Glucono Delta Lactone is the dry form of gluconic acid which is obtained by the removal of water during the crystallization process.
Glucono Delta Lactone is a natural constituent of many foods. It can be found in honey, fruit juices, wine and many fermented products. As a natural food acid it contributes to the tangy flavor of various foods and since it lowers the pH it also helps preserve the food from deterioration by enzymes and microorganisms.
GDL is commonly found in honey, fruit juices, and wine.
Uses: - Glucono Delta Lactone finds use in the cosmetic industry as a moisturizer, pH adjuster, and sequestrant or chelating agent. It is generally considered suitable for all skin types, including sensitive skin, and is non-irritating and antioxidant. - It is also widely used acidulant in meat products, especially for dry cured sausages. - Being acidic, it adds a tangy taste to foods, though it has roughly a third of the sourness of citric acid. It is metabolized to glucose; one gram of GDL is equivalent to one gram of sugar. In processed foods, GDL functions as a curing and pickling agent; leavening agent; pH control agent; and sequestrant.
Tofu making: GDL is specifically used for silken or soft tofu because it coagulates rapidly, allowing silken tofu to be made inside the container without an air-gap, which prevents the silken tofu from breaking during transport. Prior to the invention of GDL and its use in silken or soft tofu, tofu makers couldn’t reliably transport soft tofu.
GDL is commonly used with soy milk having high solids levels (10%–13% instead of 5%–10% in regular tofu). Soft and silken tofu filled containers are heated in a water bath at 80°C–90 C for 40 to 60 min to allow the GDL to transform into gluconic acid, which causes the protein to coagulate as a homogeneous gel, with no whey separation.
GDL leaves a slight sour taste in the finished product. It can be used in combination with calcium sulfate to produce a soft and smooth textured tofu. Other acids such as acetic and citric acid can be used as well, but they frequently leave undesirable flavors.
