From The Food Standards Agency
'Best before' dates appear on a wide range of frozen, dried, tinned and other foods.
The 'best before' dates are more about quality than safety, except for eggs. So when the date runs out it doesn't mean that the food will be harmful, but it might begin to lose its flavour and texture.
About a third of the food we buy ends up being thrown away and most of this could have been eaten. So think carefully before throwing away food that is past its 'best before' date.
However, you shouldn't eat eggs after the 'best before' date. This is because eggs can contain salmonella bacteria, which could start to multiply after this date.
And remember, the 'best before' date will only be accurate if the food is stored according to the instructions on the label, such as 'store in a cool dry place' or 'keep in the fridge once opened'.
So, if you want to enjoy the food at its best, use it by its 'best before' date and make sure you follow any instructions.