T.C. Figueiredo

Qualidade de ovos de consumo submetidos a diferentes condições de armazenamento

The 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). The values of Haugh Unities (HU) and albumen pH were measured. The HU values significantly decreased (P<0.05) during storage mainly at room temperature. Wrapping the eggs packages with plastic film showed efficient in preserving their internal quality since it kept HU higher for a longer storage time. The pH values of the eggs increased during the storage time (P<0.05), independently of both storage temperature and packaging. It was concluded that temperature and time of storage of eggs influenced on the values of HU and wrapping the eggs packages with plastic film improved their internal quality.

Bioactive amines and quality of egg from Dekalb hens under different storage conditions

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.

Qualidade de ovos comerciais submetidos a diferentes condições de armazenamento

Physical-chemical egg qualities of 1440 egg from commercial layer hens of different ages (30 and 60-week-old) submitted to storage under room temperature or refrigeration conditions were evaluated according to the following traits: Haugh Unities (UH); pH of albumen (pH); total solids of albumen and yolk; and weight and percentage of albumen, yolk, and shell. Decrease of inner quality of the evaluated eggs was observed during the experiment, mainly eggs from old-layers, which presented the worst values of AA and HU when stored at room temperature. It was concluded that age, temperature and time of storage of eggs influenced egg quality.

Efeito do período de jejum pré-abate sobre o rendimento de carcaça de frango de corte

Avaliaram-se os efeitos de cinco periodos (quatro, oito, 12, 14 e 16 horas) de jejum pre-abate sobre a perda de peso e rendimento de carcaca e cortes de frangos de corte. Foram utilizados 240 frangos (120 machos e 120 femeas), linhagem Cobb, criados ate 44 dias de idade. No 44o dia, as aves foram separadas de acordo com o periodo de jejum (tratamentos) e o sexo, cada tratamento com 24 repeticoes. Nos tratamentos de quatro, oito, 12 e 16 horas, o jejum foi alimentar e no tratamento de 14 horas, o jejum foi alimentar e hidrico. O teste utilizado para as analises das medias foi o SNK (Student-Newman-Keuls). Foram analisadas as seguintes variaveis: perda de peso vivo apos o jejum, taxa de absorcao de agua pela carcaca, rendimentos da carcaca inteira e dos cortes comerciais coxa e sobrecoxa, peito, dorso, asa, pes e cabeca e pescoco, rendimentos da moela e figado e peso dos intestinos. Os periodos de jejum de oito, 12, 14, e 16 horas apresentaram maior rendimento de carcaca, sendo superiores ao periodo de quatro horas de jejum (P 0,05). As femeas absorveram mais agua do que os machos, e apresentaram rendimentos de carcaca e cortes comerciais superiores aos dos machos (P<0,05).

HPLC-MS/MS method validation for the detection of carbadox and olaquindox in poultry and swine feedingstuffs

Carbadox (CBX) and olaquindox (OLA) were used in poultry and swine feed for growth promotion, to improve feed efficiency and increase the rate of weight gain. However, the use of these agents in feedingstuffs was prohibited because of concerns about their toxicity. Regulatory laboratories are required to have suitably validated analytical methods to ensure compliance with the ban. A quantitative and confirmatory method for determining the presence of CBX and OLA in poultry and swine feed by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was developed, optimized, and validated. The analytes extraction was performed with a mixture of water and acetonitrile (1:1v/v) and cleanup with hexane and C18 (dispersive phase). The method was evaluated by the following parameters: specificity, linearity, matrix effect, decision limits (CCα), detection capability (CCβ), accuracy, precision, limits of detection (LoD), limits of quantification (LoQ) and measurement uncertainty. The validated method presented a broad linear study range and no significant matrix effect. The limit of detection (LoD) was defined at 9 μg kg(-1) for CBX and 80 μg kg(-1) for OLA, and the limit of quantification (LoQ) was defined at 12 μg kg(-1) and 110 μg kg(-1) for CBX and OLA, respectively. The accuracy of the method was adequate for CBX and OLA. The recovery values found in the repeatability conditions were 99.41% for CBX and 104.62% for OLA. Under intralaboratory reproducibility conditions, the values were 98.63% for CBX and 95.07% for OLA. It was concluded that the performance parameters demonstrated total method adequacy for the detection and quantification of CBX and OLA in poultry and swine feedingstuffs.

Optimization and validation method to evaluate the residues of β-lactams and tetracyclines in kidney tissue by UPLC–MS/MS

Methods are validated by a process that defines the analytical requirements and confirms that the investigated method is capable of performing consistently. A quantitative and confirmatory method for determining the presence of β-lactam and tetracycline multiresidues in avian, bovine, equine, and swine kidney tissues using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was developed, optimized, and validated. Analytes were extracted from the kidneys by a mixture of water and acetonitrile, and the extract was then purified with hexane and C18 (dispersive phase). The method was evaluated by the following parameters: linearity, matrix effect, specificity, decision limits (CCα), detection capability (CCβ), accuracy, precision, trueness, limits of detection (LOD), limits of quantification (LOQ), and robustness. The validated method presented a broad linear study range and significant matrix effect. The limit of detection (LOD) was defined from 2.5 to 25.0 µg kg(-1), and the limit of quantification (LOQ) was defined from 5.0 to 50.0 µg kg(-1) for individual analytes. The resultant recovery values ranged from 98.1% to 107.3% in repeatability conditions and from 95.2% to 106% under intralaboratory reproducibility conditions for the studied analytes. It was concluded that the performance parameters demonstrated total method adequacy for detecting and quantifying β-lactam and tetracycline residues in swine, equine, bovine, and avian kidneys.

HPLC-UV method validation for the identification and quantification of bioactive amines in commercial eggs.

A quantitative and confirmatory high-performance liquid chromatography with ultraviolet detection (HPLC-UV) method for the determination of bioactive amines in the albumen and yolk of commercial eggs was developed, optimized and validated by analyte extraction with trichloroacetic acid and pre-column derivatization with dansyl chloride. Phenylethylamine, putrescine, cadaverine, histamine, tyramine, spermidine and spermine standards were used to evaluate the following performance parameters: limit of detection (LoD), limit of quantification (LoQ), selectivity, linearity, precision, recovery and ruggedness. The LoD of the method was defined from 0.2 to 0.3 mg kg(-1) for the yolk matrix and from 0.2 to 0.4 mg kg(-1) for the albumen matrix; the LoQ was from 0.7 to 1.0 mg kg(-1) for the yolk matrix and from 0.7 to 1.1 mg kg(-1) for the albumen matrix. The validated method exhibited excellent selectivity and separation of all amines with coefficients of determination higher than 0.99. The obtained recovery values were from 90.5% to 108.3%, and the relative standard deviation (RSD) was lower than 10% under repeatability conditions for the studied analytes. The performance parameters show the validated method to be adequate for the determination of bioactive amines in egg albumen and yolk.

Bioactive amines and internal quality of commercial eggs

The physicochemical and microbiological qualities of commercial eggs produced by layer hens of different ages (approximately 30 and 60 wk old) were submitted to storage under room temperature or refrigeration for 28 d. A total of 600 eggs were subjected to microbiological analyses of their inner contents and another 600 to a determination of Haugh units (HU) and bioactive amine content. A decrease in the quality of the inner contents of the eggs was observed during the experiment, mainly in the eggs from the 60-wk-old layers, which presented the worst HU values when stored at room temperature (P < 0.05). Microbiological analyses showed an absence of Salmonella spp., Staphylococcus aureus, and coliforms, either total or thermal-tolerant; however, low counts of other Staphylococcus species, Enterobacter spp., Pseudomonas spp., mesophilic aerobic bacteria, and fungi were also recorded. The chromatographic analysis of bioactive amines detected the presence of phenylethylamine in all albumens (38.0 mg/kg) and spermidine in the yolks (1.02 mg/kg). It was concluded that the age of the hens and the time and temperature of storage influenced the quality parameters of the eggs (P < 0.05). Furthermore, despite the low levels of microbial contamination found, phenylethylamine was detected in the albumen. It was not possible to establish index of quality of eggs using bioactive amines present in the yolk and albumen of eggs.

Effects of packaging, mineral oil coating, and storage time on biogenic amine levels and internal quality of eggs

This study was carried out with the aim of evaluating the effects of mineral oil application on eggshells and the use of plastic packages with lids on the physical-chemical and microbiological quality and biogenic amine contents of eggs stored under refrigeration for up to 125 d. A total of 1,920 eggs from 46-wk-old Hyline W36 laying hens were randomly distributed into 4 groups soon after classification: (i) 480 eggs were stored in pulp carton tray packages; (ii) 480 eggs were stored in plastic packages with lids; (iii) 480 eggs were stored in carton packages after the application of mineral oil; and (iv) 480 eggs were stored in plastic packages with lids after the application of mineral oil. The internal quality was measured by Haugh units, by the counts of mesophilic and psychrotrophic microorganisms, by the most probable number of total and thermal-tolerant coliforms, by the counts of molds and yeasts, by the analysis of Salmonella spp. and Staphylococcus spp., and by the levels of biogenic amines in the egg yolk and albumen. The application of mineral oil to the eggshell resulted in higher Haugh unit values throughout storage, and the use of plastic packages altered the internal quality. The application of mineral oil and the use of packaging had no effects on the microbiological and biogenic amine results. Microbiological analyses showed the absence of Salmonella spp., Staphylococcus aureus, thermal-tolerant coliforms, and fungi. However, the highest counts of mesophilic (1.1 × 10(7) cfu/g) and psychrotrophic (6.7 × 10(7) cfu/g) microorganisms were recorded. The highest values of biogenic amines detected and quantified were putrescine (2.38 mg/kg) and cadaverine (7.27 mg/kg) in the egg yolk and putrescine (1.95 mg/kg), cadaverine (2.83 mg/kg), and phenylethylamine (2.57 mg/kg) in the albumen. Despite these results, the biogenic amine levels recorded were considered low and would not be harmful to consumer health.

Bioactive amines and microbiological quality in pasteurized and refrigerated liquid whole egg

The objective of this study was to evaluate the correlation between the levels of bioactive amines and the microbiological quality of liquid pasteurized egg stored under refrigeration. Pasteurized whole egg liquid was obtained from 2 types of different raw materials, fresh eggs, and commercial fertile eggs. They were stored under refrigeration over a period of 21 d. The treatments were arranged in a completely randomized split plot, with the plots being the 2 types of liquid pasteurized egg, and the subplots being the 4 storage periods (1, 7, 14, and 21 d). The storage period did not contribute to the increase (P > 0.05) of contamination by mesophilic aerobic microorganisms and total coliforms in commercial liquid pasteurized egg. However, for fertile eggs, the storage period led to an increase (P < 0.05) in the numbers of microorganisms. Levels of the amines putrescine, cadaverine, and tyramine were detected only in fertile liquid pasteurized egg, and the storage period contributed to the increase (P < 0.05) in the levels of these amines. There was a high correlation between total coliform most probable number and cadaverine levels, and a moderate correlation between the numbers of aerobic mesophilic microorganisms and tyramine levels. It was concluded that the most contaminated liquid pasteurized eggs were the fertile liquid pasteurized eggs and this caused the highest levels of bioactive amines in them compared with all the eggs that had been subjected to pasteurization and refrigerated storage.