I am currently in S.korea, I was checking the ingredients of pizza in a small local restaurant, because I follow halal diet, and I was surprised to find that there is animal product in the sauce. So can anyone tell what kind of animal product that is used in making tomato sauce? Thanks is advance!!
All sorts of animal products may be used in a tomato sauce, and only the restaurant itself can tell you exactly which they used. For example, one could add anchovies for salt and umami, one could add chicken/beef/pork stock for a richer flavour, one could add a splash of cream for a rounder flavour, or one could use honey instead of sugar to balance the acidity of the sauce. This list is by no means exhaustive and only the restaurant can tell you what they did. (The "authenticity" of any of these options is up for debate.)
Pizza sauce could contain a variety of animal-derived ingredients, so you’d really have to consult with the people who made it for an authoritative answer. As an educated guess, though, salted anchovies — either chopped or puréed, or in the form of fish sauce — are a very common additive to pizza sauce.