Activity of trans-2-hexenal against Penicillium expansum in 'Conference' pears.
OBJECTIVE
To investigate the effects of trans-2-hexenal on blue mould disease, patulin content and fruit quality in 'Conference' pears.


RESULTS
Fruits, wounded and inoculated with Penicillium expansum or non-inoculated, were exposed to trans-2-hexenal vapour treatment (12.5 microl l(-1)) at 20 degrees C. A greater reduction of decay was obtained by treatment application 24 or 48 h after inoculation, in contrast trans-2-hexenal application 2 h after inoculation was ineffective. Fruit storage temperature (-1 degrees C) after treatment did not affect the antifungal activity. Although 2-h exposure to trans-2-hexenal was effective in reducing blue mould, an exposure of at least 8 h was required to reduce fruit patulin content. Treatments did not affect fruit physical-chemical characteristics. After 6 days at 20 degrees C following exposure, trans-2-hexenal residue in treated fruits was less than the natural content of the compound in unripe fruits.


CONCLUSIONS
trans-2-Hexenal treatment is effective in the reduction of blue mould infections and patulin content in Conference pears when applied 24-48 h after pathogen inoculation.


CONCLUSIONS
trans-2-Hexenal could be a natural alternative to fungicides in the control of P. expansum infections. Further work is needed to study the methods and conditions avoiding the persistence of off-odours and off-flavours in pears after their exposure to trans-2-hexenal vapours.
Neri
F
F
Criof - Department of Protection and Improvement of Agricultural Food Products, Alma Mater Studiorum - University of Bologna, Cadriano, Bologna, Italy. fiorella.neri@unibo.it
Mari
M
M
Menniti
A M
AM
Brigati
S
S
D000447:Aldehydes / Q000032:analysis / Q000494:pharmacology*; D000935:Antifungal Agents / Q000032:analysis / Q000494:pharmacology*; D004350:Drug Residues / Q000032:analysis; D005516:Food Microbiology; D005519:Food Preservation; D006801:Humans; D009812:Odorants; D010365:Patulin / Q000032:analysis; D010407:Penicillium / Q000187:drug effects* / Q000502:physiology; D010935:Plant Diseases / Q000382:microbiology*; D031989:Pyrus / Q000737:chemistry / Q000382:microbiology*; D013997:Time Factors
D000447:Aldehydes; D000935:Antifungal Agents; C051750:2-hexenal; D010365:Patulin