title: Effect of O(2)-CO(2) enriched atmospheres on microbiological growth and volatile metabolite production in packaged cooked peeled gray shrimp (Crangon crangon).
abstract: This study evaluated the effect of modified atmospheres (MAs) with different O(2) concentrations on microbial growth and volatile metabolite production in gray shrimp (Crangon crangon) during storage at 4 °C. Eight MAs were evaluated in total. Four of the MAs evaluated were without CO(2): 0/0/100, 0/10/90, 0/30/70, 0/50/50 (% CO(2)/O(2)/N(2)) whilst the other four MAs all contained 50% CO(2): 50/0/50, 50/10/40, 50/30/20, 50/50/0 (% CO(2)/O(2)/N(2)). Volatile spoilage metabolites were identified by thermal desorption GC-MS and quantified during storage by selective ion flow tube mass spectrometry (SIFT-MS). In comparison to microbial growth observed with an atmosphere of 100% N(2), microbial growth was stimulated by the addition of O(2) in the MAP in the absence of CO(2.) Under these conditions the total psychrotrophic counts exceeded 7 log cfug(-1) after just 3 days of storage. However, in the presence of 50% CO(2) the total psychrotrophic count exceeded 7 log cfug(-1) after 5 days of storage. The combination of 50% CO(2) and 50% O(2) significantly inhibited microbial growth. For this MA condition, a diminishing effect on the production of metabolites was also observed, especially for amines and sulfur compounds, which constituted the major fraction of components causing the offensive odor.
authors.affiliation: Laboratory of Food Microbiology and Food Preservation (LFMFP), Ghent University, Coupure Links 653, 9000 Ghent, Belgium. bert.noseda@ugent.be
authors.forename: Bert
authors.initials: B
authors.lastname: Noseda
authors.forename: Joke
authors.initials: J
authors.lastname: Goethals
authors.forename: Lies
authors.initials: L
authors.lastname: De Smedt
authors.forename: Jo
authors.initials: J
authors.lastname: Dewulf
authors.forename: Simbarashe
authors.initials: S
authors.lastname: Samapundo
authors.forename: Herman
authors.initials: H
authors.lastname: Van Langenhove
authors.forename: Frank
authors.initials: F
authors.lastname: Devlieghere
mesh_terms: D000818:Animals; D001419:Bacteria / Q000254:growth & development* / Q000378:metabolism; D002245:Carbon Dioxide / Q000378:metabolism; D015169:Colony Count, Microbial; D033501:Crangonidae / Q000382:microbiology*; D005506:Food Contamination / Q000032:analysis; D005511:Food Handling; D005516:Food Microbiology; D018857:Food Packaging / Q000379:methods*; D006801:Humans; D009584:Nitrogen / Q000378:metabolism; D010100:Oxygen / Q000378:metabolism; D012758:Shellfish / Q000032:analysis / Q000382:microbiology*; D055549:Volatile Organic Compounds / Q000032:analysis; D014835:Volatilization
chemical_list: D055549:Volatile Organic Compounds; D002245:Carbon Dioxide; D009584:Nitrogen; D010100:Oxygen