Submitted to: International Journal of Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 17, 2007
Publication Date: May 30, 2007
Citation: Jones, D.R. 2007. Changes in functional characteristics and quality factors of shell eggs during long-term storage. International Journal of Poultry Science.6:157-162. Interpretive Summary: Processed shell eggs were collected from an in-line facility and stored for 10 wks. During the refrigerated long-term storage, functional characteristics and quality factors were monitored. Egg functionality was determined for the albumen, yolk and whole egg via the preparation of angel food cakes, mayonnaise and sponge cakes, respectively. Total solids for the whole egg and its components, along with yolk color, were the egg quality factors examined. As the storage time progressed, average albumen total solids decreased, yolk total solids increased and whole egg solids remained the same. This indicated a shift in the water balance in the egg without a substantial loss to evaporation. Yolk color values did not change to a degree which would be noticeable to the human eye. Functional measurements were highly variable indicating the need for more objective determinations to be developed.
Technical Abstract: The current study was undertaken to determine changes that occur in the functional characteristics and quality factors of commercial shell eggs during long-term storage. Processed eggs were collected on three consecutive weeks (reps) from an in-line facility. Analyses were conducted the day after collection (0 wk) and weekly for an additional 10 wk. All eggs were stored at 4C. Total solids for the albumen, yolk and whole egg were determined. Functional properties were examined via preparation of angel food cakes, mayonnaise and sponge cakes. Color scores were also measured for both raw yolks and prepared mayonnaise. Albumen solids increased slightly during storage (12.2 to 12.6%). Whole egg solids remained the same. Yolk solids decreased throughout storage (48.2 to 43.2%). Angel food cake volume decreased during storage. Sponge cake volumes were variable throughout testing with no clear trends. Mayonnaise was tested immediately after preparation (fresh) and after incubation at 50C for 7 d. In both cases, the average force required to compress the sample was decreased during the long-term storage of the eggs. Significant differences were detected for changes in L*, a*, b* color scores, but the changes found during the long-term storage were not of a magnitude great enough to be seen by the human eye. Most parameters exhibited significant interactions for replicate and egg age. These interactions show the variability that exists between individual eggs and also the need to develop more objective methods for determining shell egg functionality.