Adição de óleos de copaíba (Copaifera langisdorffii) e sucupira (Pterodon emarginatus) na alimentação de poedeiras: estabilidade lipídica de gema de ovos armazenados em diferentes temperaturas

O objetivo deste trabalho foi avaliar a atividade antioxidante da adição de óleos de copaíba (CP) e sucupira (SC) na alimentação de poedeiras sobre a oxidação lipídica de ovos in natura armazenados em temperatura ambiente (TA) por 30 dias e sob refrigeração (R) a 4ºC por 60 dias, e de gemas cozidas mantidas sob R por 30 dias. As poedeiras foram alimentadas com ração isoproteica (15% PB) e isoenergética (2900 kcal kg-1) à base de milho e farelo de soja, com inclusão de óleo de Copaifera langsdorffii (CP) nas proporções de 0,03; 0,06 e 0,09% ou de Pterodon emarginatus (SC) nas proporções de 0,03 e 0,06%, mais um controle negativo (CN). Foram coletados 667 ovos às 37 semanas de idade e distribuídos aleatoriamente nas diferentes condições de armazenamento (TA ou R). A oxidação dos lipídios de ovos in natura foi quantificada em quadruplicata e das gemas cozidas em duplicata, utilizando-se “pool” de 3 gemas/tratamento para as análises de TBARS (thiobarbituric acid reactive substances). Os dados foram avaliados adotando um modelo misto e as médias foram comparadas pelo teste de Tukey em 5% de nível de significância e o período de armazenamento foi considerado como um fator longitudinal, variando de cinco tempos no experimento com gemas cozidas, e nos ovos in natura sob R e em TA (0 a 30 dias), até nove tempos sob R (0 a 60 dias). Foi observado que a adição de óleo de CP e SC não reduziu os valores de TBARS em ovos in natura armazenados em TA e sob R em relação ao CN. No armazenamento de gemas cozidas, a inclusão CP (0,03 e 0,06%) protegeu os lipídios até os 21 dias, mas apresentou efeito pró-oxidante quando suplementado a 0,09%. Concluiu-se que a inclusão de até 0,06% de óleorresina de CP nas rações de poedeiras pode proteger os lipídios da gema cozida contra a oxidação durante o armazenamento refrigerado por até 21 dias. The aim of this study was to evaluate the antioxidant effect of dietary supplementation of plant oil resins in laying hens on the oxidative stability of cooked egg yolk kept at 4ºC for 30 days, and fresh eggs stored under refrigeration (R) at the same temperature for 60 days or kept in room temperature (RT) for 30 days. Hens were fed corn- and soybean-based diets (15% CP and 2,900 kcal kg-1) and supplemented with two levels of Copaifera langsdorffii oil resin (CP-0.03; 0.06 and 0.09%) or Pterodon emarginatus oil resin (SC-0.03 and 0.06%), plus a negative control (CN). At 37 weeks of age, 667 eggs were collected and randomly distributed in different storage conditions, in natura or cooked. The progression of lipid oxidation of egg yolk in natura was quantified in quadruplicate and cooked egg yolks in duplicate, using pool of 3 egg yolks/treatment to analyze TBARS (thiobarbituric acid reactive substances) concentration in quadruplicate. Data analysis was performed using a mixed model and Tukey test, at a 5% significance level. The storage period was considered a longitudinal factor, which varied from five times, for R cooked yolk and TA fresh yolk (0-30 days), to nine times, for R fresh yolk (0-60 days). For fresh eggs stored at RT or R, the supplementation of plant oils did not protect egg yolks from lipid oxidation, compared to NC. However, for cooked egg yolks, the addition of 0.03 and 0.06% of CP oil resin showed antioxidant activity since it reduced lipid oxidation up to day 21 of storage, but had a prooxidant effect for 0.09%. Therefore, it can be concluded that the supplementation of copaíba oil resin had an antioxidant protection of cooked egg lipids

Antioxidant activity of cerrado’s byproducts : oxidative stability and chicken meat quality

Dissertação (mestrado)—Universidade de Brasília, Faculdade de Agronomia e Medicina Veterinária, 2014.Foram conduzidos 2 experimentos avaliando a estabilidade oxidativa e a qualidade física da carne de frangos suplementados dieteticamente com 4 extratos de plantas do Cerrado. Cada experimento utilizou 350 frangos que receberam rações com os extratos de barbatimão (BAR) e pacari (PAC), experimento 1; e sucupira (SUC) e copaíba (COP), experimento 2. Cada extrato foi fornecido em 3 dosagens 200, 400 e 600 ppm (experimento 1); e 500, 900 e 1300 ppm (experimento 2) e comparado a um tratamento controle negativo (CONT), sem adição de extratos. Ao final dos experimentos de campo, 10 animais de cada tratamento foram abatidos e as carnes do peito e da coxa e sobrecoxa foram coletadas e mantidas refrigeradas por 24 horas. Decorrido esse tempo, parte da carne de cada tratamento foi embalada à vácuo e congelada, e outra parte foi utilizada para avaliação da composição centesimal, pH e cor e, adicionalmente para o peito, perda de peso por cocção (PPC) e força de cisalhamento (CIS). As carnes congeladas foram utilizadas para a confecção de almôndegas pré-cozidas para a análise de estabilidade oxidativa durante armazenamento refrigerado. Para essa análise foram avaliados separadamente as carnes do peito e do complexo coxa e sobrecoxa para cada um dos experimentos, totalizando 4 ensaios, nos quais foram determinados periodicamente a concentração de TBARS (Thiobarbituric reactive substances). Os resultados foram analisados utilizando o programa estatístico SAS. No experimento 1, para a carne do peito, os tratamentos com BAR e PAC reduziram (P<0,05) umidade (UM) e lipídios totais (LPT) em comparação ao CONT, enquanto o oposto ocorreu para proteína bruta (PB). Para a carne da coxa e sobrecoxa, BAR e PAC elevaram (P<0,05) a PB e matéria mineral (MM) em comparação ao CONT. A adição de BAR e PAC afetou (P<0,05) as médias de L*, b*, PPC e CIS. Para a carne do complexo coxa-sobrecoxa, somente PAC200 apresentou diferença de CONT, pois elevou (P<0,05) os valores de L* e b*. Com relação a carne do peito do experimento 2, a adição de SUC e COP provocou um aumento (P<0,05) na UM e PB comparados ao CONT, exceto para SUC500 e SUC900; e uma redução nas médias de LPT e de MM comparados ao CONT, exceto para SUC500, COP900 e COP1300. Para a carne da coxa e sobrecoxa, SUC e COP aumentaram (P<0,05) a UM em comparação ao CONT. Para a qualidade da carne do peito, SUC e COP reduziram (P<0,05) PPC e para a carne da coxa e sobrecoxa, somente L* apresentou diferença estatística. Para a análise de oxidação lipídica para a carne do peito e do complexo coxa-sobrecoxa dos 2 experimentos, nenhum dos extratos foi eficiente na proteção dos lipídios da carne do peito, coxa e sobrecoxa quando comparados a seus respectivos CONT.The objective of this study was to evaluate oxidative stability and physical quality of chicken breast and thigh meat. In two experiments, with 350 broilers each, animals were fed diets supplemented with 4 plant extracts from Cerrado biome, barbatimão (BAR) and pacari (PAC) were used in experiment1 and sucupira (SUC) and copaiba (COP) in experiment 2. Extracts were used in 3 dosages: 200, 400 and 600 ppm for experiment 1; and 500, 900 and 1300 ppm for experiment 2. Each experiment had a negative control treatment (CONT), without plant extracts. At the end of each field experiment, 10 birds per treatment were slaughtered, breast and thigh meat were collected and chilled at 4°C for 24 hours. After this time, a part of the meat was vacuum-packaged and stored frozen and the other part was used to evaluate centesimal composition, pH and color and additionally cooking weight loss (PPC) and shear force (CIS) for breast meat. The previously frozen meat was used to make precooked meatballs for oxidative stability studies during four refrigerated storage trials. Periodically, TBARS (Thiobarbituric reactive substances) concentration was determined in quadruplicate in each sample. Results were analyzed with SAS statistical software. For breast meat (exp. 1), treatments with BAR and PAC reduced (p<0.05) humidity (UM) and total lipid (LPT) in comparison to CONT, meanwhile the opposite happened for crude protein (PB). For thigh meat, BAR and PAC increased (p<0.05) PB and mineral matter (MM) in comparison to CONT. Inclusion of BAR and PAC affected (p<0.05) L* and b* values. For breast meat (exp.2), the inclusion of SUC and COP increased (p<0.05) UM and PB in comparison to CONT, except for SUC500 and SUC900; and reduced LPT and MM means compared to CONT, except for SUC500, COP900 and COP1300. For thigh meat, SUC and COP increased (p<0.05) UM compared to CONT. Analyzing breast meat, SUC and COP reduced (p<0.05) PPC and for thigh meat only variable L* was affected (p<0.05) by extract supplementation. None of the dietary extracts supplementation for both experiments was effective on reducing lipid oxidation in breast and thigh meat according to results

Direct Amidation of Carboxylic Acids Catalyzed by <i>ortho</i>-Iodo Arylboronic Acids: Catalyst Optimization, Scope, and Preliminary Mechanistic Study Supporting a Peculiar Halogen Acceleration Effect

The importance of amides as a component of biomolecules and synthetic products motivates the development of catalytic, direct amidation methods employing free carboxylic acids and amines that circumvent the need for stoichiometric activation or coupling reagents. <i>ortho</i>-Iodophenylboronic acid <b>4a</b> has recently been shown to catalyze direct amidation reactions at room temperature in the presence of 4A molecular sieves as dehydrating agent. Herein, the arene core of <i>ortho</i>-iodoarylboronic acid catalysts has been optimized with regards to the electronic effects of ring substitution. Contrary to the expectation, it was found that electron-donating substituents are preferable, in particular, an alkoxy substituent positioned para to the iodide. The optimal new catalyst, 5-methoxy-2-iodophenylboronic acid (MIBA, <b>4f</b>), was demonstrated to be kinetically more active than the parent des-methoxy catalyst <b>4a</b>, providing higher yields of amide products in shorter reaction times under mild conditions at ambient temperature. Catalyst <b>4f</b> is recyclable and promotes the formation of amides from aliphatic carboxylic acids and amines, and from heteroaromatic carboxylic acids and other functionalized substrates containing moieties like a free phenol, indole and pyridine. Mechanistic studies demonstrated the essential role of molecular sieves in this complex amidation process. The effect of substrate stoichiometry, concentration, and measurement of the catalyst order led to a possible catalytic cycle based on the presumed formation of an acylborate intermediate. The need for an electronically enriched <i>ortho</i>-iodo substituent in catalyst <b>4f</b> supports a recent theoretical study (Marcelli, T. <i>Angew. Chem. Int. Ed.</i> <b>2010</b>, <i>49</i>, 6840–6843) with a purported role for the iodide as a hydrogen-bond acceptor in the orthoaminal transition state

Dietary Brazilian red pepper essential oil on pork meat quality and lipid oxidation

ABSTRACT: The purpose of this study was to evaluate the effects of feeding pigs with diets containing increasing levels of Brazilian red pepper essential oil ( Schinus terebinthifolius Raddi) on the physical attributes, fatty acid profile and oxidative stability of precooked meat. Seventy-two weanling pigs (5.7±0.8kg) were allotted in a completely randomized block design experiment with four treatments, six replicates per treatment, and three animals per experimental unit (pen). Animals were fed with a basal diet supplemented with 0, 500, 1,000, or 1,500mg kg-1 Brazilian red pepper essential oil during the 35-d experimental period. At the end of the experiment, one animal per experimental unit (16.4±2.2kg) was slaughtered to sample Longissimus dorsi muscle for analysis. Dietary supplementation of Brazilian red pepper had no effect (P>0.05) on pork meat color, pH, cooking loss and shear force. Inclusion of essential oil in the diet provided a linear increase (P<0.05) of the saturated fatty acids content of L. dorsi, especially myristic (C14:0) and stearic (C18:0) fatty acids. Utilization of essential oil in pig diets reduced significantly the production of secondary lipid oxidation compounds measured as TBARS in raw pork meat (P<0.001) and immediately after cooking (P<0.001). However, during 8-d storage assay, the addition of essential oil in the diet did not protect pork meat lipids from oxidation. Therefore, Brazilian red pepper added to pig diets increased the saturated fatty acids content and reduced lipid oxidation in fresh meat and short-term heat treatment without affecting pork meat physical attributes