Mono- and diglycerides
Mono- and diglycerides are partial glycerides of fatty acids used as emulsifiers in bread, ice cream, margarine, and shelf-stable baked goods. They can contain small amounts of trans fat depending on the source oil and — in the US — are exempt from the trans-fat labelling requirement that applies to whole fats.
What are mono- and diglycerides?
Mono- and diglycerides are partial glycerides — molecules built from a glycerol backbone bonded to one (monoglyceride) or two (diglyceride) fatty acid chains, versus the three-chain structure of a normal fat (triglyceride). Their amphiphilic structure makes them emulsifiers: they stabilise mixtures of oil and water that would otherwise separate.
They carry E-number E471 in the EU, are FDA GRAS under 21 CFR 184.1505, and are the single most common emulsifier by volume in the US food supply. Global production sits in the millions of tonnes annually.
How are they made?
- Source oil selection. Any triglyceride oil — soybean, sunflower, palm, canola, rapeseed, or animal fat — can be the starting material. Palm oil is dominant globally on cost.
- Glycerolysis. The oil is heated with glycerol and a catalyst (typically sodium or calcium hydroxide) at 200–250 °C. The reaction rearranges the fatty acids across the glycerol pool, producing a mixture of mono-, di-, and triglycerides plus free glycerol.
- Molecular distillation. The crude mixture is distilled under vacuum to concentrate the monoglyceride fraction to 40–95% purity.
- Standardisation and packaging. The finished emulsifier is supplied as a bead, flake, or paste with a defined mono-content, iodine value, and melting profile.
Where partial hydrogenation is used to harden the source oil for texture, small amounts of trans fatty acids remain in the finished mono/diglyceride. This is the source of the US labelling loophole discussed below.
What foods contain mono- and diglycerides?
- Packaged bread, buns, and rolls — softens crumb, extends shelf life 5–10 days.
- Cakes, pastries, cookies — improves aeration and volume.
- Ice cream and frozen desserts — controls ice-crystal size, improves melt behaviour.
- Margarine and shortening — stabilises the water-in-oil emulsion.
- Whipped toppings and non-dairy creamers — improves foam stability.
- Peanut butter and other nut butters — prevents oil separation.
- Infant formula and follow-on formula — historic use, largely displaced by lecithins.
- Chewing gum — plasticiser.
The trans-fat loophole
The FDA's 2015 declaration that partially hydrogenated oils (PHOs) are no longer GRAS, and the 2018 compliance deadline, ended the primary source of dietary trans fat in the US. Mono- and diglycerides made from partially hydrogenated source oils were explicitly excluded from the PHO rule and continue to be permitted.
A separate FDA rule allows any product with less than 0.5 g of trans fat per serving to be labelled "0 g trans fat." Because mono- and diglycerides are used at 0.5–2% by weight of the finished product, even a partially hydrogenated E471 that is 15–20% trans by weight contributes only fractions of a gram per serving — well below the labelling threshold.
The EU tightened its rules in 2021 with Commission Regulation (EU) 2019/649, which caps industrial trans-fat content in foods at 2 g per 100 g of fat. That cap applies to the whole fat matrix including the emulsifier fraction, closing the loophole for EU products. US products retain the loophole.
NakedCalorie surfaces the potential trans-fat contribution from mono- and diglycerides where the source oil is known to be partially hydrogenated (rare in current US formulations after the 2018 rule, common in some legacy shortenings and bakery products).
What does the health evidence say?
The emulsifier-and-microbiome debate applies to E471 by extension of the polysorbate and carboxymethylcellulose findings, but no dedicated randomised feeding trial has yet tested mono- and diglycerides directly. The 2023 NutriNet-Santé emulsifier-total analysis (Sellem et al., The BMJ) linked total emulsifier intake, including E471, with a 3% higher cardiovascular disease risk per standard-deviation increase in 95,442 adults.
Mechanistically, all emulsifiers with detergent-like properties are candidates for the mucus-layer effect Chassaing et al. described in 2015. Mono- and diglycerides have a milder detergent profile than polysorbate-80 but are consumed at much higher aggregate volumes because of their omnipresence in industrial bread, ice cream, and margarine. Total per-capita exposure is estimated at 100–200 mg/day in the US and less in the EU.
JECFA and EFSA have both reviewed E471 and set no numerical ADI, considering the intake acceptable at typical use levels. The current active research question is whether that view will change as more human data on emulsifier-microbiome interactions accumulates.
How does NakedCalorie flag mono- and diglycerides?
Mono- and diglycerides trigger NOVA Group 4 classification under Monteiro 2019, are treated as a Tier 2 evidence-linked additive in the ingredient encyclopedia (based on the Sellem 2023 signal), and are individually surfaced on every product scan.
Products where the source oil is disclosed as partially hydrogenated receive an additional trans-fat note. For the emulsifier context see soy lecithin and carrageenan; for the Group 4 rule see Group 4 — ultra-processed foods.
Frequently asked questions
- Do mono- and diglycerides contain trans fat?
- They can. In the United States they are exempt from trans-fat labelling because they are classified as emulsifiers rather than fats — but if the source oil is partially hydrogenated, small amounts of trans fatty acids can be present. The 2018 FDA final rule on partially hydrogenated oils does not close this loophole. The EU labels partially hydrogenated content on all products from 2021 onward.
- Are mono- and diglycerides vegan?
- They can be plant-derived (soybean, sunflower, palm) or animal-derived (beef tallow, pork lard). US and EU labels rarely specify. Certified-vegan products list the source; other products may not.
- Where do mono- and diglycerides show up most often?
- In bread — as a dough conditioner and softener that extends shelf life; in ice cream — as a stabiliser that controls ice-crystal formation and mouthfeel; and in margarine and shortening — as the emulsifier that stabilises the water-in-oil emulsion. They are one of the most common single ingredients on US supermarket labels.
- Are mono- and diglycerides a NOVA Group 4 marker?
- Yes. Presence of any cosmetic emulsifier triggers Group 4 classification under Monteiro 2019. A bread with mono- and diglycerides in the ingredient list is Group 4 regardless of the nutrition panel.
Written by NakedCalorie editorial team.
Medically reviewed by Pending registered dietitian review — last reviewed July 8, 2026.
Educational information only, based on peer-reviewed literature and regulatory sources. Not medical advice.
Related in the knowledge base
- IngredientsSoy lecithin
- IngredientsCarrageenan
- NOVANOVA Group 4 — ultra-processed foods