More than 90 percent of sack lunches prepared at home and sent with kids to preschool were kept at unsafe temperatures, a new study by nutritional scientists at The University of Texas at Austin found.
The study will be published in the September 2011 issue of Pediatrics and was published online Aug. 8.
"Parents need to be aware of how important the storage temperature is for foods they pack for their young children," said Fawaz Almansour, a graduate student in the Department of Nutritional Sciences and lead author of the research.
The best storage temperature is below 40 degrees Fahrenheit for cold foods and above 140 degrees for hot foods. Between 40 and 140 degrees is the "danger zone."
Study authors suggest that parents and the public need to be educated on safe food packing practices in order to prevent bacteria from growing and potentially causing illness.
Almansour and his colleagues, including Professor Margaret Briley and postdoctoral researcher Sara Sweitzer, collected data on sack lunches from more than 700 preschoolers at nine Texas child care centers. The lunches were measured with noncontact temperature guns one and one-half hours before the food was served.
They found that while 45 percent of the lunches studied had at least one ice pack, 39 percent had no supplemental ice packs. Even including lunches with ice packs, 88 percent were at room temperature. Less than 2 percent of lunches with perishable items were found to be in a safe temperature zone, while more than 90 percent (even with multiple ice packs) were kept at unsafe temperatures.
Perishable items studied included meats, cheeses and vegetables. Prepackaged foods produced by manufacturers were not included in the study.
"The simple addition of one extra icepack could have prevented many of the perishable items in lunches from reaching the danger zone," wrote the researchers in their study.
They go on to say that the addition of two or more icepacks in lunches could help prevent food-borne illness in children.