Effect of hexanal on the shelf life of fresh apple slices

In this work the effects of hexanal, as a component of packaging atmosphere , on the shelf life of and evolution of naturally occurring microbial popul ations in fresh apple slices during storage at 4 and 15 degrees C were eval uated. Although hexanal had no bactericidal effects, in all conditions cons idered, this volatile molecule significantly extended the shelf life. In fa ct, the presence of hexanal in the storage atmosphere (at 4 degrees C) tota lly inhibited mesophilic bacteria and considerably prolonged the lag phase of psychrotrophic bacteria. Also, at 15 degrees C, hexanal strongly inhibit ed molds, yeasts, and mesophilic and psychrotrophic bacteria. Moreover, hex anal led to a yeast selection favoring species having a reduced spoilage po tential due to their prevalent respiratory activity. When added to a modifi ed atmosphere (70% N-2 and 30% CO2), this molecule was also very effective in preventing browning reactions for at least 16 days at 15 degrees C. No c hanges in hue angle values were observed in samples packaged in modified at mosphere with hexanal, even after 16 days of storage at 4 degrees C.