About
Interesterified vegetable fat is produced by rearranging (transposing) fatty acids on the glycerol backbone of vegetable-oil triglycerides, either chemically (using sodium methoxide as catalyst) or enzymatically (using lipase enzymes), to modify the fat's melting point and physical texture. It is widely deployed as a low-trans-fat alternative to partially hydrogenated oils in margarines, shortenings, bakery products, confectionery fats, and infant-formula fat blends.
Safety summary
Interesterified fats carry negligible industrially produced trans fatty acids and are therefore preferable to partially hydrogenated oils in that respect; however, human intervention trials have raised concerns that certain formulations—particularly stearic-acid-rich palm-based IEF—may raise postprandial blood glucose, lower HDL cholesterol, and adversely alter endothelial-function markers. No IARC classification exists, no ADI has been formally established by any major regulatory body, and the long-term cardiovascular and metabolic effects at habitual dietary intakes remain a subject of active scientific debate.
Regulatory landscape
| Jurisdiction | Status | Note |
|---|---|---|
| FSSAI (Food Safety and Standards Authority of India) (India) | Restricted | FSS (Labelling and Display) Regulations 2020 require mandatory front-of-pack declaration of trans fat and saturated fat content, plus mono-unsaturated, polyunsaturated, and omega-3 fatty acid quantities for all packages of interesterified vegetable fat.source |
| EFSA (European Food Safety Authority) (European Union) | Approved | Interesterified vegetable fats are not food additives under Regulation (EC) No 1333/2008 and carry no E-number; they are used as food ingredients subject to general food safety law under Regulation (EC) No 178/2002. EFSA monitors process contaminants such as 3-MCPD esters and glycidyl fatty acid esters that can form in refined vegetable oils used in interesterification (EFSA Journal 2016;14(5):4426).source |
| FDA (Food and Drug Administration) (United States) | Approved | Interesterified fats are regulated as food ingredients, not food additives. Individual interesterified fat products made from FDA-approved oils are self-affirmed or notified as GRAS; FDA GRN 000654 is an example where an enzymatically interesterified cocoa butter substitute (palm oil stearin + stearic acid) was accepted as GRAS. No category-wide ADI established.source |
Who should approach with care
Research citations
- 1FSSAI. FSSAI Proposal on Regulation of Trans Fatty Acids. fssai.gov.in
- 2FSSAI. Food Safety and Standards (Prohibition and Restrictions on Sales) Regulations – Version XI, 2025. fssai.gov.in
- 3FSSAI. Food Safety and Standards (Labelling and Display) Regulations 2020 – Compendium Version II, 2022. fssai.gov.in
- 4FDA. Agency Response Letter GRAS Notice No. GRN 000654 — Cocoa Butter Substitute via Enzymatic Interesterification, 2018. fda.gov
- 5PubMed. Stearic acid-rich interesterified fat and trans-rich partially hydrogenated soybean oil adversely alter circulating markers of endothelial function in healthy men, 2007. pubmed.ncbi.nlm.nih.gov
