I took pasta salad to a picnic yesterday and put it in the refrigerator when I got home. Is it safe to eat today?
The short answer: It depends
The explanation: Because of the ingredients in foods such as pasta salads, they need to be stored in a temperature-controlled environment of less than 40°F. As we discussed in last month’s Simplified article (Testing the Sniff Test), perishable foods should not be left unrefrigerated for more than two hours, and if the temperature during your picnic rose above 90°F, the safety zone shrunk to one hour.
So, to determine the safety of a food, you need to consider its perishable nature and the length of time it was unrefrigerated. Say, for example: You made a pasta salad Friday night to take to a Saturday picnic. The park was about ½ hour from your home, and when you arrived you put the salad on the picnic table with the food others brought, while burgers and hotdogs were grilled. To give everyone a chance to eat all they wanted, the food sat out for about an hour, then got put into an ice chest. Since there was some pasta salad left when you were ready to leave, you took it home with you.
Even if you were to put it into the refrigerator immediately upon arrival, the salad had already sat out for well over 2 hours (prep time, 1/2 hour drive to the park, table time during grilling, 1 hour for all to eat, 1/2 hour back home). Additionally, you don’t know the temperature at which the ice chest kept the food, which could have been over 40°F.
Given all this, and the ability for bacteria to multiply rapidly between 40°F and 140°F degrees, eating the pasta salad would be very risky. There is, in fact, a case of a child dying due to eating a pasta salad that had been taken to a picnic, then stored in the refrigerator for two days. The bacteria in this case was Bacillus cereus, which caused liver failure, but other pathogens, such as Salmonella and Listeria, are just as likely to grow in perishable foods when temperatures are not maintained.
