Biotin diffusion in stored chicken eggs: a re-assessment

1. The possibility that biotin in stored eggs migrates from the yolk into the albumen was re-investigated. 2. Sets of eggs collected from 12 Single Comb White Leghorn hens were stored at 5, 8, 12, 15, or 18 degrees C for 5, 10, 15, 20, or 25 days and then frozen. 3. For each set, yolk and albumen samples adjacent to the yolk membrane were each pooled and assayed for protein-bound biotin by radioligand exchange with non-linear regression analysis of the data. 4. In contrast to previous work reported by Bush and White (Comp. Biochem. Physiol. 93B, 543-547, 1989), no evidence of biotin diffusion was found. 5. Non-linear regression was used to re-evaluate the data from the earlier study, confirming the results, although less strikingly. 6. The discrepancy is partly due to the method of data analysis, although differences in breed or number of hens may also be contributing factors.