Delta-Gluconolactone (GDL) is a lactone of the D-gluconate. It is a natural constituent of many foods. It can be found in honey, fruit juices, wine and many-fermented products1-3. It is used as a food additive with the E number E575 used as a sequestrant, an acidifier (it lower the pH and also help preserve the food from deterioration by enzymes and organisms), or a curing, pickling, or leavening agent. GDL has been marketed for use in feta cheese. GDL is neutral, but hydrolyses in water to gluconic acid that is acidic, adding a tangy taste to foods, though it has roughly a third of the sourness of citric acid. It can be used as nutritional supplement in beverage such as in Instant Drinks, Syrups, RTD Tea and Coffee, Sports and Energy Drinks, Waters.