title: Evaluation and predictive modeling of shelf life of minced beef stored in high-oxygen modified atmosphere packaging at different temperatures.
abstract: The aims were: (1) to follow the freshness decay of minced beef stored in high-oxygen modified atmosphere packaging at different temperatures (4.3, 8.1 and 15.5 degrees C) by applying traditional methods (microbiological counts, color evaluation, thiobarbituric acid assay TBA, headspace gas composition) and e-nose; (2) to model the decay kinetics to obtain information about the maximum shelf life as function of storage conditions. The minced beef, packaged in modified atmosphere was supplied by a manufacturer at the beginning of its commercial life. The study demonstrated the ability of the traditional methods to describe the kinetics of freshness decay. The modeling of the experimental data and the comparison with microbiological or chemical thresholds allowed the setting, for each index, of a stability time above which the meat was no longer acceptable. The quality decay of meat was also evaluated by the headspace fingerprint of the same set of samples by means of a commercial e-nose. A clear discrimination between "fresh" and "old" samples was obtained using PCA and CA, determining at each temperature a specific range of stability time. The mean value of the stability times calculated for each index was 9 days at 4.3 degrees C (recommended storage temperature), 3-4 days at 8.1 degrees C (usual temperature in household refrigerators) and 2 days at 15.5 degrees C (abuse temperature). Resolution of the stability times allowed calculation of mean Q(10) values, i.e. the increase in rate for a 10 degrees C increase in temperature. The results show that the Q(10) values from the traditional methods (3.6-4.0 range) overlapped with those estimated with e-nose and color indexes (3.4 and 3.9, respectively).
authors.affiliation: DISTAM, Università degli Studi di Milano, Milano, Italy. sara.limbo@unimi.it
authors.forename: S
authors.initials: S
authors.lastname: Limbo
authors.forename: L
authors.initials: L
authors.lastname: Torri
authors.forename: N
authors.initials: N
authors.lastname: Sinelli
authors.forename: L
authors.initials: L
authors.lastname: Franzetti
authors.forename: E
authors.initials: E
authors.lastname: Casiraghi
mesh_terms: D000818:Animals; D002245:Carbon Dioxide / Q000032:analysis; D002417:Cattle; D003080:Cold Temperature; D015169:Colony Count, Microbial; D005511:Food Handling; D005516:Food Microbiology; D018857:Food Packaging / Q000379:methods*; D005524:Food Technology / Q000379:methods; D006090:Gram-Negative Bacteria / Q000302:isolation & purification; D007700:Kinetics; D056546:Lactobacillales / Q000302:isolation & purification; D008461:Meat Products / Q000032:analysis* / Q000382:microbiology*; D008954:Models, Biological; D008962:Models, Theoretical; D010100:Oxygen / Q000737:chemistry*; D010858:Pigmentation; D025341:Principal Component Analysis; D011786:Quality Control; D012034:Refrigeration; D017392:Thiobarbituric Acid Reactive Substances / Q000032:analysis; D055549:Volatile Organic Compounds / Q000032:analysis
chemical_list: D017392:Thiobarbituric Acid Reactive Substances; D055549:Volatile Organic Compounds; D002245:Carbon Dioxide; D010100:Oxygen