The pulsed light from a high-voltage xenon dis-charge lamp is commonly used by semiconductor manufactures. It is known to sterilize UV-tolerant fungi and offers an instantaneous sterilization method. However, light-pulse sterilization apparatus is used by only a few pharmaceutical makers and is rarely used in the food industry.

This report describes the sterilization effect of UV reinforced pulsed xenon light on several microorganisms and evaluates the influence on food quality after treatment.

UV reinforced pulsed xenon light was able to sterilize UV-tolerant fungi, bacteria and their spores. Damage to microbial surfaces was observed after irradiation. Vacuum packed foods wrapped with 21 different films were tested. Packaging films having a UV transparency of over 35% and a UV transparency at 254 nm of over 25% were suitable for light pulse sterilization.

The influence of light pulse irradiation on food quality was examined. The taste and color of foods were not changed and food smells were slightly reduced after irradiation. Changes of exposed food surfaces were detected by scanning election microscopy and were supposed to be caused by instantaneous heating.

We concluded that light pulse irradiation could be effective for sterilization of food surface with less deterioration.