Sell-by and use-by dates surfaced in the 1960s and 70s, following scares such as the Aberdeen typhoid outbreak, which was blamed on the re-cycling of corned beef.

Nowadays, when a new product comes on the market, tests will be run to see how it is affected by not only the manufacturing process, but transportation from the factory, storage in the store, and then in the home. Supermarkets tend to err on the side of caution - as consumers often choose to ignore use-by dates, confident they have a couple of days grace. The trouble with a food-poisoning bug like campylobacter, however, is that you can't see it and you can't smell it.

The job of the Food Standards Agency (FSA) and their labelling regulations is 'to protect consumer interests in relation to food safety and standards.' There are leaflets, websites and entire government departments set up to monitor this process, however as a consumer looking at the fundamentals of these laws, it can get rather complicated.

Sell by dates are a legal minefield

It's easy to see why food labelling has become a tangle of legal jargon, government-speak and is ripe for litigation. But did you know that only the 'Use By' date is stipulated as a legal requirement by the FSA? And for added confusion, 'Sell by' or even 'Display until' can appear next to 'Best Before' or 'Use By' dates. However, seeing another date on the pack tends to sow a seed of doubt that again this is a date that should be abided by. In fact, these dates are probably more useful for the store - helping with stock rotation and ordering.

Artificial colourings are often a sign that real ingredients are missing

Fresh foods like fruit and vegetables are naturally full of vibrant colours. Our ancestors soon learned that such foods are good to eat, and used colours and smells to help them judge what food was safe and what was harmful. In turn, we have inherited an instinctive attraction for the wonderful colours and smells associated with good food.

Unfortunately, by the time a modern food manufacturer has put food ingredients through the mill of processes that turns them into a food or drink, they've often processed the true colours right out. The products end up looking yucky grey or brown. And some of the nutritional goodness may have been lost in the same way. To make the processed food look more attractive or tasty, manufacturers replace the missing hue by using highly concentrated colours.

Some of these come from natural sources. But many manufacturers skip using real ingredients altogether. For example, instead of orange juice they use orange colouring; red colouring replaces real strawberries; and instead of making custard with egg yolks they use yellow colouring. Is it any wonder that it's becoming increasingly harder to tell what's fresh and real anymore?

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Nanotechnologists claim that it won't be long before the food package itself will signal when its contents are no longer edible. A combination of tiny sensors and activators built into the pack will know if something is wrong - correcting the problem or warning the consumer. It might even extend a food's life by having anti-microbial properties that can detect microorganisms.

So are all these clever scientific advances yet another reason for us not to rely on our five senses, commonsense and a prehistoric aversion to bad food?

The 'one-stop' shop approach to shopping at supermarkets has stopped many of us flitting between the butcher, the baker, the fishmonger and the greengrocer, to buy our unlabelled food during the week as we run out.

"It's gardeners and people from an older generation who understand what freshness really is"

Scientists are constantly cooking up new ways to keep food looking good

It's hardly surprising that, we as consumers are losing touch with where our food comes from and knowing its true freshness. In a supermarket you can't be guided by texture or smell, because the products are so heavily packaged, and so many different new technologies are used to extend the natural life of a product. Fresh fruits or salads, for instance, are 'gas flushed', which means they are prepared and packed in a modified atmosphere.

Is irradiation killing off flavour along with the bugs?

In fact the food we buy has quite often been pre-treated with some sort of high-tech process or chemicals. Irradiation is just one of the techniques used to kill bacteria such as salmonella, E.coli O157 and stop vegetables from sprouting. Ever since Nasa first fed the Apollo 17 crew 32 years ago with irradiated meat, the technology has persisted as one of the food industry's favourite means of prolonging shelf life.

Irradiated strawberries can stay unspoiled for up to 3 weeks, versus 3 to 5 days if fresh. It could be argued that with Strawberries travelling from abroad, after being irradiated, we are losing some of the smell and flavour you'd still find in our local produce.

Another preserving technique being worked on is - high-pressure processing (HPP). This blasts orange juice with pressures up to 150,000 pounds per square inch. And you can also look forward to ready-meals in the future to be treated to bursts of high-voltage electricity with pulsed electric field (PEF) technology. Both these methods are designed to prevent bacteria from reproducing without destroying the food's texture or taste.

If we didn't have these rules, regulations and scientific inventions to abide by and rely on what would we do? You can be sure our forebears would never have been as quick as us to jettison carrots to the compost just because they were looking a bit tired. We now always expect to eat fresh food, whereas previous generations, without fridges and freezers, would have kept food cool in larders for longer and by preserving and treating it in different ways. We've included just a few of the methods, past and present, that have been proven as workable and safe. So in true Mrs Beeton style there now follows…

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