An increasing number of contemporary studies in aquatic ecology emphasize the im- portance of highly unsaturated fatty acids (HUFAs) at the plant-animal interface. Studies have demonstrated a wide range of fatty acid profiles in primary producers, forcing her- bivorous zooplankton to differentially retain fatty acids to meet somatic requirements. Herbivores also vary in their somatic fatty acid profiles; cladocerans collect Eicosapen- taenoic Acid (EPA), copepods prefer Docosahexaenoic Acid (DHA). Fatty acid internal reserves can be broken down to meet structural needs (i.e. phospholipid synthesis), fuel reproduction and may play a role in cold weather adaptation. Several authors have noted increases in HUFA concentration with lowering ambient temperatures. Cladoceran membranes form a gel at lower temperatures, while copepod membranes remain fluid and allow active overwintering. Both fish and crustaceans accumulate high concentrations of HUFAs during periods of rapid growth, but colimitation with elemental resources may exist. Recent modeling results suggest food webs with high quality (nutritional and biochemical) primary producers can attain inverted biomass distributions with efficient energy transfer between trophic levels. The adoption rate for this material into man- agement studies remains low, and while other sectors of the scientific community thrive on the potential of HUFAs, planktonic food-web studies are choosing traditional view points over forward thinking. Bearing in mind the emerging hypotheses on the critical factors that drive the energy flow in the plant-animal interface, my dissertation will at- tempt to address the following general questions: What are the distinct signatures of food quality and food quantity on planktonic food web dynamics? How do nutritional and biochemical factors affect the flow of energy at the plant-animal interface? What is our current understanding of the role of highly unsaturated fatty acids (HUFAs) in aquatic food webs? To what extent can the current generation of plankton models reproduce the lower food web patterns when explicitly accounting for HUFAs? Is the integration of the HUFA role into water quality management models feasible? Explicitly accounting for HUFAs requires integrating factors of animal physiology with macro-ecology: what are the ramifications? Finally, what are the evolutionary aspects of animals coping with food quality?

An increasing number of contemporary studies in aquatic ecology emphasize the im- portance of highly unsaturated fatty acids (HUFAs) at the plant-animal interface. Studies have demonstrated a wide range of fatty acid profiles in primary producers, forcing her- bivorous zooplankton to differentially retain fatty acids to meet somatic requirements. Herbivores also vary in their somatic fatty acid profiles; cladocerans collect Eicosapen- taenoic Acid (EPA), copepods prefer Docosahexaenoic Acid (DHA). Fatty acid internal reserves can be broken down to meet structural needs (i.e. phospholipid synthesis), fuel reproduction and may play a role in cold weather adaptation. Several authors have noted increases in HUFA concentration with lowering ambient temperatures. Cladoceran membranes form a gel at lower temperatures, while copepod membranes remain fluid and allow active overwintering. Both fish and crustaceans accumulate high concentrations of HUFAs during periods of rapid growth, but colimitation with elemental resources may exist. Recent modeling results suggest food webs with high quality (nutritional and biochemical) primary producers can attain inverted biomass distributions with efficient energy transfer between trophic levels. The adoption rate for this material into man- agement studies remains low, and while other sectors of the scientific community thrive on the potential of HUFAs, planktonic food-web studies are choosing traditional view points over forward thinking. Bearing in mind the emerging hypotheses on the critical factors that drive the energy flow in the plant-animal interface, my dissertation will at- tempt to address the following general questions: What are the distinct signatures of food quality and food quantity on planktonic food web dynamics? How do nutritional and biochemical factors affect the flow of energy at the plant-animal interface? What is our current understanding of the role of highly unsaturated fatty acids (HUFAs) in aquatic food webs? To what extent can the current generation of plankton models reproduce the lower food web patterns when explicitly accounting for HUFAs? Is the integration of the HUFA role into water quality management models feasible? Explicitly accounting for HUFAs requires integrating factors of animal physiology with macro-ecology: what are the ramifications? Finally, what are the evolutionary aspects of animals coping with food quality?

Investigating the biosynthesis of long-chain (C20–24) polyunsaturated fatty acids (LC-PUFA), physiologically important compounds including arachidonic acid (ARA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), in fish is crucial to identify dietary requirements for essential fatty acids (EFA). Moreover, knowledge of the C20–24 LC-PUFA biosynthetic capability of farmed fish species enables us to understand their ability to utilise commonly used raw materials such as vegetable oils, which naturally lack LC-PUFA but include C18 PUFA that are metabolic precursors of LC-PUFA. Studies have shown that the potential of a species for LC-PUFA biosynthesis is associated with the complement and function of fatty acyl desaturase (fads) and elongase of very long chain fatty acid (elovl) genes existing in that species. The present study therefore aimed to investigate these genes in the African catfish (Clarias gariepinus), the most commercially important farmed fish in sub-Saharan Africa. A fads2, a fads6 and four elovl (elovl2, elovl4a, elovl4b, elovl8) cDNAs were cloned and functionally characterised by heterologous expression in yeast. The Fads2 was a bifunctional desaturase enzyme with ∆6∆5 and ∆8 activities, and thus catalysing all the desaturation reactions required for ARA and EPA biosynthesis from C18 precursor fatty acids. Moreover, the C. gariepinus Fads2 enzymes also desaturated 24:5n-3 to 24:6n-3, a ∆6 desaturation required for the biosynthesis of DHA through the so-called “Sprecher pathway”. Functional characterisation of Fads6 by heterologous expression in yeast did not reveal its function. With regards to elongases, the C. gariepinus Elovl2 demonstrated the ability to elongate C20 and C22 PUFA and thus complements the Elovl5 with elongase capability towards C18 and C20 PUFA. The Elovl8 was capable of only limited elongation of C18 and C20 PUFA. Elovl4a and Elovl4b, enable the biosynthesis of very long-chain (>C24) fatty acids, compounds with major roles in vision and fertility of vertebrates. The present study confirmed that C. gariepinus possess all the enzymatic capabilities required for the biosynthesis of ARA, EPA and DHA and, therefore, its physiological EFA requirements could be satisfied with dietary provision of C18 PUFA.

ARRUDA, Paulo Cesar Lopes de. Perfil de ácidos graxos no longissimus dorsi de ovinos Santa Inês em crescimento alimentados com diferentes níveis de energia. 2010. 35 f. : Dissertação (mestrado) - Universidade Federal do Ceará, Centro de Ciências Agrárias, Departamento de Zootecnia, Programa de Pós-Graduação em zootecnia, Fortaleza-CE, 2010. / Submitted by demia Maia (demiamlm@gmail.com) on 2016-08-09T16:01:52Z No. of bitstreams: 1 2010_dis_pclarruda.pdf: 252353 bytes, checksum: 42b6aec8d747282a28bc7c6268921d7b (MD5) / Approved for entry into archive by Nádja Goes (nmoraissoares@gmail.com) on 2016-08-10T15:15:59Z (GMT) No. of bitstreams: 1 2010_dis_pclarruda.pdf: 252353 bytes, checksum: 42b6aec8d747282a28bc7c6268921d7b (MD5) / Made available in DSpace on 2016-08-10T15:15:59Z (GMT). No. of bitstreams: 1 2010_dis_pclarruda.pdf: 252353 bytes, checksum: 42b6aec8d747282a28bc7c6268921d7b (MD5) Previous issue date: 2010 / This study evaluated the influence of rations with different levels of metabolizable energy on the content of total lipids, cholesterol and fatty acid profile of the longissimus dorsi of Santa Ines lambs. Twenty Santa Ines lambs were used, with age and body weight of 50 days and 13.0 kg ± 0.56 kg, respectively, fed rations with different energy levels: 2.08; 2.28; 2.47 e 2.69 Mcal/kgDM. The rations influenced the content of total lipids, cholesterol and fatty acid profile of cis 10 -, heptadecanoic and eicosanotrienoic (P<0.05). The relations polyunsaturated fatty acids (PUFA): saturated fatty acids (SFA); PUFA: monounsaturated fatty acids (MUA), MUA: SFA, desirable fatty acids, -6: -3, atherogenicity index, thrombogenicity index, relation between hypocholesterolemic and hypercholesterolemic fatty acids and the relation (C18:0+C18:1):C16:0 were not affected by energy levels (P> 0.05). The dietary manipulation influences the lipid profile in longissimus dorsi of Santa Ines lambs. / O presente estudo objetivou avaliar a influência de rações com diferentes níveis de energia metabolizável sobre o teor de totais, colesterol e perfil de ácidos graxos no músculo longissimus dorsi de cordeiros Santa Inês. Foram utilizados 20 cordeiros, com idade e peso de 50 dias e 13,0 kg ± 0,56 kg, respectivamente, alimentados com rações contendo diferentes níveis energéticos: 2,08; 2,28; 2,47 e 2,69 Mcal/kgMS. As rações influenciaram os teores de totais, colesterol total e o perfil do ácido graxo cis 10-, heptadecanóico e eicosanotrienóico (P<0,05). As relações ácidos graxos poliinsaturados (AGPI): ácidos graxos saturados (AGS); AGPI: ácidos graxos monoinsaturados (AGM); AGM: AGS; ácidos graxos desejáveis, -6:-3, índice de aterogenicidade, índice de trombogenicidade, relação entre os ácidos graxos hipercolesterolêmicos e hipocolesterolêmicos e a relação (C18:0 + C18:1) : C16:0 não foram influenciadas pelos níveis energético (P>0,05). A manipulação dietética influencia o perfil lipídico no longissimus dorsi de cordeiros Santa Inês.

Orientador: Dennys Esper Corrêa Cintra / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Aplicadas / Made available in DSpace on 2018-08-25T14:56:46Z (GMT). No. of bitstreams: 1 Lazari_VanessadeOliveira_M.pdf: 4172597 bytes, checksum: 62cbaf2cfa729f497e7b3cc4cdf3e7a1 (MD5) Previous issue date: 2013 / Resumo: A obesidade é uma doença metabólica absolutamente fora de controle. As condições primárias associadas são hipertensão arterial, dislipidemias, diversos tipos de câncer, resistência à insulina (RI) e principalmente o diabetes mellitus tipo 2 (DM2). Dentre as características secundárias, esteatose hepática e síndrome do ovário policístico figuram entre as principais. Tais doenças acometem número cada vez maior de indivíduos e sobrecarregam sistemas públicos mundiais de saúde. A inflamação crônica e de baixo grau, designada "meta-inflamação", por acometer todo o organismo, parece ser o pano de fundo principal do processo obesogênico, resultando no descontrole da ingestão alimentar e na predisposição ao surgimento da RI podendo progredir para o DM2. Diante da ineficiência de terapêuticas farmacológicas atuais para o controle da obesidade, o investimento em estratégias anti-inflamatórias tem sido incentivado. Nesse intuito, ácidos graxos insaturados (AGIs), especialmente os ômega-3 (?3) e ômega-9 (?9) têm-se mostrado eficientes em atenuar a inflamação por meio da ativação do receptor GPR120, e em recuperar a sensibilidade à insulina em diversos tecidos. O objetivo deste trabalho foi avaliar as ações e mecanismos anti-inflamatórios dos AGIs ?-linolênico (?3) e oléico (?9), presentes em elevadas concentrações no óleo de semente de linhaça e oliva respectivamente, em tecidos periféricos metabolicamente ativos de animais obesos e diabéticos induzidos por dieta rica em gordura (HF), e suas repercussões na regulação glicêmica do organismo. O tratamento via dieta HF com substituição em 10% da fração saturada pelos respectivos óleos, foi eficiente em restabelecer o controle da fome dos animais que consequentemente ganharam menos peso em relação aos seus controles obesos. Dados fisiológicos obtidos por meio de medições de glicemia de jejum e dos testes de tolerância à insulina (ITT) e à glicose (GTT) evidenciaram melhoras na homeostase glicêmica, confirmado em nível molecular pelo aumento da atividade das principais proteínas envolvidas na via da insulina como o IR, IRS-1 e Akt. Possivelmente esses resultados deram-se em virtude da redução da expressão de peptídeos pró-inflamatórios como TNF-?, IL-6 e IL-1?, seguidos pelo aumento da expressão da IL-10, de caráter anti-inflamatório. No fígado, a melhora na sensibilidade à insulina, resultou em inibição da enzima GSK-3 propiciando o restabelecimento do controle hepático sobre o metabolismo da glicose. Análises por hematoxilina/eosina (HE) e imunohistoquímica evidenciaram menor acumulação lipídica e redução da infiltração de macrófagos M1 no parênquima hepático, resultando em melhora do fenótipo de esteatose hepática macrovesicular e recuperação funcional deste tecido. Houve diminuição da hipertrofia dos adipócitos, fato que contribuiu com a remissão da inflamação. Foi verificada a presença do receptor GPR120 nestas células, permitindo, portanto a entrada dos AGIs. A técnica de espectrometria de massa atestou a incorporação dos AGIs de interesse no fígado, sustentando a hipótese de que os efeitos benéficos encontrados ocorreram em decorrência das ações destes nutrientes. Esses achados permitem concluir que fontes alimentares dos AGs ?3 e ?9 modulam de forma potente a resposta inflamatória no organismo. Tais ações são controladas pelo GPR120, receptor comum a esses AGs, e parecem ocorrer de maneira tecido-específica com repercussões sistêmicas, positivas para o controle glicêmico / Abstract: Obesity is characterized as a metabolic disease absolutely out of control which nowadays reaches epidemic levels. The diseases associated to thiscomorbid as hypertension, dyslipidemia, several kinds of cancer, insulin resistance (IR), type 2 diabetes (DM2) and secondary conditions as hepatic steatosis and polycystic ovary syndrome affect a large number of people,burdening the public health system. The low grade chronic inflammation seems to be the main cause of the obesogenic processes, resulting in an uncontrolled food intake and the predisposition for insulin resistance (IR), which can lead to type II diabetes. Once there is no effective pharmacological therapy to treat obesity so far, the investment in anti-inflammatory approaches has been encouraged. In this regard, unsaturated fatty acid, mostly 3-omega (?3) and 9-omega (?9) have been shown effective in decreasing the inflammatory process by activating its common receptor, the GPR120, by recuperating the insulin sensibility in several tissues resulting in improvements in the systemic glucose homeostasis. The purpose of this study was to evaluate the potential antiinflammatory effects of the fatty acids ?-linolenic(?3) and oleic (?9), found in high concentrations in flaxseed and olive oil respectively on active metabolic tissue as liver, skeletal muscle and white adipose tissue of obese and diabetic animals induced by high fat diet, as well as its effects on insulin signaling and glycemic regulation. The high fat treatment with 10% replacement of the saturated portion by ?3 or ?9 oil was effective in restoring the control of food intake in the animals, which consequently gained less weight compared to the obese group. Physiological data from fasting glycemic measure, insulin and glucose tolerance test (ITT and GTT) have showed improvements in the glycemic homeostasis, which was molecularly confirmed by the increase in the activity of the main proteins involved in the insulin signaling pathway as the IR, IRS-1 and AKT. We believe that these results are due to the decrease in proinflammatory peptides expression as TNF-?, IL-6 and IL-1? and increase in the IL-10 expression, known by its anti-inflammatory effects. Improvements in insulin sensitivity in liver resulted in GSK-3 inhibition culminating in the glucose hepatic metabolic reestablishing which contributes to restore the control of plasma glucose levels. Hematoxilin/Eosin (HE) and Immunohistochemistry analysis showed lower lipid accumulation and decreased macrophage infiltration in hepatic parenchyma corroborating the reducing in macrovesicular steatosis and functional recovering of this tissue. There was reduction in adipocyte size, which contributed to "meta-inflammation" remission. We could note the presence of GPR120 receptor in membrane of these cells probably allowing the ?3 and ?9 entry. Mass spectrometry technique attested high incorporation of these fatty acids in liver suggesting the beneficial effects found were due to these nutrients actions. These findings allow us to conclude that alimentary sources of ?3 and ?9 fattty acids modulate effectively the systemic inflammatory response, resulting in the insulin sensibility restoration and in the glucose tolerance improvement. Such nutrients have shown to be important therapeutic nutrigenomic tools against obesity and its associated comorbidities / Mestrado / Nutrição / Mestra em Ciências da Nutrição e do Esporte e Metabolismo

Derivatives of 3-methyl-1-2-benzothiazolinone hydrazone were formed from the oxidation products of three oxidized unsaturated fatty acids. Aeration with oxygen and heat (65C) was used as a means of accelerating deterioration of lipid samples. Formaldehyde was recovered from oxidized pure standards of oleic, linoleic and linolenic acid methyl esters , and identified using gas chromatography. Formaldehyde was also recovered from oxidized lipid extracts of mechanic ally deboned turkey meat and turkey cluster fat. Gas chromatography was used to measure concentrations of unsaturated fatty acids during the oxidation of extracted lipids. Linoleic and linolenic fatty acids significantly decreased (p < .005) in oxidized lipid extracts from turkey cluster fat stored frozen for six months. Measurement of the amounts of formaldehyde which accumulates as a result of the oxidation of unsaturated fatty acids, may be the most reliable method of assessing the extent of oxidative deterioration in foods.

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No description available.

Thesis (PhD (Food Science))--University of Stellenbosch, 2006. / Long-chain polyunsaturated fatty acids (LCPUFA), especially the n-3 LCPUFA metabolic products eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) play an important role as regulators in many biological processes. To date hake (Merluccius capensis) heads, a rich source of EPA and DHA, have been discarded at sea. The South African Fisheries Policy Development Committee concerned with the environmental impact of this practice has rendered it undesirable. The high prevalence of under-nutrition amongst children in South Africa can be addressed by the supplementation of their diet with this unexploited fish source. The aim of the current study was to develop a microbiologically safe and sensory acceptable sandwich spread using fish flour prepared from fish heads, as a prime ingredient. The intervention trial aimed to compare the effects of an increased dietary intake of n-3 LCPUFA, specifically DHA, on the blood fatty acid levels and absenteeism (as indicator of immune function), as well as the cognitive status, of the subjects. The microbiological content of the sandwich spread was determined after storage for 20 d at 5°C and 15 d at 25°C. Sensory evaluation was performed by consumers (n = 95; M:F = 44:51; 6 – 9 yr) to determine acceptance of the five different flavours individually incorporated into the sandwich spread to mask the fishy note and to provide different flavour options. For the intervention trial subjects (n = 351) were stratified within class group (A - E) and gender and randomly assigned to two treatment categories, an experimental group (EG; n = 174) receiving 25 g sandwich spread.d-1 (191.66 mg DHA. d-1) and a control group (CG; n = 177) receiving an analogous placebo. On school days (104 d), each subject received two sandwiches consisting of two slices of bread (ca. 60 g), spread with 25 g of either the placebo or the experimental spread. Blood samples were drawn at baseline and post intervention. Plasma fatty acid and red blood cell (RBC) membrane status, C-reactive protein levels, as well as vitamin and micronutrient status, were determined. Trained test administrators conducted a battery of cognitive tests. According to South African Government health standards, the sandwich spread remained microbiologically safe after storage. Male and female consumer respondents revealed a significant difference between gender preferences of the five different spread flavours (p <0.05). Significant treatment effects (p <0.05) were observed in n-3 LCPUFA status of the EG, as well as for their absenteeism from school. The two subtests of the Hopkins Verbal Learning test, Recognition and Discrimination Index, showed significant differences between the EG and CG (p <0.05) post intervention in the Grade 2 subjects. The Spelling tests also showed a significant difference between the two groups (p <0.05). In the current study a microbiologically safe and sensory acceptable sandwich spread was developed and tested during an intervention trial, and could possibly in future, provide a healthier option in the School Nutritional Programme. This study proved that supplementation of children (6 - 9 yr) with n-3 LCPUFA, with specific reference to EPA and DHA from a marine source, could have a beneficial effect on their fatty acid status and absenteeism from school. Based on the outcomes of the Hopkins Verbal Learning test and Spelling test, the current study proved that an n-3 fatty acid-rich spread improved the learning ability and memory of children.

Fish meal (FM) and fish oil (FO) have traditionally been central in aquaculture feed formulation but the finite global supply situation limiting future use along with issues of contaminant levels in these feed ingredients have become critical issues. The objectives of the present study were to investigate alternative feed ingredients as substitutes for both FM and FO in feeds for Atlantic salmon (Salmo salar) to ensure optimal growth, feed efficiency and health of the fish as well as maintaining the nutritional quality of the fish product to the human consumer, especially the levels of n-3 highly unsaturated fatty acid (HUFA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), in the flesh. The results of the present study revealed that there were no negative effects on growth performance, feed utilisation and apparent digestibility in Atlantic salmon when FO was substituted with vegetable oil (VO) but these parameters were affected when FM was replaced with alternative protein sources from plants and animals at high levels, despite dietary supplementation with crystalline amino acids and lecithin. Reduction in feed intake was a factor affecting growth retardation when FM inclusion decreased. However, replacing FM with alternative plant and animal proteins along with partial replacement of FO had no major effect on nutritional quality, particularly n-3 HUFA content of salmon tissues. Replacing Northern FO with decontaminated FO or blends of southern hemisphere FO and VOs strategies to reduce POP contaminants and retain high nutritional values in flesh were very successful. Dietary treatments and genetic origin of fish both had effects on tissue compositions and gene expression. All fish groups (strain/family), consist of CAL, LEAN and FAT strains, fed a diet containing VO showed significant differential expression of lipid metabolism-related genes compared to fish fed a FO diet with LEAN strain appearing to adapt to VO inclusion better than FAT strain. This thesis has demonstrated dual replacement of FM and FO with alternative raw materials in salmon feeds without a major negative impact on nutritional quality.