Hydrogen is a radiolysis product of water.

Hydrogen is a radiolysis product of water and other food components. Usually it diffuses away rapidly, but researchers have found that hydrogen can be useful as a marker for irradiated frozen chicken. The technique for measuring hydrogen levels involves using an electronic sensor incorporated into a headspace analyzer. This makes it attractive as an inexpensive onsite screening procedure. The technique works well with frozen foods that can be thawed inside the analyzer. You need samples of at least 100 g to confidently detect irradiated doses greater than 0.5 kGy after 15 weeks of storage at -20 C. A similar procedure is applicable to other solid foods, such as eggshells, that can be dissolved inside the analyzer. However, the failure to detect hydrogen levels is not proof that a sample has not been irradiated. Contact: Christopher Hitchcock, the University of Surrey Food Safety Research Group, School of Biological Sciences, Guildford, Surrey GU2 5XH, England, U.K. Phone: [phone]. Fax: [phone]. URL: http://www.surrey.ac.uk.