Do you throw away food as soon as it reaches its best-before date? If so, you're probably wasting a lot of perfectly edible food.In fact, collectively, consumers' rigid compliance to conservative "expiry dates" is partly to blame for the fact that about a third of the world's food ends up being wasted.At a food-labelling seminar hosted by the Department of Trade and Industry and the National Consumer Commission in Pretoria recently, consumer goods and services ombudsman Neville Melville suggested that since millions of South Africans are food insecure, there may be merit in selling certain non-perishable food products after their best-before dates at discounted prices.Several delegates took exception to his comments, arguing that it was unconscionable to suggest selling "rotten" food to the poor.Such misperceptions about "expiry dates" are rife.The distinction which most consumers don't get is that best-before dates, found mostly on shelf-stable foods such as canned goods, pasta, coffee and biscuits, are about food quality and taste, not safety.While a biscuit eaten a few weeks or even months past its best-before date may not taste great, it's unlikely to make you ill.Essentially, the best-before date means "not of ideal quality after this date, but still edible".But you shouldn't risk eating meat products or other perishables which are past their use-by dates, because those dates are indeed about food safety, and there's a good chance you'll end up with food poisoning.So where do sell-by dates fit in? They are a guide for retailers, being a few days before the use-by date, and give consumers some time to safely consume the product after purchase - having stored it appropriately.Interestingly, South Africa's food labelling regulations don't outlaw the selling of food products past their best-before dates, but clearly, given that they are no longer at their best, they should be sold at a discounted price, as Melville suggested.Given the safety implications, it's illegal to sell or even donate food past its "use-by" date.There is growing pressure in Europe to ban best-before dates on shelf-stable food, in a bid to cut down on the amount of edible food that is unnecessarily wasted.In light of Melville's comments,I asked major supermarket groups about their policies on "expired" products.Pick n Pay and Shoprite Checkers send food which has reached its sell-by date, but not yet its use-by date, to FoodBank SA, a not-for-profit organisation which collects "surplus" food from manufacturers and retailers and redistributes it to needy people.Shoprite Checkers said it would support any initiative that would curb the "overzealous discarding of food", including "a change to food expiry date labelling and education to change consumer behaviour".Neil Davison, FoodBank SA's operations manager, confirmed that the organisation only distributed food that was within its use-by or best-before date."Several countries, including the US, have national 'good samaritan' laws that protect donors against legal liability connected with donating food, as long as the donated food is fit for human consumption," he said.If a similar law were to be implemented here, FoodBank SA would be able to collect and distribute much larger volumes of donated food that would otherwise go to waste.Asked for its views on the issue, the South African Association for Food Science and Technology said that once food with a "use-by" date had been opened, it was important that consumers followed the manufacturer's instructions - "eat within three days of opening", for example.But not all "off" food was unsafe to eat."Take pasteurised milk," the association said. "Beyond its use-by date it will go sour because of spoilage organisms in the milk. It may taste bad, but drinking it will not cause illness, aspasteurisation kills any disease-causing micro-organisms that may have been present in the raw milk."US scientist Dana Gunders makes the same point in her Waste-Free Kitchen Handbook."Food-borne illness comes from contamination, not from the natural process of decay," she writes.Given that best-before dates are about aesthetic appeal and taste, rather than food safety, does the food science association advocate the consumption of food beyond its best-before date?Well, no, not exactly. The organisation leans on the side of caution."The manufacturer has good reasons for prescribing whatever 'best-before' date has been chosen and, at the very least, you should seek advice from the manufacturer on individual products before [eating them].CONTACT WENDY:E-mail: consumer@knowler.co.zaTwitter: @wendyknowler..