Koutsoumanis K P, Stamatiou A P, Drosinos E H, Nychas G-J E
Laboratory of Food Microbiology and Hygiene, Faculty of Agriculture, Department of Food Science and Technology, Aristotle University of Thessalonica, Thessalonica, GR-54124, Greece.
Food Microbiol. 2008 Oct;25(7):915-21. doi: 10.1016/j.fm.2008.05.006. Epub 2008 May 29.
The changes in microbial flora of minced pork during aerobic storage at 0, 5, 10 and 15 degrees C were studied. Minced pork samples (100g) were packed using two types of packaging films: (a) a common food film with high permeability (HPF) and (b) a film with low permeability (LPF). The respiratory activity of meat microflora and the use of a LPF resulted in a modified atmosphere in the package headspace developed during storage. Oxygen concentration decreased from 18.7% (after packaging) to 7% (after 15 days of storage) in packages with LPF, stored at 0 degrees C, while CO(2) increased from 3% to 10.5%, respectively. On the contrary, no significant atmosphere changes were observed during storage of HPF packages. The self-developed modified atmosphere in LPF packages resulted in a significant inhibition of pseudomonad growth which was more pronounced at low storage temperatures. For example, during storage at 0 degrees C, the growth rate of pseudomonads in meat packed with LPF was reduced by 48.7% compared to HPF. At 10 degrees C the latter reduction decreased to 13.7%. LPF packaging was also found to inhibit the growth of Brochothrix thermosphacta but this inhibition was weaker compared to pseudomonads. The effect of storage temperature on the growth rate of pseudomonads and B. thermosphacta in minced pork packed with the different films was modeled using an Arrhenius equation. For both bacteria, the activation energy was higher for LPF packaging. This can be attributed to the increased inhibitory effect of the modified atmosphere at lower storage temperature. The Arrhenius model was further used to evaluate the effect of temperature on the time required by the two bacteria to reach a spoilage level of 10(7)CFU/g. The results showed that when LPF packaging is combined with effective temperature control the time-to-spoilage can be significantly extended compared to HPF packaging.
研究了碎猪肉在0、5、10和15℃有氧储存期间微生物菌群的变化。使用两种包装薄膜对100克碎猪肉样品进行包装：（a）具有高渗透性的普通食品薄膜（HPF）和（b）具有低渗透性的薄膜（LPF）。肉类微生物菌群的呼吸活性以及使用LPF导致储存期间包装顶空形成了改性气氛。在0℃储存的LPF包装中，氧气浓度从18.7%（包装后）降至7%（储存15天后），而二氧化碳分别从3%增加到10.5%。相反，在HPF包装储存期间未观察到明显的气氛变化。LPF包装中自行形成的改性气氛导致假单胞菌生长受到显著抑制，在低温储存时更为明显。例如，在0℃储存期间，与HPF相比，用LPF包装的肉类中假单胞菌的生长速率降低了48.7%。在10℃时，后者的降低降至13.7%。还发现LPF包装抑制了热杀索丝菌的生长，但这种抑制作用比假单胞菌弱。使用阿伦尼乌斯方程对储存温度对用不同薄膜包装的碎猪肉中假单胞菌和热杀索丝菌生长速率的影响进行了建模。对于这两种细菌，LPF包装的活化能更高。这可归因于在较低储存温度下改性气氛的抑制作用增强。阿伦尼乌斯模型进一步用于评估温度对两种细菌达到10⁷CFU/g腐败水平所需时间的影响。结果表明，当LPF包装与有效的温度控制相结合时，与HPF包装相比，腐败时间可显著延长。
