Thursday, 11 January 2018

Chips should be brown

I do like chips. I also like roast potatoes. Pies with a thick crisp pastry are also quite lovely. Fresh baked bread with lashings of butter melting through that gooey yeast-formed lattice of heartening carbohydrate, all held together with a nice, crunchy brown crust is just the ticket. Oh, and toast, just at that point of not quite being burnt, but almost there. Heaven!

Recent scientific health research pours terrible doubt on the future of foods that are naturally browned through baking, grilling or frying, which I feel is something of a terrible shame. Unfortunately, as is often the case, the results of the scientific research is inconclusive regarding the actual health hazards associated with naturally browning food at elevated temperatures. In being overzealous with caution regarding the health of the population I fear the Food Standards Agency are propagating what I believe to be a food risk myth and in so doing turning science into pseudoscience. There is no proof that eating burnt toast or crispy roast potatoes increases your risk of cancer.

I enjoy eating these things. I enjoy cooking these things. I always enjoy these food stuffs most when I make them myself. You see, there seems to be an ever increasing trend these days to make stuff anaemic rather than the colour they should be, a nice deep brown.

Browning of food during cooking, and incidentally the colouration of malted barley that goes to make your beer, occurs due to the Maillard reaction. This reaction changes the colour, flavour and brittleness of food. It becomes darker, tastier and more crunchy. The reaction is between reducing sugars and amino acids. The reactions, and therefore the resultant compounds can be complex and are dependant on the particular types of amino acid present, as well as the time, temperature and chemical conditions (PH for example) of the cooking process.

From a culinary point of view this is often referred to as caramelisation. Chemically, caramelisation is different to the Maillard reaction and therefore does not produce acrylamide. But in starchy foods both reactions tend to occur together and contribute to the overall deliciousness of properly cooked items such as chips.

Roast potatoes, made by me. Probably quite high in acrylamide, but they were delicious.
The problem it seems is that there has been scientific research that links a substance called acrylamide to cancer in laboratory animals. It is thought that acrylamide is formed as one of the products of the Maillard reaction, in any case it is present in starchy foods that have been heated over 120ºC. Such foods include chips, bread, biscuits and crisps.

Recently the FSA have issued advice that is designed to decrease the consumption of acrylamide. This advice includes cooking chips until they are "golden" rather than brown. It also includes the advice that cooking times should be reduced and preferably that cooking temperatures be lower.  Advising that production of acrylamide is reduced by reducing the surface area to volume ratio, for instance by making chips chunky rather than skinny1.

Now, if dietary acrylamide was proven to be a significant risk to human health then perhaps we should consider these recommendations. If reduction of cancer rates could be guaranteed by simply ensuring the population was eating pale food then there would be some point to the FSA scaremongering.

However, no epidemiological study has yet found a link between dietary acrylamide and cancer. The World Cancer Research Fund has carried out their own research and "this study didn’t find any strong evidence for a link between eating overcooked starchy foods that contain acrylamide and cancer risk in humans". Moreover, although they are falling short of calling out the FSA for overzealous caution, they do list the issue amongst 5 diet and cancer myths debunked. Indeed, there is no report anywhere that I can find that shows a link and even in the FSA reports there is yet to be a proven link.2

There is new legislation3 coming into force in April that is designed to manage the levels of acrylamide in food that are produced by food business operators. This bothers me hugely. Legislation brought in to address a problem that has yet to even be proven to exist seems over the top in the extreme. Legislation which will inevitably cause food producers to worry more about meeting the demands of the rules rather than making tasty food, and goes some way to explaining in my mind why most chips these days have virtually no colour about them at all.

A good while ago I wrote a whole post on the subject of chips4, and how I like to make them. Double frying ensures fully cooked fluffy interior and and a nice crisp brown exterior. And yes, the brown colour on the outside of chips does improve the flavour somewhat. I love bread with a thick brown crust, and pastry nicely coloured on the outside. Sadly, with the monstrosity that is Greggs bakery, the UK seems to be losing the idea of what a proper pie should be like, but make no doubt about it, no pastry item should be pale and limp.

The only remaining glimmer of hope is optimistic application of the ALARA principle, detailed at the end of this post. Standing for "As Low As Reasonably Achievable" the principle does permit some justified wriggling. If you are a restaurant, for instance, and you consciously and deliberately make the choice to create menu items designed to have a high level of browning of starch products then it is perfectly legitimate to argue that it is impossible to make such items properly without increased levels of acrylamide. However, in my experience environmental health officers lack the ability to understand the intricacies of such arguments and would rather dogmatically apply their own interpretation of the the rules.

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1However, it was interesting that in a certain study a supermarket's own brand crispy roast potatoes with goose fat seemed to come out with a greater level of acrylamide than the skinny chips from most well known fast food chains. We all know that crispy roast potatoes with goose fat are food things to die for. It may well be that there is a reaction with certain amino acids in the goose fat and the carbohydrates in the potatoes that ensure such deliciousness, but equally cause increased levels of acrylamide. Indeed, looking down the list of things in the results of the above mentioned study and it becomes apparent to me that there is a strong link between deliciousness and levels of acrylamide.

2I want to expand a little on my thoughts regarding the effect of acrylamide on the body. The substance is potentially carcinogenic, this is true. When exposure by inhalation is at substantially elevated levels there is some proof that there is some cancer risk, for example in smokers. In laboratory animals cancer risk is shown to be present from exposure.
"The National Toxicology Program’s Report on Carcinogens considers acrylamide to be reasonably anticipated to be a human carcinogen, based on studies in laboratory animals given acrylamide in drinking water. However, toxicology studies have shown that humans and rodents not only absorb acrylamide at different rates, they metabolize it differently as well." - National Cancer Institute (USA)
Acrylamide can be metabolised in different ways. It is possible that ingested acrylamide does find it's way to DNA in the body and so cause the mutations, it is also entirely possible that humans metabolise ingested acrylamide in a way that prevents it being damaging to DNA.

Homo Sapiens have also ways cooked food, and we evolved out of earlier species that also cooked food. Cooking by our ancestors has probably been a thing for about a million years. Cooking is possibly one of the reasons our species has become so successful, and therefore it is also highly likely we have developed an evolutionary tolerance to acrylamide in our food. It is certain that humans and rats metabolise acrylamide differently. Rats have never evolved to use fire for cooking.

3This legislation is actually coming from the EU. More evidence, I guess, to backup the Brexiteers case. However, drilling down through the information it seems it is the UK that is driving this, and besides, I'm not convinced that we won't just copy and paste EU legislation once we are out.

4I'm intregued that actually the picture of my chips in that by now rather ancient post shows them to be quite pale. Some varieties of potatoes, especially early season are notoriously difficult to brown owing to low concentrations of sugars. I assume this was the case in this sample.


Some background information

Acrylamide in malted barley

Pale malts 630-660µg kg-1
Coloured malts 2200µg kg-1
(source http://acta-arhiv.chem-soc.si/54/54-1-98.pdf)

Calculation of acrylamide in beer

1 pint of beer = 0.568 litres
assume beer has OG = 1.050
Litre degrees per pint = 0.568 x 50 = 28.4lº
Assume yield of 300lº/kg
Mass of malt per pint of beer = 28.4/300 = 0.095kg or 95g
Pale beer acrylamide content = 0.095 x 650 = 62µg
Dark beer (20% dark malt) acrylic content = 0.095 x (650 x 0.8 + 2200 x 0.2)
        = 0.095 x (520 + 440) = 0.095 x 960 = 91µg

Safe levels of consumption

182µg/day for a 70kg human https://www.bakeryandsnacks.com/Article/2009/12/08/Scientists-determine-safe-acrylamide-levels

ALARA

ALARA is an acronym for the concept “As Low As Reasonably Achievable”. This simply means that a Food Business Operator (FBO) should take appropriate measures to reduce the presence of a given contaminant in a final product to a minimum: taking account of the risk presented, but also taking account of other legitimate considerations, such as potential risks from other contaminants, organoleptic properties and quality of the final product, and the feasibility and effectiveness of controls.


6 comments:

Jeff Pickthall said...

The one that bugs is the warning that "processed" food is somehow bad. Which bloody process? Isn't any kind of food preparation a "process"?

Yvan Seth said...

It's a bit like eggs really... for years governments tell us eggs are going to kill us based entirely on non-science. The whole concept is thoroughly debunked but it takes 10 years to change the general health policy on eggs, and it'll be decades before this percolates through to the general public.

Jeff Pickthall said...

I am reminded of this scene: https://www.youtube.com/watch?v=D2fYguIX17Q

Dave Bailey said...

Shit Yvan, the egg thing started nearly 30 years ago in this country caused by Edwina Currie.

At the time, for my relatively juvenile self, the term Egg(wina) Curry brought great hilarity.

Unfortunately the current myth propagation is brought about by civil servants rather than politicians. The fact that there seems to be no accountability worries me a lot.

Dave Bailey said...

Jeff, indeed. What we obviously should be doing is picking berries and nuts off the trees and eating them raw.

Curmudgeon said...

Great to see a proper scientific explanation of why properly-cooked food is good, but sad that it's necessary.