Internal quality and shelf life of eggs coated with oils from different sources.
UNLABELLED
Selected internal quality and shelf life of eggs coated with oils from differences sources (mineral oil, canola oil, corn oil, grape seed oil, olive oil, soybean oil, and sunflower oil) were evaluated during 5 wk of storage at 25 °C. As the storage time increased, weight loss increased whereas Haugh unit and yolk index values decreased. Throughout the 5 wk of storage, eggs coated with oils, regardless of oil sources, possessed better albumen and yolk quality than the control noncoated eggs. Oil coating minimized weight loss of eggs (<0.8%) compared with that (7.26%) of the noncoated eggs after 5 wk of storage at 25 °C. No significant differences in internal quality (weight loss, Haugh unit, yolk index, and albumen pH) were generally observed among oil-coated eggs during 5 wk of storage. Based on the Haugh unit, the grade of noncoated eggs changed from AA at 0 wk to A at 1 wk and to B after 3 wk whereas that of oil-coated eggs from AA at 0 wk to A at 4 wk and maintained A grade until 5 wk. This study demonstrated that oil coating, irrespective of oil sources, preserved the internal quality, minimized weight loss (<0.8%), and extended the shelf life of eggs by at least 3 wk longer than observed for the noncoated eggs at 25 °C storage. Soybean oil was a more practical option as a coating material for eggs due to its low cost.


PRACTICAL APPLICATION
Eggs are highly perishable and susceptible to internal quality deterioration when stored above 7 °C. Refrigeration of eggs may be seldom practiced in some developing regions of the world. Therefore, an alternative method, that is inexpensive yet effective, to preserve the internal quality of eggs and to prevent microbial contamination is needed. Oil coating has been proven to preserve the internal quality, prolong shelf life, and minimize weight loss of eggs. This study demonstrated that, compared with other vegetable oils, soybean oil was a more practical option as a coating material for eggs during 5 wk of storage at 25 °C due to its low cost.
EFEITO DO PERÍODO DO ANO SOBRE A QUALIDADE DE OVOS COMERCIALIZADOS NO SUL DO BRASIL
O ovo e um produto que apresenta queda de qualidade quando submetido a condicoes improprias de armazenamento. O objetivo desse trabalho foi avaliar as caracteristicas qualitativas de ovos marrons tipo grande comercializados na cidade de Chapeco, SC, Brasil nos periodos de inverno e verao. Utilizou-se um delineamento inteiramente casualizado em esquema fatorial 2 x 4, sendo 2 periodos de coleta e 4 mercados analisados, com 4 repeticoes. Todos os ovos foram da mesma marca, lote e periodo de armazenamento de 9 dias apos a embalagem. Foram analisados os parâmetros de unidade Haugh, indice gema, coloracao da gema pelo leque colorimetrico DSM, pH do albumen e da gema e gravidade especifica. Os resultados obtidos foram submetidos a analise de variância atraves do programa SAS e as diferencas entre as medias comparadas pelo teste de Tukey a 5% de significância. Houve aumento significativo da gravidade especifica, da unidade Haugh e do indice de gema no periodo de inverno. No periodo do verao, foi observado aumento significativo dos valores de pH da gema e do albumen. Pode-se concluir que os ovos de galinha comercializados no inverno apresentaram melhor qualidade interna quando armazenados em temperatura ambiente, em relacao aos ovos comercializados no verao sob as mesmas condicoes de armazenamento.
Turbulent boundary layer wall‐pressure fluctuations downstream from an abrupt change in surface roughness
Spectra of wall‐pressure fluctuations beneath a turbulent boundary layer have been investigated immediately downstream from an abrupt change in surface roughness, from slightly rough to very rough. Over the measurable frequency band (400 Hz to 7 kHz), the spectra in the first 150 mm scale on wall variables. This indicates that the motions responsible for the pressure fluctuations measured in this region are very close to the wall. Farther downstream this scaling procedure breaks down. It is suggested that the initially thin internal layer behaves independently of the flow external to it until it has grown appreciably and only then interacts with the outer boundary layer. It was found that, for all frequencies measured, the dimensional spectral level decreases initially then rises to a maximum at 250 mm from the roughness change before decreasing once more. The position of the maximum is close to where the internal layer ceases to have a distinct edge.