Marcos Begonya, Aymerich Teresa, Monfort Josep M, Garriga Margarita
IRTA-Food Technology, Finca Camps i Armet, E-17121 Monells, Spain.
Int J Food Microbiol. 2007 Nov 30;120(1-2):152-8. doi: 10.1016/j.ijfoodmicro.2007.06.003. Epub 2007 Jun 12.
The antimicrobial effect against L. monocytogenes of biodegradable films (alginate, zein and polyvinyl alcohol) containing enterocins was investigated. Survival of the pathogen was studied by means of challenge tests performed at 6 degrees C during 8 and 29 days, for air-packed and vacuum-packed sliced cooked ham, respectively. Air packaging was tested with two concentrations of enterocins (200 and 2000 AU/cm2). Control air-packed cooked ham showed an increase of L. monocytogenes from 10(4) to 10(7) CFU/g after 8 days. By contrast, packaging with antimicrobial films effectively slowed down the pathogen's growth, leading to final counts lower than in control lots. Air-packaging with alginate films containing 2000 AU/cm2 of enterocins effectively controlled L. monocytogenes for 8 days. An increase of only 1 log unit was observed in zein and polyvinyl alcohol lots at the same enterocin concentration. Vacuum packaging with films containing enterocins (2000 AU/cm2) also delayed the growth of the pathogen. No increase from inoculated levels was observed during 15 days in antimicrobial alginate films. After 29 days of storage, the lowest counts were obtained in samples packed with zein and alginate films containing enterocins, as well as with zein control films. The most effective treatment for controlling L. monocytogenes during 6 degrees C storage was vacuum-packaging of sliced cooked ham with alginate films containing 2000 AU/cm2 of enterocins. From the results obtained it can concluded that antimicrobial packaging can improve the safety of sliced cooked ham by delaying and reducing the growth of L. monocytogenes.
研究了含有肠毒素的可生物降解薄膜（藻酸盐、玉米醇溶蛋白和聚乙烯醇）对单核细胞增生李斯特菌的抗菌效果。通过分别在6℃下对气调包装和真空包装的切片熟火腿进行8天和29天的挑战试验，研究了该病原体的存活情况。气调包装试验使用了两种浓度的肠毒素（200和2000 AU/cm²）。对照气调包装的熟火腿在8天后单核细胞增生李斯特菌数量从10⁴增加到10⁷ CFU/g。相比之下，用抗菌薄膜包装有效地减缓了病原体的生长，导致最终计数低于对照批次。用含有2000 AU/cm²肠毒素的藻酸盐薄膜进行气调包装可有效控制单核细胞增生李斯特菌8天。在相同肠毒素浓度下，玉米醇溶蛋白和聚乙烯醇批次仅观察到1个对数单位 的增加。用含有肠毒素（2000 AU/cm²）的薄膜进行真空包装也延迟了病原体的生长。在抗菌藻酸盐薄膜中，15天内未观察到接种水平以上的增加。储存29天后，用含有肠毒素的玉米醇溶蛋白和藻酸盐薄膜以及玉米醇溶蛋白对照薄膜包装的样品中计数最低。在6℃储存期间，控制单核细胞增生李斯特菌最有效的处理方法是用含有2000 AU/cm²肠毒素的藻酸盐薄膜对切片熟火腿进行真空包装。从获得的结果可以得出结论，抗菌包装可以通过延迟和减少单核细胞增生李斯特菌的生长来提高切片熟火腿的安全性。
