Unidade Haugh como medida da qualidade de ovos de galinha armazenados sob refrigeração

Abstract

RESUMO: Durante o armazenamento, ocorrem alterações nas características físicas, químicas e funcionais das proteínas de ovos em cascas. Essas mudanças dependem das condições de armazenamento, como o tempo, a temperatura e a umidade relativa do ar. Neste trabalho, compararam-se os valores da unidade "Haugh" de ovos frescos e de ovos armazenados à temperatura ambiente (25°C) e à temperatura de refrigeração (8°C), durante 7, 14 e 21 dias de armazenamento. Os valores da unidade "Haugh" e da altura da clara espessa diminuíram, consideravelmente, com o armazenamento à temperatura de 25°C. No ambiente refrigerado, não houve diferença significativa na unidade "Haugh", nos períodos de armazenamento, mas seus valores foram menores do que obtidos para ovos frescos. O peso dos ovos não diferiu, significativamente, durante o período de armazenamento, independentemente da temperatura. O pH correlacionou-se, positivamente, nas duas temperaturas com a unidade "Haugh" e negativamente com a altura do albume denso. Palavras-chave: ph do albume, peso do ovo, altura do albume, armazenamento de ovos ABSTRACT: Alterations in physical, chemical and functional characteristics of egg proteins occur during storage. These changes depend on the storage conditions, mainly duration, temperature and relative humidity. This study examined the fresh egg Haugh unit score and the storage egg Haugh unit score, at room temperature (25°C) and under refrigeration conditions (8°C), during 7, 14 and 21 days of storage. Haugh units and albumin height decreased considerably during storage at room temperature. At 8°C, there was no significant difference in the Haugh unit for different periods of storage, but their values were smaller as compared to fresh eggs. The weight of the eggs was not affected by both storage and temperature. For both temperatures, pH was positively correlated with Haugh units and negatively with the albumin height.

Quality of eggs sold in different commercial establishments and the study of the conditions of storage

“…The average values found by Alleoni & Antunes (2001) for the albumen height ranged from 2.00 to 9.70 mm.…”

“…According Alleoni & Antunes (2001), the pH of the egg white of a newly laid egg usually ranges from 7.6 to 7.9. Most microorganisms grow at this pH although this value is above the ideal.…”

“…Alleoni & Antunes (2001) found that the weight of the eggs at room temperature ranged from 56.40 g to 67.56 g. Leandro et al (2005) analyzed large size eggs sold in different types of establishments in the city of Goiânia/GO and found an average weight of 60.92 g. Means followed by the same lowercase letter in the columns and uppercase letter in the rows do not differ statistically from one another by the Tukey test at 5% probability, considering the same physicochemical parameter.…”

“…The egg main function is reproduction but, it is highly consumed by the Brazilian population due to its affordable price, and it is also a part of a consumption pattern because it can be consumed in its natural form or as an ingredient in some foodstuffs such as cakes, meringues, and confectionery products and derivatives (Aragon-Alegro et al, 2005). Its use in these food preparations is due to its capacity to form a foamy texture due to the air entrapment in a prosthetic net, which is an important property to obtain a foamy emulsion and mousse (Alleoni & Antunes, 2001). …”

Yolk Color and Lipid Oxidation of the Eggs of Commercial White Layers Fed Diets Supplemented with Vegetable Oils

“…The main egg quality aspects considered by egg producers are egg weight and eggshell quality, whereas consumers are interested in shelf life, external appearance, and sensorial qualities, such as eggshell and yolk color. On the other hand, processors take into account easy eggshell removal and separation of the yolk from the albumen, as well as egg functional properties (Alleoni & Antunes, 2001).…”