RESUMO
Maternal colostrum provides the neonate with immunoglobulins, essential for passive immunity. However, storage and handling of colostrum can alter its physical and nutritional characteristics. The aim of this study was to evaluate the effects of three conservation methods on colostrum density, pH, total antioxidant capacity (TAC), protein (PP) and lipid peroxidation (LP). Colostrum samples were collected from 15 Bos indicus cows, and divided into three aliquots for storage using three methods: refrigeration at 4°C, freezing at -20°C, and lyophilization. For each method, four evaluation times were performed: day (d) 5, 10, 15, and 20 for refrigeration and d 15, 30, 45, and 60 for freezing and lyophilization. pH and density analyses were performed at each evaluation time for each method. On d 0 and 15 of storage, TAC, LP, and PP analyses were performed. A generalized linear model, Tukey's test for means comparisons, and a Pearson correlation analysis were conducted. A decrease in refrigerated colostrum pH was observed on d 15. Density of the lyophilized colostrum decreased, as compared with that of frozen colostrum. Lyophilization exhibited the lower PP values of samples, whereas refrigeration presented the highest values of LP and PP. No differences in colostrum TAC were observed between storage methods. A positive correlation between PP and colostrum density and a negative correlation between colostrum density and TAC were found. It was concluded that both freezing and lyophilization are suitable storage methods for bovine colostrum, as they limit proteins and lipids oxidation, and maintain the TAC of fresh colostrum.
O colostro materno fornece ao recém-nascido imunoglobulinas que são essenciais para a imunidade passiva. No entanto, o armazenamento e o manuseio do colostro podem alterar suas características físicas e nutricionais. O objetivo deste estudo foi avaliar os efeitos de três métodos de conservação na densidade, pH, capacidade antioxidante total (CAT), peroxidação protéica (PP) e lipídica (LP) do colostro. Amostras de colostro foram coletadas de 15 vacas Bos indicus, e divididas em três alíquotas para armazenamento usando três métodos: refrigeração a 4 °C, congelamento a -20 °C e liofilização. Em cada método, foram realizados quatro tempos de avaliação: dia (d) 5, 10, 15 e 20 para refrigeração e dia 15, 30, 45 e 60 para congelamento e liofilização. Além disso, as análises de pH e densidade foram realizadas em cada momento de avaliação para cada método. No dia 0 e 15 de conservação foram realizadas análises da CAT, PL e PP. Foi realizado um modelo linear generalizado, teste de Tukey para comparação de médias e análise de correlação de Pearson. Uma diminuição no pH do colostro refrigerado foi encontrada no dia 15. A densidade do colostro liofilizado diminuiu em comparação com o colostro congelado. A liofilização apresentou menor PP das amostras, enquanto a refrigeração apresentou os maiores valores de PL e PP. Não foram observadas diferenças no TAC do colostro entre os métodos de armazenamento. Foi encontrada uma correlação positiva entre PP e densidade do colostro e uma correlação negativa entre densidade do colostro e CAT. Assim, concluiu-se que tanto o congelamento quanto a liofilização são métodos adequados de armazenamento do colostro bovino, pois limitam a oxidação de proteínas e lipídios e mantêm o TAC do colostro fresco.
Assuntos
Animais , Feminino , Bovinos , Bovinos , Colostro/química , Armazenamento de Alimentos/métodos , Oxidação/análise , Alimentos Resfriados , Liofilização , CongelamentoRESUMO
O estado de oxidação é um importante aspecto relacionado à qualidade nutricional e sensorial dos óleos vegetais, que pode limitar a utilização dos mesmos. Assim, objetivou-se com este estudo avaliar o estado oxidação de óleo de abacate produzido nacionalmente, comparativamente a azeite de oliva extra virgem e a óleo de arroz refinado. Avaliaram-se nos produtos os índices de peróxidos, p-anisidina e coeficiente de extinção específica (K232 e K270). Os resultados indicaram que, de um modo geral, as amostras lipídicas mostravam bom estado de conservação, tanto em relação a produtos primários quanto secundários de oxidação. Entretanto, com base na legislação para azeite de oliva, pode-se inferir que o óleo de arroz apresentava elevado valor para produtos de oxidação secundários, expressos pelo K270. O óleo de abacate mostrou os mais baixos valores em todas as determinações realizadas, portanto, indicando estar em ótimo estado de conservação em relação à presença de produtos de oxidação.
Assuntos
Azeite de Oliva/análise , Oryza , Oxidação/análise , Persea , Óleos/análise , Óleos/normas , Peróxidos/análise , Qualidade dos AlimentosRESUMO
O estado de oxidação é um importante aspecto relacionado à qualidade nutricional e sensorial dos óleos vegetais, que pode limitar a utilização dos mesmos. Assim, objetivou-se com este estudo avaliar o estado oxidação de óleo de abacate produzido nacionalmente, comparativamente a azeite de oliva extra virgem e a óleo de arroz refinado. Avaliaram-se nos produtos os índices de peróxidos, p-anisidina e coeficiente de extinção específica (K232 e K270). Os resultados indicaram que, de um modo geral, as amostras lipídicas mostravam bom estado de conservação, tanto em relação a produtos primários quanto secundários de oxidação. Entretanto, com base na legislação para azeite de oliva, pode-se inferir que o óleo de arroz apresentava elevado valor para produtos de oxidação secundários, expressos pelo K270. O óleo de abacate mostrou os mais baixos valores em todas as determinações realizadas, portanto, indicando estar em ótimo estado de conservação em relação à presença de produtos de oxidação.(AU)
Assuntos
Óleos/análise , Óleos/normas , Persea , Azeite de Oliva/análise , Oryza , Oxidação/análise , Peróxidos/análise , Qualidade dos AlimentosRESUMO
The aim of present study was to evaluate the effect of feeding vegetable waste (VW) to broilers on their growth performance, serum chemistry, immune status, meat mineral content and lipid oxidation status. For this purpose, 100 one-day-old chicks (Cobb 500) were acquired from a commercial hatchery and allocated according to a completely randomized design into five dietary treatments with four replicates of five birds each. The dietary treatments included: T1 ( 100 % c o m m e r c i a l f e e d ( C F ) + 0 % V W), T2 ( 75 % C F + 25 % V W), T3 ( 50 % C F + 50 % V W), T4 ( 25 % C F + 75 % V W) and T5 ( 0 % C F + 100 % V W). Experimental birds were subjected to dietary treatments from 5 to 7 weeks of age. At the end of week 7 (49 days), eight birds with uniform average body weight were selected per treatment (2birds/replicate), kept off-feed for 4 h and then manually slaughtered according to the Halal method to collect data for serum chemistry, meat minerals and lipid oxidation status. The results indicated better meat lipid oxidation status (p0.05) and lower meat mineral content (p0.05) when birds fed VW at 25, 50, 75, and 100% of the diets compared with 100% commercial feed. On the other hand, blood chemistry and antibody response parameters did not respond (p>0.05) to dietary intervention. In conclusion, dietary inclusion of vegetable waste had positive influence on meat quality in terms of meat lipid oxidation and meat mineral content, and may be replace up to 75% of commercial broiler feeds with beneficial effects.(AU)
Assuntos
Animais , Galinhas/sangue , Galinhas/metabolismo , Galinhas/fisiologia , Oxidação/análise , PlantasRESUMO
The aim of present study was to evaluate the effect of feeding vegetable waste (VW) to broilers on their growth performance, serum chemistry, immune status, meat mineral content and lipid oxidation status. For this purpose, 100 one-day-old chicks (Cobb 500) were acquired from a commercial hatchery and allocated according to a completely randomized design into five dietary treatments with four replicates of five birds each. The dietary treatments included: T1 ( 100 % c o m m e r c i a l f e e d ( C F ) + 0 % V W), T2 ( 75 % C F + 25 % V W), T3 ( 50 % C F + 50 % V W), T4 ( 25 % C F + 75 % V W) and T5 ( 0 % C F + 100 % V W). Experimental birds were subjected to dietary treatments from 5 to 7 weeks of age. At the end of week 7 (49 days), eight birds with uniform average body weight were selected per treatment (2birds/replicate), kept off-feed for 4 h and then manually slaughtered according to the Halal method to collect data for serum chemistry, meat minerals and lipid oxidation status. The results indicated better meat lipid oxidation status (p0.05) and lower meat mineral content (p0.05) when birds fed VW at 25, 50, 75, and 100% of the diets compared with 100% commercial feed. On the other hand, blood chemistry and antibody response parameters did not respond (p>0.05) to dietary intervention. In conclusion, dietary inclusion of vegetable waste had positive influence on meat quality in terms of meat lipid oxidation and meat mineral content, and may be replace up to 75% of commercial broiler feeds with beneficial effects.
Assuntos
Animais , Galinhas/fisiologia , Galinhas/metabolismo , Galinhas/sangue , Oxidação/análise , PlantasRESUMO
Peanut grains are an excellent source of proteins and lipids. Before consumption, peanuts are subjected to a roasting process to acquire desirable sensory characteristics, in addition to eliminating microorganisms present. However, this processing step can cause various changes in lipid and protein fraction of grains, which are not totally elucidated in the literature. This study evaluated parameters such as the lipid acidity, peroxide value, primary (K232) and secondary (K270) products of lipid oxidation, fatty acid profile, reducing sugars, browning index, protein solubility, protein content and intention to purchase of peanut kernels with four colors of testa (striped, rose, red and black), subjected to the roasting process in microwave or oven. After processing, there was a reduction in lipid acidity and unsaturated fatty acids and an increase in saturated fatty acids, peroxide value, K232 and K270 in oil. There was a reduction in protein solubility and reducing sugars, with an increase in browning index. The purchase intention was higher for microwave-roasted red and rose peanut grains, which makes this form of processing interesting due to its convenience and speed.(AU)
Os grãos de amendoim são excelente fonte de proteínas e lipídios. Antes de serem consumidos, os grãos de amendoim são submetidos a um processo de torrefação para adquirir características sensoriais desejáveis, além de eliminar os microrganismos presentes, no entanto, essa etapa de processamento pode causar várias alterações na fração lipídica e proteica dos grãos, as quais não são totalmente elucidadas pela literatura. Esse estudo avaliou parâmetros como a acidez lipídica, o índice de peróxidos, os produtos primários (K232) e secundários (K270) de oxidação lipídica, o perfil de ácidos graxos, açúcares redutores, índice de escurecimento, solubilidade proteica, teor de proteína e intenção de compra de grãos de amendoim com quatro cores de tegumento (listrado, rosa, vermelho e preto), submetidos ao processo de torrefação em micro-ondas ou forno. Após o processamento, ocorreu uma redução da acidez lipídica e de ácidos graxos poli-insaturados e um aumento de ácidos graxos saturados, índice de peróxidos, K232 e K270 no óleo. Houve uma redução da solubilidade proteica e de açúcares redutores, com aumento no índice de escurecimento. A intenção de compra foi maior nos grãos de amendoim vermelho e rosa torrados em micro-ondas, o que torna essa forma de processamento interessante devido a sua rapidez e conveniência.(AU)
Assuntos
Arachis/química , Células Receptoras Sensoriais/química , Micro-Ondas , Oxidação/análiseRESUMO
Peanut grains are an excellent source of proteins and lipids. Before consumption, peanuts are subjected to a roasting process to acquire desirable sensory characteristics, in addition to eliminating microorganisms present. However, this processing step can cause various changes in lipid and protein fraction of grains, which are not totally elucidated in the literature. This study evaluated parameters such as the lipid acidity, peroxide value, primary (K232) and secondary (K270) products of lipid oxidation, fatty acid profile, reducing sugars, browning index, protein solubility, protein content and intention to purchase of peanut kernels with four colors of testa (striped, rose, red and black), subjected to the roasting process in microwave or oven. After processing, there was a reduction in lipid acidity and unsaturated fatty acids and an increase in saturated fatty acids, peroxide value, K232 and K270 in oil. There was a reduction in protein solubility and reducing sugars, with an increase in browning index. The purchase intention was higher for microwave-roasted red and rose peanut grains, which makes this form of processing interesting due to its convenience and speed.
Os grãos de amendoim são excelente fonte de proteínas e lipídios. Antes de serem consumidos, os grãos de amendoim são submetidos a um processo de torrefação para adquirir características sensoriais desejáveis, além de eliminar os microrganismos presentes, no entanto, essa etapa de processamento pode causar várias alterações na fração lipídica e proteica dos grãos, as quais não são totalmente elucidadas pela literatura. Esse estudo avaliou parâmetros como a acidez lipídica, o índice de peróxidos, os produtos primários (K232) e secundários (K270) de oxidação lipídica, o perfil de ácidos graxos, açúcares redutores, índice de escurecimento, solubilidade proteica, teor de proteína e intenção de compra de grãos de amendoim com quatro cores de tegumento (listrado, rosa, vermelho e preto), submetidos ao processo de torrefação em micro-ondas ou forno. Após o processamento, ocorreu uma redução da acidez lipídica e de ácidos graxos poli-insaturados e um aumento de ácidos graxos saturados, índice de peróxidos, K232 e K270 no óleo. Houve uma redução da solubilidade proteica e de açúcares redutores, com aumento no índice de escurecimento. A intenção de compra foi maior nos grãos de amendoim vermelho e rosa torrados em micro-ondas, o que torna essa forma de processamento interessante devido a sua rapidez e conveniência.
Assuntos
Arachis/química , Células Receptoras Sensoriais/química , Micro-Ondas , Oxidação/análiseRESUMO
The objective of this study was to evaluate the effects of different types of thermal processing on the physiochemical characteristics and lipid oxidation of chicken inner fillets. The study was divided into three assays. In the first assay, 50 chicken inner fillets were divided into five treatments, totaling 10 samples per treatment. Treatments consisted in cooking in water bath, electric oven, microwave oven, deep frying, or grilling. The analyzed variables were: cooking weight loss (CWL) and lipid oxidation determined by thiobarbituric acid reactive substances (TBARS). In the second assay, 50 chicken inner fillets were divided into five treatments, totaling 10 samples per treatment. Each treatment consisted of the same cooking methods applied in the first assay, and storage for 48 hours under refrigeration and reheating in a microwave oven. The variable analyzed in the second assay was lipid oxidation (TBARS). In the third assay, 30 samples of chicken inner fillets were subjected to one, four and eight freeze-thaw cycles, after which meat pH, myofibrillar fragmentation index (MFI), water retention capacity (WRC), and lipid oxidation (TBARS) were determined. Chicken inner fillets submitted to deep frying and cooked in a microwave oven presented greater lipid oxidation than the other cooking methods, and deep frying resulted in the highest cooking weight loss. Reheating chicken inner fillets in a microwave oven caused the highest meat lipid oxidation. Increasing the number of freeze-thaw cycles increases the pH, MFI, WRC and TBARS values of chicken inner fillets.
Assuntos
Carne/análise , Culinária , Lipídeos , Oxidação/análise , Congelamento , Galinhas/anatomia & histologia , Reaquecimento , Temperatura , Temperatura AltaRESUMO
The objective of this study was to evaluate the effects of different types of thermal processing on the physiochemical characteristics and lipid oxidation of chicken inner fillets. The study was divided into three assays. In the first assay, 50 chicken inner fillets were divided into five treatments, totaling 10 samples per treatment. Treatments consisted in cooking in water bath, electric oven, microwave oven, deep frying, or grilling. The analyzed variables were: cooking weight loss (CWL) and lipid oxidation determined by thiobarbituric acid reactive substances (TBARS). In the second assay, 50 chicken inner fillets were divided into five treatments, totaling 10 samples per treatment. Each treatment consisted of the same cooking methods applied in the first assay, and storage for 48 hours under refrigeration and reheating in a microwave oven. The variable analyzed in the second assay was lipid oxidation (TBARS). In the third assay, 30 samples of chicken inner fillets were subjected to one, four and eight freeze-thaw cycles, after which meat pH, myofibrillar fragmentation index (MFI), water retention capacity (WRC), and lipid oxidation (TBARS) were determined. Chicken inner fillets submitted to deep frying and cooked in a microwave oven presented greater lipid oxidation than the other cooking methods, and deep frying resulted in the highest cooking weight loss. Reheating chicken inner fillets in a microwave oven caused the highest meat lipid oxidation. Increasing the number of freeze-thaw cycles increases the pH, MFI, WRC and TBARS values of chicken inner fillets.(AU)
Assuntos
Oxidação/análise , Culinária , Carne/análise , Lipídeos , Temperatura , Temperatura Alta , Congelamento , Reaquecimento , Galinhas/anatomia & histologiaRESUMO
The present study was carried out to investigate the influence of freezing-thawing cycles (0, 2, 4 and 6) on lipid oxidation and myowater contents and distribution. Nine replicates of chicken breast meat samples were used for each cycle. Lipid oxidation was determined by measuring peroxide value, and malondialdehyde (MDA) concentrations, which reflect thiobarbituric acid reactive substance (TBARS). Color was determined with a digital colorimeter. Muscle moisture contents were determined by drip loss and thawing loss, water holding capacity, and nuclear magnetic resonance (NMR). The results showed that, as the number of freeze-thaw cycles increased, meat redness decreased and MDA and peroxide values increased. Drip loss and thawing loss tended to decreasing as the number of freeze-thaw cycles increased. Water holding capacity also decreased as a function of increasing freeze-thaw cycles. NMR relaxometry profile showed freeze-thaw cycles change the water distribution of meat subjected to multiple freeze-thaw cycles. In conclusion, multiple freezing and thawing rate (6 cycles) increased lipid oxidation, decreased myowater, and impaired the color of chicken meat.(AU)