I've had this question in my head since forever, it's kind of a food sciencey question. I understand that cooking changes the properties of food including their nutritional value, sometimes positively, sometimes negatively. It appears per this link (https://healthyeating.sfgate.com/health-benefits-eating-cooked-tomato-products-4444.html) that cooking does not affect Vitamin C and lycopene (but it does affect Vitamin A).
But every time I go to buy a tomato sauce (see important note below***), the nutritional label shows literally no vitamins, why? Is it a labeling problem? Like lycopene doesn't show up on labels. Maybe Vitamin C becomes some new form that's not label-able?? Or is it that cooking doesn't kill vitamins but the high pressure canning process does? (implying that if I make homemade tomato sauce, I won't have this problem)
My motivation for this is that I like healthy eating and am just trying to understand how to healthily consume tomatoes.
***A note on the tomato sauce I'm talking about
I'm talking specifically about the kinds of tomato sauce that vendors at farmer's markets make using their own products. I can't speak for all farms, but having worked at one that did sell our products, I know exactly how this gets made. We harvest tomatoes, we cook & process everything in our own kitchen, we hire a contracted nutritionist to analyze the product & write the label, then we print the label and off it goes. Like, the process is basically exactly like a home cook's. It's not over-processed, over-salted like some industrial makers' products would be. I imagine this process is similar for some other local, premium organic brands that you find at small grocers (except they don't grow their own tomatoes). So given this is so similar to a home cook's process, why are there no nutritional points? I know what you're thinking... yes I am an idiot that I didn't think to ask our nutritionist this question. But I didn't and now I don't have a person to talk to.