Citric Acid vs Mono- and Diglycerides: which is worse?

What is Citric Acid?

Citric acid is a weak organic acid naturally occurring in citrus fruits. Commercial citric acid is produced almost entirely by fermentation of sugar substrates (typically molasses or corn syrup) using the mold Aspergillus niger. It is the most widely used food acidulant and preservative globally, also functioning as a chelating agent and flavor enhancer.

What is Mono- and Diglycerides?

Mono- and diglycerides are emulsifiers derived from glycerol and fatty acids, most commonly sourced from soybean, palm, or sunflower oil. They are partial glycerides that exist between monoglycerides (one fatty acid chain) and diglycerides (two chains). They are chemically similar to fats but are not classified as trans fats even when made from partially hydrogenated sources.

Documented risks

Citric Acid: Generally recognized as safe. Excessive consumption can erode tooth enamel due to its acidic nature — dentists recommend rinsing with water after consuming highly citric drinks. A 2018 report in the journal BMJ Case Reports described a cluster of inflammatory reactions (joint pain, muscle weakness) in individuals who reported reactions specifically to industrially produced citric acid, hypothesizing residual Aspergillus proteins from the fermentation process as a potential cause. This remains a hypothesis without controlled clinical evidence, and regulatory agencies maintain its safety status.

Mono- and Diglycerides: Generally recognized as safe at typical food levels. However, mono- and diglycerides can be derived from partially hydrogenated oils, meaning they may carry trace trans fats that do not appear on the trans fat label because they are classified as emulsifiers, not fats. Some researchers have noted this labeling gap. A 2019 study published in Lipids in Health and Disease noted potential concerns with industrial trans fatty acids in these additives. For most consumers, exposure is low, and regulatory agencies including FDA and EFSA consider them safe at permitted levels.