Temperature effect on triacylglycerol species in seed oil from high stearic sunflower lines with different genetic backgrounds.

BACKGROUND: This study characterized the influence of temperature during grain filling on the saturated fatty acid distribution in triacylglycerol molecules from high stearic sunflower lines with different genetic backgrounds. Two growth chamber experiments were conducted with day/night temperatures of 16/16, 26/16, 26/26 and 32/26 °C. RESULTS: In all genotypes, independently of the genetic background, higher temperatures increased palmitic and oleic acid and reduced linoleic acid concentrations. Increasing night temperature produced an increase in saturated-unsaturated-saturated species, indicating a more symmetrical distribution of saturated fatty acids. The solid fat index was more affected by temperature during grain filling in lines with high linoleic than high oleic background. Higher variations in symmetry among night temperatures were observed in lines with high oleic background, which are more stable in fatty acid composition. CONCLUSION: The effect of temperature on triacylglycerol composition is not completely explained by its effect on fatty acid composition. Thus night temperature affects oil properties via its effects on fatty acid synthesis and on the distribution of fatty acids in the triacylglycerol molecules. © 2016 Society of Chemical Industry.

Effect of the cryopreservation method used, the embryonic stage and the use of conjugated linoleic acid isomers on the cryotolerance of in vitro-produced bovine embryos / Efeito do método de criopreservação utilizado, estágio de desenvolvimento embrionário e uso de isômeros do ácido linoleico conjugado na criotolerância de embriões bovinos produzidos in vitro

Conjugated linoleic acid (CLA) might be able to improve the cryotolerance of in vitro-produced (IVP) embryos. The effect of two CLA isomers on the cryotolerance of bovine IVP embryos, as well as that of the stage of embryonic development and the method used for cryopreservation was evaluated by three experiments. In Experiment 1, oocytes (n = 3,917) were fertilized in vitro and cultured with 0, 50, 100, or 200 μM trans-10, cis-12 (t10, c12 CLA). In Experiment 2, fertilized oocytes (n = 2,131) were cultured with 100 μM t10, c12 or cis-9, trans-11 (c9, t11 CLA), or a combination of both isomers. The embryos were vitrified at the blastocyst (BL) or the expanded blastocyst (EB) stage. In Experiment 3, oocytes (n = 1,720) were fertilized and cultured with or without 100 μM t10, c12 CLA, and the blastocysts were vitrified or frozen. Blastocyst development rate as well as the rates of re-expansion and hatching after thawing was recorded. Moreover, the mean cell number and mRNA expression of acetyl-CoA carboxylase (ACC1) and stearoyl-CoA desaturase (SCD1) as well as fatty acid synthase (FASN) multienzyme complex were determined. In Experiment 1, the highest concentration of t10, c12 CLA that did not reduce blastocyst development rate was 100 μM. In Experiment 2, the rates of re-expansion and hatching among the EBs obtained through IVP after supplementation with t10, c12 CLA (73.1% and 57.7%), with c9, t11 CLA (80.0% and 68.6%), with the combination (78.3% and 52.2%), and with the control group (85.4% and 58.3%) were similar. At the BL stage, the rates of re-expansion and hatching were lower than those at the EB stage, and CLA combination allowed a hatching rate (8.0%) lower than that observed in the control group (40.0%). In Experiment 3, the hatching rates for vitrified EBs (vitrified control; 67.4%) and vitrified CLA EBs (65.8%) were higher than those obtained for frozen EBs, exposed (13.3%) or not exposed (28.6%) to CLA.

Existem evidências de que o ácido linoleico conjugado (CLA) pode aumentar a criotolerância de embriões produzidos in vitro (PIV). O efeito de dois isômeros do CLA na criotolerância de embriões bovinos PIV, assim como o estágio de desenvolvimento e o efeito do método de criopreservação, foi avaliado através de três experimentos. No Experimento 1, oócitos (n = 3.917) foram fecundados in vitro e embriões foram cultivados com 0, 50, 100 ou 200 μM de trans-10, cis-12 (t10, c12 CLA). No Experimento 2, oócitos fecundados (n = 2.131) foram cultivados com 100 μM de t10, c12 ou cis-9, trans-11 (c9, t11 CLA), ou ainda com uma associação de ambos. Os embriões foram vitrificados nos estágios de blastocisto (BL) ou blastocisto expandido (BE). No Experimento 3, oócitos (n = 1.720) foram fecundados e cultivados com ou sem 100 μM de t10, c12 CLA e os blastocistos foram vitrificados ou congelados. As taxas de desenvolvimento dos blastocistos, bem como de re-expansão e eclosão após o reaquecimento foram observadas. Adicionalmente, o número médio de células e a expressão de mRNA das enzimas acetil-CoA carboxilase (ACC1) e estearoil-CoA dessaturase (SCD1) e do complexo enzimático ácido graxo sintase (FASN) foram avaliados. No Experimento 1, a maior concentração de t10, c12 CLA que não reduziu a taxa de blastocisto foi 100 μM. No Experimento 2, as taxas de re-expansão e eclosão obtidas entre EB obtidos por PIV após suplementação com t10, c12 CLA (73,1 e 57,7%), com c9, t11 CLA (80,0 e 68,6%), com a associação de ambos (78,3 e 52,2%) e com o grupo Controle (85,4 e 58,3%) foram similares. As taxas de re-expansão e eclosão foram mais baixas no estágio de BL do que no estágio de BE, e a associação dos isômeros apresentou taxa de eclosão (8,0%) mais baixa do que a do grupo controle (40,0%).

Effect of the cryopreservation method used, the embryonic stage and the use of conjugated linoleic acid isomers on the cryotolerance of in vitro-produced bovine embryos / Efeito do método de criopreservação utilizado, estágio de desenvolvimento embrionário e uso de isômeros do ácido linoleico conjugado na criotolerância de embriões bovinos produzidos in vitro

Conjugated linoleic acid (CLA) might be able to improve the cryotolerance of in vitro-produced (IVP) embryos. The effect of two CLA isomers on the cryotolerance of bovine IVP embryos, as well as that of the stage of embryonic development and the method used for cryopreservation was evaluated by three experiments. In Experiment 1, oocytes (n = 3,917) were fertilized in vitro and cultured with 0, 50, 100, or 200 μM trans-10, cis-12 (t10, c12 CLA). In Experiment 2, fertilized oocytes (n = 2,131) were cultured with 100 μM t10, c12 or cis-9, trans-11 (c9, t11 CLA), or a combination of both isomers. The embryos were vitrified at the blastocyst (BL) or the expanded blastocyst (EB) stage. In Experiment 3, oocytes (n = 1,720) were fertilized and cultured with or without 100 μM t10, c12 CLA, and the blastocysts were vitrified or frozen. Blastocyst development rate as well as the rates of re-expansion and hatching after thawing was recorded. Moreover, the mean cell number and mRNA expression of acetyl-CoA carboxylase (ACC1) and stearoyl-CoA desaturase (SCD1) as well as fatty acid synthase (FASN) multienzyme complex were determined. In Experiment 1, the highest concentration of t10, c12 CLA that did not reduce blastocyst development rate was 100 μM. In Experiment 2, the rates of re-expansion and hatching among the EBs obtained through IVP after supplementation with t10, c12 CLA (73.1% and 57.7%), with c9, t11 CLA (80.0% and 68.6%), with the combination (78.3% and 52.2%), and with the control group (85.4% and 58.3%) were similar. At the BL stage, the rates of re-expansion and hatching were lower than those at the EB stage, and CLA combination allowed a hatching rate (8.0%) lower than that observed in the control group (40.0%). In Experiment 3, the hatching rates for vitrified EBs (vitrified control; 67.4%) and vitrified CLA EBs (65.8%) were higher than those obtained for frozen EBs, exposed (13.3%) or not exposed (28.6%) to CLA.(AU)

Existem evidências de que o ácido linoleico conjugado (CLA) pode aumentar a criotolerância de embriões produzidos in vitro (PIV). O efeito de dois isômeros do CLA na criotolerância de embriões bovinos PIV, assim como o estágio de desenvolvimento e o efeito do método de criopreservação, foi avaliado através de três experimentos. No Experimento 1, oócitos (n = 3.917) foram fecundados in vitro e embriões foram cultivados com 0, 50, 100 ou 200 μM de trans-10, cis-12 (t10, c12 CLA). No Experimento 2, oócitos fecundados (n = 2.131) foram cultivados com 100 μM de t10, c12 ou cis-9, trans-11 (c9, t11 CLA), ou ainda com uma associação de ambos. Os embriões foram vitrificados nos estágios de blastocisto (BL) ou blastocisto expandido (BE). No Experimento 3, oócitos (n = 1.720) foram fecundados e cultivados com ou sem 100 μM de t10, c12 CLA e os blastocistos foram vitrificados ou congelados. As taxas de desenvolvimento dos blastocistos, bem como de re-expansão e eclosão após o reaquecimento foram observadas. Adicionalmente, o número médio de células e a expressão de mRNA das enzimas acetil-CoA carboxilase (ACC1) e estearoil-CoA dessaturase (SCD1) e do complexo enzimático ácido graxo sintase (FASN) foram avaliados. No Experimento 1, a maior concentração de t10, c12 CLA que não reduziu a taxa de blastocisto foi 100 μM. No Experimento 2, as taxas de re-expansão e eclosão obtidas entre EB obtidos por PIV após suplementação com t10, c12 CLA (73,1 e 57,7%), com c9, t11 CLA (80,0 e 68,6%), com a associação de ambos (78,3 e 52,2%) e com o grupo Controle (85,4 e 58,3%) foram similares. As taxas de re-expansão e eclosão foram mais baixas no estágio de BL do que no estágio de BE, e a associação dos isômeros apresentou taxa de eclosão (8,0%) mais baixa do que a do grupo controle (40,0%).(AU)

Biomass, lipid content, and fatty acid composition of freshwater Chlamydomonas mexicana and Scenedesmus obliquus grown under salt stress.

Two freshwater microalgae including Chlamydomonas mexicana and Scenedesmus obliquus were grown on Bold Basal Medium (BBM) with different levels of salinity up to 100 mM NaCl. The dry biomass and lipid content of microalgae were improved as the concentration of NaCl increased from 0 to 25 mM. Highest dry weight (0.8 and 0.65 g/L) and lipid content (37 and 34 %) of C. mexicana and S. obliquus, respectively, were obtained in BBM amended with 25 mM NaCl. The fatty acid composition of the investigated species was also improved by the increased NaCl concentration. At 50 mM, NaCl palmitic acid (35 %) and linoleic acid (41 %) were the dominant fatty acids in C. mexicana, while oleic acid (41 %) and α-linolenic acid (20 %) were the major fractions found in S. obliquus.

Fatty acids and bioactive compounds of the pulps and kernels of Brazilian palm species, guariroba (Syagrus oleraces), jerivá (Syagrus romanzoffiana) and macaúba (Acrocomia aculeata).

BACKGROUND: Bioactive compounds are capable of providing health benefits, reducing disease incidence or favoring body functioning. There is a growing search for vegetable oils containing such compounds. This study aimed to characterize the pulp and kernel oils of the Brazilian palm species guariroba (Syagrus oleracea), jerivá (Syagrus romanzoffiana) and macaúba (Acrocomia aculeata), aiming at possible uses in several industries. RESULTS: Fatty acid composition, phenolic and carotenoid contents, tocopherol composition were evaluated. The majority of the fatty acids in pulps were oleic and linoleic; macaúba pulp contained 526 g kg⁻¹ of oleic acid. Lauric acid was detected in the kernels of all three species as the major saturated fatty acid, in amounts ranging from 325.8 to 424.3 g kg⁻¹. The jerivá pulp contained carotenoids and tocopherols on average of 1219 µg g⁻¹ and 323.50 mg kg⁻¹, respectively. CONCLUSION: The pulps contained more unsaturated fatty acids than the kernels, mainly oleic and linoleic. Moreover, the pulps showed higher carotenoid and tocopherol contents. The kernels showed a predominance of saturated fatty acids, especially lauric acid. The fatty acid profiles of the kernels suggest that these oils may be better suited for the cosmetic and pharmaceutical industries than for use in foods.

Culture age and carbamoylcholine increase the incorporation of endogenously synthesized linoleic acid in lipids of Trypanosoma cruzi epimastigotes.

Physiological and cellular adaptations to environmental changes are known to be related to modifications in membrane lipids. This work provides metabolic and compositional evidence that Trypanosoma cruzi epimastigotes are able to synthesize and desaturate fatty acids, to incorporate them into their lipids, and to modify this incorporation when carbamoylcholine is present in the medium. The fatty acids formed from [2-(14)C]acetate in the period from 2 to 9 days were mostly (70%) incorporated in phospholipids, the remainder 30% being recovered in neutral lipids, such as triacylglycerols (TAG) and diacylglycerols (DAG). The main fatty acids formed from [2-(14)C]acetate were saturates (16:0, 18:0), monoenes (16:1, 18:1) and dienes (mostly 18:2). The ratios between labelled unsaturated and saturated fatty acids increased continuously with growth, consistent with a precursor-product relationship between the main fatty acids, and with the occurrence in T. cruzi of Delta(9)- and Delta(12)-desaturases. From days 2 to 5, [(14)C]18:2 was the main fatty acid produced. Accordingly, the fatty acid profiles showed a significant increase in the percentage of 18:2 in all lipids in the period under study, especially in the first 2 to 5 days. In the presence of carbamoylcholine, the labelling of DAG and TAG with [(14)C]18:2 augmented. The results indicate that T cruzi is able to synthesize the main types of fatty acids required to form its membrane lipids, and to exchange them actively in response to environmental stimuli.

Hidroperóxidos de lipídios como fonte biológica de oxigênio singlete: estudos com marcação isotópica, espectrometria de massa e luminescência / Lipid hydroperoxides as biological source of singlete oxygen: study with isotopic labeling, mass spectrometry and luminescence

Evidências apontam para o envolvimento da peroxidação lipídica em diversas patologias. Os hidroperóxidos de lipídios (LOOH) são os produtos primários da peroxidação lipídica e sua decomposição resulta em produtos de maior reatividade e toxicidade, como os radicais peroxila. Esses radicais desempenham papel importante na propagação da peroxidação lipídica e também podem gerar oxigênio molecular singlete (`¹O IND. 2´) por meio da combinação de dois radicais peroxila. Neste trabalho investigamos a possibilidade dos LOOH, em particular dos hidroperóxidos de ácido linoléico (LAOOH), de servirem como fonte `¹O IND. 2´ na presença de oxidantes de relevância biológica como metais, peroxinitrito ou ácido hipocloroso...

Acido linoleico conjugado: un ácido graso con isomeria trans potencialmente beneficioso / Conjugated linoleic acid: a trans isomer fatty acid potentially beneficial

El ácido linoleico conjugado (ALC) es un ácido graso que presenta un tipo de isomeria trans, y que tiene variados efectos beneficiosos para la salud. La estructura de ALC más común que existe en la naturaleza, corresponde a la configuración de isómero 9c (cis), 11t (trans). El ALC se encuentra normalmente en tejidos y/o secreciones (leche) de rumiantes y es formado por la isomerización del ácido linoleico, por acción de la bacteria del rúmen llamada Butyrivibrio fibrisolven. ALC puede ser sintetizado, tanto en rumiantes como en no rumiantes, por la desaturación del ácido vaccenico (18:1, 11t) en el tracto intestinal y/o en el hígado de estos animales. La ingestión diaria de ALC es muy variable (0,5g/día-1,5g/día), ya que depende por una parte de los hábitos nutricionales ya sea individuales o regionales, o por otra, del consumo de carne, leche o derivados de la leche. Se han descritos diversas propiedades nutricionales y biológicas para los diversos isómeros de ALC, entre las más relevantes se destacan: su efecto hipocolesterolémico y antiaterogénico, su acción inmuno-estimulante, la protección que ofrece contra cierto tipo de cánceres, su función antioxidante y la participación en la reducción de peso corporal. Sin embargo, la confirmación definitiva de todos estos efectos beneficiosos para la salud, requiere de un mayor cuerpo de evidencias clínicas y experimentales que avalen sin lugar a dudas estas acciones de ALC. En la actualidad, diversos productos que contienen ALC se ofrecen en los mercados para la venta, los de mayor éxito, son aquellos productos que muestran que los isómeros de ALC que contienen, permiten reducir peso