Decontamination of cut carrot by Persteril® agent based on the action of peroxyacetic acid

The use of cleaned and cut fresh vegetables for direct consumption without cooking is limited by the short shelf life caused by the fast growth of contaminating microflora. With the aim of reducing the contamination, we tested the possible use of peroxyacetic acid (brand name Persteril) as an additive. Peroxyacetic acid breaks down quickly into oxygen and acetic acid; with the latter quickly vaporising through the packaging. Tests were carried out on a model of pre-washed, cut, and re-washed carrots, which were left naturally contaminated to resemble real grocery store conditions. Four decontamination regimens were applied: (1) rinsing with ordinary tap (drinking) water, (2) rinsing with a 0.2% solution of Persteril, (3) rinsing with a 0.2% solution of Persteril + the addition of concentrated Persteril into the packaging before sealing, and (4) rinsing with a 0.2% solution of Persteril + the addition of concentrated Persteril into the packaging before sealing + another addition of concentrated Persteril after 24 hours. The total number of aerobe mesophilic microorganisms (TNM) and the numbers of yeasts and molds were monitored in the samples taken during 28-days of storage. The last decontamination regimen reduced the initial contamination by TNM by about 1× 104 CFU/g or 4 log units and no further microbial growth was observed during storage. Yeasts and molds were reduced by about 3.16 × 103 CFU/g or 3.5 log units. No statistically significant changes in colour, texture or taste were noted during storage. There was a slight change immediately after the application in the odour of samples treated with concentrated Persteril; however, the odour returned to original levels during storage.