title: Efficacy of chlorine and peroxyacetic acid on reduction of natural microflora, Escherichia coli O157:H7, Listeria monocyotgenes and Salmonella spp. on mung bean sprouts.
abstract: Sprouts-related outbreaks have risen due to increased raw sprouts consumption. To minimize such cases, chemical sanitations are applied. While chlorine is commonly used, concerns with its effectiveness and health implication have prompted researchers to seek alternatives. Peroxyacetic acid (PAA) has shown efficacy in inactivating foodborne pathogens on fresh vegetables, and hence could be considered as an alternative. Thus, the objective of this study was to compare the efficacy of chlorine and PAA in inactivating Escherichia coli O157:H7, Listeria monocytogenes, Salmonella spp., and natural microflora on mung bean sprouts. Resistance of non- and acid-adapted pathogens to these sanitizer treatments was also evaluated. Un-inoculated and inoculated sprouts were treated with chlorine at 106, 130 and 170 ppm and PAA at 25, 51 and 70 ppm for 90 and 180 s at room temperature. Overall, the greater log reductions were obtained with the increase in the sanitizer concentration. For 180 s, chlorine treatment at 170 ppm reduced 2.0, 1.3, 1.5, 0.9-logs and PAA treatment at 70 ppm resulted in 2.3, 1.8, 2.1, 1.1-log reductions for non-adapted E. coli O157:H7, L. monocytogenes, Salmonella spp., and natural microflora, respectively. These results revealed that the efficacy of PAA was significantly better than or similar to that of chlorine. For acid-adapted cells, these sanitizer treatments were less effective with the ranges of 1.0-1.2-log reductions for chlorine and 1.1-1.6-log reductions for PAA compared to non-adapted cells, indicating that acid-adapted cells were more resistant to the sanitizing treatment. These data suggest that PAA may replace chlorine in the disinfection of mung bean sprouts and that acid-adapted pathogens should be used to design an effective sanitizing strategy.
authors.affiliation: Post-Harvest Technology Department, Technology & Industry Development Group, Agri-Food & Veterinary Authority of Singapore, Singapore 718915, Singapore.
authors.forename: Shan Yu
authors.initials: SY
authors.lastname: Neo
authors.forename: Pei Yan
authors.initials: PY
authors.lastname: Lim
authors.forename: Li Kai
authors.initials: LK
authors.lastname: Phua
authors.forename: Gek Hoon
authors.initials: GH
authors.lastname: Khoo
authors.forename: Su-Jung
authors.initials: SJ
authors.lastname: Kim
authors.forename: Seung-Cheol
authors.initials: SC
authors.lastname: Lee
authors.forename: Hyun-Gyun
authors.initials: HG
authors.lastname: Yuk
mesh_terms: D002713:Chlorine / Q000494:pharmacology*; D003257:Consumer Product Safety; D019453:Escherichia coli O157 / Q000187:drug effects* / Q000254:growth & development; D007887:Fabaceae / Q000254:growth & development / Q000382:microbiology*; D005520:Food Preservatives / Q000494:pharmacology*; D018525:Germination; D008089:Listeria monocytogenes / Q000187:drug effects* / Q000254:growth & development; D010463:Peracetic Acid / Q000494:pharmacology*; D012475:Salmonella / Q000187:drug effects* / Q000254:growth & development; D012639:Seeds / Q000254:growth & development / Q000382:microbiology; D014675:Vegetables / Q000382:microbiology*
chemical_list: D005520:Food Preservatives; D002713:Chlorine; D010463:Peracetic Acid
keywords: Acid adaptation; Chlorine; Foodborne pathogens; Mung bean sprouts; Peroxyacetic acid