Ronald Pegg, an associate professor of food science and technology, led a group that looked at vitamin and mineral content of eight fruits and vegetables. They included blueberries, strawberries, broccoli, green beans, corn, spinach, cauliflower and green peas, according to a news release.
The researchers analyzed the nutrient values on the day they were purchased from a grocery store and again five days later after being stored in a household refrigerator.
They collected samples from several different grocery stores to mimic shopping patterns of consumers.
The researchers compared the values to those found in the same fruits and vegetables that had been frozen and packaged commercially.
They found that some fruits and vegetables had higher levels of vitamin A, Vitamin C and folates than produce that had been stored for five days.
Pegg called freezing "nature's pause button."
"The vitamins and nutrients in fruits and vegetables degrade over time, and we found that frozen fruits and vegetables may offer more nutrition than fresh, when storage is taken into account," Pegg said in the release. "(Fruits and vegetables) are going to have a different nutrient profile after storage than they had when they were taken from the field ... (These pieces of produce) are living things. They respire; they age and they break down over time."
Because vegetables are blanched as part of the freezing process shortly after harvest, it stops the enzymatic reactions that can break down many nutrients.
Although fruits are not blanched during freezing, the process nonetheless slows enzymatic breakdown and decreases microbial breakdown.
The study was funded by the Frozen Food Foundation.