Published at 1:13 am. Updated at 7:00 a.m.
An unopened bag of blanched almond slices was stored in the freezer. It's swollen now. The expiration date is April 13, 2023. What happened?
Ginette Petit
Bacteria cannot grow in the freezer, but mold can grow if the freezing temperature is not lower than -18 degrees Celsius.
“This is a very, very, very rare case,” says Alexandre Thibodeau, a microbiologist at the University of Montreal’s Faculty of Veterinary Medicine. “The consumer is very unlucky. When I saw the photo I thought I should include it in a review. »
PHOTO PROVIDED BY GINETTE PETIT
The bag of almonds our reader kept in the freezer is now swollen.
A freezer typically has a temperature of -18 to -20°C. However, if snow has formed there, which often happens, the temperature can rise to around -12 to -15°C.
The swelling is related to the emission of CO2 during slow mold growth at this low temperature. “It was probably a bag that had too much moisture in it, which encouraged mold growth,” Mr. Thibodeau said.
Is it dangerous?
PHOTO TAKEN FROM THE UNIVERSITY OF MONTREAL SITE
Alexandre Thibodeau, a microbiologist at the Faculty of Veterinary Medicine at the University of Montreal
It's better to throw away the almonds. Mold can produce mycotoxins that can cause health problems. We should even avoid opening it, there might be mold spores inside. Some people are allergic.
Alexandre Thibodeau, microbiologist
Typically, an airtight bag of almonds can be stored in the freezer for two years, according to Mr. Thibodeau. The same goes for meat, although the meat can age and lose fat over time.
“Control of critical points”
Pathogenic bacteria such as listeria or salmonella do not multiply at temperatures below freezing. Other harmless bacteria that alter the appearance and texture of food can survive down to -15°C.
Are almonds checked during packaging? “There is control at critical points in the packaging line,” says Mr. Thibodeau. We check whether the product has been washed correctly and then whether it is dry enough. There is also a sample of some almonds. A mold test is usually carried out on dry products, and depending on the food, a salmonella test may also be carried out. »
Almonds are occasionally responsible for cases of salmonellosis. In 2022, a California manufacturer, Blue Diamond, recalled nearly 200 tons of contaminated almonds in the United States, but no human cases were reported. There are also recalls related to peanut butter and almond butter. In 2001, 160 cases of salmonellosis in Canada were linked to a case of contaminated almonds.
A search of the Canadian government's recall website revealed 60 almond recalls since 2013, mostly due to almonds of undeclared origin.
Learn more
An estimated 88,000 cases of salmonellosis per year in Canada
Source: Public Health Agency of Canada
17 Estimated number of annual deaths caused by salmonellosis in Canada
Source: Public Health Agency of Canada