MIT News: New Sensor Developed To Detect Spoilage in Fresh Foods

Every year, U.S. supermarkets lose roughly 10 percent of their fruits and vegetables to spoilage, according to the Department of Agriculture. To help combat those losses, MIT chemistry professor Timothy Swager and his students have built a new sensor that could help grocers and food distributors better monitor their produce.

The new sensors, described in the journal Angewandte Chemie, can detect tiny amounts of ethylene, a gas that promotes ripening in plants. Swager envisions the inexpensive sensors attached to cardboard boxes of produce and scanned with a handheld device that would reveal the contents’ ripeness. That way, grocers would know when to put certain items on sale to move them before they get too ripe.

“If we can create equipment that will help grocery stores manage things more precisely, and maybe lower their losses by 30 percent, that would be huge,” says Swager, the John D. MacArthur Professor of Chemistry.

Detecting gases to monitor the food supply is a new area of interest for Swager, whose previous research has focused on sensors to detect explosives or chemical and biological warfare agents.

“Food is something that is really important to create sensors around, and we’re going after food in a broad sense,” Swager says. He is also pursuing monitors that could detect when food becomes moldy or develops bacterial growth, but as his first target, he chose ethylene, a plant hormone that controls ripening.

Canned Food Cheaper and Offers As Much Nutrition As Fresh Food

The current trend in food is fresh and organic. It is believed that fresh vegetables are more nutritious than canned ones.

But in a 1997 study by the University of Illinois Department of Food Science and Human Nutrition, canned fruits and vegetables have as much dietary fiber and vitamins as the same corresponding fresh foods, and in some cases, even more.

Some companies take advantage of this and charge more for fresh and organic fruits and vegetables than their canned counterparts.

Obtaining key nutrients from canned foods can save consumers money

Amid the steady drumbeat from nutrition experts and others to consume a healthier diet – particularly one rich in fruits and vegetables – there often is a bias to eat more of the fresh variety for optimal nutrition. But is fresh always best? Not necessarily.

Dr. Cathy Kapica, PhD, RD, adjunct professor of nutrition at Tufts University, and Wendy Weiss, MA, RD, both with Ketchum Global Health and Wellness, conducted a market-basket study comparing the cost of obtaining key nutrients from canned, fresh, frozen and dried varieties of common foods. The study found that when price, waste and preparation time are considered, canned foods almost always offered a more affordable, convenient way to get needed-nutrients. The results of this research, funded by the Canned Food Alliance, was presented at a poster session at Experimental Biology 2012 in San Diego, CA.