Effect of modified atmosphere packaging on the growth of spoilage microorganisms and Listeria monocytogenes on fresh cheese
| Autor: | Stephanie R.B. Brown, Emily C. Forauer, Dennis J. D'Amico |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
Vacuum
Food spoilage Colony Count Microbial Cold storage Food Contamination medicine.disease_cause Shelf life 0404 agricultural biotechnology Starter Listeria monocytogenes Cheese Food Preservation Genetics medicine Animals Food science Chemistry Atmosphere Food Packaging 04 agricultural and veterinary sciences 040401 food science Coliform bacteria Modified atmosphere Food Microbiology Animal Science and Zoology Food Science Mesophile |
| Zdroj: | Journal of dairy science. 101(9) |
| ISSN: | 1525-3198 |
| Popis: | Queso Fresco has a limited shelf life and has been shown to support the rapid growth of Listeria monocytogenes during refrigerated storage. In addition to improving quality and extending shelf life, modified atmosphere packaging (MAP) has been used to control the growth of pathogenic microorganisms in foods. The objectives of this study were to determine the effects of MAP conditions on the survival and growth of spoilage microorganisms and L. monocytogenes during storage of Queso Fresco manufactured without starter cultures. For L. monocytogenes experiments, cheeses were surface inoculated at ∼4 log10 cfu/g before packaging. Inoculated and uninoculated (shelf life experiments) cheeses were placed in 75-µm high-barrier pouches, packaged under 1 of 7 conditions including air, vacuum, or combinations of N2 and CO2 [100% N2 (MAP1), 30% CO2:70% N2 (MAP2), 50% CO2:50% N2 (MAP3), or 70% CO2:30% N2 (MAP4), 100% CO2 (MAP5)], and stored at 7°C. Samples were removed weekly through 35 d of storage. Listeria monocytogenes counts were determined for inoculated samples. Uninoculated samples were assayed for mesophilic and psychrotolerant counts, lactic acid bacteria, coliforms, and yeast and mold. In general, cheeses packaged under conditions consisting of higher contents of CO2 had lower pH levels during storage compared with those stored in conditions with lower levels or no CO2 at all. Similarly, the antimicrobial efficacy of MAP in controlling spoilage microorganisms increased with increasing CO2 content, whereas conditions consisting of 100% N2, vacuum, or air were less effective. Mean L. monocytogenes counts remained near inoculation levels for all treatments at d 1 but increased ∼2 log10 cfu/g on cheeses packaged in air, vacuum, and 100% N2 (MAP1) conditions at d 7 and an additional ∼1.5 log10 cfu/g at d 14 where they remained through 35 d. In contrast, treatments consisting of 70% CO2 (MAP4) and 100% CO2 (MAP5) limited increases in mean L. monocytogenes counts to |
| Databáze: | OpenAIRE |
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