Decontamination of Green Onions and Baby Spinach by Vaporized Ethyl Pyruvate

Durak M. Z., Churey J. J., Gates M., Sacks G. L., Worobo R. W.

JOURNAL OF FOOD PROTECTION, vol.75, no.6, pp.1012-1022, 2012 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 75 Issue: 6
  • Publication Date: 2012
  • Doi Number: 10.4315/0362-028x.jfp-12-008
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.1012-1022
  • Yıldız Technical University Affiliated: Yes


Foodborne illnesses associated with fresh produce continue to be a major concern as consumer demand for healthier and nonthermally processed food increases. The objective of this study was to evaluate vaporized ethyl pyruvate (EP; CAS 617-35-6) as a safe alternative antimicrobial agent for the decontamination of Escherichia coli O157:H7 on green onions and spinach. Baby spinach leaves and green onions were inoculated with a five-strain cocktail of E. coli O157:H7 (pGFP) by the dipping method. Samples were treated with concentrations of 0, 42, 105, and 420 mg/liter vaporized EP in a 2.6-liter enclosed container. The efficacy of EP vapors for reducing E. coli O157:H7((GFP)) populations on green onions and baby spinach at 4 and 10 degrees C was monitored for 7 and 5 days, respectively. The lowest EP concentration (42 mg/liter) resulted in 1.7-log reduction of E. coli O157:H7((GFP)) on green onions after 7 days at 4 degrees C and a 1.9-log reduction after 5 days at 10 degrees C (P < 0.05). In baby spinach, the same concentration resulted in 0.9-log and 1.4-log reductions (P < 0.05) of E. coli O157:H7((GFP)) after 7 days at 4 degrees C and 5 days at 10 degrees C, respectively. On green onions, the highest concentration of EP (420 mg/liter) reduced the population of E. coli O157:H7((GFP)) by >4.7 log CFU/g after 7 days at 4 degrees C and 5 clays at 10 degrees C. The same concentration was also effective for reducing E. coli O157:H7((GFP)) populations in baby spinach by 4.3 log CFU/g after 7 days at 4 degrees C and by >6.5 log CFU/g after 3 days at 10 degrees C. Although the successful EP treatments minimally affected the sensory attributes of green onions, the treatments resulted in significant changes in the sensory attributes of baby spinach samples stored at 4 and 10 degrees C. These results indicate that EP is an effective antimicrobial that could be used to enhance the safety of fresh produce depending on the sensory characteristics of the product.