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

Abstract

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.