Beware the Rink Food

© Aleksandr Stennikov - Fotolia.com

Anyone who has ever had a stint of cooking at the rink will be familiar with the dark, murky depths of the deep fryer, from whence emerges french fries, onion rings, popcorn chicken - even perogies and hotdogs (whatever happened to boiling water?)

Well, before you stuff your face (or worse - your child's face) full of this greasy, deep-fried, fat-laden fare, maybe take a gander at a recently released study from the University of the Basque Country (UPV/EHU) in Spain. They are the first researchers to discover that certain cooking oils, when heated to the high temperatures used for deep frying, produce toxic compounds called aldehydes that have been linked to  neurodegenerative diseases such as Alzheimer's and Parkinson's and some types of cancer.

"The toxic aldehydes are a result of degradation of the fatty acids in oil, and although some are volatile, others remain after frying. That is why they can be found in cooked food. As they are very reactive compounds they can react with proteins, hormones and enzymes in the organism and impede its correct functioning."

The scientists compared three types of cooking oils, sunflower, linseed and olive oil, which they heated in an industrial deep fryer to 190 degrees C for 40 hours (in the case of the sunflower and olive oil) and 20 hours for the linseed oil.

Results from the study were published in the Food Chemistry Journal.

"After applying gas chromatography/mass spectrometry techniques, the results show that sunflower and linseed oil (especially the first) are the ones that create the most toxic aldehydes in less time. These oils are high in polyunsaturated fats (linoleic and linolenic).

Adversely, olive oil, which has a higher concentration of monounsaturated fats (such as oleic), generate these harmful compounds in a smaller amount and later.

In previous studies, the same researchers found that in oils subjected to frying temperatures, other toxic substances, alkyl benzenes (aromatic hydrocarbons) were found. They concluded that of the oils studied, olive oil is the one that creates the least."

Previous research has already shown that degraded frying oil (in other words oil that has been used over and over and over again) can contain increased levels of oxidized lipids, which can be harmful to health and prompted some recommendations, which were adopted at the 3rd International Symposium on Deep-Fat Frying (ISDFF) in Hagen Germany in 200,0 about when frying oils should be changed, based on a measure of the Total Polar Materials (TPM) content. TPM are non-triglyceride materials that begin to accumulate as heated oils begin to breakdown and are an indicator that the quality of the oil is seriously downgrading. giving increased risk of toxic compounds being produced. Experts at the ISDFF recommended that oils should be tested and discarded once the TPM reaches 24%.
 
But it appears that some countries are more concerned about what's in their fast food industry's deep-fryers than others. In some European countries like Spain and Germany there are specific regulations for the maximum percentage (25% and 24% respectively) of TPM. Other countries, like Canada, only have recommended guidelines for TPM, based on the ISDFF recommendations. The US does not even have a recommended safe level of TPM.
  
Which means that in North America it's largely up to the fast food industry to determine when they think they need to change the oil in their deep fryers.

McDonald's do have their own Quality Management system and claims to have a policy in place where they change their frying oil, which is tested at least daily, once it reaches the 24% TPM.


But what about small, independent restaurants without the resources (human and financial) of McDonald's and those small, country arenas, all struggling to make ends meet by churning out the ubiquitous fries and onion rings?

In Canada the maximum recommendation for TPM in frying oil is 24%, and it has some further recommendations about food safety and deep fryers which came from an Expert Committee on Fats, Oils and Other Lipids (a subcommittee of the Canadian Agri-Food Research Council's Canada Committee on Food), which were also published in 2000.

These include:
        •  Frying oil should not be heated above 180°C (355°F).
        •  Measure the level of degradation (TPM) with a commercial test kit or hand held measuring 
            device 

        •  Remove food particles and crumbs from the deep fryer frequently.
        •  When not in use, lower the temperature of the fryer to 120°C (250°F).
        •  Turn the deep fryer off and cover with a metal lid when not in use or the kitchen is closed.
        •  Use separate deep fryers for potatoes from those used for meats, chicken and/or fish

You could probably walk into any rink kitchen, anywhere, and find most of these recommendations being ignored, and quite frankly, most, which are run by volunteers, have no food service industry training and probably have never heard of TPM or are aware of the health implications of using degraded oil, which now could be more serious than anyone previously thought.

Rink burgers never looked so good.

Information from the Alpha Galileo Foundation