Ah, these are the 'codes' used throughout the European Union for additives to food.

To be honest it was unfair to say this about Heinz Baked Beanz as the tinning process meanz they aren't really needed.

Apparantly the ingredients are these:
Beans (49%), Tomatoes (27%), Water, Sugar, Glucose-Frutose Syrup, Modified Cornflour, Salt, Spirit Vinegar, Spice Extracts, Herb Extract

Have a look at any food products from Europe and most of them will have a series of E numbers. http://en.wikipedia.org/wiki/E_number helps explain them.
There was a real backlash against E numbers so many companies try and avoid having any where possible. In the past baked beanz might have had E1401 for 'modified starch' instead of modified cornflour, but the product is now 'natural' enough to get away with stating their ingredients and not listing any.

When I flew bmi in C a couple of years ago baked beans on toast was on the menu, I was nervous of someone sitting near me ordering it. The smell from the sauce is really unpleasant, the resulting exhaust fumes... just as bad. My husband is fully Britanicised - he loves them.