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Effectiveness of superheated steam for inactivation of Escherichia coli O157:H7, Salmonella Typhimurium, Salmonella Enteritidis phage type 30, and Listeria monocytogenes on almonds and pistachios
- Ban, Ga-Hee, Kang, Dong-Hyun
- International journal of food microbiology 2016 v.220 pp. 19-25
- Escherichia coli O157, Listeria monocytogenes, Salmonella Enteritidis, Salmonella Typhimurium, almonds, bacteriophages, color, food pathogens, heat, industry, peroxide value, pistachios, steam, texture
- This study was undertaken to evaluate the effectiveness of superheated steam (SHS) on the inactivation of Escherichia coli O157:H7, Salmonella Typhimurium, Salmonella Enteritidis phage type (PT) 30 and Listeria monocytogenes on almonds and in-shell pistachios and to determine the effect of superheated steam heating on quality by measuring color and texture changes. Almonds and in-shell pistachios inoculated with four foodborne pathogens were treated with saturated steam (SS) at 100°C and SHS at 125, 150, 175, and 200°C for various times. Exposure of almonds and pistachios to SHS for 15 or 30s at 200°C achieved >5log reductions among all tested pathogens without causing significant changes in color values or texture parameters (P>0.05). For both almonds and pistachios, acid and peroxide values (PV) following SS and SHS treatment for up to 15s and 30s, respectively, were within the acceptable range (PV<1.0meq/kg). These results show that thermal application of 200°C SHS treatment for 15s and 30s did not affect the quality of almonds and pistachios, respectively. Therefore, SHS treatment is a very promising alternative technology for the tree nuts industry by improving inactivation of foodborne pathogens on almonds and pistachios while simultaneously reducing processing time.