Is it obligatory to check all food and ingredient components to ensure their permissibility (halal), especially with the presence of substances like lecithin E322, which may sometimes be impermissible (haram) and at other times permissible (halal)?

The fundamental principle regarding foodstuffs is that they are permissible and lawful unless there is evidence to the contrary. Doubt does not necessitate prohibition. It is a mercy from Allah and a leniency of Islam not to burden oneself with investigating the ingredients of foods unless there is strong evidence to suspect them.

The substances referred to by the letter (E) followed by a number are additive compounds of various origins (chemical, plant, animal, or dissolved in alcohol), and they do not affect the lawfulness of the food. Chemical and plant-based origins are permissible. Animal-based ingredients undergo a chemical transformation (istihalah) that converts them into a new, pure substance. A small, consumed amount of substances dissolved in alcohol is excused.

Therefore, foods containing these substances remain subject to their original permissibility.