Expansion and Contraction Characteristics of Albumen and Yolk

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Expansion and contraction characteristics of albumen and yolk were studied. An apparatus used to determine changes in albumen and yolk volume is described. Coefficients of albumen and yolk volume expansion were .43 × 10−3 and .78 × 10−3, respectively. When expansion characteristics of both albumen and yolk are considered, 42 to 53% of the expansion occurred in the first minute. Volume expansion after 15 min was linear as temperature was increased from 29 C to 39 and 49 C. Contraction occurred with a rate similar to that for expansion.Removal of gases from the albumen using aspirator vacuum tended to increase volume expansion. Storage of eggs for up to 21 days at different temperatures followed by expansion of albumen and yolk at 39 C produced no differences in the yolk. Differences in albumen expansion were found and were associated with albumen pH differences.Albumen was separated into thick and thin fractions and stored for a maximum of 21 days at 13 or 22 C. Thin albumen had larger expansion volume than thick albumen only for fresh albumen after expansion at 29 C and albumen after 21 days at 13 C followed by expansion at 29 C. Thick albumen stored for 21 days had larger expansion volumes than fresh thick albumen only when stored at 13 and 22 C followed by expansion at 29 C and when stored at 22 C with expansion at 39 C. No differences were found when fresh was compared to stored thin albumen under any of the treatments. When the same samples were expanded and contracted for a second time, differences in the contraction volumes were found.