UV INACTIVATION OF E. COLI O157:H7 IN APPLE CIDER: QUALITY, SENSORY AND SHELF-LIFE ANALYSIS

Increasing concern about food safety following contamination of unpasteurized apple cider with Escherichia coli O157:H7 reinforces the need for using the best technologies in apple cider production. Pasteurization of apple cider with ultraviolet irradiation (UV) is a low‐cost alternative to heat pasteurization for small processing operations. UV treatment efficacy applied to raw unpasteurized apple cider was examined through evaluation of physical parameters, exposure time and treatment dosage. A UV light processing system was used to treat apple cider. The apple cider received a calculated average dosage of 8777 µW‐s/cm ² per pass through the system. UV light (at 254.7 nm) was effective in reducing bacteria‐inoculated apple cider by an average of 2.20 logs per pass. In multiple passes, the 5‐log reduction mandated by the Food and Drug Administration was achieved. Sensory analysis yielded no significant differences between the UV‐treated and control apple ciders. Experiments with UV‐treated apple cider indicated a significant extension of product shelf life through inhibition of yeast and mold growth. For low throughput apple cider processing operations, this technology is a viable cost‐effective alternative.