Inactivation of Salmonella enterica ser. Enteritidis in tomato juice by combining of high-intensity pulsed electric fields with natural antimicrobials

The effect of high-intensity pulsed electric field (HIPEF) treatment (35kV/cm, 4 Its pulse length in bipolar mode without exceeding 38 degrees C) as influenced by treatment time (200,600, and 1000 mu s) and pulse frequency (100, 150, and 200 Hz) for Inactivating Salmonella enterica ser. Enteritidis inoculated in tomato juice was evaluated. Similarly, the effect of combining HIPEF treatment with citric acid (0.5%, 1.0%, 1.5%, and 2.0% [wt/vol]) or cinnamon bark oil (0.05%, 0.10%, 0.2%, and 0.3% [vol/vol]) as natural antimicrobials against S. Enteritidis in tomato juice was also studied, Higher treatment and lower pulse frequency produced the greater microbial Inactivation. Maxi-me an mum Inactivation of S. Enteritidis (4.184 log(10) units) in tomato juice by HIPEF was achieved when 1000 As and 100 Hz; of treatment time and pulse frequency, respectively, were applied. However, a greater microbial inactivation was found when S. Enteritidis was previously exposed to citric acid or cinnamon bark oil for 1 h in tomato juice. Synergistic effects were observed in HIPEF and natural antimicrobials. Nevertheless, combinations of HIPEF treatment with 2.0% of citric acid or 0.1% of cinnamon bark oil were needed for inactivating S. Enteritidis by more than 5.0 log(10) units (5.08 and 6.04 log(10) reductions, respectively). Therefore, combinations of HIPEF with organic acids or essential oils seem to be a promising method,to achieve the pasteurization in these kinds of products.