Food contamination can cause everything from annoying to catastrophic, from stomach upset in the mildest cases to death in the most extreme.
The United States is much safer in this regard than most countries, but the federal Centers for Disease Control reports that salmonella bacterial contamination causes about 1.3 million infections each year. It sent about 26,500 Americans to the hospital and ultimately claimed about 420 lives.
Husker scientist Bing Wang, a world-renowned expert in food risk assessment, is at the forefront of cutting-edge science to reduce these and other food safety risks in the US and around the world. Her lab at the University of Nebraska–Lincoln uses advanced computational analysis methods that strengthen defenses in many ways.
Farmers and the food industry benefit because the methods used by Wang, associate professor of food science and technology, enable detailed food risk analysis at every stage of field management and food processing. Agencies in the US and internationally draw on her scientific insights to better understand food risk opportunities and implement more effective protections.
The analytical methods used by her lab have broad practical utility, from Chilean farmers who learned the source of E. coli bacterial contamination of raspberry production thanks to Wang’s analysis to soy sauce company Kikkoman improving its procedures for food storage as a result of her work.
An ongoing study requested by the Chilean government is analyzing the safety of reusing greywater – waste water from bathrooms, sinks, washing machines and other appliances – to irrigate crops. Findings from Wang’s lab could have widespread use worldwide.
“Bing’s risk assessment and analysis work, both nationally and internationally, is designed to benefit the health and well-being of consumers in Nebraska, the United States, and the world,” said Kurt Weller, professor and head of the Department of Nutrition of Science and Technology in Nebraska. “This in turn will lead to a higher level of resilience and greater risk mitigation for the global food system.”
Wang has contributed to key research in this area of microbial safety and serves as an expert advisor to the Food and Agriculture Organization of the United Nations and the World Health Organization. This year she attended two international conferences as an expert contributor, providing scientific advice to the Codex Alimentarius Commission, which establishes international food standards for consumer health and fair global food trade.
In the United States, the most common bacterial cause of diarrheal disease is Campylobacter bacteria. Campylobacter the infection affects about 1.5 million US residents each year, according to the CDC. An academic paper co-authored by Wang with Husker colleagues helps private sector and government regulators strengthen consumer protections against this food threat.
Wang’s lab used advanced analytical methods to conduct an in-depth study of broiler chicken processing, then identified the most effective production actions the industry could adopt to reduce bacterial contamination.
The study uses cutting-edge analytical methods that Wang’s lab is at the forefront of using:
Quantitative microbial risk assessment. This systems approach analyzes food production and processing practices to assess the likelihood of food contamination. This method considers factors including foodborne pathogen contamination, pathogen growth factors, and the effectiveness of specific food safety interventions.
Predictive Microbiological Modeling. This quantitative tool is used to predict the behavior of microorganisms in response to food characteristics and production/processing conditions.
A systematic review and meta-analysis. It is a comprehensive review of all available research on a specific dietary risk topic, combining the results of multiple studies to produce a more accurate and reliable assessment of dietary risk.
Wang used similar analytical rigor in a wide-ranging study of field management and processing practices for the raspberry sector in Chile. Her research, done at the request of the Chilean government, found that the main source of E. coli bacterial contamination of raspberries in the country was water used to dilute pesticides.
“Since we found that water is the most important factor affecting the quality of fresh and frozen raspberries,” Wang said, “we continued to evaluate what type of water treatment could be used by smallholder farmers, as 80% of families for raspberry production are small farmers. We needed to identify an approach that was feasible and affordable for manufacturers.”
Two staff members of Chile’s Food Safety and Quality Agency studied in Wang’s lab and earned master’s degrees in food science before returning to Chile to work as analysts for the agency. Wang continues to collaborate with the Chilean agency, this time through a study evaluating whether gray water can be safely reused to irrigate crops.
Wang has applied a similar analytical approach in partnership with soy sauce maker Kikkoman. Because heat treatment cannot be used to eliminate possible microbial contamination in some soy sauce products, Wang said, “you have to hold it long enough to make sure that the acidity can kill the pathogen before the product is released on the market.”
Predictive modeling from the Wang lab helped determine the appropriate retention time. In general, such forecasting methodology has wide use for private industry in terms of new product development and food safety.
A common challenge in food safety work is the need for scientists to translate their complex research approach into simpler, easy-to-use assessment tools that food risk managers can use. In its partnership with Kikkoman, Wang’s lab set a positive example by creating a web-based tool for the company.
Wang currently serves on the US National Advisory Committee on Microbiological Food Criteria to provide independent scientific support for federal regulators. Although food risks are lower in the U.S. than in most of the world, she said, “there are still ongoing issues that need to be addressed, and the government is paying close attention.”
Her laboratory is among the US institutions making leading contributions to this effort.