Vintessential: Gluconic Acid Test Kits for Wine

Gluconic acid is a non-volatile organic acid produced in grapes when certain bacteria and mould (especially Botrytis cinerea) cause glucose to oxidise. This simple test is performed with a spectrophotometer to provide an accurate result in real units of grams per litre.

Free D-Gluconic acid (D-gluconate) is an important metabolite of Botrytis cinerea, and is the best marker to estimate the level of infection. D-glucono-δ-lactone is a cyclic ester of D-gluconic acid. It exists in equilibrium with the D-gluconic acid and can represent between 2-10% of the acid level in musts from botrytized grapes. D-Gluconic acid (D-gluconate) is phosphorylated to D-gluconate-6-phosphate by adenosine-5′-triphosphate (ATP) in the presence of the enzyme gluconate kinase with the simultaneous formation of adenosine-5′-diphosphate.

Gluconic Acid 30 Test kit

Product Code: 4A130

Please note these tests require the use of a spectrophotometer.

Reagent No.	Reagent	Preparation	Quantity	Stability
1	Buffer	To activate the Buffer, add the contents of Reagent No.2 and mix with inversion until completely dissolved.	33 ml	18 months at 4°C (6 months once activated)
2	Coenzymes (ATP/NADP)		0.2 g	18 months at 4°C
3	6-PGDH	Swirl gently before use	0.7 mL	18 months at 4°C
4	GNTK	Swirl gently before use	0.7 mL	18 months at 4°C
5	Standard	Nil	3.3 mL	18 months at 4°C