Sheikh `Abd al-Rahmân al-Jar`î, professor at King Khâlid University in Abhâ
Each code stands for a particular chemical. The issue requires first finding out exactly what each e-code stands for. This can be solicited from the experts in the appropriate fields.
If it is established that a certain chemical is always of porcine origin, then it will be unlawful to eat products containing that e-code in their list of ingredients.
However, if the e-code stands for a certain chemical of uncertain origin, since a good number of these chemicals can be derived from a variety of sources, then a Muslim may consume a product containing that e-code in its ingredients. The legal principle being employed here is that any issue wherein there is doubt is presumed to be nonexistent.
Source: Islam Today