Arroyo Cristina, Dorozko Anna, Gaston Edurne, O'Sullivan Michael, Whyte Paul, Lyng James G
UCD School of Agriculture and Food Science, University College Dublin, Belfield, Dublin 4, Ireland.
UCD School of Agriculture and Food Science, University College Dublin, Belfield, Dublin 4, Ireland.
Food Microbiol. 2017 Oct;67:49-57. doi: 10.1016/j.fm.2017.06.001. Epub 2017 Jun 1.
This study evaluates the potential of continuous wave Ultraviolet C light (UV-C) and broad-spectrum intense pulsed light (in this study referred to as High Intensity Light Pulses, HILP) for the inactivation of pathogens of public concern in powdered infant formula (PIF) producers. To achieve this goal a sequential set of experiments were performed, firstly in clear liquid media, secondly on the surface of spherical beads under agitation and, finally in PIF. L. innocua was the most sensitive microorganism to both technologies under all conditions studied with reductions exceeding 4 log cycles in PIF. In the clear liquid medium, the maximum tolerance to light was observed for C. sakazakii against UV-C light and for B. subtilis spores against HILP, with a fluence of approximately 17 mJ/cm required for a 1 log cycle inactivation (D value) of each species. In PIF it was possible to inactivate >99% of the vegetative cell populations by HILP with a fluence of 199 mJ/cm and of B. subtilis spores by doubling the fluence. By contrast, for UV-C treatments a fluence of 2853 mJ/cm was needed for 99.9% reduction of C. sakazakii, which was the most light-resistant microorganism to UV-C. Results here obtained clearly show the potential for light-based interventions to improve PIF microbiological safety.
本研究评估了连续波紫外线C光（UV-C）和广谱强脉冲光（在本研究中称为高强度光脉冲，HILP）对婴幼儿配方奶粉（PIF）生产中公众关注的病原体的灭活潜力。为实现这一目标，进行了一系列实验，首先在清澈液体培养基中进行，其次在搅拌下的球形珠粒表面进行，最后在PIF中进行。在所有研究条件下，无害李斯特菌对这两种技术最为敏感，在PIF中的减少量超过4个对数循环。在清澈液体培养基中，阪崎肠杆菌对UV-C光、枯草芽孢杆菌孢子对HILP的光耐受性最强，每种菌1个对数循环灭活（D值）所需的辐照剂量约为17 mJ/cm²。在PIF中，通过199 mJ/cm²的辐照剂量，HILP可灭活>99%的营养细胞群体，将辐照剂量加倍可灭活枯草芽孢杆菌孢子。相比之下，对于UV-C处理，需要2853 mJ/cm²的辐照剂量才能使对UV-C最具光抗性的阪崎肠杆菌减少99.9%。此处获得的结果清楚地表明了基于光的干预措施改善PIF微生物安全性的潜力。
