Food Safety and Intervention Technologies Research Unit, USDA, ARS, ERRC, Delaware State University, Dover, DE, USA.
Food Safety and Intervention Technologies Research Unit, USDA, ARS, ERRC, Wyndmoor, PA, USA.
J Appl Microbiol. 2018 Apr;124(4):1017-1022. doi: 10.1111/jam.13638. Epub 2018 Jan 31.
The study aim was to evaluate the potential of 405-nm light as a virus intervention for blueberries.
Tulane virus (TV)-inoculated blueberries were treated with 4·2 mW cm of 405-nm light for 5-30 min. To mitigate thermal heating due to the intense light, a dry ice-chilled, nitrogen-based cooling system was utilized. Blueberries were rotated to ensure exposure of all surfaces to 405-nm light. Five-, 15- and 30-min treatments resulted in little or no inactivation of TV on blueberries (average log reductions of -0·18; -0·02; and +0·06 respectively). Since 405-nm light's inactivation mechanism may involve singlet oxygen, two singlet oxygen enhancers, riboflavin and rose bengal, were used to coat the blueberries prior to 405-nm light treatment. When 0·1% riboflavin or rose bengal was added, resulting in an average PFU reduction of -0·51 and -1·01 logs respectively. However, it was noted that the addition of riboflavin and rose bengal in the absence of 405-nm light treatment produced some inactivation. Average untreated log reductions for riboflavin and rose bengal were -0·13 and -0·66 respectively. Also, 60-30-s 405-nm light pulses with 2-min ambient cooling periods without the dry ice nitrogen cooling system did not inactivate TV, suggesting that oxygen limitation by the nitrogen CO mixture was not the cause of limited inactivation.
Overall results indicate that 405-nm light has some potential to inactivate viruses if singlet oxygen enhancers are present.
The potential of visible monochromatic violet/blue light (405 nm) as a nonthermal intervention for viruses on foods, such as berries that are prone to norovirus contamination, had not been previously evaluated. Use of food-grade singlet oxygen enhancer compounds in combination with visible spectra light may offer a means to inactivate foodborne viruses.
本研究旨在评估 405nm 光作为蓝莓中病毒干预手段的潜力。
用 4·2mW·cm 的 405nm 光对感染了 Tulane 病毒（TV）的蓝莓进行 5-30 分钟的处理。为了减轻由于强光产生的热加热，使用了干冰冷却的氮基冷却系统。蓝莓被旋转以确保所有表面都能暴露在 405nm 光下。5、15 和 30 分钟的处理导致 TV 在蓝莓上的失活很少或没有（平均对数减少分别为-0·18；-0·02；和+0·06）。由于 405nm 光的失活机制可能涉及单线态氧，因此在进行 405nm 光处理之前，使用两种单线态氧增强剂，核黄素和玫瑰红 Bengal，对蓝莓进行了涂层处理。当添加 0·1%核黄素或玫瑰红 Bengal 时，导致平均 PFU 减少分别为-0·51 和-1·01 个对数。然而，值得注意的是，在没有 405nm 光处理的情况下添加核黄素和玫瑰红 Bengal 也会产生一些失活。核黄素和玫瑰红 Bengal 的未经处理的平均对数减少分别为-0·13 和-0·66。此外，没有干冰氮气冷却系统的情况下，60-30 秒的 405nm 光脉冲，在 2 分钟的环境冷却期内，没有使 TV 失活，这表明氮 CO 混合物中的氧气限制不是失活有限的原因。
总体结果表明，如果存在单线态氧增强剂，405nm 光具有一定的潜力来使病毒失活。
作为一种非热干预手段，可见光单色紫/蓝光（405nm）对食品中病毒（如易受诺如病毒污染的浆果）的潜在应用尚未得到评估。使用食品级单线态氧增强化合物与可见光谱光的结合可能提供一种使食源病毒失活的方法。
