The effects of different dietary lipids on the fatty acid profiles of eggs produced by 20- and 54-wk-old Dekalb laying hens were investigated. The 4 treatments were based on the lipid source added to the diet: soybean oil, sunflower oil, linseed oil, or control (no added oil). The experimental design was a simple random-sample design using a 4 × 2 factorial arrangement (4 treatments and 2 ages). The fatty acid composition of the yolks of eggs produced by the laying hens was analyzed. The fatty acid profiles found in the egg yolks were the same as those provided in each diet. Eggs laid by hens fed the diet containing soybean oil had a large amount of n-6 polyunsaturated fatty acids (PUFA), whereas eggs laid by hens fed the diet containing linseed oil had the highest percentage of n-3 PUFA. A decrease in PUFA deposition in egg yolks was observed as the laying hens got older. Eggs of hens fed the diet containing linseed oil presented an n-6:n-3 ratio of 2.01 in younger chickens and 2.17 in older ones. The trans fat percentages found in the egg yolks of all treatments were very low. It was concluded that the quantity of fatty acids present in the egg yolk may be altered according to the source of lipids in the diets; the addition of linseed oil to the ration of laying hens resulted in the production of n-3-enriched eggs and excellent n-6:n-3 ratios, and the egg yolks had insignificant amounts of trans fat, irrespective of the different lipid sources added to the diets or the age of the chickens.

Qualidade de ovos de consumo submetidos a diferentes condições de armazenamento[ RESUMOVerificou-se a qualidade interna de ovos de consumo armazenados sob diferentes condições, utilizando-se 768 ovos, provenientes de galinhas Hy-line com 40 semanas de idade. Os tratamentos foram dispostos no delineamento inteiramente casualizado em arranjo fatorial 2x4x8 (ovos embalados em filme plástico e não embalados), quatro períodos de estocagem em temperatura ambiente (zero, cinco, 10 e 15 dias) e oito períodos de armazenamento sob refrigeração (zero, cinco, 10, 15, 20, 25, 30 e 35 dias). Foram avaliados os valores das Unidades Haugh (UH) e os de pH do albúmem (pH). Os valores de UH diminuíram com a estocagem, e houve uma queda mais acentuada nos ovos que permaneceram em temperatura ambiente. A embalagem das bandejas de ovos mostrou-se eficaz na preservação da qualidade interna dos ovos, pois os valores de UH mantiveram-se altos por um maior período de estocagem. Os índices de pH aumentaram com o período de armazenamento dos ovos (P≤0,05) independentemente da temperatura de estocagem e do uso da embalagem. Foi concluído que a temperatura e o tempo de armazenamento dos ovos exercem influência nos valores de UH, e que a embalagem das bandejas de ovos em filme plástico melhora a qualidade interna dos ovos.Palavras-chave: ovo, estocagem, unidade Haugh, pH do albúmen ABSTRACTThe internal quality of 768 commercial white eggs from 40-week-old Hy-Line laying hens was evaluated after storage under different conditions. The eggs were submitted to treatments in a factorial scheme of 2x4x8, being two types of package (using plastic film or not), four periods of storage (zero, five, 10, and 15 days), and eight refrigerated storage times (zero, five, 10, 15, 20, 25, 30 and 35 days) (Brasil, 1997) determine condições mínimas internas (câmaras de ar variando de 4 a 10mm; gemas translúcidas, firmes, consistentes e sem germe desenvolvido; claras transparentes, consistentes, límpidas, sem manchas e com as chalazas intactas), na prática, somente o peso e as características da casca têm sido considerados.

Qualidade de ovos comerciais submetidos a diferentes condições de armazenamento

Efeito da classificação dos ovos sobre o rendimento de incubação e os pesos do pinto e do saco vitelino

The objective of this study was to investigate the possibility of using bioactive amines as an index of quality of fresh and stored eggs. Large white eggs from 24-wk-old Dekalb layers were randomly distributed in 3 groups: (i) 10 freshly laid eggs, (ii) 60 eggs stored at 25 +/- 1 degrees C and 60% RH for 30 d, and (iii) 50 eggs stored at 6 +/- 1 degrees C and 60% RH for 50 d. The eggs were weighed and the internal quality was evaluated by Haugh units (HU), pH of albumen, total solids, total volatile bases, and bioactive amines in the albumen and yolk. The fresh eggs had, on average, 56.85 g, 98.55 HU, albumen pH of 8.02, total solids of 12.17 g/100 g in the albumen and 52.43 g/100 g in the yolk, and absence of volatile bases. None of the 10 amines investigated were detected in the albumen; however, the yolk contained 0.37 mg/kg of spermidine. Throughout storage, there was a significant decrease in the weight of the egg and HU and a significant increase in the pH and in the total solids of the albumen. The decrease in HU and the increase in the total solids of the albumen were faster at 25 +/- 1 degrees C compared with 6 +/- 1 degrees C. At 50 and 30 d of storage at 6 +/- 1 and 25 +/- 1 degrees C, respectively, significant levels of total volatile bases were detected. The levels of spermidine in the yolk increased significantly at the 40th and 15th days of storage at 6 +/- 1 and 25 +/- 1 degrees C, respectively. At these storage times, the presence of putrescine and agmatine was also detected. Therefore, the presence of other amines besides spermidine or spermidine levels higher than 1.0 mg/kg in the yolk could be used as an index of quality of fresh eggs and throughout storage.