Know your cod from your catfish in Camden chippies

Quick bring the troops back from Helmand, our national dish is under attack!

According to today's Times, the next time you buy your cod n' chips you might not be getting what you paid for.

Trading Standards officials in one area of the country put out a national alert after it was discovered that Vietnamese River Cobbler (pictured) is being passed off as cod in some chippies. The Cat Hill fish bar in Bromsgrove was fined over £4000 for disguising a battered piece of Pangasius hypophthalmus as a traditional Cod.

Council officers visited the shop after a consumer complaint in May 2008. Analysis apparently proved that the fish purchased was indeed Pangasius catfish meat, which can be bought here for around two thirds of the price of cod.

There's nothing wrong with catfish (or pollock, another substitute), just not when you try and pass them off as something else. People rave about it on catfish Jamie Oliver Forum, for example, although there is a moan about the airmiles involved.

But for the cunning profiteer, it seems easy to serve up a faux cod and chips by using pollock or catfish substitutes: so here are some tips on how you can spot the difference -

- cobbler filets are "noticeably uniform", whereas cod fillets tend to be thicker in the middle and are more irregular

- cobbler has no strong taste, while cod has a mild but 'fishy' aspect

- cod is flakey when cooked, while cobbler is chunky (better for fish pie apparently)

That said: cod has been classified as overfished since about 2000, so you should probably be limiting your intake of it anyway and seeking alternatives.

I'm not sure whether Camden Council's Trading Standards Department has had any complaints on this front recently about Camden eateries, but Trading Standards in Bromsgove notified the Office of Fair Trading with their concerns that the scam was taking place nationwide.

Personally, I'd smother my catfish in tartar sauce, vinegar and salt - who'd know the difference?

But on a more serious note - Trading Standards departments never get the full resources that they need in councils up and down the country and yet they fulfill a key role. From shops selling booze, knives or fireworks to kids through to health and safety inspections they perform a key role locally.

Consumer champion Which? reckons that 'food fraud' could be worth more than £7 bn a year in substitution of cheaper products for advertised ones.

With the recession, food is being doctored more, particularly in restaurants. So you might find lamb or beef mince is bulked out with cheap chicken. Trading Standards are also coming across spirit substitution. Supermarket-bought gin and vodka is being put in the big-brand bottles in pubs and restaurants.

This is an important point, which is why I will be writing to the council to see what steps they are taking, and what cases they have on 'food fraud' locally.

The problem of food fraud is highlighted tomorrow night at 9pm on the BBC 1 programme What's Really in Our Food?, presented by Tom Heap.