De Baerdemaeker Klaas, Van Reepingen Amber, Nikiforov Anton, De Meulenaer Bruno, De Geyter Nathalie, Devlieghere Frank
Research Unit Food Microbiology and Food Preservation (FMFP), Department of Food Technology, Safety and Health, Ghent University, Coupure Links 653, 9000 Ghent, Belgium.
Research Unit Plasma Technology (RUPT), Department of Applied Physics, Ghent University, Sint-Pietersnieuwstraat 41, 9000 Ghent, Belgium.
Foods. 2023 Jan 13;12(2):386. doi: 10.3390/foods12020386.
The non-thermal plasma (NTP) treatment of food products as an alternative for thermal processing has been investigated over the last few years. This quasi-neutral gas contains a wide variety of reactive oxygen and nitrogen species (RONS), which could be lethal for bacterial cells present in the product. However, apart from only targeting bacteria, the RONS will also interact with components present in the food matrix. Therefore, these food components will protect the microorganisms, and the NTP treatment efficiency will decrease. This effect was investigated by supplementing a plain agar medium with various representative food matrix components. After inoculation with O157:H7 (STEC) MB3885, the plates were treated for 30 s by a multi-hollow surface dielectric barrier discharge (MSDBD) generated in either dry air or air at 75% humidity, at constant power (25.7 ± 1.7 W). Subsequently, the survival of the cells was quantified. It has been found that the addition of casein hydrolysate (7.1 ± 0.2 m%), starch (2.0 m%), or soybean oil (4.6 m%) decreased the inactivation effect significantly. Food products containing these biomolecules might therefore need a more severe NTP treatment. Additionally, with increasing humidity of the plasma input gas, ozone levels decreased, and the bactericidal effect was generally less pronounced.
在过去几年中，人们对用非热等离子体（NTP）处理食品作为热加工的替代方法进行了研究。这种准中性气体含有多种活性氧和氮物种（RONS），它们可能对食品中存在的细菌细胞具有致死性。然而，RONS除了仅靶向细菌外，还会与食品基质中存在的成分相互作用。因此，这些食品成分会保护微生物，从而降低NTP处理效率。通过在普通琼脂培养基中添加各种具有代表性的食品基质成分来研究这种效应。接种O157:H7（STEC）MB3885后，平板在恒定功率（25.7±1.7W）下，用在干燥空气或75%湿度空气中产生的多空心表面介质阻挡放电（MSDBD）处理30秒。随后，对细胞的存活率进行定量。已发现添加酪蛋白水解物（7.1±0.2m%）、淀粉（2.0m%）或大豆油（4.6m%）会显著降低灭活效果。因此，含有这些生物分子的食品可能需要更严格的NTP处理。此外，随着等离子体输入气体湿度的增加，臭氧水平降低，杀菌效果通常也不那么明显。
