Food Protection Trends - October 2009 - 685

ment when an outbreak occurs. Challenges to preventing norovirus outbreaks on cruise ships include the diversity of the ships in size which can range from 50 m in length with 49 passengers to 339 m in length with 3,600 passengers and also the large number of surfaces to be disinfected when an outbreak occurs. Dr. Lee-Ann Jaykus of North Carolina State University reported on a study of an outbreak of norovirus from rafting trips on the Colorado River. One of the major concerns about these trips is that the toilets on the rafts are so close to the food and the contamination could be coming from that problem. The definition of “ill trips” was 3 or more rafters who experience vomiting or diarrhea. Of the rafting trips observed, 14% were considered “ill trips” and all were found from 5 different rafting companies. An investigation showed that the contamination did not come from the water or the guides. Further analysis clearly showed that an infected food handler who did not wear any gloves was the cause of the outbreak. The strain that was involved has been determined to be rare. During the panel discussion, two main points were made very clear. There is little science that shows that typical hand sanitizers are effective against noroviruses. The second point was made by Captain George Vaughan about where norovirus is usually found after the boat is sanitized. He stated that the areas that are known as the ‘hot spots’ are sanitized so well that they are not of concern. The other areas are of more concern because of noroviruses ability to be carried so easily by infected humans. S5 – Pathogen and Spoilage Persistence in the Processing Environment and Food Products: Where, Why and How Do We Know? Melissa Hughes,Texas Tech University Jie Wei, University of Delaware The symposium opened with R. B. Tompkin (retired, ConAgra Foods), who introduced the topic of factors affecting microbial persistence in the food industry. Microorganisms such as Salmonella and Listeria monocytogenes become established and persist over time, and are responsible for food contamination in harborage sites. Weaknesses favoring this persistence included inadequate monitoring and assessment programs, hoping that the problem will go away by ignoring positive samples, lack of investigational skills, and not recognizing the significance of proper construction. Kendra Nightingale (Colorado State University) focused on the molecular ecology of Listeria monocytogenes (LM). LM is capable of surviving in 40 species of animals and birds, and accounts for 30% of deaths due to foodborne pathogens annually. The inlA and inlB genes are key in the spread of this genetically diverse organism, and strains that persist in ready-to-eat processing plants are associated with virulenceattenuating mutations in inlA. Environmental sampling and molecular subtyping are necessary in controlling LM and verifying its removal. Thomas Hill (FDA) discussed the persistence of Salmonella Newport on tomato farms in Virginia. S. Newport lives in the ponds, and the development of a natural antagonist for this strain in tomatoes is needed. Possible contamination sources on the farm include soil, water source and quality, farm workers, and animals. Growers need to become more conscience of the environment and follow GMPs in order to increase sanitary handling of fresh produce. After the break, Robert Tauxe (CDC) talked about the role of pathogen persistence in foodborne disease and outbreaks from the view of epidemiological approach. Recently, events of outbreaks have been connected with the same subtype of pathogen or the same source, revealing the impact of localized persistence of a pathogen. The mechanism of the persistence in absence of the host was still not very clear, but it had been found that Salmonella could survive 180 days in soils at 20°C. Repeated outbreaks could happen years later, and control strategies are crucial. The following presentation was on microbial spoilage from an industry perspective, by Susan Freund (Kraft Foods). She pointed out that spoilage was challenging in today’s environment, as consumers demand ‘fresher’ foods with less preservatives. The most common spoilage organisms are acid-resistant yeast, heat-resistant mold and lactic acid bacteria. These particular organisms are difficult to monitor, produce low microbial counts, and start the “screening” process after slight changes in product formulation. In order to control and avoid product spoilage, raw material testing and change management is critical. The last presenter was Don Zink (CFSAN, FDA), and his talk was on the regulatory implications of persistence in the processing environment and the final product. He gave a lot of examples of governing laws as the basis for many FDA acts. For adulteration, the US Food Drug and Cosmetic Act Section 402(a)(1) focuses on when the product is directly contaminated with pathogens, and Section 402(a)(4) was for contaminated food production facilities but not the food itself. Chapter 21 of the US Code of Federal Regulations (Part 110) was also discussed. S6 – Zapped! Optimizing the Consumer Experience of Microwave Cooking through Labeling, Infrared Thermography, and Validation Silvia Dominguez, Rutgers University Sarah Markland, University of Delaware The symposium started with a presentation by Julie Zimmerman from Target, where she described the initiatives taken by this corporation in order to address the challenges posed by microwave cooking of not-ready-to-eat food products. The Microwave Food Safety working group was created, and among their accomplishments so far is the establishment of a standard wattage symbol for all microwave ovens sold by Target, as well as the use of this symbol in the development of microwave cooking instructions for Targetowned brand foods. A validation protocol for these cooking instructions has also been developed, considering factors such as product and oven variability, consumer knowledge of oven wattage, testing protocol, etc. The following speaker, Greg Hooper from Campden BRI, discussed the applications of thermal imaging for microwave heating. Temperature-measurement systems, like thermocouples and fiberoptic thermometry were introduced, as well as thermal imaging. Thermocouples and fiberoptic OCTOBER 2009 | FOOD PROTECTION TRENDS

Food Protection Trends - October 2009

Table of Contents for the Digital Edition of Food Protection Trends - October 2009