Gluconic acid

Gluconic acid is a fruit acid approved as a food additive under the number E 574 in Europe. It is produced from glucose by oxidation at C1 of the glucose molecule. Today, gluconic acid is almost exclusively produced biotechnologically using cultures of Aspergillus niger.

The salts of gluconic acid are called gluconates. Gluconic acid as well as its salts are excellently absorbed in the intestine, are almost non-toxic and are used in food technology, medicine (sodium, potassium and calcium gluconate) and industry (tanning agents). The consumption of large amounts of gluconic acid can cause diarrhoea.

Gluconic acid occurs naturally in small amounts in honey and wine. Various teas may also contain gluconic acid.

Gluconic acid (E 574) and its salts, sodium (E 576), potassium (E 577), calcium gluconate (E 578) are used in foods as artificial acidity regulators and as stabilizers. Gluconic acid is used in desserts, fruit and vegetable products, and soft drinks.

Gluconates are well absorbed in the intestine. This is used medicinally in that the molecule transports trace elements (e.g. iron, zinc) bound as cations.

Ferrous gluconate (E 579) is used to intensify the black color of black olives. Medically, iron gluconate is used for iron deficiency.

D-gluconolactone (glucono-delta-lactone - E 575) is also used as a food additive.

Zinc gluconate is contained in medicines for zinc substitution. Furthermore, topical zinc gluconate has been used in animal experiments for wound healing.

A calcium gluconate gel is used topically for hydrofluoric acid burns.

The gluconic acid is used in cosmetic formulations. It acts as a moisturizer (preserves the moisture of the skin), buffer substance and solvent.

Calcium gluconate (INCI) is used as humectant in cosmetics.

Magnesium gluconate is used in cosmetic formulations as a skin care product.

1. Evers JE (1977) Iron-poly (sorbitol-gluconic acid) complex and iron-dextran in the treatment of severe iron deficiency anaemia. Scand J Haematol Suppl. 1977;32:279-85.
2. Kaufman KL et al,(2014) Evaluation of the effects of topical zinc gluconate in wound healing. Vet Surgery 43:972-982.
3. Sainz F et al (2016) Comparison of D-gluconic acid production in selected strains of acetic acid bacteria. Int J Food Microbiol222:40-47.
4. Wegmüller R et al (2014) Zinc absorption by young adults from supplemental zinc citrate is comparable with that from zinc gluconate and higher than from zinc oxide. J Nutr 144:132-136.
5. Zhang H et al (2016) High titer gluconic acid fermentation by Aspergillus niger from dry dilute acid pretreated corn stover without detoxification. Bioresour Technol 203:211-219