While fresh unpasteurized juices account for only 2 percent of the total juice sold in the United States each year, they have been linked to an estimated 16,000 to 48,000 cases of food-borne illness. Cross-contamination from workers during juice preparation may be another source. While the acid content of fruit juice prevents many bacteria from growing, this particular microbe survives quite well in an acid environment. Refrigeration doesn't help much. Whereas most strains of E. coli are harmless, this particular strain attaches itself to the intestinal wall and releases a toxin that causes severe abdominal cramps, bloody diarrhea and vomiting.
Symptoms usually take four to five days to appear and last a week or longer.
In small children and the elderly, the illness can progress to kidney failure. To allow flexibility in meeting the new labeling requirement, for up to a year the FDA will allow manufacturers to place the warning statement on signs and placards displayed at points of purchase. Products you can count on to be safe from harmful bacteria include juices made from frozen concentrate, shelf-stable juices in hermetically sealed containers, and canned juices. Juices most likely to be unpasteurized are those found in the grocers' refrigerated sections or sold at cider mills and farm markets. If you can't tell whether a juice product has been processed to destroy harmful bacteria, it's best to not serve it at all, or to bring it to a boil to kill potentially harmful bacteria before serving.