An intervention technology employing simultaneous ultraviolet (UV)-C and cold plasma (CP) treatments was developed to inactivate indigenous mesophilic aerobic bacteria in black peppercorns. At higher UV intensity of UV-CP treatment and water activity of black peppercorns, microbial inactivation levels increased up to 0.6 and 1.7 log CFU/g, respectively. Using a response surface analysis, optimum CP voltage and treatment time for inactivating indigenous bacteria in black peppercorns by UV-CP treatment were predicted to be 10.3 kV and 22.1 min, respectively; these inactivated indigenous bacteria and Bacillus tequilensis spores by 3.4 log CFU/g and 1.7 log spores/g, respectively, with minimal increase in temperature (4.5 ± 1.2 °C). The bacterial inactivation rate (3.4 log CFU/g) achieved by UV-CP treatment was higher than the sum (2.7 log CFU/g) of the inactivation rates of individual UV and CP treatments. UV-CP treatment did not alter the color of black peppercorns and shows potential for application in non-thermal microbial decontamination of black peppercorns.

Industrial relevance

This study has developed a novel system for non-thermal microbial inactivation in black peppercorns using simultaneous UV-C and CP treatment (UV-CP treatment). UV-CP treatment was effective in inactivating indigenous bacteria in black peppercorns, including Bacillus tequilensis spores, and had an additive effect on microbial inactivation. The efficacy of treatment in microbial inactivation increased with higher water activity of black peppercorns. The bacterial inactivation efficacy was also influenced by the UV intensity and treatment time. The results of this study demonstrated that UV-CP treatment has the potential to be employed as a non-thermal technology to disinfect black peppercorns and possibly other spices, without affecting their color.

中文翻译：

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通过冷血浆和紫外线C同时处理对黑胡椒进行微生物净化

开发了一种采用同时紫外线（UV）-C和冷等离子体（CP）处理的干预技术，以灭活黑胡椒中的固有嗜温需氧细菌。在较高的UV-CP处理紫外线强度和黑胡椒的水活度下，微生物的失活水平分别增加至0.6和1.7 log CFU / g。使用响应表面分析，通过UV-CP处理灭活黑胡椒中本地细菌的最佳CP电压和处理时间预计分别为10.3 kV和22.1分钟。这些灭活的本土细菌和芽孢杆菌孢子分别以3.4 log CFU / g和1.7 log孢子/ g的温度变化（4.5±1.2°C）。通过UV-CP处理达到的细菌灭活率（3.4 log CFU / g）高于各个UV和CP处理的灭活率总和（2.7 log CFU / g）。UV-CP处理不会改变黑胡椒的颜色，并显示出在黑胡椒的非热微生物净化中的应用潜力。

行业相关性

这项研究开发了一种新的系统，可通过同时进行UV-C和CP处理（UV-CP处理）实现黑胡椒非热微生物灭活。UV-CP处理可有效灭活黑胡椒中的本地细菌，包括龙舌兰芽孢杆菌的芽孢，并且对微生物灭活具有累加作用。黑胡椒的较高水分活度可提高微生物灭活的治疗效果。细菌灭活功效还受到紫外线强度和治疗时间的影响。这项研究的结果表明，UV-CP处理有可能被用作非热技术来消毒黑胡椒和其他香料，而不会影响其颜色。