E384 - Isopropyl citrates
What it is and how it is used
Isopropyl citrates are a mixture of mono-, di- and tri-isopropyl esters of citric acid — citric acid made oil-soluble by esterifying it with isopropyl alcohol. That solubility change is the whole point.
Plain citric acid is a good metal chelator but it will not dissolve in fat, so it cannot reach the trace copper and iron that catalyse rancidity inside an oil. The isopropyl esters can, which makes them synergists: used alongside a true antioxidant such as a tocopherol, they tie up the metal ions that would otherwise keep the oxidation chain running.
Foods commonly containing it
None in Great Britain. Where permitted elsewhere, isopropyl citrates are used in edible oils, margarines and fat-based products.
Safety summary
Isopropyl citrates (E 384) does not appear in the FSA Register of Food Additive Authorisations, the official list of additives authorised for the market in Great Britain, and it is not on the DHSC/FSA list of approved additives and E numbers. On the current GB list it is not an authorised food additive.
No GB or EFSA acceptable daily intake applies to it as a food additive.
The GB-authorised route to the same effect is the sequestrant list: citric acid and its salts (E 330–E 333), the phosphates, and calcium disodium EDTA (E 385). For chelation inside a fat phase specifically, UK formulators generally use citric acid esters of mono- and diglycerides (E 472c) instead.