The relations between absorbed dose, molecular mass distribution, and viscosity studied on aqueous solution of ovalbumin agglomerated by gamma irradiation

The gamma-irradiation induced stepwise genesis of dimer, trimer, tetramer, and higher agglomerates in 1% ovalbumin aqueous solution was quantitatively followed by a SDS-PAGE analytical method. The molecular mass distributions obtained in the dose interval form 0 to 2 kGy were used to calculate the g el dose by using Good's theory of cascade processes. The difference between the calculated value (3.5 kGy) and the measured value (8.5 kGy) is attribu ted to the competition between the agglomeration and the interradical conve rsion processes, which prevails in the higher dose region. It was estimated from the gel dose that 1 (.) 10(20) of intermolecular bonds per dm(3) were necessary to form a gel from 1% ovalbumin solution. A dynamic viscosity of the solution was also measured simultaneously. A simple semiempirical equa tion was developed eta/eta 0 = exp(-D/Dg)/1-D/Dg containing only one parameter-gel dose, D-g-and it fits the viscosity-dose data fairly well. (C) 2000 John Wiley & Sons, Inc.