title: Differentiation of Volatile Profiles from Stockpiled Almonds at Varying Relative Humidity Levels Using Benchtop and Portable GC-MS.
abstract: Contamination by aflatoxin, a toxic metabolite produced by Aspergillus fungi ubiquitous in California almond and pistachio orchards, results in millions of dollars of lost product annually. Current detection of aflatoxin relies on destructive, expensive, and time-intensive laboratory-based methods. To explore an alternative method for the detection of general fungal growth, volatile emission profiles of almonds at varying humidities were sampled using both static SPME and dynamic needle-trap SPE followed by benchtop and portable GC-MS analysis. Despite the portable SPE/GC-MS system detecting fewer volatiles than the benchtop system, both systems resolved humidity treatments and identified potential fungal biomarkers at extremely low water activity levels. This ability to resolve humidity levels suggests that volatile profiles from germinating fungal spores could be used to create an early warning, nondestructive, portable detection system of fungal growth.
authors.affiliation: Chemistry Research Unit, Center for Medical, Agricultural and Veterinary Entomology, Agricultural Research Service, U.S. Department of Agriculture , 1700 SW 23rd Drive, Gainesville, Florida 32608, United States.
authors.forename: John J
authors.initials: JJ
authors.lastname: Beck
authors.affiliation: Chemistry Research Unit, Center for Medical, Agricultural and Veterinary Entomology, Agricultural Research Service, U.S. Department of Agriculture , 1700 SW 23rd Drive, Gainesville, Florida 32608, United States.
authors.forename: Denis S
authors.initials: DS
authors.lastname: Willett
authors.affiliation: Foodborne Toxin Detection and Prevention, Western Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture , 800 Buchanan Street, Albany, California 94710, United States.
authors.forename: Wai S
authors.initials: WS
authors.lastname: Gee
authors.affiliation: Foodborne Toxin Detection and Prevention, Western Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture , 800 Buchanan Street, Albany, California 94710, United States.
authors.forename: Noreen E
authors.initials: NE
authors.lastname: Mahoney
authors.affiliation: Wonderful Orchards , 6801 E. Lerdo Highway, Shafter, California 93263, United States.
authors.forename: Bradley S
authors.initials: BS
authors.lastname: Higbee
mesh_terms: D001230:Aspergillus / Q000737:chemistry / Q000254:growth & development / Q000378:metabolism*; D002140:California; D005506:Food Contamination / Q000032:analysis*; D008401:Gas Chromatography-Mass Spectrometry / Q000295:instrumentation / Q000379:methods*; D000068181:Prunus dulcis / Q000382:microbiology*; D012639:Seeds / Q000382:microbiology; D013172:Spores, Fungal / Q000254:growth & development / Q000378:metabolism; D055549:Volatile Organic Compounds / Q000737:chemistry* / Q000378:metabolism; D014867:Water / Q000032:analysis / Q000378:metabolism
chemical_list: D055549:Volatile Organic Compounds; D014867:Water
keywords: aflatoxin; fungal detection; signaling volatiles; spore; water activity