摘要
This study elucidated the antimicrobial effect of ammonium persulfate(PS),ultrasound(US),and 40-60℃mild heat on Staphylococcus aureus ATCC 27213 under various growth conditions,including non-adaptation,pHadaptation,and aridity-adaptation,in buffered peptone water(BPW)and on orange peel surfaces.For nonadapted,pH-adapted,and aridity-adapted S.aureus,the combined treatment of PS,US,and mild heat showed a synergistic effect,with log reductions of 2.05,6.44,and 1.11 log CFU/mL in BPW after 6 min,respectively.Mechanistic experiments showed that pH-adapted S.aureus had increased SOD activity due to oxidative stress from the acidic environment,but the introduction of PS further elevated this stress,leading to greater cell death primarily through membrane damage,as confirmed by TEM,with leakage of nucleic acids and proteins.This technique was applied to an orange peel washing system,effectively inactivating aridity-adapted S.aureus,resulting in 3.51 log CFU/cm^(2)and 3.20 log CFU/mL reductions on orange peel and in BPW washing water,respectively,after a 6-min treatment,without any quality changes,including color and texture attributes.The enhanced inactivation on orange peel may be attributed to the presence of compounds such as ascorbic acid and limonene,which further activate persulfate and exhibit antimicrobial properties,thereby contributing to the increased efficacy of the treatment.The combined PS,US,and mild heat treatment provides an effective strategy for controlling resilient bacterial strains in the food industry,enhancing food safety through oxidative stress and mild thermal effects.
基金
supported by the New Faculty Startup Fund from Seoul National University.
