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Spring 2006 - Strawberries

Destination Purdue > Spring 2006 - Strawberries

Taking a fresher look at strawberries

By Jenn Stewart

Who doesn't like a refreshing bowl of strawberries covered with pathogens and mold on a hot summer day? Just add whipped cream for a refreshing treat second-to-none. Right? Wait a minute. Pathogens and mold?

Nigel Harper

Photo by Jenn Stewart

Nigel Harper, a senior food science major from Hagerstown, Ind., conducts strawberry research for Rich Linton, a Purdue food science professor. Harper started working in the lab as a freshman washing glassware.

According to Rich Linton, a Purdue University food science professor, that is exactly what many consumers are finding on at least one strawberry in nearly every package they buy. But Purdue researchers have developed a new technique to ease or even eliminate some of these problems.

Linton, his colleagues and several Purdue students have spent many hours studying the effects of chlorine dioxide gas on the pathogens and mold often found on this popular fruit.

Current berry-cleansing technologies give strawberries an average three- to five-day shelf-life before mold and quality degradation become a factor. But when treated with chlorine dioxide gas, those same strawberries can last up to six weeks, said Linton.

His research began nearly two years ago. Within the first year the project was published for other scientists and the strawberry industry to review. Now, Linton and colleagues are receiving funding to perform more research on a larger scale within the food science pilot labs. These labs contain large-scale machinery, but this equipment is a scale-model of the larger equipment used in industry.

Using Linton's technique, strawberries are treated by placing them in a 30-gallon chamber, then giving them the chlorine dioxide gas treatment. Although the idea of this gas may frighten some consumers, Linton says the amount of chemical residue remaining on the surface is undetectable. In fact, these levels are lower than the amounts of chlorine dioxide found in drinking water.

Aside from the importance of this research to the food industry, it is also important to undergraduate students who have the opportunity to work in Linton's lab. Students interested in working for Linton start out by doing tasks such as cleaning glassware. Once they show an interest and willingness to work, Linton moves them into active projects. As their interests grow, students' roles increase.

One such student is Nigel Harper, a senior food science major from Hagerstown, Ind. Harper began working in Linton's lab as a freshman, cleaning the glassware used for experiments, such as petri dishes, beakers and test tubes. As he continued showing interest by asking questions and letting Linton know he'd like to be more involved in the research, Harper's opportunities for participation grew. Harper said that these opportunities have proven very helpful, and will continue to be as he attends graduate school. Harper also suggests that any underclassman wishing to get involved should be willing to start small.

"Start out at the bottom and work your way up," said Harper. "Talk to the professor that you're working under and make sure they know you're interested in doing research."