Maintenance of quality of eggs submitted to treatment with propolis extract and sanitizers

This study aimed to evaluate the internal and microbiological quality of eggs submitted to different types of shell treatments. One hundred and forty-four fresh red eggs were distributed in a scheme of 4 treatments (no washing; washing and immersion in chlorine; washing and immersion in peracetic acid; and washing and spraying of propolis extract) x 5 storage periods (7, 14, 21, 28,and 35 days), stored at 25°C, in each period 6 eggs per treatment were analyzed. The parameters to assess were: weight loss; shell weight; yolk weight; albumen weight, yolk diameter; yolk height; albumen height and Haugh unit (HU). The microbiological quality of eggs was evaluated at 35 days through analysis for aerobic mesophilic bacteria, thermotolerant coliforms, Staphylococcusspp., Salmonellaspp. and molds and yeasts. The treatment with propolis extract was the only effective one to maintain the high HU quality of the eggs until 21 days of storage at 25°C and was effective against microbiological contamination of all bacterial groups. The results presented showed greater effectiveness of the propolis extract for maintenance of internal and microbiological quality of eggs, it can be an alternativeproduct to chemical sanitizers.(AU)

Volatile carbonylic compounds in downtown Santiago, Chile.

Formaldehyde, acetaldehyde, acetone, propanal, butanal, 2-butenal, 3-methylbutanal, hexanal, benzaldehyde, 2-methylbenzaldehyde, and 2,5-dimethylbenzaldehyde were measured during six spring days at downtown Santiago de Chile. Measurements were performed 24h/day and averaged over three hour periods. The averages of the maxima (ppbv) were, formaldehyde: 3.9+/-1.4; butanal: 3.3+/-3.4; acetaldehyde: 3.0+/-0.9; acetone: 2.4+/-1.0; 2-butenal: 0.56+/-0.52; propanal: 0.46+/-0.21; benzaldehyde: 0.34+/-0.3; 3-butanal: 0.11+/-0.05; hexanal: 0.11+/-0.08; 2-methylbenzaldehyde: 0.08+/-0.05; 2,5-dimethylbenzaldehyde: 0.05+/-0.03. Aliphatic aldehydes (C1-C3) are strongly correlated among them and weakly with primary (toluene) and secondary (ozone plus nitrogen dioxide or PAN) pollutants. In particular, the correlation between acetaldehyde and propanal values remains even if diurnal and nocturnal data are considered separately, indicating similar sources. All these aldehydes present maxima values in the morning (9-12h) and minima at night (0-3h). The best correlation is observed when butanal and 2-butenal data are considered (r=0.99, butanal/2-butenal=6.2). These compounds present maxima values during the 3-6h period, with minima values in the 0-3h period. These data imply a strong pre-dawn emission. Other aldehydes show different daily profiles, suggesting unrelated origins. Formaldehyde is the aldehyde whose concentration values best correlate with the levels of oxidants. The contribution of primary emissions and photochemical processes to formaldehyde concentrations were estimated by using a multiple regression. This treatment indicates that (32+/-16)% of measured values arise from direct emissions, while (79+/-23)% is attributable to secondary formation.