Relationship of temperature and length of storage on pH of internal contents of chicken table egg in humid tropics

Abstract

All foods have limited shelf life which vary depending on the food and storage conditions. Table eggs are perishable food and storage temperature is an important factor that affects the shelf life. In tropical countries like Nigeria, eggs are usually preserved under ambient condition due to erratic power supply, which reduces the efficiency of refrigeration system. The aim of the present study was to examine the effects of storage periods, temperature and their relationship on the pH of chicken egg internal properties (yolk, albumen and whole egg). Fresh chicken table eggs were randomly allotted to three treatments of storage temperatures; refrigerator (40C ± 2), laboratory (320c ± 4), and poultry store room (370C ± 4). Eggs were assigned to treatments in a completely randomized design, and each treatment was replicated thrice. The pH was measured daily for each storage temperature in all treatments. Storage temperature and periods had significant (P<0.05) effect on pH of measured parameters. The pH values increased with storage temperature and period of storage. The rate of pH increase was significantly (P<0.05) higher in ambient as compared to refrigerator temperature. In this study, only the refrigerator storage has pH values within the range for fresh table eggs. At storage period above three weeks, pH values increased beyond the range for fresh egg. It is validated that storage temperature and period affected egg shelf life, the rate of freshness reduced with increased temperature, thus, storage beyond three weeks of ambient temperature is not advisable in humid tropics.