Mary Anne Amalaradjou, assistant professor in the Department of Animal Science, is currently working on several projects related to food safety, an interest that goes back to her days in veterinary school.
“We were exposed to diverse fields of study from pathobiology and zoonotic diseases to nutrition,” she says. “I was always interested in microbiology and immunology. I like the small critters.”
Her doctoral research focused on natural antimicrobials, which led to an interest in probiotics. Amalaradjou says, “The driving factor in my research is human health. A single pathogen can have a profound effect on health as well as the economy.”
According to the Centers for Disease Control and Prevention, there are approximately 1.2 million illnesses, 23,000 hospitalizations and 450 deaths attributable to foodborne salmonellosis each year in the United States.
The project stems from a recent salmonella incident that affected whole, uncut mangoes. Before entering the United States, mangoes must go through a three-step cleaning process that includes an initial bulk tank washing to remove dirt and debris, then a hot water treatment followed by a cooling dip. This treatment eliminates any fruit fly larvae
Unfortunately, the sudden change in temperature associated with the cooling dip causes a vacuum action, and any salmonella on the outside of the fruit is then sucked into the pulp, where it cannot be removed.
Amalaradjou is evaluating several antimicrobial agents, including chlorine, chlorine dioxide and peroxyacetic acid, for use as an additive to the washing process. These disinfectants are cost effective and commonly used by fruit growers on other fruits such as apples and cantaloupes. So far, peroxyacetic acid has proven to be the most effective at reducing salmonella contamination.
In another project, a five-year $25,000 study supported through a USDA Hatch Fund grant and the Storrs Agricultural Experiment Station, Amalaradjou is using probiotics to reduce Salmonella enterica contamination in chicken meat and chicken products, the most common source for Salmonella poisoning.
Amalaradjou started with twenty-three different probiotic strains, testing their efficacy in vitro. She has isolated three strains that appear to be most effective against Salmonella, and will test these with live birds at UConn’s Spring Hill Farm by adding probiotics to the chicken feed and water.
Based on early data, the probiotic was extremely effective in preventing Salmonella invasion. “We are highly hopeful,” Amalaradjou says. “We are searching for a cost-effective and natural method of reducing salmonella infection.”
In a collaborative project with UConn’s Department of Computer Science and Engineering (CSE), Amalaradjou and Ion Mandoiu, associate professor in CSE, are studying cheese and cheese starter cultures as a dietary source of probiotics to possibly aid those suffering from inflammatory bowel disease (IBD). The project is funded by a one-year $25,000 grant through the UConn Research Excellence Program.
Amalaradjou explains that while IBD is a complex disease involving immunology, genetics and the environment, it is thought that two environmental factors—food and gut microbiota—play a crucial role in IBD onset and progression.
“Probiotics have a protective effect on the gut microbiome,” Amalaradjou explains. “We hope to discover the genetic mechanism behind the protective effects of probiotics.”
Amalaradjou chose cheddar cheese because cheese is a highly popular food that contains natural probiotics, and cheddar is lactose-free, making it more digestible to those suffering from IBD.
The study will use a mice, which will be fed cheese at a dose that corresponds to the USDA’s recommended daily allowance. “Cheese is an easy food to recommend,” Amalaradjou says. “We don’t have to advocate for people to eat cheese, and it contains other health benefits such as the calcium.”
In a collaborative project with two faculty members from UConn’s Department of Chemical and Biomolecular Engineering, associate professors Yu Lei and Mu-Ping Nieh, and Amalaradjou are developing a biosensor to detect pathogens in food. The project is funded with a three-year $300,000 grant from the National Science Foundation.
Current testing protocols used by food processing plants require highly skilled personnel using an enzyme-linked immunosorbent assay (ELISA) test, the results taking two to seven days. A biosensor could use a more efficient and less complicated process to detect multiple pathogens, reducing testing time to between six and twelve hours. Every batch of food must be tested, so this could be very cost effective for the industry.
CBE is designing the sensor chip, while Amalaradjou will perform food tests. If the product is deemed worthy of production, the team will use the project to train students in the fields of nano-biosensing and entrepreneurship.