"Faster" food creates a furore

The finding of horse meat at up to 30% of a "beef" burger in Ireland has created a furore this week, both in the mainstream and social media.

The Irish Agriculture Minister, Simon Coveney, has blamed a single meat processor and has further stated that the horse meat entered the product via an imported additive, though the nature or identity of the additive was not mentioned.

You can't tell by looking at a burger just what sort of meat is present, so some fairly sophisticated laboratory methods must be used.  Though not stated in the press articles I have read, the chances are that the burger was tested for specific DNA markers for horse meat.  Indeed, both horse and pig DNA were found in some burgers.

It appears that "traces" of pig DNA were also found in 85% of the burger products tested.  The fact that only traces were detected suggests to me that either a pig-derived additive was used in the manufacture of the burgers, or the beef was ground in equipment improperly cleaned after processing pork.  This latter suggestion is perhaps unlikely, as the traces were found in burgers supplied by a number of manufacturers.

In itself, the finding of traces of DNA from meat animals other than beef cattle should not be cause for alarm - no harm can come from consuming the burgers.  However, some religious and cultural sensibilities may be offended - if you are not allowed to eat pork for whatever reason, you should be able to purchase "beef" products with the expectation that they don't contain pork.  Of course, 30% horse meat in a beef burger is not a trace and the implication is that in this case there was a deliberate attempt to deceive the customer.

While I don't condone the addition of meats not appearing on the label, I wonder if this is another of those situations where the use of highly sensitive analytical techniques has raised a storm.  Something similar happened many years ago when milk was tested by a new, sensitive method for detecting dioxin.  In that case, the dioxin came from the chlorine-bleached paperboard used in manufacture of the milk cartons and was at extremely low levels in the milk. 

How many other foods that we take for granted contain minuscule traces of DNA, and, by implication, foreign plant or animal materials, which get there as a result of the use of natural additives?

Sodium in food

Most people like to have salt on their food. In mediaeval England, salt was expensive and only the nobility could afford it, as it was made by evaporating salt water over a fire. The salt was placed in the middle of the high table; the commoners sat at lower trestle tables and did not have access to the salt. Thus they were "below the salt" and this came to be an indication of rank.

Around 1650, rock salt was mined in Cheshire and salt became more readily available. The connotation of the value of salt remains, however, in expressions like "He's worthy of his salt".

These days, we probably have too much salt in our diets. In New Zealand, for instance, we consume around 150% of the recommended upper intake level. Much of this intake is involuntary - manufacturers add it to foods including bread, sausages and pies. The recent television series "Master Chef" had the judges saying repeatedly "Don't forget the seasonings", meaning not just herbs and spices, but also salt.

So, should we just ban salt in food and let individuals add salt to taste?

The answer may surprise some readers. Salt (sodium chloride) contributes to the safety of food and is essential for developing texture and flavour in processed meats. It helps to bind proteins, improving texture; it increases water binding capacity of proteins, also contributing to texture and assists in stabilising meat batters by improving fat binding. It also decreases fluid loss in vacuum-packed, thermally processed products.

Not only that - salt improves safety and shelf life by inhibiting the growth of bacteria, though relatively high levels are required if salt is used alone. It helps to reduce the water activity^* of the food, making it more difficult for bacteria to grow. That's why salted beef and pork were carried on long sea voyages - the meat was preserved.

Stringer and Pin (Institute of Food Research, Norwich, UK) have noted that "There is scope to reduce salt in foods. However, as salt influences bacterial growth, survival and recovery after adverse treatments, reducing salt in foods will have consequences for food safety that must be considered". These researchers used predictive models to show that reducing sodium content from 1.5g/100g to 0.76g/100g food allowed a much greater growth rate of certain foodborne pathogens. This could be acceptable, but other preservative mechanisms would need to be put in place. For example, other preservatives might be added at low levels and refrigeration might be necessary. Above all, reducing salt content would require even stricter adherence to good manufacturing practices, particularly with respect to plant and operator hygiene.

I'll write more on sodium in food in a follow-up posting.

* See the end of "Free Choice or Safety of the Population" in this blog for an explanation of water activity.

Guest Editorial - Additives in New Zealand Foods

This blog has not been updated for some time, mainly because we have been hard at work studying the growth of Cronobacter sakazakii. This work has now been submitted for publication and I have time to write more articles. Some of our work on C. sakazakii will appear in a later post.

To get us off to a good start, here is a guest article, written by one of my colleagues, Associate Professor Owen Young of Auckland University of Technology:

Food Additives in New Zealand

I recently had AUT University students systematically survey packaged food labels in Auckland supermarkets for health claims. These could be real (e.g. ‘if you eat this food your cholesterol will be lower’), or implied (e.g. ‘contains no additives’, ‘all natural ingredients’ etc.).

Over 30% of products surveyed had a ‘fat’ claim such as ‘lo fat’, ‘low in saturated fat’, or ‘98% fat-free’. Arguably these claims could be useful to a buyer seeking to control their weight, but overlooks the fact that total energy intake is really what matters for obesity. Fat is not the only beast with calories.

But of more interest to me were the claims for avoiding Public Enemy Numbers 1, 2 and 3: artificial colours (28% with claims), preservatives and artificial flavours (both 24%). Anyone would think these things were dangerous. But are they dangerous in the way they are used in foods?

Take the yellow food colouring tartrazine for example. Googling ‘tartrazine allergy’ will score you thousands of hits. On the face of it you would have to wonder why Food Standards Australia New Zealand (FSANZ) allows artificial food colouring to be used at all. The reason is because the evidence for adverse effects from these colours is so flimsy as to be laughable. Colours have been used in foods for decades with no adverse effects. So why are some colours banned in certain countries? The reason is that pressure groups have been so strident that it becomes politically expedient to roll over and appease the activists.

Preservatives are sometimes put in prepared foods to minimise the growth of bacteria. These bacteria can either degrade the food, but be otherwise harmless, or they can be pathogens. At best the latter can make you sick and at worst can kill you. The maximum quantity of preservative added is typically hundreds of times lower that the amounts required to show any kind of response in humans. Preservatives have excellent safety records, and that is why FSANZ allows their use. You would have to wonder about a food manufacturer who neglected to add a preservative to a susceptible food. Such action should be viewed as callous indifference to your health.

The so-called artificial flavour that gets most bad press is MSG, monosodium glutamate. Ostensibly MSG is responsible for the Chinese restaurant syndrome with its claimed headache, flushing, and tingling symptoms. But MSG has been used extensively in Asian cooking for donkey’s years. If it’s so bad, why doesn’t everyone in Asia have a headache? The truth is that it is not bad for you.

Very many common foods have high concentrations of MSG, but no one complains about MSG in cheese, soy sauce, walnuts and broccoli, and a host of other foods. Chinese restaurant syndrome is nothing but an enduring urban myth. So why does MSG have to be declared on labels? One reason is that regulators are simply responding to activist demands. Any hint of a potential problem is dealt with by a label declaration that presumably implies that the additive is a risk and so feeds the myth.

What can or cannot be added to food in New Zealand is governed by FSANZ’s Food Code, which is online for all to read. One guiding principle is you can put additives into foods only where allowed and where needed – up to a specified limit – and crucially, only enough to achieve the required result. You cannot add stuff just for the hell of it, and indeed why would you? Additives cost money and there is often no need for them.

Take beer for example. Current advertisements frequently have an ‘all natural ingredients’ claim ­– whatever ‘natural’ means – and a ‘no preservatives added’ claim. The Food Code allows only one preservative in beer, sulphur dioxide, but it is seldom added because beer, by its very nature, keeps well without preservatives. Similarly, preservatives are not added to breakfast cereals because they are not needed in these dried foods.

The Food Code is thus a very conservative document, making New Zealand food supplies among the safest in the world.

So feel free to ignore the implied health claims that are built on the flimsiest of evidence, and are used to part you and your money through a fear of chemicals – chemophobia (n): an irrational fear of chemicals, particularly those man-made.

Associate Professor Owen Young is Academic Leader, Food Science, AUT University, Auckland