Locust Bean Gum vs Propylene Glycol: which is worse?

What is Locust Bean Gum?

Locust bean gum (LBG) is a galactomannan polysaccharide extracted from the seeds of the carob tree (Ceratonia siliqua), native to the Mediterranean. It is a fine white to yellow powder that forms a thick gel when dissolved in hot water. It synergizes strongly with xanthan gum and carrageenan to enhance gel strength.

What is Propylene Glycol?

Propylene glycol is a synthetic organic compound used as a humectant, solvent, and emulsifier in food, pharmaceuticals, cosmetics, and industrial applications. It is produced from propylene oxide (derived from petroleum). Its chemical formula is C3H8O2.

Documented risks

Locust Bean Gum: Generally recognized as safe. EFSA's Panel on Food Additives confirmed the safety of LBG in 2017, noting no concerns at current dietary exposures. It functions as a soluble dietary fiber and can have mild prebiotic effects. No significant adverse effects have been documented in human or animal studies at food-relevant doses.

Propylene Glycol: Propylene glycol is generally considered safe by the FDA and is metabolized by the liver to lactic acid and pyruvate (normal metabolites). However, at high doses — particularly from intravenous pharmaceutical formulations — propylene glycol can accumulate and cause lactic acidosis, kidney toxicity, and CNS effects. These effects are seen in critically ill patients receiving high-dose PG-containing intravenous medications, not from food consumption. In children and people with impaired liver or kidney function, PG accumulation may occur at lower doses than in healthy adults. Animal studies have found reproductive and developmental effects at high doses. EFSA's 2018 re-evaluation found no concerns at typical food use levels but noted the EU limits PG use as a direct food additive, using it only as a carrier solvent for permitted additives.