Apesar da eficácia dos antimicrobianos como melhoradores no desempenho animal, questões relativas à seleção de microorganismos resistentes e transferência desses para o consumo humano de carne vêem trazendo uma crescente preocupação que tem provocado diminuição do seu uso. Assim, há necessidade da busca de alternativas, destacando-se as ervas medicinais, as quais apresentam ações, antimicrobiana, antioxidante, imunomodulatória e ainda, estimulante da secreção de enzimas digestivas. O objetivo do estudo foi avaliar a ação de um fito composto, produzido pela adição de partes aéreas secas e trituradas de plantas medicinais (Rosmarinus officinalis, Mentha piperita, Lippia sidoides e Lychnophora pinaster), em leitões, desde a creche até o abate, sobre parâmetros de desempenho, freqüência de diarréia, eliminação fecal de salmonelas, lesões histopatológicas intestinais e oxidação lipídica da carcaça. Os animais foram submetidos a duas situações: uma de desafio experimental (D, com inoculação de Salmonella typhimurium aos 35 dias de idade) e outra sem desafio (SD), permanecendo ambos grupos em salas isoladas. O delineamento experimental foi inteiramente casualizado, com arranjo fatorial 3x2, sendo um fator o desafio, e outro, a suplementação de aditivos na ração (fito composto FITO; antibióticos ATB; e controle negativo, sem adição de promotores CTRL). Foram alojados 120 leitões recém-desmamados aos 21 dias de idade, na unidade de creche do Laboratório de Pesquisa em Suínos. Os animais foram pesados aos 21, 35, 49, 63 dias (creche) aos 96 e 106 dias (crescimento) e 131 dias de idade (terminação), e verificado o consumo de ração. Foi avaliada a freqüência de dias com diarréia (FDD) na creche, além da eliminação fecal de S. typhimurium, observando-se lesões histopatológicas causadas pela bactéria no trato entérico, e oxidação lipídica da carcaça aos 131 dias de idade. Não houve interação entre aditivos e desafio para nenhuma variável estudada. O peso médio (PM) do grupo ATB foi mais elevado durante todos os períodos em relação a FITO e CTRL, e estes não diferiram entre si; no entanto, aos 96 e 106 dias, o PM dos animais CTRL foi maior que FITO. De 21 a 35 dias de idade, a conversão alimentar (CA) do grupo ATB foi significativamente menor que CTRL; no entanto, FITO promoveu valor intermediário, não diferindo estatisticamente de ambos. O desafio experimental levou à queda no consumo diário de ração (CDR) de 35 a 48 dias. No entanto, no período final de crescimento, houve um efeito compensatório sobre as variáveis de desempenho, sendo PM, ganho diário de peso (GDP), CDR e CA significativamente melhores na sala D. Ainda, nesse período, na sala D, todas essas variáveis foram melhores para FITO, apesar da diferença ser meramente numérica, sugerindo efeito compensatório desse aditivo. O ATB promoveu menor FDD dos 21 aos 48 dias; no entanto, dos 35 aos 48 dias, FITO promoveu uma melhora mais rápida no quadro que CTRL. Não houve influência dos aditivos sobre a eliminação fecal de salmonelas, lesões histopatológicas no trato entérico ou sobre a oxidação lipídica na carcaça. Assim, a melhor CA na creche, e o efeito compensatório no final da fase de crescimento justificam futuras pesquisas sobre a ação do produto. / Despite the proven efficiency of antibiotics as growth promoters, issues associated to selection of microbial resistance and its impact over human health are rising concern between consumers and decreasing their use. Therefore, alternatives must be found, and medical herbs, with antimicrobial, antioxidant, immunomodulatory and stimulatory of digestives enzymes properties, seem promising. This study was carried out in order to evaluate the action of a phyogenic compound of medical herbs (Rosmarinus officinalis, Mentha piperita, Lippia sidoides and Lychnophora pinaster) towards piglets from weaning to slaughter, on performance parameters (body weight BW; average daily gain ADG; average daily feed intake ADFI; and feed conversion FC), frequency of diarrhea, fecal shedding of salmonellas, gut hystopatological lesions and lipid oxidation of meat, either under a challenged condition (C) or a non-challenged condition (NC). Experimental challenge consisted of oral administration of Salmonella typhimurium to piglets, at 35 days of age. Both groups were kept in isolated rooms. Experimental design was at random, and the treatments distributed in a 3x2 factorial arrangement. Factors were: challenge (C and NC) and additives (phytogenic compound PHYTO; antibiotic ATB; and control CTRL). 120 weaned piglets (21 days years old) were housed at nursery unit of Laboratory of Researche in Swine (LPS), and weighted at 21, 35, 49, 63 (nursery), 96, 105 (growing) and 131 (finishing) days of age. There was not interaction between factors. BW of ATB group was higher througout the experimental period. From 21 to 35 days of age, FC of ATB group was significantly lower than CTRL; however, PHYTO showed intermediary value, which did not statistically differ from both ATB and CTRL. Challenge caused lower ADFI from day 35 to 48. Nevertheless, at the final of growing period (96 to 105 days of age), there was a compensatory effect on performance, and animals out of C room had showed better values of BW, ADG, ADFI, FC than NC. At C room, such parameters were better for animals out of PHYTO group (although the differences were merely numerical), suggesting thus a compensatory effect of this compound. ATB has lead to lower FDD from day 21 to 48; however, from day 35 to 48, FDD of PHYTO group was lower than CTRL. There was not effect of additives on fecal shedding of salmonellas and on lipd oxidation of carcass. Further studies on the effect of the phyto compound must be carried out, especially during the growing and finishing periods.

A atividade antioxidante de dois extratos comerciais de alecrim e chá verde foi comparada com a atividade do sintético BHA para substituição total do sintético em hambúrguer de frango. A quantificação foi determinada pelos métodos Folin-Ciocalteau, FRAP e DPPH. De acordo com as análises de atividade antioxidante, as dosagens dos extratos naturais foram determinadas, utilizando-se como base o limite de dosagem do BHA (0,01% base gordura) e aplicadas em hambúrgueres de frango: T1: Controle; T2: 0,002% BHA; T3: 0,0038% Chá Verde; T4: 0,001% Chá Verde; T5: 0,048% Alecrim; T6: 0,00186% Alecrim. Foram realizadas análises de composição centesimal e pH e análises de estabilidade no armazenamento congelado: rendimento e redução do diâmetro, índice de TBARs, cor objetiva (parâmetros L*, a* e b*) e teste sensorial de aceitação. No método Folin-Ciocalteau, das análises de atividade antioxidante, o BHA não apresentou diferença com o chá verde (p > 0,05), no método FRAP o melhor (p < 0,05) desempenho foi do BHA e no DPPH o chá verde apresentou maior atividade (p < 0,05). Os resultados de TBARS, nos hambúrgueres, mostraram diferença significativa entre as amostras e também interação amostras x tempo do armazenamento (p < 0,05), sendo que após 120 dias o teste com maior dosagem do extrato de alecrim (T5) não diferiu do sintético (T2) (0,423 e 0,369 índice de TBARs, respectivamente). No aspecto sensorial as amostras não diferiram entre si (p>0,05) nem durante todo o período de armazenamento (p > 0,05). Dentro das condições experimentais pode-se afirmar que o extrato comercial de alecrim pode substituir totalmente o antioxidante BHA em hambúrguer de frango, garantindo a mesma estabilidade oxidativa e sem interferir em sua aceitação sensorial. / The antioxidant activity of two commercial extracts, rosemary and green tea, were compared with the activity of the synthetic BHA for total replacement of the synthetic in chicken burger. The spectrometric quantification was determined by UV - VIS methods: Folin - Ciocalteu , FRAP and DPPH . In the Folin-Ciocalteau method the BHA showed no difference with green tea (p > 0.05), in the FRAP method the BHA obtained better (p < 0.05) performance and for DPPH the green tea showed greater activity (p < 0.05). According to the analysis of antioxidant activity, dosages of natural extracts were determined, using as basis the limit dosage of BHA (0.01 % fat base) and applied in chicken burgers: T1: Control, T2: 0.002 % BHA, T3: 0.0038 % Green Tea, T4: 0.001 % Green Tea, T5: 0.048 % Rosemary and T6: 0.00186 % Rosemary. Chemical-physical analysis of chemical composition and pH were made, and also stability analysis: cooking loss and reducing the diameter, TBARs index, objective color (parameters L *, a * and b *) and sensory acceptance test. The results of TBARS showed a significant difference between samples and also samples interaction x storage time (p < 0.05), after 120 days the test with higher dosage of rosemary extract (T5) did not differ from synthetic (T2) (0.423 and 0.369 TBARS index, respectively), thus better performance than the other tests. The sensory evaluation results showed that the samples did not differ during the storage period (p > 0.05). According the experimental conditions can be concluded that the commercial rosemary extract can completely replace the antioxidant BHA.

Este estudo foi estruturado em cinco capítulos. No capítulo I temos um breve referencial teórico sobre a importância da carne de frango, os mecanismos da oxidação lipídica e a utilização de antioxidantes naturais. O capítulo II traz os ensaios da avaliação da atividade antioxidante in vitro do mel e das especiarias orégano (Origamum vulgare L.) e sálvia (Salvia officinalis L.) durante a vida de prateleira. Os resultados de fenólicos totais do orégano indicaram um aumento de 1154,09 a 1611,28 mgEAG/100g (O a 12 meses), na sálvia os valores variaram entre 1309,8 a 2032,4 mgEAG/100g no decorrer do tempo (O a 12 meses) e no meios valores medidos foram 1007,1; 1830,4 e 2129,9 mg/100g/EAG para tempos 0,6 e 12 meses, respectivamente. Os resultados da porcentagem da inibição da oxidação lipídica (% IOL), pelo sistema (β-caroteno/ácido linoléico mostrou que a sálvia inibiu a oxidação em 74,6, 81,3 e 81,3%, nos tempos (O, 6 e 12 meses) e o orégano apresentou valores de inibição de (43,2, 63,3 e 50,7%). Quando se avaliou o índice de atividade antioxidante (IAA) utilizando o aparelho Rancimat, a sálvia apresentou um índice de atividade antioxidante (3,35) superior aos demais, que apresentaram 1,69, 1,25 e 1,08 para o BHT, orégano e mel, respectivamente. Os resultados do ensaio da capacidade de absorbância do radical oxigênio (ORAC) revelou que o orégano apresentou valores de 544,6, 430,7 e 1019,6 ET μmol/g, nos tempos 0, 6 e 12 meses, respectivamente. A sálvia apresentou valores de ORAC de: 610,45(0 mês), 467,44(6 meses) e 822,21(12 meses) e no mel foram de: 47,3; 22,4 e 26,1 ET μmol/g, nos tempos 0, 6 e 12 meses. Comparando estes resultados com os descritos na literatura podemos concluir que as especiarias e o mel possuem alto potencial antioxidante. No capítulo III mostramos a influência dos compostos bioativos da sálvia e de orégano na proteção da oxidação lipídica em substrato microssomal de carne de frango. As concentrações médias de TBARS (μMol de MDA/mg de proteína) observadas nas amostras de peito foram: controle (7,45); BHT (1,91) e orégano + sálvia (3,45) e na carne de sobrecoxa, observou-se os seguintes resultados: controle (9,83); BHT (4,27); orégano + sálvia (3, 15). Os tratamentos (BHT e orégano+sálvia) atingiram o ápice de inibição no tempo de 3 horas (82,42 % e 82,25 %), respectivamente. Porém quando analisamos a inibição da oxidação lipídica na fração microssomal da carne de sobrecoxa, o tratamento BHT apresentou o seu ápice de inibição (66,50 %) no tempo de 1 hora de indução e o tratamento orégano + sálvia alcançou a maior porcentagem de inibição no tempo de 3 horas (82,25 %). Os resultados da inibição da oxidação lipídica durante o período de indução mostram que em relação ao controle, os tratamentos realizados apresentaram influência positiva na proteção da oxidação lipídica em substrato microssomal de carne de peito de frango. No capítulo IV avaliamos o efeito de especiarias e mel na proteção da oxidação lipídica em sistema modelo homogenato de carne de frango refrigerada. Os resultados de atividade de água nos homogenatos de peito e sobrecoxa (crus ou cozidos) o tratamento (orégano+sálvia+10%Mel) reduziu a quantidade de água livre durante o tempo de refrigeração. Em relação aos valores de pH nos homogenatos de peito notou-se uma elevação nos valores de pH durante o período de refrigeração, em todos os tratamentos avaliados. Na carne de sobrecoxa os valores de pH foram maiores aos observados na carne de peito. Nos homogenatos de peito cru observou-se uma perda acentuada de umidade em todos os tratamentos, e particularmente em todos os tempos de refrigeração. Nas amostras de peito cozido não foram observadas diferenças significativas na umidade entre os tratamentos controle e orégano+sálvia+5%Mel. Nos homogenatos de sobrecoxa crua os valores de umidade variaram entre 60,82 e 66,96 g/100 g. Os teores de mioglobina nos homogenatos de peito cru variaram entre 1,95 % a 2,01 % no tempo 0. Ao final de 96 horas de refrigeração, a porcentagem de Mb variou entre 1,85 e 1,96, com redução das concentrações nas amostras tratados com especiarias e mel. Comportamento diferente foi apresentado nos homogenatos de peito cozido, onde após 96 horas de refrigeração observou-se aumento das concentrações de mioglobina em todos os tratamentos avaliados, com exceção do homogenato contendo orégano+sálvia+10% de mel. Em relação aos valores de metamioglobina (% MMb) para os homogenatos de peito crus e cozidos observou-se pequenas variações ao longo do tempo de refrigeração. Nas amostras de peito cru, as concentrações de oximioglobina (%O2Mb) apresentaram-se similares após 96 horas de refrigeração nos tratamentos controle, BHT e orégano+sálvia. Já nas amostras cozidas, os resultados foram similares entre as amostras controle e BHT. Nas amostras de sobrecoxa cruas, após 96 horas de refrigeração, observou-se redução das concentrações de metamioglobina (% MMb) e elevação dos teores de· mioglobina (% Mb) para todos os tratamentos avaliados. Nas amostras submetidas ao preparo térmico, ao contrário dos homogenatos crus, os teores de metarnioglobina (% MMb) elevaram-se após 96 horas de refrigeração nos tratamentos BHT e orégano+sálvia, permanecendo estáveis nos demais. Nos resultados da inibição da oxidação lipídica da carne de peito cozida durante o tempo de refrigeração, observamos que em relação ao controle, os tratamentos realizados apresentaram influência positiva. O tratamento com BHT inibiução oxidação em 51,4 % no tempo 0 e após 48 horas 74,3 %. Atingiu o ápice de inibição no tempo de 96 horas com 77,7 %. Dentre os tratamentos avaliados, o contendo orégano+sálvia+l0%Mel foi o mais efetivo contra a oxidação em relação aos demais. Nas amostras de sobrecoxa cozida, o tratamento BHT, não inibiu a oxidação em relação ao controle no tempo 0. Entretanto, nos outros tempos ocorreu um efeito protetor de 78,1 após 48 horas e 76,3 % após 96 horas de refrigeração. Nos tratamentos com especiarias, novamente o tratamento com orégano+sálvia+10%Mel foi o mais eficaz, com efeito protetor de 98%. No capítulo V avaliou-se o efeito da combinação de especiarias e mel na estabilidade oxidativa em carne de frango assada e refrigerada. Ao final das 96 horas, as amostras com adição de especiarias e mel apresentaram valores de TBARs mais baixos em relação ao controle e ao BHT, sugerindo que a sálvia, o orégano e o mel tenham exercido efeito antioxidante durante o experimento. Quando avaliamos os resultados da análise de dienos conjugados e hexanal, todas as amostras analisadas apresentaram um acréscimo nos valores dos dienos e de hexanal para todos os tempos de refrigeração. O tratamento que apresentou os menores valores de hexanal após 96 horas de refrigeração foi o (orégano+sálvia+5% de mel), seguido de (orégano+sálvia+10% de mel). Durante o processamento e ao longo do tempo de estocagem foram encontrados apenas traços dos óxidos (25-0H, 7-Ceto, 7α-OH e 7β-OH), com exceção apenas para o tratamento BHT no tempo de 48 horas (sobrecoxa assada) onde foi quantificada a presença de 7α-OH. Quando avaliamos os resultados dos ácidos graxos poli saturados da carne de peito, observamos alterações significativas nos tratamentos BHT, orégano+sálvia e orégano+sálvia+10%mel, provavelmente ocasionada pela refrigeração. Nas amostras de sobrecoxa, foram observados efeitos de interação entre tratamentos e tempos de refrigeração para todas as classes de ácidos graxos (saturados, insaturados, monoinsaturados e polinsaturados). As amostras oferecidas na análise sensorial receberam notas acima da nota de corte, no entanto, a maior parcela dos provadores atribuiu notas altas às amostras submetidas aos tratamentos com especiarias e mel. Os resultados obtidos neste estudo reafirmam a hipótese de que os compostos bioativos da sálvia, orégano e do mel foram capazes de inibir a oxidação lipídica, em todas as amostras. / This study has been structured into five chapters. Chapter I provides a brief historical theoretical reference point regarding the importance of chicken meat, the mechanisms of lipid oxidation and the use of natural antioxidants. Chapter II presents trials evaluating the in vitro antioxidant activity, of honey and the spices oregano (Origanum vulgare L.) and sage (Salvia officinalis L.) over their shelf life. The results for oregano indicated an increase in total phenols from 1154.09 to 1611.28 mg of gallic acid equivalent (GAE)/100 g (0 to 12 months). For sage, the values changed from 1309.8 to 2032.4 mg GAE/100 g over the period (0 to 12 months) and for honey, the values measured were 1007.1, 1830.4 and 2129.9 mg GAE/100 g at the times of 0,6 and 12 months, respectively. The results relating to the percentage inhibition of lipid oxidation(% ILO) by the β-carotene/linoleic acid system showed that sage inhibited oxidation by 74.6, 81.3 and 81.3% at the times of 0,6 and 12 months, while oregano presented inhibition values of 43.2, 63.3 and 50.7%. Evaluation of the antioxidant activity index (AAI) using the Rancimat apparatus showed that the AAI for sage (3.35) was greater than the indices for the other agents, which were 1.69, 1.25 and 1.08 for BHT, oregano and honey, respectively. The results from testing the oxygen radical absorbance capacity (ORAC) showed that oregano presented values of 544.6, 430.7 and 1019.6 TE μmol/g at the times of 0,6 and 12 months, respectively. Sage presented ORAC values of 610.45, 467.44 and 822.21 at the times of 0,6 and 12 months and honey presented 47.3, 22.4 and 26.1 ET μmol/g, at the times of 0,6 and 12 months. Comparing these results with those described in the literature, it can be concluded that these herbs and honey have high potential as antioxidants. Chapter III shows the influence of the bioactive compounds in sage and oregano for protection against lipid oxidation, in a microsomal substrate of chicken meat. The mean concentrations of TBARS (μmol of MDA/mg of protein) observed in the breast meat samples were, for the control, 7.45; for BHT, 1.91; and for oregano+sage, 3.45. In the thigh meat samples, the following results were observed: control (9.83); BHT (4.27); oregano+sage (3.15). The treatments (BHT and oregano+sage) reached their peak inhibition after three hours (82.42% and 82.25%, respectively). However, analysis of the inhibition of lipid oxidation in the microsomal fraction of the thigh meat showed that the BHT treatment reached its peak inhibition (66.50%) after one hour of induction and the oregano+sage treatment reached its peak inhibition after three hours (82.25%). The results relating to inhibition of lipid oxidation during the induction period showed that, in relation to the control, the treatments implemented had a positive influence regarding protection against lipid oxidation in a microsomal substrate of chicken breast meat. Chapter IV evaluates the effect of spices and honey with regard to protecting against lipid oxidation in a system consisting of a homogenate model of chilled chicken meat. The results from water action on the breast and thigh meat homogenates (either, raw or cooked) showed that the treatment (oregano+sage+10%honey) reduced the quantity of free water over the period of refrigeration. With regard to the pH values in the breast meat homogenates, it was seen that they rose over the period of refrigeration, in all the treatments evaluated. In the thigh meat, the pH values were higher than those observed in the breast meat. In the homogenates of raw breast meat, a marked loss of moisture was observed in all of the treatments and, particularly, at all durations of refrigeration. In the samples of cooked breast meat, no significant differences in moisture were seen between the control and the treatment with oreganó+sage+5%honey. In the homogenates of raw thigh meat, the moisture values ranged from 60.82 to 66.96 g/100 g. The myoglobin content in the homogenates of raw breast meat ranged from 1.95% to 2.01% at time zero. After 96 hours of refrigeration, the percentage myoglobin ranged from 1.85 to 1.96, with lower concentrations in the samples treated with spices and honey. A different pattern of behavior was presented by the homogenates of cooked breast meat, in which after 96 hours of refrigeration, higher concentrations of myoglobin were observed in all the treatments evaluated, with the exception of the homogenate containing oregano+sage+10%honey. With regard to the met myoglobin values (% MMb) for the homogenates of raw and cooked breast meat, small variations were observed over the refrigeration period. In the samples of raw breast meat, the oxymyoglobin concentrations (% O2Mb) were similar after 96 hours of refrigeration in the control and BHT and oregano+sage treatments. On the other hand, in the cooked samples, the results were similar between the control and BHT samples. In the raw thigh meat samples after 96 hours of refrigeration, it was observed that the met myoglobin concentration (% MMb) was lower and the myoglobin content (% Mb) was higher, for all the treatments evaluated. In the samples that were subjected to cooking, contrasting with the raw homogenates, the metmyoglobin content (% MMb) was higher after 96 hours in the BHT and oregano+sage treatments, while it remained stable in the other samples. The results relating to inhibition of lipid oxidation in the cooked breast meat over the refrigeration period showed that, in relation to the control, the treatments had a positive influence. The treatment with BHT inhibited oxidation by 51.4% at time zero and by 74.3% after 48 hours. The peak inhibition was reached after 96 hours, with 77.7%. Among the treatments evaluated, the one containing oregano+sage+10%honey was the most effective treatment against oxidation, in relation to the others. Among the samples of cooked thigh meat, the BHT treatment did not inhibit oxidation in relation to the control at time zero. However, at the other times, there was a protective effect of 78.1% after 48 hours and 76.3% after 96 hours of refrigeration. Among the treatments with spices, the one with oregano+sage+10%honey was again the most effective treatment, with a protective effect of 98%. Chapter V evaluates the effect of combinations of spices and honey on the oxidative stability of roasted and chilled chicken meat. After 96 hours, the samples with added herbs and honey presented TBARS values that were lower than in the control and BHT samples, thus suggesting that sage, oregano and honey had an antioxidant effect during the experiment. Evaluation of the results from analyzing the conjugated dienes and hexanal concentrations showed that all of the samples analyzed presented increased diene and hexanal leveIs at all durations of refrigeration. The treatment that presented the lowest hexanal values after 96 hours of refrigeration was oregano+sage+5%honey, folIowed by oregano+sage+10%honey. During the processing and over the course of storage, only traces of oxides were found (25-OH, 7-keto, 7 α -OH and 7 β-OH), with the sole exception of the BHT treatment on roast thigh meat after 48 hours, in which the presence of 7 α -OH was quantified. Evaluation of the results relating to polyunsaturated fatty acids in the breast meat showed significant changes in the BHT, oregano+sage and oregano+sage+10%honey treatments, probably caused by the refrigeration. In the samples of thigh meat, interaction effects between the treatments and duration of refrigeration were observed for all classes of fatty acids (saturated, unsaturated, monounsaturated and polyunsaturated). The samples offered in the sensory analysis received scores that were above the cutoff score, but most of the testers attributed high scores to the treatments with herbs and honey. The results obtained from this study reaffirm the hypothesis that the bioactive compounds in sage, oregano and honey were capable of inhibiting lipid oxidation in all the samples.

Background: There has been very little research regarding the metabolic health of women during the postpartum period. Metabolic flexibility is the physiological ability to alter substrate oxidation in response to substrate availability and is a good indicator of overall metabolic health. Metabolic flexibility can be assessed by placing metabolic demands on the body and observing metabolic responsiveness- two examples of such metabolic stressors are lipid oxidation rates in response to a high-fat meal and as well as exercise. However, it is unknown whether postpartum women will respond similarly to these two different types of metabolic stressors. This information will allow researchers and clinicians to understand whether postpartum women can be considered more or less metabolically flexible based on one of these tests alone, or if both types of metabolic stress should be incorporated into research designs and/or clinical practice to fully understand one’s metabolic health during this critical time period. Objective: To determine the association between the metabolic responsiveness to a high-fat meal and a 30- minute continuous, moderate-intensity exercise among women during the sixth- month postpartum period. Methods: Seventeen healthy, postpartum women (age: 32 ± 4.5 year; body mass index: 24.74 ± 3.97 kg/m²) participated approximately six months after delivery. Metabolic measurements VO2 and VCO2 (L. min ̄ ¹) were measured and used to calculate the rates of lipid oxidation (g. min ̄ ¹) at baseline, two-hour post consumption of a high-fat meal and during a moderate-intensity exercise for 30-minutes. Results: A correlation was found between the lipid oxidation fold change in response to a high-fat meal and exercise (r= 0.45, p= 0.08; however, it was not statistically significant. There was a significant effect of time on lipid and carbohydrate oxidation rates (p<0.001) during baseline, after consumption of a high-fat meal and during a 30-minute exercise bout. Conclusion: A trending relationship was observed between the metabolic responsiveness to a high-fat meal and a 30-minute moderate-intensity exercise bout among women during the six-month postpartum

Fresh beef was modified-atmosphere packaged in carbon monoxide or oxygen to prolong red surface color. After comparison of several packaging method using carbon monoxide, steaks pretreated with 5% carbon monoxide for 24 hours and then vacuum packaged had the best combination of color and microbial stability (5 weeks), with the least potential for carbon monoxide inhalation. In the evaluation of ground beef in high-oxygen, modified-atmosphere-packaging, thiobarbituric-acid numbers increased over time, and the flavor was disliked slightly after 6 or 10 days of storage at 2° Celsius. The antioxidant effect of milk-mineral was tested in raw and cooked ground pork stored refrigerated or frozen. Thiobarbituric-acid numbers were low for all raw treatments. For cooked ground pork, thiobarbituric-acid numbers were lower for samples with milk-mineral or sodium-tripolyphosphate, compared to control or samples with butylated-hydroxytoluene. Sodium-tripolyphosphate, a type 2 antioxidant (iron chelator), was also very effective in preventing heme degradation during refrigerated storage.

Gallic acid esters (GAE) of varying alkyl chain length were used to determine how antioxidant physical location and partitioning influence hemoglobin-catalyzed lipid oxidation. Specific GAE used were propyl gallate (PG), octyl gallate (OG), and lauryl gallate (LG). GAE partitioning experiments were performed with either isolated cod muscle membranes or washed cod muscle, which primarily contain polar membrane lipids and myofibrillar proteins. Canola oil was used in some experiments to determine how neutral lipids impact partitioning behavior. GAE distribution was determined spectrophotometrically in the recovered membranes, aqueous phase, and oil layer after employing differential centrifugation. Oxidation was monitored by measuring thiobarbituric acid reactive substances (TBARS) and lipid hydroperoxides development.When GAE were added to the membrane suspensions, significant differences (p < 0.05) in GAE partitioning were observed in the aqueous phase and membrane sediment, where increases in GAE alkyl chain length corresponded with a decrease in aqueous phase concentrations and increases in the membranes. GAE partitioning in the oil fraction did not show significant differences. Also, increases in GAE alkyl chain correlated with increases in GAE membrane detection when GAE were added to the washed fish muscle (p < 0.05).Adding GAE to the washed cod muscle before the canola oil was the most effective sequence of addition for extending the storage time before lipid oxidation was detected. Among the three GAE tested, PG showed the greatest inhibition against lipid oxidation. The effectiveness of the GAE in the washed cod-canola oil system follows the order, PG > OG > LG, which corresponds with decreasing hydrophobicity.The conclusions of this study are twofold. First, GAE partitioning into the muscle membranes was not the primary factor for delaying the onset of lipid oxidation. Rather, solubility in the aqueous phase showed the greatest impact on extending storage time. Secondly, the order in which GAE and canola oil were added to the washed cod (WC) muscle system influenced hemoglobin-catalyzed lipid oxidation behavior. Adding GAE before the neutral oil may have allowed the GAE to partition more easily into the polar regions of the washed muscle, which in turn provided the most effective protection against oxidation.

Quercetin-3-O-glucoside (Q3G), a glycosylated derivative of quercetin, is a polyphenolic compound known to possess diverse biological activities. Its moderately hydrophilic nature is a critical factor governing the accessibility to the active sites of oxidative damages in vivo. It was hypothesized that biological activities of Q3G can be further enhanced by regioselective acylation with fatty acids which gives more lipophilicity. Q3G was acylated with six selected long chain fatty acids: stearic acid, oleic acid, linoleic acid, ?-linolenic acid, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA), using Candida antactica lipase. The derivatives were evaluated for their potential in inhibiting lipid oxidation in food systems and human low density lipoprotein (LDL), and cytoprotection and anti-inflammatory effect in cell culture model systems. The fatty acid derivatives of Q3G possessed greater effectiveness in inhibiting lipid oxidation in oil-in-water emulsions, and better cytoprotective effect against H2O2- and cigarette smoke toxicant-induced cytotoxicity when compared to Q3G.

The oxidation of lipids and antioxidants has been extensively studied in human plasma but little attention has been given to how plasma proteins are oxidised. Proteins make up the majority of biomolecules in cells and plasma and therefore are the most likely reactants with oxidants and free radicals. Previous studies in the laboratory had shown that peroxyl radicals generated by the thermolytic decay of 2-azobis (2-amdinopropane) dihydrochloride (AAPH) generated significant amounts of protein hydroperoxides, but only after a six hour lag period. In this study the existence of the six hour lag period was confirmed and shown by dialysis of the plasma to be due to the presence of low molecular weight antioxidants. The addition of both uric acid and ascorbic acid to the dialysed plasma restored the lag phase suggesting that in vivo these antioxidants act to prevent protein hydroperoxide formation. Lipid oxidation was also observed in the plasma but only after a two hour lag phase. This was the first time lipid oxidation has been observed in the absence of protein oxidation. The lipid lag phase was also abolished by dialysis of the plasma and restored by the addition of ascorbic acid and uric acid. The kinetics of tocopherol loss suggests that the tocopherol radicals act to inhibit lipid oxidation by transferring the electrons to the water-soluble ascorbate. The loss of ascorbate appears to cause the formation of a tocopherol radical mediate the lipid peroxidation process. Overall the data shows ascorbic acid scavenging the peroxyl radicals while uric acid acts to reduce the overall AAPH generated radical flux. In a separate investigation, the production of protein-bound DOPA (PB-DOPA) on albumin during X-ray radiolysis and copper mediate Fenton oxidation was investigated using a fluorescence based derivatisation method (ED-DOPA), which was compared with the more specific acid hydrolysis and HPLC analysis method. The ED-DOPA method consistently gave a much higher reading that the HPLC based methods, suggesting that the ED-DOPA method was measuring DOPA plus DOPA oxidation products. This was confirmed by oxidising X-ray radiolysis generated PB-DOPA with Cu++ to cause DOPA oxidation. The Cu++ treatment drastically increased the level of signal given by the ED-DOPA assay while HPLC analysis showed all the DOPA had been oxidised.

Orientador: Maria Regina Barbieri de Carvalho / Banca: José Paschoal Batistuti / Banca: Maria da Penha Longo Mortatti Catanozi / Banca: Rose Meire Vidotti / Banca: Lea Silvia Santana / Resumo: O objetivo deste trabalho foi elaborar um produto cárneo a partir da CMS de tilápia-do- Nilo contendo os antioxidantes naturais: alecrim, orégano, sálvia e moringa e o antioxidante sintético propil galato, visando sua utilização como recheio ou acompanhamento da refeição. As degradações químicas e microbiológicas constituem os principais fatores de deterioração dos alimentos, sendo a oxidação um dos mais importantes processos de degradação por gerar sabores e odores desagradáveis. Como forma de prevenir ou retardar a oxidação, são adicionados ao alimento substâncias antioxidantes, e os condimentos têm demonstrado certo poder antioxidante, oferecendo uma alternativa ao uso de antioxidantes sintéticos. A composição centesimal, avaliação microbiológica e análise sensorial foram realizadas no início e final do armazenamento e, periodicamente foram determinados TBARS, BNVT, pH, cor instrumental e contagem de microrganismos psicrotróficos. Os resultados mostraram que os diferentes antioxidantes influenciaram o índice de oxidação lipídica e os valores de pH durante o período de armazenamento da CMS. Os valores de pH ficaram compreendidos entre 6,17 e 6,55 e os valores iniciais de malonaldeído foram semelhantes no início e a com orégano apresentou a menor oxidação (0,158 mg de MDA.kg-1 ), a qual foi acompanhada pela que continha sálvia (0,186 mg de MDA.kg-1 ). A maior oxidação, neste período, foi verificada para a CMS sem antioxidante, e o alecrim e moringa foram os antioxidantes naturais menos efetivos. Os valores da intensidade de vermelho (a*) para as CMS elaboradas sem antioxidante e com alecrim não apresentaram alterações durante o armazenamento e os valores de BNVT (11,41 a 12,35 mgN.100g-1 ) não foram alterados com os condimentos. Considerando o efeito dos antioxidantes x armazenamento os recheios apresentaram valores diferentes de pH quando ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The aim of this study is to evaluate the efficiency of oregano, sage, moringa and rosemary as natural antioxidants and propyl gallate as artificial antioxidant used in stuffed food made with minced fish of tilapia and stored frozen for 120 days. Chemistry and microbiological degradations are the main causes of food deterioration, and oxidation is one of the most important process of degradation because it can generate unpleasant flavor. Lipid oxidation is one of the most important alterations that affect both oils or fats and foods that contain them, as a way to prevent or retard oxidation, antioxidant substances are added in the food. The condiments have demonstrated antioxidant activity and offer an alternative in order to replace synthetic antioxidants. Protein, fat, moisture and ashes determination, microbiological analysis and sensory evaluations were conducted in the beginning and the end of storage period. TBARS, BNVT, pH, instrumental color and psychrotrophic microorganism count were determined periodically. The antioxidants interfered in pH (6,17 and 6,55) and TBARS values during 120 days under freezing (-18 o C). The lowest TBA values were found for oregano (0,158 mg de MDA.kg-1 ) and sage (0,186 mg de MDA.kg-1 ). The stuffed food made with minced fish of tilapia, without antioxidant, had the most oxidation, and sage and moringa were not good source of antioxidant. Red color (a*), in products with rosemary and control, and BNVT values (11,41 - 12,35 mgN.100g-1 ) were not altered. The lowest pH value was found for the product with sage (6,20), but similar to the moringa and propyl gallate, while oregano and rosemary showed the highest values (6,63 and 6,29), at 5 days of storage. Microbiological analyses were in accordance with Brazilian legislation. Sensory evaluation indicated that the panelists preferred the formulations made with oregano and propyl gallate. The results showed ... (Complete abstract click electronic access below) / Doutor

Made available in DSpace on 2014-06-11T19:22:23Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-01-27Bitstream added on 2014-06-13T19:48:40Z : No. of bitstreams: 1 fogaca_fhs_me_jabo.pdf: 596326 bytes, checksum: 558f30e4e45f55982f56059d2fab70b4 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Universidade Estadual Paulista (UNESP) / A vitamina E é usada nas dietas com a finalidade de melhorar o crescimento, a resistência ao estresse e a doenças, assim como a sobrevivência de peixes. Também pode ser eficiente na conservação do pescado durante o processamento e estocagem, inibindo a degradação dos lipídios pela oxidação. O presente trabalho avaliou os efeitos antioxidantes da vitamina E in vivo e in vitro na qualidade final dos hambúrgueres produzidos com filés de tilápias congelados durante 0, 30, 60 e 90 dias. Foi utilizado um delineamento inteiramente casualizado, com seis tratamentos, em esquema fatorial 3x2, caracterizado pela suplementação de dois níveis de vitamina E nas dietas (100 e 200 mg / kg de ração) e o grupo controle (zero mg/kg de ração) e adição ou não de 100 ppm de vitamina E aos hambúrgueres, com quatro repetições. Os peixes, com peso médio inicial de 184,23 + 1,68g foram alimentados com as dietas experimentais durante 63 dias. Após esse período, foram abatidos e os filés processados em hambúrgueres. Foram avaliados os parâmetros de desempenho, composição centesimal e a oxidação lipídica, determinada pelas substâncias reativas ao ácido tiobarbitúrico (SRATB). Os resultados mostraram que não houve diferença significativa para as variáveis de ganho de peso, conversão alimentar e crescimento específico entre os tratamentos. A composição química variou dentro dos valores encontrados para pescados. O aumento do nível de vitamina E promoveu redução nos valores de SRATB das amostras em todos os intervalos de tempo, e que a adição in vivo da vitamina E protegeu os hambúrgueres da oxidação lipídica de forma mais eficiente do que a adição in vitro, sendo que a interação entre ambas resultou em maior redução nas taxas de oxidação. / Vitamin E is used in diets with the aim of enhancing growth, resistance to stress and pathology, and also fish survival. It can be efficient in fish conservation during processing and frozen storage, inhibiting lipid degradation from oxidation. The present work evaluated the antioxidant effects of vitamin E utilization in vivo and in vitro in the final quality of hamburgers made from tilapia filets during frozen storage over 3 months. A randomized design, in a 3x2 factorial scheme was utilized, which correspond to the two levels of diet vitamin E (100 and 200 mg / kg diet) and the control group (zero mg/kg diet) and addition or not of 100 ppm of vitamin E to the hamburgers, with four repetitions. The fishes, with initial weight 184.23 + 1.68 g, were fed the experimental diets for 63 days, after which they were killed and processed into hamburgers. The performance parameters analyzed were centesimal composition and lipid oxidation, determined by the thiobarbituric acid reactive substances (TBARS). The results showed no significant difference between treatments for weight gain, food conversion or specific growth. The chemical composition varied within the values found for fish. Increased vitamin E levels promoted reduction of TBARS values over all time intervals. This means values suggested that the addition in vivo of tocopherol protected the hamburgers from lipid oxidation more efficiently when compared to in vitro addition, but the interaction between both resulted in higher reduction in rate of oxidation.