Opinion | 10 November 2021
By
Dr Ellen Evans, Research Fellow
As a research fellow at the ZERO2FIVE Food Industry Centre specialising in food safety research and as a member of the International Association for Food Protection, I'm fascinated by people's food related behaviours and the impact it has upon the safety of food. However, in recent years, because of my concerns regarding climate change, I've started thinking more about how ensuring food safety practices in the home may actually help to reduce our own carbon footprint.
Although many people believe that the food manufacturing sector is predominantly responsible for food wastage, in the UK around 70% of food waste comes from people's homes (WRAP, 2021).
As part of my research, I have conducted a number of studies that focus specifically on refrigeration practices in the home. The perceptions of some research participants regarding refrigerators have really stuck with me. For example, an individual who had much less disposable income after retirement explained to me that they were concerned regarding the cost of their electricity bill and explained they have their fridge "on the lowest setting, so it uses less electric"; another proudly told me about the 40-year-old fridge that they had inherited, they felt it would have been "wasteful to get rid of it just because it was old". So when inspecting these fridges I found that they were operating at temperatures exceeding the recommended 5°C (Food Standards Agency, 2020).
My research has determined that despite people having positive attitudes towards the importance of refrigeration, the majority are not aware of recommended operating temperatures and reportedly "never check" the operating temperature of their refrigerators (Evans & Redmond, 2016), further research has found that 91% of fridges in people's homes operate at temperatures exceeding recommended temperatures (Evans & Redmond, 2015b).
I have had the privilege of visiting many home kitchens and inspecting their refrigerators over the years (Evans & Redmond, 2015a, 2015b), I have established that there is no correlation between the number on the dial of your refrigerator and the actual operating temperature, the only way to determine the actual temperature is to use a refrigerator thermometer. These are widely available and are a small price to pay to ensure the safety of the food we eat and to reduce food wastage.
Many a time I have been told "when I was young we didn't have a fridge" and I've been questioned "why have we all become so reliant on fridges?" Nowadays, our food shopping and eating habits have dramatically changed to years gone by. Gone are the days we purchased everything from the local shop and cooked from scratch every day, consumer demand for convenient, fresh foods with minimal preservatives has led to increased sales of refrigerated, ready-to-eat food products. Consequently, as preservation processes have become milder (less usage of acids, salt and chemical additives) to control the growth of bacteria, the safety of food products are maintained by the combination of modified atmosphere packaging and refrigeration. Therefore, strict temperature control is required to prevent growth of bacteria, to ensure food safety and prevent food wastage.
But you may be thinking "what difference does it make if my fridge is a few degrees too warm?" In a laboratory experiment (Evans & Redmond, 2019), I investigated what happens to bacteria in food when stored at different temperatures, I discovered that food poisoning bacteria and food spoilage bacteria grow at significantly faster rates at refrigeration temperatures just above recommendations (7.8°C), compared to temperatures within recommendations (2.5°C), indicating that inadequate refrigeration temperatures result in potentially unsafe foods and food wastage.
Even if you can remember a time before 'use by' dates. The date labels on foods are also really important in terms of food safety and food wastage. Our research has found that many people are confused between 'best before' and 'use by' dates (Evans & Redmond, 2016). So to clarify, the 'best before' is an indicator of food quality, some people may dispose of food when it is beyond the 'best before' date, however you can eat the food after the date, it will be safe but it might not be of the best quality, for example the texture may not be as intended. Whereas the 'use by' date is an indicator of food safety, this is calculated based on the growth ability of bacteria, food that is beyond the 'use by' date should not be consumed – even if the food seems to be ok, as food poisoning bacteria can grow to high numbers without having an impact on the taste, smell and appearance of food. Although we shouldn't be eating food beyond the 'use by' date, there are a number of steps we can take to prevent wasting food because it has passed the 'use by' date; such as planning what we purchase and freezing food products that will not be eaten before the 'use by' date.
So, there are many simple steps that we can all take to help reduce food wastage in our own homes that also help to ensure the food that we eat is safe. Indeed, earlier this year, WRAP launched the first Food Waste Action Week, in an attempt to tackle household food waste with the simple message that "Wasting Food Feeds Climate Change". In addition to ensuring safe refrigeration temperatures and freezing food before the 'use by' date, the campaign also encourages us to plan our meals and make a shopping list – so we only buy what we really need.
I know that lots of people have already changed what they eat to reduce their carbon footprint, but I believe that how we approach food shopping, preparation and storage can also be beneficial. Small changes – such as ensuring our refrigerators are operating at temperatures below 5°C, and making good use of the freezer – may enhance food safety, reduce food wastage and the potential impact upon climate change.
References
Evans, E. W., & Redmond, E. C. (2015a). Analysis of Older Adults' Domestic Kitchen Storage Practices in the United Kingdom: Identification of Risk Factors Associated with Listeriosis. J. Food Prot., 78(4), 738-745.
Evans, E. W., & Redmond, E. C. (2015b). Time Temperature Study of UK Consumers' Domestic Refrigerators Time Temperature Study of UK Consumers' Domestic Refrigerators. In International Association for Food Protection (IAFP) European Symposium on Food Safety. Cardiff, UK. 20th - 22nd April 2015.
Evans, E. W., & Redmond, E. C. (2016). Older adult consumer knowledge, attitudes and self-reported storage practices of ready-to-eat food products and risks associated with listeriosis. J. Food Prot., 79(2), 263-272.
Evans, E. W., & Redmond, E. C. (2019). Laboratory re-enactment of storage practices of older adults to determine potential implications for growth of Listeria monocytogenes. Food Protection Trends., 39(3), 225-236.
Food Standards Agency. Food safety and hygiene at home. Chilling. How to chill, freeze and defrost food safely. (2020). Accessed 27th April 2021.
WRAP. WASTING FOOD FEEDS CLIMATE CHANGE: Food Waste Action Week launches to help tackle climate emergency. (2021). Accessed 20th October 2021.
