A lot of parasites can look like food - corn, peanuts, rice & black pepper - are canine tapeworm segments ONLY IF a person is parasite cleansing and has not eaten these foods.
Liver flukes look like rolled up tomato skins - and they will pass during a cleanse (if a person is infected with them) even if that person does not eat tomatoes.
It's more of a common sense call - if a person eats a lot of tomato slices with skin attached - and they then pass undigested tomato skins and they are not parasite cleansing - it is probably just undigested food.
BUT - on the other hand - if a person has not eaten tomato slices with attached skin for a few weeks or months or never - and they parasite cleanse - and they pass "rolled up tomato skins" - then it is most likely liver flukes.