Saturday, 16 July 2016

Mealamine not!

Melamine [R for structure] is a super useful chemical: look at all those nitrogens. Without a chemist's eye, it looks a bit like TNT tri-nitro-toluene. But with TNT it's a case of look at all those oxygens: the chemically embedded oxygens help the explosive reaction along, giving it desirable qualities of brisance, although lots of other explosives - RDX, PETN - have more.  So one of melamine's uses is as a fire-retardant - nitrogen is a sort of anti-oxygen and we're right happy that it makes up 78% of the atmosphere - any less and we'd all go whoomph in a spontaneous combustion.

Melamine also combines very handily with formaldehyde [the body pickler] to make thermosetting plastics like Formica.  Formica was The Thing when I was growing up: super for counter-tops - a swipe with a wet cloth sure beats scrubbing down a deal table with a bristled brush. Back then the other techno-wonder was 'melamine' cups and plates which are essentially the same as Formica. You could fire a melamine plate at the floor and it would bounce. Much lighter than china, too, if you're going for a picnic.

Switch tracks here. The difference among the major food groups fats, carbs and proteins is that the proteins are made of amino [-NH2] acids. Each unit has at least one nitrogen atom. I think most of us think of 'protein' as more valuable than mere carbohydrates. None of us, not even the vegetarians, in the West have diets deficient in protein although vegans [no eggs, no dairy] have to work hard to make up their quota.  In the Third World, otoh, getting enough protein can be a bit of a scrabble, and this is particularly imperative for infants: without sufficient protein you have really short kids.

How do food manufacturers get the data to fill in the 'quantity of protein' line the table-of-contents? They use the Kjeldahl test, a classic 19thC chemical assay invented by Johan Kjeldahl in 1883. I've done [or students have done under my supervision] a Kjeldahl test and, ominously mistakes were made.  But if you leave me out of the equation, the Kjeldahl test is universally adopted to estimate the protein content of foods, because it is simple, reliable and reproducible; and it scales up.

But Kjeldahl is 'gamable': you can adulterate, say, milk powder with a white dust that is particularly rich in nitrogen . . . Melamine!  Today marks the anniversary of when the Chinese milk powder scandal of 2008 blew up. Mao and his people in the PRC had a vision of a socialist paradise where no child was left behind and everyone had a fair chance at getting an education and making an honest living. But it's really difficult to make everyone a saint and as the PRC started to join the rest of us in a financial incentive driven economy, opportunities presented themselves. ANNyway, on 16th July 2008, 16 (sixteeen!) infants in Gansu were diagnosed with kidney stones.  It must have been a bit like the multiple cases microcephaly that's blown across South America this year. Nevertheless, it took a smart epidemiologist to recognise that there was a case to answer. Then it took a bit of legwork to a) find further cases in neighbouring provinces and b) track down a cause. A nice controlled experiment I reckon - some Chinese mothers still using their breasts for the purpose intended and some thinking that 'formula' was the coming thing. The formula babies had all the kidney damage. In the heel of the hunt, 300,000 small children were found to have consumed the melamine-tainted milk, 54,000 were hospitalised and a handful sustained so much kidney damage that they died. Zhang Yujun and Geng Jinping, adults, died as well - executed by the central government for making too much money distributing 'protein-rich' milk. Multinational capitalism had a case to answer also because Western dairy combines, including NestlĂ©, Unilever, Heinz and Cadbury, had bought into Chinese concerns because, frankly, the market in China is HUGE. The market in China affects the price Irish dairy farmers get at the farm gate - that's globalisation.

No comments:

Post a Comment