Without having any knowledge of the science of cooking, etc. I am wondering if the red colour that we are all used to in purchased tomatoes and pasta sauces, etc. is due to additives in the processing of the product??? I have always ended up with slightly orange pasta and tomato sauces when I make them myself and that's just the conclusion I came up with.
when I had my bulk buy of tomatoes the other week (it was mushrooms today lol - a whole 4kg box for $8.00 ) I made MJ's passata sauce and it came out orange but when I made Chelsea's Condensed Tomato Soup it is a deep dark red. Think it does have something to do with added ingredients.