Selection of process conditions by risk assessment for apple juice pasteurization by UV-heat treatments at moderate temperatures.
The effect of bactericidal UV-C treatments (254 nm) on Escherichia coli O157:H7 suspended in apple juice increased synergistically with temperature up to a threshold value. The optimum UV-C treatment temperature was 55 °C, yielding a 58.9% synergistic lethal effect. Under these treatment conditions, the UV-heat (UV-H55 °C) lethal variability achieving 5-log reductions had a logistic distribution (α = 37.92, β = 1.10). Using this distribution, UV-H55 °C doses to achieve the required juice safety goal with 95, 99, and 99.9% confidence were 41.17, 42.97, and 46.00 J/ml, respectively, i.e., doses higher than the 37.58 J/ml estimated by a deterministic procedure. The public health impact of these results is that the larger UV-H55 °C dose required for achieving 5-log reductions with 95, 99, and 99.9% confidence would reduce the probability of hemolytic uremic syndrome in children by 76.3, 88.6, and 96.9%, respectively. This study illustrates the importance of including the effect of data variability when selecting operational parameters for novel and conventional preservation processes to achieve high food safety standards with the desired confidence level.
Food Science and Technology, University of Zaragoza, C/ Miguel Servet 177, CP 50013, Zaragoza, Spain.
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Gayán
Food Processing Engineering Group, Department of Food Science and Technology, Oregon State University, Corvallis, Oregon 97331, USA.
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Torres
Food Science and Technology, University of Zaragoza, C/ Miguel Servet 177, CP 50013, Zaragoza, Spain.
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Alvarez
Food Science and Technology, University of Zaragoza, C/ Miguel Servet 177, CP 50013, Zaragoza, Spain. scondon@unizar.es.
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Condón
D001628:Beverages / Q000382:microbiology* / Q000592:standards; D002648:Child; D015169:Colony Count, Microbial; D019453:Escherichia coli O157 / Q000254:growth & development* / Q000528:radiation effects; D005506:Food Contamination / Q000032:analysis / Q000517:prevention & control; D005511:Food Handling / Q000379:methods; D005514:Food Irradiation / Q000379:methods*; D005516:Food Microbiology; D005519:Food Preservation / Q000379:methods; D006358:Hot Temperature; D006801:Humans; D027845:Malus / Q000382:microbiology; D061352:Pasteurization / Q000379:methods*; D018570:Risk Assessment; D014466:Ultraviolet Rays