姜黄素联合乙二胺四乙酸对荧光假单胞菌的光动力灭活作用

为探讨姜黄素对荧光假单胞菌的光动力灭活（photodynamic inactivation，PDI）作用，提高光动力杀菌效果，本研究以乙二胺四乙酸（ethylene diamine tetraacetic acid，EDTA）为协同剂，对PDI的应用条件进行优化，探讨姜黄素联合EDTA对荧光假单胞菌生物膜的PDI作用，并进一步将姜黄素联合EDTA应用于新鲜猪肉的保鲜。结果表明，与空白组相比，0.5%（质量分数，下同）EDTA与75 μmol/L 姜黄素经光照（功率密度200 mW/cm2、波长460 nm、光照时间20 min），荧光假单胞菌的菌落数对数值减小了6.40（lg（CFU/mL）），玻璃及丙烯腈二乙烯丁二烯树脂（acrylonitrile-butadiene-styrene，ABS）板表面生物膜中荧光假单胞菌菌落数对数值分别减小4.57、6.60（lg（CFU/mL）），均显著高于单独使用姜黄素组的灭活效果（P＜0.05）。新鲜猪肉经75 μmol/L姜黄素和0.5% EDTA处理并光照后（功率密度100 mW/cm2、波长460 nm、光照时间20 min），与空白组相比，保存到第10天其表面荧光假单胞菌菌落数对数值减小3.05（lg（CFU/mL）），质量损失率为2.14%，色差ΔE随姜黄素浓度增加而增大；且处理后的猪肉随贮藏时间的延长pH值变化缓慢。说明PDI处理对猪肉的感官品质影响较小，能较好地维持猪肉pH值，对猪肉表面荧光假单胞菌有显著抑制作用。结论：姜黄素联合EDTA的PDI处理显著延长了猪肉的保鲜期，本研究可为光动力技术在食品杀菌及贮藏保鲜中的应用提供新的理论参考和技术支持。

Photodynamic Inactivation Effect of Curcumin Combined with Ethylene Diamine Tetraacetic Acid on Pseudomonas fluorescens

In order to investigate the photodynamic inactivation (PDI) effect of curcumin on Pseudomonas fluorescens and to improve the efficiency of photodynamic sterilization, ethylene diamine tetraacetic acid (EDTA) was used as a synergist to enhance the bactericidal efficacy of curcumin and the PDI conditions were optimized. The PDI effect of curcumin combined with EDTA on P. fluorescens biofilm was investigated. Curcumin combined with EDTA was further applied to the preservation of fresh pork. The results showed that after 20?min of illumination at a power density of 200?mW/cm2 and a wavelength of 460?nm, the total count of P. fluorescens was decreased by 6.40?(lg(CFU/mL)) by treatment with 0.5% (m/V) EDTA and 75?μmol/L curcumin, and the count of P. fluorescens in the biofilms formed on glass and acrylonitrile-butadiene-styrene (ABS) plates by 4.57 and 6.60?(lg(CFU/mL)), respectively; the effect of the combined treatment was significantly more pronounced than that of curcumin alone (P < 0.05). Fresh pork was treated with 75?μmol/L curcumin and 0.5% EDTA and illuminated at a power density of 100?mW/cm2 and a wavelength of 460?nm for 20?min. On day 10 of storage, the count of P. fluorescens on pork was decreased by 3.05?(lg (CFU/mL)) compared to the untreated control group, and the mass of pork was decreased by 2.14%. The color difference ΔE increased with increasing curcumin concentration. The pH of the treated pork changed slowly during storage. It was indicated that PDI treatment had a slight impact on the sensory quality of pork while maintaining its pH, and significantly inhibited the proliferation of P. fluorescens on it. In conclusion, photodynamic treatment using curcumin combined with EDTA significantly prolongs the shelf life of pork. This study is expected to provide a new theoretical reference and technical support for the application of photodynamic technology in food sterilization and preservation.