Effects of Egg Storage Conditions on Eggshell Resonant Frequency and Albumen Characteristics

Abstract

3 Abstract: Increasing egg storage duration affects egg internal quality, especially albumen quality by increasing pH and decreasing Haugh Unit (HU). But, in most of African contexts, egg producers, sellers and consumers store the eggs in different conditions regardless of quality deterioration. In this study, 1920 eggs produced by Lohmann layer flocks of 48 weeks and 58 weeks of age were investigated. The eggs were divided randomly and equally in 4 groups and stored at 3 different conditions for 21 days at: 1) Roo m Conditions (RoC); 2) Super Market Conditions (SmC) and 3) Refrigerator Conditions (RfC). During storage, all the eggs were weighed and Resonant Frequency (RF) were measured at day 3, 6, 9, 12, 15, 18 and 21 according to flock age and storage condition. Then at the same days, sample of 30 eggs per flock and per storage condition were used to measure albumen pH and HU. The results indicate that eggs weight decreased significantly with storage duration (P<0.001). But, egg relative weight loss was lower (P<0.01) for eggs of RfC group than that of SmC and RoC groups. There was a positive linear relationship between RF and storage duration. But, daily increase in RF was affected by layer flock age. The highest daily increase was obtained in RoC group or SmC group, respectively for flock of 48 weeks of age or flock of 58 weeks of age. Eggs of RfC groups had the highest albumen HU and the lowest albumen pH (P<0.001). It is concluded that detrimental effects of storage duration are more or less pronounced depending on storage conditions especially storage environmental temperature. It is recommended that, in African countries, consumption eggs can be stored at room or super market conditions not longer than 6 days but in the refrigerator up to 21 days.