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1.
São Paulo; s.n; s.n; 2008. 162 p. tab, graf, ilus.
Thesis in Portuguese | LILACS | ID: biblio-837334

ABSTRACT

O leite humano é um alimento completo, possui todos os nutrientes em quantidade e qualidade necessárias, proporciona proteção contra infecções e alergias e estimula o sistema imunológico. Os lipídios do leite humano são fonte energética; veículos para as vitaminas lipossolúveis; contêm ácidos graxos poliinsaturados necessários para o desenvolvimento cerebral; contêm precursores de prostaglandinas e hormônios; e são constituintes essenciais para as membranas celulares. Muitas mães, por razões médicas, metabólicas ou econômicas, dependem de fórmulas artificiais para alimentar seus filhos. Portanto, a composição dos ácidos graxos e a sua distribuição nas cadeias dos triacilgliceróis devem ser alvos de estudos em fórmulas infantis, sendo que os triacilgliceróis do leite humano devem servir de modelo para os componentes lipídicos. Recentemente, diversos estudos apontam a interesterificação como alternativa para a produção de sucedâneos da gordura do leite humano. Assim, o objetivo deste trabalho foi explorar diversas possibilidades da modificação lipídica para a obtenção deste sucedâneo. As matérias-primas utilizadas foram banha e óleo de soja, gorduras facilmente obtidas e de baixo custo no Brasil. Neste trabalho, foram produzidos lipídios estruturados por interesterificação química e enzimática, sendo que na interesterificação enzimática foram utilizadas duas lipases puras, a AY30TM (Candida cylindracea) e a M10TM (Mucor circinelloides), e a lipase imobilizada Lipozyme TL IM (Thermomices lanuginosa). Os lipídios estruturados foram submetidos a análises de suas propriedades químicas e físicas, que foram comparadas às propriedades da gordura do leite humano e do lipídio estruturado comercial BetapolTM. Os resultados apresentados demonstraram a viabilidade da interesterificação como método de modificação para obtenção de lipídios estruturados sucedâneos da gordura do leite humano. Tendo em vista a possibilidade de maior controle reacional devido à especificidade das lipases e a busca por processos ambientalmente corretos, a interesterificação enzimática mostra-se alternativa mais interessante para esta modificação lipídica. A mistura de banha e óleo de soja demonstrou ser opção viável para a produção de sucedâneos da gordura do leite humano


Human milk is a complete food with all the nutrients in quantity and quality provides protection against infections and allergies and stimulates the immune system. The lipids of human milk are source of energy; vehicles for liposoluble vitamins; contain polyunsaturated fatty acids for brain development; contain precursors of prostaglandins, hormones; and are essential constituents to the cell membranes. Many mothers, for medical, metabolic or economic reasons, depend on artificial formulas to feed their children. Therefore, the composition of fatty acids and their distribution chains in the triacylglycerols must be targets of studies on infant formula, and the human milk triacylglycerols should be a model for the lipid components. Recently, several studies indicate the interesterification like an alternative for the production of substitutes of human milk fat. The objective of this study was to explore various possibilities of lipid modification to achieve this substitute. The raw materials used were lard and soybean oil, fats easily obtained and cheap in Brazil. In this work, were produced structured lipids by chemical and enzymatic interesterification. For enzymatic interesterification were used two pure lipases, AY30 TM (Candida cylindracea) and M10 (M (Mucor circinelloides) and one immobilized lipase, Lipozyme TL IM (Thermomices lanuginosa). The structured lipids were submitted to analysis of their chemical and physical properties, which were compared with the human milk fat and the structured commercial lipid Betapol TM. The results demonstrated the feasibility of interesterification as a method of modification to obtain structured lipids substitutes of human milk fat. The possibility of greater control reaction because the specificity of lipases and the search for environmentally correct procedures makes enzymatic interesterification the most attractive alternative for modifying lipids. The mixture of soybean oil and lard is a viable alternative for the production of human milk fat substitutes


Subject(s)
Humans , Female , Soybean Oil/adverse effects , Breast-Milk Substitutes , Vegetable Fats , Breast Feeding/instrumentation , Dietary Fats/analysis , Fatty Acids, Unsaturated , Immune System/immunology , Lipids/chemical synthesis
2.
Braz. j. med. biol. res ; 34(5): 627-631, May 2001. ilus
Article in English | LILACS | ID: lil-285878

ABSTRACT

2-Hydroxybutyric acid appears at high concentrations in situations related to deficient energy metabolism (e.g., birth asphyxia) and also in inherited metabolic diseases affecting the central nervous system during neonatal development, such as "cerebral" lactic acidosis, glutaric aciduria type II, dihydrolipoyl dehydrogenase (E3) deficiency, and propionic acidemia. The present study was carried out to determine the effect of 2-hydroxybutyric acid at various concentrations (1-10 mM) on CO2 production and lipid synthesis from labeled substrates in cerebral cortex of 30-day-old Wistar rats in vitro. CO2 production was significantly inhibited (30-70 percent) by 2-hydroxybutyric acid in cerebral cortex prisms, in total homogenates and in the mitochondrial fraction. We also demonstrated a significant inhibition of lipid synthesis (20-45 percent) in cerebral cortex prisms and total homogenates in the presence of 2-hydroxybutyric acid. However, no inhibition of lipid synthesis occurred in homogenates free of nuclei and mitochondria. The results indicate an impairment of mitochondrial energy metabolism caused by 2-hydroxybutyric acid, a fact that may secondarily lead to reduction of lipid synthesis. It is possible that these findings may be associated with the neuropathophysiology of the situations where 2-hydroxybutyric acid is accumulated


Subject(s)
Animals , Rats , Carbon Dioxide/metabolism , Cerebral Cortex/drug effects , Energy Metabolism , Hydroxybutyrates/pharmacology , Lipids/chemical synthesis , Analysis of Variance , Hydroxybutyrates/chemistry , Mitochondria/metabolism , Rats, Wistar
3.
Medical Journal of Islamic World Academy of Sciences. 1998; 10 (1): 13-18
in English | IMEMR | ID: emr-48674
4.
Hamdard Medicus. 1997; 40 (2): 62-66
in English | IMEMR | ID: emr-44733

ABSTRACT

Production of lipids by Mucor mucedo was studied in a medium containing glucose and carrot waste as the carbon source. Growth and lipid synthesis were influenced by different factors like temperature, incubation period and sugar concentration. The mycelial weight and the lipids% was lower in carrot waste medium under the optimum conditions. However, the chemical composition of the lipids was almost the same in both cases. The general composition of the lipids showed that the proportion of neutral to polar lipids increased [range 30% -55%] with the incubation period. Among the polar lipids a significant amount of phosphatidylethanolamine [PE] and phosphatidyl serine [PS] was found


Subject(s)
Lipids/chemical synthesis , Lipids/chemistry , Temperature
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