What is the ruling on consuming foods and beverages that contain preservatives denoted by the letter E followed by a number, which — according to chemistry — are esters often manufactured by a reaction between a specific alcohol and a specific organic compound?

The basic principle regarding foods and drinks is permissibility. Nothing is forbidden except what has been explicitly prohibited by an authentic text.

Accordingly, there is no harm in consuming foods that contain preservatives, even if they include a percentage of alcohol, as long as it is not proven that it has not undergone a transformation. This is because the default principle is permissibility unless there is evidence that shifts it away from this original ruling.