oleic acid in suspension. The results of our experiments show that the oleic acid partitioning increases when the membrane strain is increased. The observed behavior is interpreted on the basis of a tension-dependent intercalation of oleic acid into the membrane.

Comparative study of olive oil quality from Chemlali Sfax versus Arbequina cultivated in Tunisia

AbstractThe effects of the geographical region on the behavior of the Arbequina olive cultivar (cv) cultivated in the south of Tunisia (in the arid zone of Sfax) was compared to an autochthonous cultivar (Chemlali Sfax). Various olive parameters were analyzed, such as ripening index, pulp/stone ratio, oil contents, and sensory profiles. Most of the quality indices and fatty acid composition showed significant variations among olive cultivars. Arbequina cv is characterized by high oil yield with a less total phenols and pigments content than Chemlali Sfax cv. Cielab spectrophotometer coordinate L*, b*, and a* values show a great difference in olive oil colors. In spite of their low oleic acid contents, autochthonous cultivar presented a higher induction time (6.82 and 2.68 h for Chemlali and Arbequina, respectively) and high contents of phenolic compounds (158.28 and 110.27 mg/kg for Chemlali Sfax and Arbequina, respectively). The most important compounds identified were oleuropein aglycon (45.50 mg/kg), hydroxytyrosol (3.68 mg/kg), 1‐acetoxypinoresinol (6.23 mg/kg) in Chemlali Sfax oil and hydroxytyrosol glucoside (25.15 mg/kg), tyrosol (12.51 mg/kg), and oleuropein aglycon (30.60 mg/kg) in Arbequina oil. Chemlali Sfax also possessed a very bitter taste, whereas the Arbequina had a sweet taste amongst its attributes. The principal component analysis of the results indicated that the geographical region has significantly affected the olive oil quality.