Salad bar safety put to the test
HORRY COUNTY, SC (WMBF) - Open salad bars make it easy to customize your own salad for a healthy meal, but is that salad actually safe for your health?
Samantha McDowell, a food safety and nutrition agent for Clemson Extension, said several factors go into ensuring salad bars don't become a source of a foodborne illness.
"People think of outbreaks as mass, large groups of people, but in actuality, it only has to be two or more," McDowell said.
McDowell teaches the eight hour class the South Carolina Department of Health and Environmental Control requires for food safety certification.
She said even cold raw foods can be as risky as hot cooked foods if they're stored at an improper temperature.
WMBF News put some salad to the test to see if it's as safe as it should be. We went to four different local grocery stores with open salad bars to collect food samples. We divided the salad bar into four categories, so we could test a wide variety of items: leafy greens, raw vegetables, cooked meats and mayonnaise-based salads.
15 samples were then packed up in a cooler and shipped overnight to IEH Laboratories outside of Seattle.
IEH Laboratories CEO Dr. Mansour Samadpour explained the results. The lab tested every sample for E. coli, listeria and salmonella, which all came back negative.
The lab then tested for the number of microbes in one gram of food. Dr. Samadpour said those microbes can either be harmful to humans causing illness, beneficial to humans actually helping the digestive tract, harmful to the food causing spoilage or inconsequential.
The leafy greens samples all showed up as having a larger number of microbes, more than 1,000,000 colony forming units per gram, or CFU/g. Dr. Samadpour said this is the result of the greens having a larger surface area and being raw, so they contain more of those microbes than food that has been cooked, such as potato salad.
The lab also tested for a wider variety of E. coli, which Dr. Samadpour said can also be harmful or beneficial to humans. This is a food industry indicator of food quality and safety. All of the samples passed the test.
Another industry standard for quality and safety is total coliform. Dr. Samadpour said experts would generally like to see the number of colony forming units per gram of total coliform under 200.
One of the leafy green samples contained 80,000 CFU/g. Another had 13,000 CFU/g. The other two samples contained fewer than 10 CFU/g.
Three of the four raw vegetable samples also tested high for total coliform: a mix of carrots, broccoli and celery contained 35,000 CFU/g, a sample of tomatoes, carrots and banana peppers showed up at 6,000 CFU/g and a combination of broccoli, carrots, cucumbers had 1,000 CFU/g. The fourth sample, a mixture of cucumbers, peppers and broccoli had under 10 CFU/g.
All of the mayonnaise-based salads were well within the acceptable total coliform range in addition to all but one protein sample, which had 13,000 CFU/g.
The lab also tested for yeast and mold counts, which also aren't necessarily harmful, Dr. Samadpour said.
Dr. Samadpour said people need to understand food isn't really sterile, especially when it's being handled and processed.
He said the total coliform test is an outdated form of measurement, but it's still being used in the food safety industry.
He said 80,000 CFU/g isn't a total coliform level experts want to see from a food quality standpoint, but it wouldn't actually make people sick because the individual pathogens were all negative.
McDowell said any restaurant or grocery store with a salad bar is instructed on how to prevent germs from falling into the food.
"Generally each food bar should have an employee that's there monitoring to make sure people aren't coming up with dirty plates, so they're using a clean plate every time, that you don't have terrorist acts or people trying to deliberately contaminate the salad bar," McDowell said.
The glass covering and countertop serve a greater purpose of protecting the salad bar from the bacteria customers bring in with them.
Customers also transfer germs to tongs, which McDowell said are supposed to be changed out every four hours. She recommends trading out the tongs even more frequently.
"Any kind of germs just from people's hands that are on that that can get into the food, if they're changing them out regularly that can help regulate some of that," she said.
Controlling temperature is also important to prevent pathogens from growing.
"Like your TCS foods, which are time and temperature controlled for safety, pathogens grow anywhere between the temperatures of 41 degrees to 135," McDowell said.
McDowell said she thinks DHEC's requirements are effective and most food service establishments are doing what they're supposed to in order to keep salad bars safe.
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