Tag Archives: Additives

Onerous ovens: why is cleaning the cooker such a chore?

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As I write Thanksgiving was a few days ago, when most Americans traditionally cook a very large meal based around roasted turkey. Most Brits – and other countries of course – have the same thing coming up soon in the form of Christmas, and there are lots of other celebrations around this time of year that seem to feature cooking and food quite heavily.

Whatever your traditions, then, it’s a time when many of us frown critically at the dark, sticky depths of our oven and wonder if, perhaps, we should attempt to give it a clean. Or at least pay someone else to come and clean it.

Why is oven cleaning such a difficult and unpleasant job, anyway? It’s not that hard to clean other surfaces, is it? Why are ovens so particularly awful?

Well, to explain this, we first need to understand fats.

Fats vaporise during cooking.

Most of the grime in your oven is fat, combined with the carbonised remains of… something or other. The sorts of fats that are common in animal and plant products have boiling points around the 300 oC mark (animal fats typically having higher values than plant oils), but they start to form vapours at much lower temperatures, and certainly at typical cooking temperatures there’s plenty vaporised oil around. Besides, under typical conditions most oils will “smoke” – i.e. start to burn – long before they get close to boiling.

We’re all familiar with the idea that fats don’t mix well with water, and herein lies the problem: all that fatty gloop that’s stuck to the inside of your oven just doesn’t want to come off with standard cleaning methods, particularly when it’s built up over time.

Can chemistry help us here? What are fats, chemically? Well, they’re esters. Which may or may not mean anything to you, depending on how much chemistry you can remember from school. But even if you don’t remember the name, trust me, you know the smell. In particular, nail polishes and nail polish removers contain the simple ester known as ethyl acetate, otherwise known as ethyl ethanoate. (Some people say this chemical smells like pear drops which… only really helps if you know what pear drops smell like. Look, it smells of nail polish, okay?)

Fats are esters (image source)

Anyway, the point is that esters have a particular sequence of atoms that has a carbon bonded to an oxygen, which is bonded to another carbon, which is in turn double-bonded to oxygen. This is a bit of a mouthful, so chemists often write it as COOC. In the diagram here, oxygen atoms are red while carbon atoms are black.

There are actually three ester groups in fat molecules – which explains why fats are also known as triglycerides.

In terms of general chemistry, esters form when a carboxylic acid (a molecule which contains a COOH group) reacts with an alcohol (a molecule that contains an OH group). And this is where it all starts to come together – honest – because you’ve probably heard of fatty acids, right? If nothing else, the words turn up in certain food additive names, in particular E471 mono- and diglycerides of fatty acids, which is really common in lots of foods, from ice cream to bread rolls.

Glycerol is a polyol — a molecule that contains several alcohol groups (image source)

Well, this reaction is reversible, and as a result fats (which are esters, remember) break up into fatty acids and glycerol – which is a polyol, that is, a molecule with several alcohol groups. Or, to look at it the other way around: fats are made by combining fatty acids with glycerol.

And the reason it’s useful to understand all this is that the way you break up esters, and therefore fat, is with alkalis. (Well, you can do it with acid, too, but let’s not worry about that for now.)

Strong alkalis break up fats in a chemical reaction called hydrolysis — the word comes from the Greek for water (hydro) and unbind (lysis) and so literally means “split up with water”. Humans have known about this particular bit of chemistry for a long time, because it’s fundamental to making soap. As I said a few months ago when I was banging on about hand-washing, the ancient Babylonians were making soap some 4800 years ago, by boiling fats with ashes – which works because alkaline compounds of calcium and potassium form when wood is burnt at high temperatures.

The grime in ovens is mostly fat.

The really clever thing about all this is that two things are happening when we mix alkali with fat: not only are we breaking up the fat molecules, but also the substances they break up into are water-soluble (whereas fats, as I said at the start, aren’t). Which makes them much easier to clean away with water. Obviously this is the very point of soap, but it’s also handy when trying to get all that baked-on gunk off your oven walls.

Now, in theory, this means you could get some lye (aka sodium hydroxide, probably), smear it all over your oven and voilà. But I don’t recommend it, for a few reasons. Firstly, it’s going to be difficult to apply, since sodium hydroxide is mostly sold as pellets or flakes (it’s pretty easy to buy, because people use it to make soap).

Sodium hydroxide, sometimes called lye, is often sold in the form of pellets.

But, you say, couldn’t I just dissolve it in water and spray or spread it on? Yes, yes you could. But it gets really, really hot when you mix it with water. So you need to be incredibly careful. Because, and this is my next point, chemically your skin is basically fat and protein, and this reaction we’re trying to do on oven sludge works equally well on your skin. Only, you know, more painfully, and with scarring and stuff. In short, if you’re handing lye, wear good nitrile on vinyl gloves and eye protection.

Actually, regardless of how you’re cleaning your oven you should wear gloves and eye protection, because the chemicals are still designed to break down fats and so… all of the above applies. It’s just that specially-designed oven cleaners tend to come with easier (and safer) ways to apply them. For example, they might come as a gel which you can paint on, and/or with bags that you can put the racks into, and may also be sold with gloves and arm protectors (but rarely goggles – get some separately). They might also have an extra surfactant, such as sodium laureth sulfate, added to help with breaking down grease. The main ingredient is still either potassium hydroxide or sodium hydroxide, though.

Well, possibly, but also not really, if you’re sensible.

As an aside, it makes me smile when I come across an article like this which talks about the “serious” chemicals in oven cleaners and more “natural” ways to clean your oven. The “natural” ways are invariably weak acids or alkalis such as lemon juice or baking soda, respectively. They’re essentially ineffective ways of trying to do exactly the same chemistry.

And okay, sure, the gel and the bag and so on in the modern kits are newer tech, but the strong alkali? Nothing more natural than that. As I said at the start, humans have literally been using it for thousands of years.

A point which really cannot be repeated enough: natural does not mean safe.

Fumes can be irritating to skin, eyes and lungs.

Speaking of which, you will get fumes during oven cleaning. Depending on the exact cleaning mixture involved, these will probably be an alkaline vapour, basically (haha) forming as everything gets hot. Such vapour is potentially irritating to skin, eyes and lungs, but not actually deadly toxic. Not that I recommend you stick your head in your freshly-scrubbed oven and inhale deeply, but you take my point. It might give food a soapy, possibly bitter (contrary to what’s stated in some text books, not all alkalis taste bitter, but do not experiment with this) taste if you really over-do it.

In short, if you’re cleaning your oven yourself: follow the manufacturer’s instructions, make sure your kitchen is well-ventilated, leave the oven door open for a while after you’ve finished and, to be really sure, give all the surfaces an extra wash down with plenty of water.

Put the cleaning off until January – after all, the oven’s only going to get dirty again.

And that’s… it, really. Whether you’re cleaning your own oven or getting someone else to do it for you, the chemistry involved is really, really old. And yes, the chemicals involved are hazardous, but not because they’re not “natural”. Quite the opposite.

Or you could just leave it. I mean, it’s only going to get dirty again when you cook Christmas dinner, right?

If you’re studying chemistry, have you got your Pocket Chemist yet? Why not grab one? It’s a hugely useful tool, and by buying one you’ll be supporting this site – it’s win-win! If you happen to know a chemist, it would make a brilliant stocking-filler! As would a set of chemistry word magnets!

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Just what is blk water, and should you drink it?

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Christmas is almost here! Are you ready yet? Are you fed up with people asking if you’re ready yet? Have you worked out what to buy for Great-uncle Nigel, who says he neither needs nor wants anything? Always a tricky scenario, that. Consumables are often a safe fallback position. They don’t clutter up the house, and who doesn’t enjoy a nice box of luxury biscuits, or chocolates, or a bottle of champagne, or spirts, or a case of blk water.

Wait, what?

Yes, this mysterious product turned up in my feed a few weeks ago. It’s water (well, so they say), but it’s black. Actually black. Not just black because the bottle’s black, black because the liquid inside it is… black.

It’s black water.

A bit like… cola. Only blacker, and not fizzy, or sweet, or with any discernable flavour other than water.

It raises many questions, doesn’t it? Let’s start with why. Obviously it’s a great marketing gimmick. It definitely looks different. It also comes with a number of interesting claims. The suppliers claim it contains “no nasties” and “only 2 ingredients”, namely spring water and “Fulvic Minerals” (sic). (Hang on, I hear you say, if it’s minerals, plural, surely that’s already more than two ingredients? Oh, but that’s only the start. Stay with me.)

It claims to “balance pH levels” and help “to regulate our highly acidic diets”. Yes, well, I think I’ve covered that before. Absolutely nothing you drink, or eat, does anything to the pH in any part of your body except, possibly, your urine – where you might see a small difference under some circumstances (but even if you do it doesn’t tell you anything significant about the impact of your diet on your long-term health). And bear in mind that a few minutes after you drink any kind of alkaline water it mixes with stomach acid which has a pH of around 2. Honestly, none of that alkaline “goodness” makes it past your pyloric sphincter.

Finally, blk water apparently “replenishes electrolytes”. Hm. Electrolytes are important in the body. They’re ionic species, which means they can conduct electricity. Your muscles and neurons rely on electrical activity, so they are quite important. Like, life or death important. But because of that our bodies are quite good at regulating them, most of the time. If you run marathons in deserts, or get struck down with a nasty case of food poisoning, or have some kind of serious health condition (you’d know about it) you might need to think about electrolytes, but otherwise most of us get what we need from the food and drink we consume normally every day.

Besides which, didn’t they say “only 2 ingredients”? The most common electrolytes in the body are sodium, potassium, magnesium, chloride, hydrogen phosphate and hydrogen carbonate. Most spring waters do contain some, if not all, of these, in greater or smaller amounts, but it’s not going to be enough to effectively “replenish” any of them. If, say, you are running marathons in the desert, the advice is actually to keep a careful eye on your water intake because drinking too much water can dangerously lower your sodium levels. Yes, there are sports drinks that are specifically designed to help with this, but they taste of salt and sugar and/or flavourings which have been added in a desperate attempt to cover up the salty taste. This is apparently not the case with blk water which, to repeat myself, contains “only 2 ingredients”.

And, according to the blk website the drink contains “0 mg of sodium per 500ml” so… yeah.

Speaking of ingredients, what about those so-called fulvic minerals? Maybe they’re the source of those all-important electrolytes (but not sodium)? And maybe they’re magically tasteless, too?

And perhaps, like other magical objects and substances, they don’t actually exist – as geologist @geolizzy told me on Twitter when I asked.

It’s not looking good for blk water (£47.99 for a case of 24 bottles) at this point. But hang on. Perhaps when they said fulvic minerals, what they meant was fulvic acid – which is a thing, or possibly several things – in a the presence of oh, say, some bicarbonate (*cough* 2 ingredients *cough*).

That could push the pH up to the stated 8-9, and didn’t we learn in school that:
acid + alkali –> salt + water
and maybe, if we’re being generous, we could call the salts of fulvic acids minerals? It’s a bit shaky but… all right.

So what are fulvic acids?

That’s an interesting question. I had never heard of fulvic acids. They do, as it turns out, have a Wikipedia page (Wikipedia is usually very reliable for chemical information, since no one has yet been very interested in spoofing chemical pages to claim things like hydrochloric acid is extracted from the urine of pregnant unicorns) but the information wasn’t particularly enlightening. The page did inform me that fulvic acids are “components of the humus” (in soil) and are  “similar to humic acids, with differences being the carbon and oxygen contents, acidity, degree of polymerization, molecular weight, and color.” The Twitter hive-mind, as you can see, was sending me down the same path…

A typical example of a humic acid.

Next stop, humic acids. Now we’re getting somewhere. These are big molecules with several functional groups. The chemists out there will observe that, yes, they contain several carboxylic acid groups (the COOH / HOOC ones you can see in the example) so, yes, it makes sense they’d behave as acids.

“No nasties”, blk said. “Pure” they said. When you hear those sorts of things, do you imagine something like this is in your drink? Especially one that, let’s be clear, is a component of soil?

Oh, hang on, I should’ve checked the “blk explained” page on the blk water website. There’s a heading which actually says “what are Fulvic Minerals”, let’s see now…

“Fulvic minerals are plant matter derived from millions of years ago that have combined with fulvic acid forming rare fulvic mineral deposits. They deliver some of the most powerful electrolytes in the world.”

“Fulvic minerals contain 77 other trace minerals, most of which have an influence on the healthiness of our body. They are very high in alkaline and when sourced from the ground contain a pH of 9.”

I don’t know about you, but I’m not totally convinced. I mean, as @geolizzy says in her tweet here (excuse the minor typo, she means humic, not humid),  it sounds a bit like… water contaminated with hydrocarbon deposits?

Yummy.

And, by the way, the phrase “very high in alkaline” is utterly meaningless. Substances are alkaline, or they contain substances which are alkaline. “Alkaline” is not a thing in itself. This is like saying my tea is high in hot when sourced from the teapot.

There’s one more thing to add. So far this might sound a bit weird but… probably safe, right? What could be more wholesome than a bit of soil? Didn’t your granny tell you to eat a pinch of soil to boost your immune system, or something? At worst it’s harmless, right?

Tap water is chlorine-treated to keep it free of nasty bacteria.

Maybe. But then again… water is often treated with chlorine compounds to keep it bacteria-free. Now, blk water is supposedly spring water, which isn’t usually treated. But hypothetically, let’s consider what happens when humic acids, or fulvic acids, or whatever we’re calling them, come into contact with chlorine-treated water.

Oh dear. It seems that dihaloacetonitriles are formed. (See also this paper.) This is a group of substances (possibly the best known one is dichloroacetonitrile) which are variously toxic and mutagenic. Let’s hope that spring water is totally unchlorinated, 100% “we really got it from out of a rock” spring water, then.

To sum up: it is black, and that’s kind of weird and a fun talking point – although if you like the idea of a black drink you can always drink cola. It doesn’t balance your pH levels – nothing does. I don’t believe it replenishes electrolyte levels either – how can it when it doesn’t contain sodium? – and I’m dubious about the “2 ingredients” claim (could you tell?). And the oh-so-healthy-sounding fulvic minerals are most likely due to contamination from coal deposits.

All in all, whilst it might not be quite such a conversation piece, I think it would be better to get Great-uncle Nigel a nice box of chocolates this year.

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The Chronicles of the Chronicle Flask: 2016

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2016 is limping to its painful conclusion, still tossing out last-minute nasty surprises like upturned thumb tacks in the last few metres of a marathon. But the year hasn’t been ALL bad. Some fun, and certainly interesting, things happened too. No, really, they did, honestly.

So with that in mind, let’s have a look back at 2016 for the Chronicle Flask….

January kicked off with a particularly egregious news headline in a well-known broadsheet newspaper: Sugar found in ketchup and Coke linked to breast cancer. Turns out that the sugar in question was fructose. Yes, the sugar that’s in practically everything, and certainly everything that’s come from a plant. So why did the newspaper in question choose ketchup and Coke for their headline instead of, oh, say, fruit juice or honey? Surely not just in an effort to sell a few more newspapers after the overindulgent New Year celebrations. Surely.

octarineThere was something more lighthearted to follow when IUPAC  verified the discoveries of elements 113, 115, 117 and 118. This kicked off lots of speculation about the elements’ eventual names, and the Chronicle Flask suggested that one of them should be named Octarine in honour of the late Sir Terry Pratchett. Amazingly, this suggestion really caught everyone’s imagination. It was picked up in the national press, and the associated petition got over 51 thousand signatures!

In February I wrote a post about the science of statues, following the news that a statue to commemorate Sir Terry Pratchett and his work had been approved by Salisbury City Council. Did you know that there was science in statues? Well there is, lots. Fun fact: the God of metalworking was called Hephaestus, and the Greeks placed dwarf-like statues of him near their Hearths – could this be where the fantasy trope of dwarves as blacksmiths originates?

MCl and MI are common preservatives in cosmetic products

MCl and MI are common preservatives in cosmetic products

My skeptical side returned with a vengeance in March after I read some online reviews criticising a particular shampoo for containing a substance known as methylchloroisothiazolinone. So should you be scared of your shampoo? In short, no. Not unless you have a known allergy or particularly sensitive skin. Otherwise, feel free to the pick your shampoo based on the nicest bottle, the best smell, or the forlorn hope that it will actually thicken/straighten/brighten your hair as promised, even though they never, ever, ever do.

Nature Chemistry published Another Four Bricks in the Wall in April – a piece all about the potential names of new elements, partly written by yours truly. The month also brought a sinus infection. I made the most of this opportunity by writing about the cold cure that’s 5000 years old. See how I suffer for my lovely readers? You’re welcome.

In May I weighed in on all the nonsense out there about glyphosate (and, consequently, learned how to spell and pronounce glyphosate – turns out I’d been getting it wrong for ages). Is it dangerous? Nope, not really. The evidence suggests it’s pretty harmless and certainly a lot safer than most of its alternatives.

may-facebook-postSomething else happened in May: the Chronicle Flask’s Facebook page received this message in which one of my followers told me that my post on apricot kernels had deterred his mother from consuming them. This sort of thing makes it all worthwhile.

In June the names of the new elements were announced. Sadly, but not really very surprisingly, octarine was not among them. But element 118 was named oganesson and given the symbol Og. Now, officially, this was in recognition of the work of Professor Yuri Oganessian, but I for one couldn’t help but see a different reference. Mere coincidence? Surely not.

July brought another return to skepticism. This time, baby wipes, and in particular a brand that promise to be “chemical-free”. They’re not chemical-free. Nothing is chemical-free. This is a ridiculous label which shouldn’t be allowed (and yet, inexplicably, is still in use). It’s all made worse by the fact that Water Wipes contain a ‘natural preservative’ called grapefruit seed extract which, experiments have shown, only actually acts as a preservative when it’s contaminated with synthetic substances. Yep. Turns out some of Water Wipes claims are as stinky as the stuff they’re designed to clean up.

Maria Lenk Aquatic Enter, Tuesday, Aug. 9, 2016. (AP Photo/Matt Dunham)

Maria Lenk Aquatic Enter, Tuesday, Aug. 9, 2016. (AP Photo/Matt Dunham)

August brought the Olympics, and speculation was rife about what, exactly, was causing the swimming pools to turn such strange shades of green. Of course, the Chronicle Flask knew the correct solution…

August also saw MMS and CD reared their ugly heads on social media again. CD (chlorine dioxide) is, lest we forget, a type of bleach solution which certain individuals believe autistic children should be made to drink to ‘cure’ them. Worse, they believe such children should be forced to undergo daily enemas using CD solutions. I wrote a summary page on MMS (master mineral solution) and CD, as straight-up science companion to the commentary piece I wrote in 2015.

mugsSeptember took us back to pesticides, but this time with a more lighthearted feel. Did you know that 99.99% of all the pesticides you consume are naturally-occurring? Well, you do if you regularly read this blog. The Chronicle Flask, along with MugWow, also produced a lovely mug. It’s still for sale here, if you need a late Christmas present… (and if you use the code flask15 you’ll even get a discount!)

In October, fed up with endless arguments about the definition of the word ‘chemical’ I decided to settle the matter once and for all. Kind of. And following that theme I also wrote 8 Things Everyone Gets Wong About ‘Scary’ Chemicals for WhatCulture Science.

Just in case that wasn’t enough, I also wrote a chapter of a book on the missing science of superheroes in October. Hopefully we should see it in print in 2017.

Sparklers are most dangerous once they've gone out.

Sparklers are most dangerous once they’ve gone out.

I decided to mark Fireworks Night in November by writing about glow sticks and sparklers. Which is riskier? The question may not be as straightforward as you’d imagine. This was followed by another WhatCulture Science piece, featuring some genuinely frightening substances: 10 Chemicals You Really Should Be Scared Of.

And that brings us to December, and this little summary. I hope you’ve enjoyed the blog this year – do tell your friends about it! Remember to follow @ChronicleFlask on Twitter and like fb.com/chronicleflask on Facebook – both get updated more or less daily.

Here’s wishing all my lovely readers a very Happy New Year – enjoy a drop of bubbly ethanol solution and be careful with the Armstrong’s mixture…. 

See you on the other side!

new-year-1898553_960_720

8 Things Everyone Gets Wrong About ‘Scary’ Chemicals

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scaryChemicals. The word sounds a little bit scary, doesn’t it? For some it probably conjures up memories of school, and that time little Joey heated something up to “see what would happen” and you all had to evacuate the building. Which was actually good fun – what’s not to love about an unplanned fire drill during lesson time?

But for others the word has more worrying associations. What about all those lists of additives in foods, for starters? You know, the stuff that makes it all processed and bad for us. Don’t we need to get rid of all of that? And shouldn’t we be buying organic food, so we can avoid ….

….Read the rest of this article at WhatCulture Science.

This is my first article for WhatCulture Science – please do click the link and read the rest!

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A scary Halloween tale…

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Food additives, E-numbers – they’re scary aren’t they? Everyone knows they’re horrible, toxic things that make kids jump around, refuse to go to bed, go purple in the face and generally drive their parents around the bend (do kids really need chemical help with any of those things?)

pumpkin eating

Be careful what you eat…

It’s Halloween, a day when children traditionally stuff their faces fully of sugary, brightly-coloured sweeties. But never mind those, let’s give some thought to the humble pumpkin. Yes the orange things that grow in the ground. Did you know they’re stuffed full of additives too? Even ‘organic’ ones? They are, really! Here’s an ingredients list…

Water, carbohydrate, protein, E300, E375, E101, pyridoxine, thiamine, E470a, pteroyl-L-glutamic acid, E306, E160a, palmitic acid, linoleic acid, oleic acid, palmitic acid, stearic acid, purines, E621, potassium, calcium, phosphorous, magnesium, sodium, iron, zinc.

Scared yet?

Ok ok, don’t panic. Put down the baseball bat. It’s all right really, allow me to translate…

E300 is ascorbic acid, otherwise known as vitamin C. E375 is niacin (vitamin B3). E101 is riboflavin (vitamin B2). Pyridoxine is vitamin B6. Thiamine is vitamin B1 (seeing a pattern here? Pumpkin is good for B vitamins). E470a represents potassium salts of fatty acids. Pteroyl-L-glutamic acid is another name for folic acid. E306 is tocopherol, or vitamin E. E160a is beta-carotene (vitamin A).

Palmitic acid is the most common fatty acid found in animals and plants, and linoleic, oleic, palmitic and stearic acids are essential fatty acids particularly found in pumpkin seeds (very tasty roasted). Purines are some of the building blocks of DNA (the word purine comes from ‘pure urine’ because they were first synthesised from uric acid, isolated from kidney stones – ewwww). E621 is the dreaded monosodium glutamate. A lot of people fear this one, but actually it’s just a sodium salt of glutamic acid, which is another key amino acid. Totally natural. In fact, it’s one of the most abundant naturally occurring non-essential amino acids. (I will confess I’m improvising a wee bit here, but there’s no doubt that there’s glutamic acid in pumpkin – very abundant amino acid see – and there’s also sodium, so chances are there’s some monosodium glutamate knocking around in there.)

Potassium, calcium, phosphorous, magnesium, sodium, iron and zinc are all elements, and also important nutrients – you’ll find them all listed on the back of any good multivitamin and mineral supplement.

Food for thought? There’s a lot of nonsense spouted about additives and E numbers. For starters, that E? It means they’re regulated food additives that have been tested and approved for use with the European Union. They are, by definition, safe. Not only that, but quite a few of them are in your food to keep you safe by preventing harmful bacteria growing in it, for example. Lots and lots of them come from natural sources. Chemists like to extract and identify things, which is why lots of entirely natural substances have ended up with chemical names. An unfamiliar and complicated-sounding name doesn’t make something inherently dangerous.

On the other hand, there is something that’s been proven time and time again to cause numerous health issues from crashing energy levels to obesity, type two diabetes and dental problems. Yup. Sugar. E numbers have nothing on it.

I’m not suggesting anyone gives up sugar (where would be the fun in that, especially on Halloween?) but it’s always worth thinking about relative risk. If you’re going to accept a bit of sugar isn’t the end of the world, then give additives a break as well.

Right, I’m off to eat some Halloween biscuits – trick or treat!

Are artificial preservatives really that bad?

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Are preservatives really such a bad thing?

But are preservatives really such a bad thing?

As something of a skeptic, I am fond of myth- and hoax-busting type things.  I find them reassuring.  If I had to accept that absolutely everyone swallowed stories about poisonous bottled water, free Disneyland tickets, and the Pope coming out as gay without a second thought, I really would lose all faith in humanity.  But occasionally, just occasionally, a bizarre story pops up that actually turns out to be true.

And so it was a few days ago, when the Hoax Slayer feed on Facebook threw up a story about the luminous, foil-packed beverage Capri-Sun.  It would appear that mould (or, indeed mold – never mind fungi growing in children’s drinks, the story generated far more upset over American versus British spelling) has actually been found growing in Capri-Sun containers, in some cases in some really rather spectacular shapes and sizes.  This was no hoax.  It wasn’t even, unlike the story of the giant snake hanging around a mechanical digger, a twisted misrepresentation of the facts.  No, mould really has been found growing in more than one Capri-Sun container.

In a statement, Kraft, who make Capri-Sun, said:

“Among the many, many millions of pouches we sell each year, it does happen from time to time because the product is preservative free. A statement is included on all cartons telling consumers to discard any leaking or damaged packages. If mold does occur, we completely agree that it can be unsightly and gross, but it is not harmful and is more of a quality issue rather than a safety issue.”

This got me thinking, and funnily enough my thoughts were less “never, ever buy Capri-Sun” but rather “why is ‘preservative free’ such a good thing”?

salt-sugar-fatHumans have been preserving food for a very long time.  In fact, arguably since we first learned that holding bits of dead mammoth over that new-fangled fiery stuff makes it taste nicer and a bit less chewy.  The earliest preservatives are, of course, those oh-so-healthy staples of salt, sugar and fat.  And they’re still in use today.

Salt, otherwise known as sodium chloride, found in rocks and seawater.  We all like our salty foods, but how often do you stop and wonder why that delicious slice of ham is traditionally so salty?  It’s not just for flavour.  Salt is an excellent preservative, and humans have been using it for that reason for at least eight thousand years.  It’s a drying agent, drawing moisture from cells by osmosis, and since bacteria and fungi need moisture to grow salting food keeps them at bay.  Adding salt to food allowed people to travel over long distances and reduced the problem of seasonal availability.  As such it was an important commodity, even being used as a form of currency.  These days of course it’s far less valuable, until Britain suffers a dusting of snow that is.

Salt may help to keep our food fresh, but it’s not great when it comes to keeping us healthy.  In recent years too much salt has been increasingly associated with certain health problems.  Salt appears to raise blood pressure, and raised blood pressure puts you at increased risk of heart disease and stroke.  There is some controversy over exactly how causal this link is, but most health professionals agree that we could do with eating a bit less NaCl.

Next on the list, sugar.  Again, it’s been used since ancient times.  Preserves aren’t called preserves for nothing.  Jam (for our American cousins, jelly) wasn’t invented purely because it was delicious on toast.  No, jam, marmalade and the like are a handy way of making the summer fruit glut last all through the year.  Sugar works in a similar, although sweeter, way to salt: drawing water from cells by osmosis and producing an environment that’s hostile to bacteria.  Of course, as we all know, too much sugar isn’t great for our waistlines and it’s really bad for our teeth.  And tooth decay is far more than a cosmetic problem: in extreme cases infection can spread from the tooth to the surrounding tissues and lead to potentially fatal (really) complications such as cavernous sinus thrombosis and Ludwig’s angina.

What about fat?  Traditionally used as a layer on top of foods such as shrimp, chicken liver and pâté, it produces an air- and water-tight seal that makes a very effective barrier to bacteria.  Very high-fat foods, such as butter and cream, aren’t bacteria-friendly because, again, they have a low water content and bacteria need water to grown and reproduce.  Such foods also have fewer sugars, in particular lactose, that provide bacteria with their lunch.  This is why the use-by date on the cream is longer than the one on the milk, and why you can safely store the butter out of the fridge (you can, honestly).  Funnily enough, fat is probably the most controversial ‘additive’ from a health point of view.  Increasingly various groups are questioning the conventional wisdom that a high intake of saturated fat leads to cardiovascular disease, and of course there are essential fatty acids that are, well, essential.  We definitely need fat, at least certain kinds of fat, in our diet.  But there’s no doubt it’s high in calories, and it’s clear that being overweight is bad your health, so moderation is key.

So, salt, sugar and fat are all natural preservatives which are all associated with genuine health concerns.  What about artificial preservatives?  Well there are quite a few, and it would take a while to list them all (I’m not going to).  Some of them are definitely controversial.  Nitrates and nitrites, for example, form nitrosamines when foods are cooked, and these have been linked to an increased cancer risk.  But on the other hand, nitrates and nitrites prevent the growth of botulinum toxin, and if you ingest that, we’re not talking about a small increased risk, we’re talking about dead.  Plus, unlike fat, sugar and salt, their addition to foods is strictly regulated, so you’re unlikely to consume dangerously high quantities unless you’re practically living off processed meat.  In which case… well we’re back to salt and saturated fat again.

Sulfites, such as potassium and sodium sulfite, are common food additives which are known to be problematic for certain individuals, particularly if they have asthma or aspirin sensitivity.  But then, some people are allergic to peanuts and they haven’t been banned, yet.  There’s no evidence that sulfites are dangerous to everyone.

Sodium benzoate is another preservative that’s been linked with health problems, in particular hyperactivity in children.  But, and it’s quite a big but, only in combination with certain artificial colours.  And the effects observed weren’t consistent.  The Food Standards Agency concluded that, if real, the observed increases in hyperactive behaviour were more likely to be linked to the colours rather than the preservative.  Professor Jim Stevenson, author of the report, commented that “parents should not think that simply taking these additives out of food will prevent hyperactive disorders”.

dscf28802And this brings us back to soft drinks, because sodium benzoate is, or at least was, a fairly common ingredient in flavoured beverages.  Although, not Capri-Sun, as we’ve already established.

But Capri-Sun does contain sugar.  Admittedly, it’s main purpose isn’t preservative – there’s not quite enough for that – but still it’s an ingredient, and a significant one.  A quick glance at the nutritional information reveals that Capri-Sun contains 10.5 g of sugar per 100 g.  That’s 21 g in one of the foil packs, or roughly 5 teaspoons.  Some of this comes from the fruit juices the drink is made of, but not all.  Sugar is clearly listed as an added ingredient.  NHS guidelines suggest we shouldn’t be eating more than about 50 g (for women) or 70 g (for men) of sugar a day, so that one, really quite small, packet of Capri-Sun contains about half of a woman’s recommended daily sugar intake.

Make no mistake, sugar is bad.  It’s really bad.  Quite apart from dental decay and obesity, excessive sugar exposure has been firmly linked to type 2 diabetes.  And, guess what, eating less sugar cuts the risk of developing this potentially life-threatening illness.  Want to look after your family’s health?  You could do a lot worse than cutting back on sugar.

Let’s briefly consider some other favourite sticky beverages.  The Coca Cola Company is in the process of phasing sodium benzoate out of its products — including Coke, Sprite, Fanta, and Oasis — as soon as a “satisfactory alternative” is developed, and a quick look at some cans in my fridge (oh the shame) suggests they’ve already done it, in this country anyway.  Sugar, not so much (diet alternatives aside, obviously).  Sprite contains 6.6 g of sugar per 100 g (less than Capri-Sun, hmmm) and Coke contains 10.6 g per 100 g.

Now, I find this very interesting.  We have a small risk from sodium benzoate, when it’s combined with other additives, maybe.  And suddenly food companies are desperate to get it out of their products, and to prominently label everything as “free from artificial preservatives”.  It’s a real sales point.  Sugar, on the other hand, is definitively bad.  No argument.  Over-consumption of sugar is definitely associated with a number of negative health outcomes.  But we don’t seem to see quite so much enthusiasm for lowering the sugar content of foods or drinks, unless they’re being marketed as diet options.

Why so keen to get rid of one but not the other?  Sugar is cheap and tasty, and consumers like sweetness.  Artificial preservatives, on the other hand, cost money, don’t add anything to the taste (until the product goes off, that is) and make products last longer.  Preservative-free products have shorter use-by dates, and so people throw more away with the result that… they end up buying more.

A cynical person might wonder who really benefits from these “free from artificial preservatives” policies…. especially when the result is freaky lumps of mould in your sugary orange drink.