Being cool about food safety

Posted by Josette Dunn on 17th November 2010

As summer heats up the New Zealand Food Safety Authority (NZFSA) is encouraging people to be cool about food safety in the wake of a new study that shows three out of four Kiwi fridges are not running at the recommended cool temperature range of 2-4°C to keep food safe.NZFSA microbiology principal advisor Roger Cook says keeping your fridge suitably cool is important because not only does it maintain the expected quality of the food but it helps prevent harmful foodborne bacteria from growing as most of them cannot grow at low refrigeration levels.

The study – commissioned by NZFSA for this year’s FoodSmart Week (November 22-28) – was carried out in 158 households. Participants recorded the temperature in the middle and near the door hinge of their fridge every morning and evening for a week.

At the start of the week only a quarter of fridges were in the recommended range of 2-4°C, while 72% were too warm (36% at 4-6ºC and 36% were over 6ºC). Participants were prompted to adjust the fridge control if the temperature was not in the recommended range. Of those surveyed who made an adjustment, 77% were successful in moving the temperature to the 2-4°C range.

Not surprisingly, older fridges were over-represented in the plus 6°C category. A third of the fridges in this category were more than 20 years old. Also, fridges with seals that were in poor condition were twice as likely to be over 6°C as fridges that had good seals.

Roger recommends checking the temperature by putting a thermometer into a glass of water kept in the fridge. This is because a built-in thermometer will measure the air temperature, which is likely to change whenever the door is opened and when new food is put into the fridge.

“For best results the container needs to be sitting on the middle shelf of the unit for more than two hours, which will enable you to get an accurate reading,” he says.

“If the temperature in the middle is consistently above the recommended temperature range, you should adjust the thermostat to lower the temperature. Check other possible causes such as faulty door seals, ventilation or the location of your fridge. If that fails you may need to contact your local repair service.”

He adds that it’s also important to know that even though bacteria and fungi don’t like the cold, some will still grow slowly and many will survive on fridge surfaces and contaminate food where they can then grow. “So it’s a good idea to have a general stocktake and clean your fridge every few weeks.”

Anything in your fridge with an expired ‘use by’ date should be thrown out as it could be unsafe to eat and leftovers should only be kept for a few days before being thrown away or reheated until piping hot before being eaten.