Egg quality assessment at different storage conditions, seasons and laying hen strains

Abstract

Eggs are one of nearly perfect protein foods, offering nutrients of great biological value. However, during storage, egg albumen and yolk components may alter and deteriorate egg quality. Therefore, the aim of this work was to assess egg quality during 9-week storage. Parameters such as Haugh unit, weight loss, egg width and length, specific gravity, yolk and albumen dimensions and their pH were evaluated weekly. A total of 270 eggs (n=5) collected from two different hen strains were evaluated under room (20 to 35 °C in summer; 11.2 to 29.7 °C in autumn) and refrigerated (0 to 5 °C in summer; -3.1 to 6.5 °C in autumn) temperatures. For storage time, an unfolding analysis was accomplished by regression analysis using orthogonal polynomials. As a second approach, principal component analysis (PCA) was performed in order to assess correlations among quality parameters on storage conditions and laying hen strains. By the end of the 9-week storage period, eggs kept under refrigeration presented similar quality parameters to eggs stored at room temperature for only 3 weeks. In contrast, eggs kept at room temperature presented faster degradation from week 1 to 5. No differences on egg quality parameters were noticed between white and brown shells eggs. PCA suggests that better egg quality (first week) was associated mainly with higher egg weight and its specific gravity, Haugh unit and albumen height. Eggs stored at room temperature should be consumed in 2 weeks or refrigerated until 8 weeks, preserving internal quality from farm to retail.Index terms: Weight loss; shell color; Haugh unit; yolk index. RESUMOOs ovos são um dos alimentos que oferecem nutrientes de grande valor biológico. Entretanto, no armazenamento, alguns componentes da clara e gema podem se alterar, deteriorando a qualidade dos ovos. Assim, este trabalho objetivou avaliar semanalmente parâmetros de qualidade como unidade Haugh, perda de peso, largura/comprimento do ovo, densidade específica, dimensões da clara/gema e pH durante 9 semanas de armazenamento. Foram coletados 270 ovos de duas linhagens de poedeiras e avaliados a temperatura ambiente (20 a 35 °C no verão; 11,2 a 29,7 °C no outono) e refrigerada (0 a 5 °C no verão; -3,1 a 6,5 ºC no outono). Para as condições de armazenamento, foi realizada uma análise de desdobramento por regressão por polinômios ortogonais. Ainda, análise de componentes principais (PCA), objetivou avaliar correlações entre parâmetros de qualidade em diferentes condições de armazenamento e linhagens de poedeira. Após 9 semanas de armazenamento, os ovos refrigerados apresentaram qualidade similar àqueles armazenados a temperatura ambiente por 3 semanas. Porém, sem refrigeração, os ovos apresentaram uma degradação mais rápida da semana 1 a 5. Não foram observadas diferenças nos parâmetros de qualidade dos ovos entre as diferentes colorações de casca (linhagens de poedeiras). PCA sugere que a melhor qualidade dos ovos (primeira semana) foi associada principalmente com valores elevados de peso e densidade específica do o...

Farklı Sıcaklıklarda Depolanan Tavuk Yumurtalarının Kalite Parametrelerinin Değerlendirilmesi

“…Şamlı et al [26] study determined that the egg yolk index was 44.09 in fresh eggs; 40.77 (5°C ) and 32.73 (29°C ) at the end of 10 days. In our study, it was seen that the value of fridge group egg yolk index obtained from day 28 was compatible with the value taken from Şamlı et al 's [30] fridge group (5°C ) on 10 th day.…”

“…In the study of Feddern et al [30] the HU value decreased from 95.75 to 88.19 in the eggs they kept in the cold chain (0-5°C ) for 3 weeks, whereas in the warm environments (20-30°C ) the values were reduced from 98.60 to 51.92. According to our research results, HU values were found to be statistically significant between the groups kept at fridge versus at room temperature (P<0.05).…”

“…This finding supports the results of our study. Feddern et al [30] stated that there was a rapid deterioration in the eggs stored at room temperature in 1 to 5 weeks, and recommended that these eggs should be consumed in 2 weeks to maintain their internal quality until they reach the consumer from the farm or stored in the refrigerator for up to 8 weeks.…”

Impacts of red pepper supplemented diets and different storage conditions on eggs obtained from free-range laying hens

“…Albumen height and Haugh unit values tend to decrease during storage, which concurs with the findings of Feddern et al (2017). According to egg quality grades of USDA (2000) manual, a higher HU means higher egg quality.…”

“…Because of that, increasing the storage time and temperature affected YI and YI might be a indicator of deterioration. Feddern et al (2017) reported that YI has to be between 0.39 and 0.45. The current results showed that YI values of eggs stored at room temperatures for two and three weeks are lower than 0.39.…”