Structured phospholipids with conjugated linolenic acid were produced for potential applications in nutraceuticals and functional foods. Structured phospholipids were synthesized with conjugated linolenic acid (CLnA) from natural sources by catalytic enzymatic reaction. Pomegranate seed oil, as a natural source of CLnA, and an isomerized-concentrated mixture (ICM) of CLnA from flaxseed oil were used for the enzymatic reaction with phosphotidylcholine (PC) using Liposyme TL IM for fatty acid modification at 57 °C for 96 h. The enzymatic process was an effective way to produce structured phospholipids with CLnA. The maximum incorporation of CLnA from pomegranate seed oil and ICM from flaxseed oil into PC was 11.3% and 4.9% after 72 h, respectively. Structured lysophospholipids were also obtained as a result of the enzymatic reaction. The maximum incorporation of CLnA from pomegranate oil and ICM from flaxseed oil into lysophospholipids was 17.2% and 13.5% after 72h, respectively. Physical properties such as dropping point and viscosity at 40 and 50 °C of the structured phospholipids produced were measured when they were added to a chocolate mixture (unsweetened chocolate 94.6%, coconut oil 5% and 0.4 % phospholipids). Two controls were used for comparison: the chocolate mixture without phospholipids and the chocolate mixture with Lipoid S100 (phosphatidylcholine 94%). Structured phospholipids with CLnA showed lower dropping point and viscosities than the controls. Oil-in-water emulsions were prepared with whey protein (1%), soy bean oil (10%) and phospholipids (0.5%) in a high pressure homogenizer at 20MPa. The emulsion stability of the emulsions prepared, control (without phospholipids), Lipoid S 100 and structured phospholipids with CLnA were determined by visual observation of phase separation. The structured phospholipids emulsion showed higher emulsion stability than the controls. This emulsion was stable up to 108 h while the emulsion without phospholipid and Lipoid S100 were 48 h and 96 h stable, respectively. Oxidative stability of the emulsions prepared was determined by measuring the peroxide value and p-anisidine value after 1, 3 and 7 days at 50 °C. Oil was extracted from the emulsions using isooctane:isopropanol (3:2 v/v). The structured phospholipid emulsions showed lower oxidative stability than the controls.

Structured phospholipids with conjugated linolenic acid were produced for potential applications in nutraceuticals and functional foods. Structured phospholipids were synthesized with conjugated linolenic acid (CLnA) from natural sources by catalytic enzymatic reaction. Pomegranate seed oil, as a natural source of CLnA, and an isomerized-concentrated mixture (ICM) of CLnA from flaxseed oil were used for the enzymatic reaction with phosphotidylcholine (PC) using Liposyme TL IM for fatty acid modification at 57 °C for 96 h. The enzymatic process was an effective way to produce structured phospholipids with CLnA. The maximum incorporation of CLnA from pomegranate seed oil and ICM from flaxseed oil into PC was 11.3% and 4.9% after 72 h, respectively. Structured lysophospholipids were also obtained as a result of the enzymatic reaction. The maximum incorporation of CLnA from pomegranate oil and ICM from flaxseed oil into lysophospholipids was 17.2% and 13.5% after 72h, respectively. Physical properties such as dropping point and viscosity at 40 and 50 °C of the structured phospholipids produced were measured when they were added to a chocolate mixture (unsweetened chocolate 94.6%, coconut oil 5% and 0.4 % phospholipids). Two controls were used for comparison: the chocolate mixture without phospholipids and the chocolate mixture with Lipoid S100 (phosphatidylcholine 94%). Structured phospholipids with CLnA showed lower dropping point and viscosities than the controls. Oil-in-water emulsions were prepared with whey protein (1%), soy bean oil (10%) and phospholipids (0.5%) in a high pressure homogenizer at 20MPa. The emulsion stability of the emulsions prepared, control (without phospholipids), Lipoid S 100 and structured phospholipids with CLnA were determined by visual observation of phase separation. The structured phospholipids emulsion showed higher emulsion stability than the controls. This emulsion was stable up to 108 h while the emulsion without phospholipid and Lipoid S100 were 48 h and 96 h stable, respectively. Oxidative stability of the emulsions prepared was determined by measuring the peroxide value and p-anisidine value after 1, 3 and 7 days at 50 °C. Oil was extracted from the emulsions using isooctane:isopropanol (3:2 v/v). The structured phospholipid emulsions showed lower oxidative stability than the controls.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The objective of the present work was to evaluate the effect of dietary linseed oil with or without injection of sodium selenite upon fatty acid profile and oxidative stability of milk from dairy cows as well as the acceptance of the milk and the increasing order of preference by the evaluators. Chapter 1 describes the experiment where fourteen cows were allocated into four treatments: Group 1 which received daily 400 mL of linseed oil (LIN); Group 2, 400 mL of linseed oil + 0.2 mg/BW sodium selenite IM (LINSe); Group 3, untreated controls (C). The oil was supplied daily after 15 days of de single application of sodium selenite. Treatments lasted 4 weeks. Linseed oil supplemented animals produced milk with higher levels of conjugated linoleic acid and omega 3 but also more susceptible to oxidation. The application of sodium selenite was effective to prevent premature oxidation of milk. Chapter 2 describes the acceptance and increasing order of preference by the evaluators. The evaluators were not able to identify differences in color, odor and flavor among samples of milk from treated and control groups in relation to a known standard. The inclusion of linseed oil on the cows diet promotes and increase in CLA and omega 3 in milk, which in turn becomes more susceptible to oxidation, requiring the use of antioxidants. Even though causing biochemicals alterations, the addition of 400 mL daily of linseed oil in the diet of dairy cows is not capable of causing sensory changes in milk. / O presente trabalho descreve as avaliações feitas no leite de vacas leiteiras submetidas a suplementação com óleo de linhaça na dieta, com ou sem injeção de selenito de sódio, quanto ao perfil de ácidos graxos, estabilidade oxidativa e em relação às propriedades organolépticas do leite. O capítulo 1 descreve o experimento em que catorze vacas foram distribuídas em três tratamentos: Grupo 1, que recebeu diariamente 400 mL de óleo de linhaça (LIN); Grupo 2, 400 mL de óleo de linhaça + 0,2 mg / Kg de selenito de sódio IM (LINSe) e Grupo 3 controles não tratados (C). O óleo foi fornecido diariamente após 15 dias da aplicação única de selenito de sódio, e o experimento teve duração de quatro semanas. Foram feitas análises do perfil de ácidos graxos e de reações ao ácido tiobarbitúrico, que mede a estabilidade oxidativa do produto. Os animais suplementados com o óleo de linhaça produziram leite com altos níveis de ácido linoleico conjugado e de ômega 3, contudo, mais suscetível à oxidação. A aplicação injetável de selenito de sódio mostrou-se eficaz ao impedir a oxidação prematura do leite. O capítulo 2 descreve o experimento onde se verificou a aceitação e a ordem crescente de preferência pelos avaliadores, de amostras de leite, através de análises de cor, odor e sabor. Catorze vacas foram distribuídas em três tratamentos: Grupo 1, que recebeu diariamente 400 mL de óleo de linhaça (LIN), Grupo 2, 400 mL de óleo de linhaça + 0,2 mg /Kg de selenito de sódio IM (LINSe) e Grupo 3 controles não tratados (C). O óleo foi fornecido diariamente após 15 dias da aplicação única de selenito de sódio, e o experimento teve duração de dez semanas. O resultado deste estudo foi de que os avaliadores não foram capazes de identificar diferenças de cor, odor e sabor entre as amostras de leite dos grupos tratados e do controle, em relação a um padrão conhecido. Assim, concluiu-se que a inclusão do óleo de linhaça na dieta de vacas leiteiras resulta em aumento do CLA, ômega 3 e consequentemente da oxidação do leite, necessitando assim o uso de substâncias antioxidantes ou promotores antioxidantes, como o selenito de sódio injetável para retardar a oxidação. Entretanto, a inclusão de 400 mL diários de óleo de linhaça na dieta de vacas leiteiras não é capaz de provocar alterações sensoriais no leite.