Storage and ultraviolet-induced tissue stress effects on fresh-cut pineapple

The effect of UV-induced stress on the volatile aroma compounds in cut pineapple was compared with that of storage at 4degreesC for 24h. Eighteen volatile compounds were identified by solid-phase microextraction (SPME) in fresh-cut pineapple. Methyl-2-methylbutanoate, methyl hexanoate, methyl 5-hexenoate, ethyl hexanoate and ethyl 5-hexenoate were the major aroma compounds. Storage at 4degreesC for 24h, and exposure of cut fruit to UV radiation for 15min caused a considerable decrease in the concentration of esters and increase in the relative amount of copaene. This sesquiterpene, when added to crushed cantaloupe melon (0.1mg g(-1)), inhibited microbial growth in the fruit over a period of 24h at 20degreesC. Cis- and trans-ocimene were present in the fruit but their production was not photo-induced by UV irradiation. Ocimene, however, was a potent antimicrobial agent that killed microorganisms when added to the crushed fruit and stored at 20degreesC for 24h. The results indicate that sesquiterpene phytoalexins could contribute to the defense mechanism in wounded pineapple tissue. Published in 2004 for SCI by John Wiley Sons, Ltd.