title: Volatile trans-2-hexenal, a soybean aldehyde, inhibits Aspergillus flavus growth and aflatoxin production in corn.
abstract: Trans-2-hexenal, a volatile aldehyde, is produced by soybean (Glycine max [L.] Merr) and other plants via the lipoxygenase pathway. In vitro tests showed it significantly (P < 0.001) reduced Aspergillus flavus germinating conidial viability at 10 μM, with approximately 95% viability reduction observed at 20 μM. The viability of nongerminated conidia was not reduced. To test the effectiveness of this volatile to prevent fungal growth in stored corn, trans-2-hexenal was pumped intermittently into glass jars containing corn. Experiments were performed to determine the ability of 2 different pump cycle time-courses to prevent A. flavus growth on sterile corn (23% moisture). Intermittently (30-min pumping period) over 7 d, this volatile was pumped through 350 g of corn kernels inoculated with 1 mL of 3 × 10⁴ conidia of A. flavus. Controls consisted of (1) sterile corn, (2) corn inoculated with A. flavus with no pumped air, and (3) corn inoculated with A. flavus with intermittently pumped air. Aflatoxin B₁ (AFB₁), viability counts, and aldehyde concentration in the headspace were performed in each experiment. To determine whether an increased time period between volatile pumping would prevent A. flavus growth, a 2nd series of experiments were performed that were similar to the 1st series except that trans-2-hexenal (only) was pumped for a 30-min period every 12 h. Experiments were performed 3 times for each time course. Both experiments showed that intermittent pumping of volatile trans-2-hexenal significantly (P < 0.001) prevented A. flavus growth and aflatoxin B₁ production over a 7-d period.
  
  
  CONCLUSIONS
  Results from this study indicate that intermittent pumping of volatile trans-2-hexenal could be used to protect stored corn from A. flavus growth and aflatoxin contamination.
authors.affiliation: Southern Regional Research Center, Agricultural Research Service, U.S. Dept. of Agriculture, 1100 Robert E. Lee Blvd., New Orleans, LA 70124, USA. AnthonyDeLucca@ars.usda.gov
authors.forename: A J
authors.initials: AJ
authors.lastname: De Lucca
authors.forename: C H
authors.initials: CH
authors.lastname: Carter-Wientjes
authors.forename: S
authors.initials: S
authors.lastname: Boué
authors.forename: D
authors.initials: D
authors.lastname: Bhatnagar
mesh_terms: D016604:Aflatoxin B1 / Q000032:analysis / Q000378:metabolism*; D000447:Aldehydes / Q000032:analysis / Q000737:chemistry / Q000494:pharmacology*; D001231:Aspergillus flavus / Q000187:drug effects* / Q000254:growth & development / Q000302:isolation & purification / Q000502:physiology; D015169:Colony Count, Microbial; D005506:Food Contamination / Q000517:prevention & control; D005520:Food Preservatives / Q000032:analysis / Q000737:chemistry / Q000494:pharmacology*; D005659:Fungicides, Industrial / Q000032:analysis / Q000737:chemistry / Q000494:pharmacology; D050296:Microbial Viability / Q000187:drug effects; D009994:Osmolar Concentration; D012639:Seeds / Q000737:chemistry / Q000382:microbiology*; D013025:Glycine max / Q000737:chemistry; D013172:Spores, Fungal / Q000187:drug effects / Q000254:growth & development / Q000302:isolation & purification / Q000502:physiology; D013237:Stereoisomerism; D013997:Time Factors; D014835:Volatilization; D014867:Water / Q000032:analysis; D003313:Zea mays / Q000737:chemistry* / Q000382:microbiology*
chemical_list: D000447:Aldehydes; D005520:Food Preservatives; D005659:Fungicides, Industrial; D014867:Water; C051750:2-hexenal; D016604:Aflatoxin B1