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P1-28 Efficient Reduction of Cryptosporidium parvum Oocysts from Apple Cider by Combining Microfiltration with Ultraviolet Treatment

Monday, July 29, 2013
Exhibit Hall (Charlotte Convention Center)
Jessie Usaga, Cornell University, Geneva, NY
Dongjun Zhao, Cornell University, Ithaca, NY
Qing Wang, University of Delaware, Newark, DE
Sarah Markland, University of Delaware, Wilmington, DE
Olga Padilla-Zakour, Cornell University, Geneva, NY
Randy Worobo, Cornell University, Geneva, NY
Kalmia Kniel, University of Delaware, Newark, DE
Carmen Moraru, Cornell University, Ithaca, NY
Introduction: Outbreaks of cryptosporidiosis due to the consumption of unpasteurized apple cider have been reported in recent years. Ultraviolet (UV) is a FDA recognized alternative to thermal processing of apple juice and cider and can achieve a 5-log reduction of Escherichia coli O157:H7 and Cryptosporidium parvum. However, high doses of UV can negatively affect juice color and flavor, while suspended solids in cider can limit the process efficiency. Microfiltration (MF) can physically remove suspended solids and microorganisms from apple cider, which can enhance the effectiveness of UV and allow a lower UV dose to be used.

Purpose: In this study, the efficiency of a combined UV & MF treatment in the reduction of Cryptosporidium parvum from apple cider was evaluated.

Methods: Apple cider (pH3.7, 14.1°Brix) was inoculated with Cryptosporidium parvum at 106 oocysts/ml, and subjected to the individual or combined treatments. MF was performed with 0.8µm and 1.4µm ceramic membranes at 10°C and 155kPa. UV treatments were conducted using CiderSure 3500, at a low UV dose of 1.75 mJ/cm2. Oocyst viability before and after processing was assessed by a cell culture infectivity assay using a human ileocecal cell line (HCT-8) and quantification was done by DNA extraction coupled with PCR for the sporozoite heat shock and oocyst wall proteins. The study was performed in triplicate.

Results: After MF of cider using 0.8µm and 1.4µm membranes, no oocysts were detected. No oocysts were detected after the combined MF & UV treatment. MF alone was shown to achieve greater than 5-log reduction of Cryptosporidium parvum, and could be combined with UV as a final kill step.

Significance: The developed non-thermal hurdle treatment can significantly reduce this protozoan parasite in apple cider, as well as spores, yeasts, molds and bacterial pathogens. This will help processors improve the safety and quality of apple juice and cider and potentially other beverages.

Back to: Poster Session 1 - Risk Assessment, Food Toxicology, Beverages & Water, Meat & Poultry, Dairy & Other Food Commodities, Food Defense, Communication Outreach & Education, Non-microbial Food Safety, General Microbiology, Epidemiology, Seafood, Microbial Foo
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