Hexanal vapor is a natural, metabolizable fungicide: inhibition of fungal activity and enhancement of aroma biosynthesis in apple slices.
Song, J.; Leepipattanawit, R.; Deng, W.; Beaudry, R. M.;
Journal of the American Society for Horticultural Science Year: 1996 Vol: 121 Issue: 5 Pages: 937-942 Ref: 28 ref.
1996
บทคัดย่อ
Hexanal vapour inhibited hyphal growth of Penicillium expansum and Botrytis cinerea on potato dextrose agar (PDA) and on minimally processed apple slices (cultivars Jonagold and Golden Delicious). After 48 h of exposure to hexanal at 4.1 micro mol/litre (100 ppm), the hyphal growth of both fungi was about 50% that of untreated controls. At a concentration of 10.3 micro mol/litre (250 ppm), neither fungus grew during the treatment period, but some growth of both fungi occurred 120 h after treatment. At hexanal vapour concentrations of more than or equal to 18.6 micro mol/litre (450 ppm), growth of both fungi ceased and the organisms were apparently killed, neither showing regrowth when moved to air. When fungi were allowed to germinate and grow for 48 h in hexanal-free air, a subsequent 48-h exposure to 10.3 micro mol hexanal/litre slowed colony growth relative to controls for several days and a 48-h exposure to 18.6 micro mol/litre stopped growth completely. Concentrations of hexanal that inhibi
ted fungal growth on PDA also retarded decay lesion development on the apple slices. Hexanal was actively converted to aroma volatiles in the slices, with hexanol and hexylacetate production strongly enhanced after 20-30 h of treatment. A small amount of butylhexanoate and hexylhexanoate production was also noted. Within 16 h after treatment, no hexanal could be detected emanating from treated fruit slices. Since hexanal was metabolized to aroma-related volatiles by the fruit slices, the possibility of hexanal being an essentially residue-less antifungal agent seems likely. The possibility of developing a system for treating apple slices with hexanal in modified-atmosphere packages was also examined. The permeability of low-density polyethylene (LDPE) film to hexanal and hexylacetate was, respectively, about 500- and 1000-fold higher than its permeability to O2. The permeability to both compounds increased exponentially with temperature, with hexanal permeability increased 6-fold while hexylacetate permeabil
ity increased only 2.5-fold between 0 and 30 deg C.