The Effect of Irradiation on Sodium Alginate

There has been considerable interest in recent years in the development of suitable test methods to characterize foods that have been irradiated, as part of a continuing effort to prolong shelf life. This note describes work undertaken on a grade of sodium alginate used as a food thickening agent using the miniDAWN multi angle light scattering detector in conjunction with SEC to determine the effect of gamma irradiation on the molecular weight distribution. Sodium alginates are polysaccharides widely used as a food additive or as a sterile wound dressing. The molecular weight properties of the alginate contribute directly to the end-use performance of these products. When used as a thickening agent, the higher the molecular weight, the better the gel properties will be.