Plasma-functionalized liquids (PFL) emerge as an effective sanitizer with great potential to be against a variety of microorganisms but their applications on seafood products are limited. In the current study, the physicochemical properties of plasma-functionalized water (PFW) and plasma-functionalized buffer (PFB), and their antimicrobial activities on grass carp, were investigated under different conditions of applied voltage, plasma exposure time and immersion time. Results indicated that increasing voltage and exposure time led to an increase in levels of reactive species in PFW and PFB, while the presence of citric acid in the buffer accelerated possible reactions of active species and enhanced acidification, electrical conductivity (EC) and oxidation-reduction potential (ORP) as compared with PFW. Results also showed that the decontamination efficiency depended on voltage and exposure time, which could be up to 1.21 and 1.52 log reductions for L. monocytogenes, and 1.44 and 1.75 log reductions for S. Typhimurium for PFW and PFB, respectively. Immersing fish fillet samples in both solutions also led to a reduced pH and increased total acidity level in the samples with no significant difference (p > 0.05) between PFW and PFB, while PFB greatly affected the colour change in fish fillets. This study provided a basis for the potential development of novel sanitizers to decontaminate microorganism in fish and seafood products.

Key points

• Cold plasma induced a time-dependent change of active species in water and buffer.

• Ionic equilibria of conjugate base and weak acid in buffer enhanced RNS and ROS.

• Decontamination depended on voltage and exposure time of liquids to cold plasma.

• Reduced pH, increased acidity and colour change were noticed in treated fish.

• A basis for developing potential sanitizers for seafood products is provided.

血浆功能化液体（PFL）成为一种有效的消毒剂，具有抗多种微生物的巨大潜力，但它们在海产品上的应用受到限制。在本研究中，研究了在不同施加电压，血浆暴露时间和浸泡时间条件下，血浆功能化水（PFW）和血浆功能化缓冲液（PFB）的理化性质，以及它们对草鱼的抗菌活性。结果表明，增加电压和暴露时间会导致PFW和PFB中反应性物种的水平增加，而缓冲液中柠檬酸的存在会加速活性物种的可能反应，并增强酸化，电导率（EC）和氧化还原与PFW相比的潜力（ORP）。单增李斯特菌，和1.44和1.75的对数减少为S.鼠伤寒沙门氏菌分别PFW和PFB。将鱼片样品浸入这两种溶液中还导致样品中的pH降低和总酸度升高，PFW和PFB之间没有显着差异（p > 0.05），而PFB极大地影响了鱼片的颜色变化。这项研究为新型杀菌剂潜在的开发提供了基础，该杀菌剂可以净化鱼类和海鲜产品中的微生物。

关键点

•冷等离子体诱导了水和缓冲液中活性物质的时间依赖性变化。

•缓冲液中共轭碱和弱酸的离子平衡增强了RNS和ROS。

•去污取决于电压和液体对冷等离子体的暴露时间。

•在处理过的鱼中发现pH降低，酸度增加和颜色改变。

•为开发潜在的海产品消毒剂提供了基础。