It isn't really as clear cut as that: So, some are haraam whereas some are doubtful. Mono- and diglycerides can be from plants, fish, or animals. If they're from the latter, they're haraam.
E471s (Mono & di glycerides of fatty acids) are always Halal [for Hanafis] because it undertakes istihalah (change of nature and quality) as is the case of vinegar, which is halal for hanafis regardless of the origin (alcohol). I think the jami'at ul muftiyeen of SA or Mufti Husain (hafidhahullah) published something on this years ago, but can't find this now.