I have just taken a look of my jar of tomato paste (Intercasa brand, double concentrated, 28-30 % tomato paste, made in the Canaries, Spain) and looks, smells and TASTES good ;D I don?t like throwing away food and I cant find anything written on another and unopened tin about that it must be eaten in a few days after opening, ok, I suppose I must throw it already as it is almost gone and what you say looks serious and I will but it doesnt seem to me such a perishable food, like, for instance, chopped tomato tins, that get mouldy after a week after opening.
Best regards