FOOD SECRETS UNWRAPPED

INSPIRED by the popular Channel 4 series Food Unwrapped, a new book by DANIEL TAPPER explores the myths and facts about the things we eat and reveals the often unsettling truth about how they reach our plates. In our first extract, on Saturday, he revealed how supermarket ham is often made from pink gloop mixed with chemicals. Today, he reveals even more unpalatable discoveries about other favourite foods . . .

Never reheat takeaway rice

Every year, there are around 1.7 million cases of food poisoning recorded in the UK, and a whopping 15 per cent of these result from people eating reheated rice. This is thanks to a bacteria called Bacillus cereus, found in the soil and dust of almost all rice-growing regions around the world. No amount of washing will remove it, and it can even tolerate boiling water.

In dry conditions, the bacteria stay in their spores but, as soon as their surroundings are warm and wet, they begin to grow and breed. Most of the time, this is not a problem, since the rice is consumed so soon after being cooked that they haven’t had time to reproduce. But leave the rice at room temperature overnight and you give them every chance to multiply.

The good news is that rice can be reheated and eaten — but only if it’s been stored and cooked in the correct way. The key, say chefs, is storage and temperature control.

All rice should be kept bone- dry, cooked thoroughly to a temperature of at least 75c and then served immediately. If it is not to be served straight away, it should be kept at 63c or above, or cooled to at least 15c as quickly as possible.

The best way to do this is by placing the rice in a colander or sieve and running it under cold water for a couple of minutes. It will then be ready to put straight into the fridge, and this should be done within an hour of cooking.

Reducing the temperature in this way means the bacteria don’t have time to multiply and produce toxins. Nevertheless, it is strongly recommended that properly- stored leftover rice is consumed within one or two days.

Lastly, never reheat rice from a takeaway, as many restaurants make their rice in bulk and then reheat it as and when they need it — and rice should never be reheated twice.

Best of all, cook the correct amount of rice in the first place. Not that that’s likely to happen any time soon.

Bin it or eat it? The guide to mouldy food

BREAD: Bin it. Some people take a pragmatic approach to mouldy bread, bravely cutting away the offending part and toasting the rest in the belief that this will make it safe.

But it can contain strains of a toxic, yellow-green mould called Aspergillus flavus. This produces aflatoxin — which is one of the most poisonous substances known to man and has been linked to liver cancer.

Scarily, this strain of mould is actually pretty common; if you leave a slice of bread out in the open long enough, it’s likely to make an unwelcome appearance, no matter how clean your kitchen is. That’s why it’s never a good idea to eat a slice of mouldy bread. HARD CHEESE: Keep it. If only a small amount of white, powdery mould has formed on hard cheese, it’s generally fine to use. A good rule of thumb is to remove about an inch around the affected area before consuming.

Just be sure to keep your knife out of the mould to avoid cross-contamination and always rewrap the cheese in a fresh covering afterwards. NUTS AND PEANUT BUTTER: Throw away. Mouldy nuts can contain aflatoxin, the same potentially deadly substance that’s sometimes found on mouldy bread. HARD SALAMI AND DRY-CURED HAM: Keep them. Such products are often covered in a fine layer of white mould. This is more often than not completely benign, and is almost always introduced by the manufacturer to aid the development of flavour.

However, if you spot anything more than this white dusting, chuck it. BLUE CHEESE: It depends. The blue veins in cheeses such as Roquefort, gorgonzola and Stilton are key to giving them their distinctive, creamy texture and zingy, salty flavour.

But again, if you spot any other strains of mould that you don’t recognise (particularly if they’re not blue), it’s always best to throw it in the bin. YOGHURT AND SOUR CREAM: Throw away. Mould and bacteria can accumulate throughout the product, meaning not all the harmful bacteria will be visible.

Apart from ruining the taste, these moulds can cause numerous health problems, including allergic reactions and respiratory complications. FIRM FRUITS AND VEG: Keep them. A tough vegetable, such as a carrot, can have a small amount of white mould on its surface, but still be perfectly edible, mainly because the mould has trouble penetrating deep into the food.

Trim off about an inch around the mould before consuming. SOFT FRUITS: Throw them. Very soft fruits, such as raspberries and strawberries, are clearly inedible when mouldy, but even those with thick rinds, such as oranges, are easily affected by mould, which can spread quickly through the fleshy interior.

A morning bowl of metal

HoVeR a magnet over your cornflakes in the morning and you should be able to see a few individual flakes moving around the bowl.

This is because the additives in Britain’s favourite breakfast cereal include iron filings — tiny particles of pure iron metal, which are processed in a way that renders them tasteless.

Iron is just one of the nutrients and vitamins added to cornflakes, and you might wonder why this is necessary. Surely corn is nutritious enough without having to be fortified?

The answer is that much of its natural goodness is removed once the kernels arrive in the factory. First, the husks are discarded to give the cornflakes a smoother texture, then the wheatgerms are squeezed out to give the cornflakes a longer shelf-ife.

This leaves the ‘corn grits’, as they’re known in the industry. Some 90 per cent starchy carbohydrate, these are both lacking in nourishment and largely flavourless, which is why they are then combined with sugar, glucose and salt before being baked in pressure cookers, rolled into flakes and toasted.

At that point, they are sprayed with a combination of nutrients, including folic acid, vitamins A,B, C and D and, of course, iron.

How fresh is ‘pure’ orange juice?

To SLow down decomposition, the big manufacturers give orange juice a 30-second blast of heat at temperatures of up to 95c, and then bubble nitrogen through it to displace any oxygen.

once treated in this way, it is fed in to huge cold- storage tanks, some containing the equivalent of 40 million one-litre cartons.

while suppliers aim to shift all their orange juice as quickly as possible, it can be stored like this for up to two