Abstract
An intermediate radical, CH2OH, was produced in aqueous methanol solution containing nitrous oxide by γ-irradiation. Yields of ethylene glycol and formaldehyde, the major and the minor product from CH2OH, respectively, changed on the addition of some solutes. Cysteine lowered the both product yields to zero even at a low concentration of 5×10-5M. Oxygen of low concentrations (2.5_??_7.5×10-5M) changed effectively the major product from ethylene glycol to formaldehyde. k(CySH+CH2OH)/k(O2+CH2OH) was calculated as 0.5.
Ascorbic acid (5×10-5M) lowered ethylene glycol yield to 48%, cystine (10-3M) to 15%, methionine (10-3M) to 31%, , histidine (10-3M) to 42%, tryptophan (10-3M) 46%, tyrosine (10-3M) to 77%, phenylalanine (10-3M) to 73%, hypoxanthine (10-3M) to 37%, adenine (10-3M) to 52%, uracil (10-3M) to 20%, thymine (10-3M) to 10%, cytosine (10-3M) to 49%, rutin (10-3M) to 23%, pyrogallol (10-3M) to 41%, and gallic acid (10-3M) to 78% of the control. These results suggest that the reactions of the secondary radicals such as CH2OH perform an important role in material change of foods irradiated with γ rays.
