AIM: To investigate the efficacy of steam pasteurization for reducing Salmonella serotype Enteritidis on raw almond surfaces. METHODS AND RESULTS: Nonpareil almonds were inoculated to 10(7-8) CFU g(-1) with a Salm. Enteritidis cocktail (Salm. Enteritidis 43353, ME-13, ME-14) or Salm. Enteritidis phage type 30, dried overnight and subjected to steam treatments through a pilot-sized vertical pasteurization machine for 5, 15, 25, 35, 45, 55 and 65 s to investigate the effect of steam on a single layer of almond. Survival of Salm. Enteritidis was evaluated with tryptic soy agar and xylose lysine desoxycholate overlay for total and healthy cells, respectively. No significant differences (P > 0.05) in reduction were observed between the Salm. Enteritidis cocktail and Salm. Enteritidis PT 30 inoculum. Reduction of Salm. Enteritidis increased as a function of treatment time, with 25 s being sufficient to achieve a 5-log reduction. Discolouration and visible formation of wrinkles were observed following steam pasteurization of more than 35 s. CONCLUSIONS: Steam pasteurization of 25 s is sufficient to achieve a 5-log reduction of Salm. Enteritidis inoculated on raw almonds without visual quality degradation. SIGNIFICANCE AND IMPACT OF THE STUDY: Steam pasteurization is an effective alternative to reduce or prevent Salm. Enteritidis contamination on raw almonds.
AIM: To investigate the efficacy of steam pasteurization for reducing Salmonella serotype Enteritidis on raw almond surfaces. METHODS AND RESULTS: Nonpareil almonds were inoculated to 10(7-8) CFU g(-1) with a Salm. Enteritidis cocktail (Salm. Enteritidis 43353, ME-13, ME-14) or Salm. Enteritidis phage type 30, dried overnight and subjected to steam treatments through a pilot-sized vertical pasteurization machine for 5, 15, 25, 35, 45, 55 and 65 s to investigate the effect of steam on a single layer of almond. Survival of Salm. Enteritidis was evaluated with tryptic soy agar and xylose lysine desoxycholate overlay for total and healthy cells, respectively. No significant differences (P > 0.05) in reduction were observed between the Salm. Enteritidis cocktail and Salm. Enteritidis PT 30 inoculum. Reduction of Salm. Enteritidis increased as a function of treatment time, with 25 s being sufficient to achieve a 5-log reduction. Discolouration and visible formation of wrinkles were observed following steam pasteurization of more than 35 s. CONCLUSIONS: Steam pasteurization of 25 s is sufficient to achieve a 5-log reduction of Salm. Enteritidis inoculated on raw almonds without visual quality degradation. SIGNIFICANCE AND IMPACT OF THE STUDY: Steam pasteurization is an effective alternative to reduce or prevent Salm. Enteritidis contamination on raw almonds.