Glucono Delta-Lactone Uses
Glucono delta-lactone (GDL) is a natural organic acid that is part of chemical leavening systems. It reacts slowly but steadily with sodium bicarbonate and is fully activated by oven heat.1
It is also a key component in reduced sodium raising agents used in the production of sweet baked goods, such as cakes and muffins. Two main properties differentiate GDL from other acid leaveners:
- Its slow and progressive hydrolysis and pH drop make it a slow release acidifier
- Due to its initial sweet taste, hydrolysis of GDL results in lower tartness than other acidifiers.
Glucono-delta-lactone is an inner, neutral cyclic ester of gluconic acid produced by acid fermentation of glucose. It occurs naturally in honey, wine, fruit juices and many fermented products.
GDL is a fine white powder which dissolves quickly in water. Upon hydration, GDL slowly breaks down into gluconic acid, which then reacts with baking soda to produce carbon dioxide. The hydrolysis process is slow at cold/low temperatures but is accelerated by heat during baking.1
Leavening reaction of GDL with baking soda:
C6H12O7 + NaHCO3 → C6H11O7Na + H2O + CO2
Gluconic Acid + Baking Soda → Sodium Gluconate (salt) + Water + Carbon Dioxide
In food, glucono delta lactone functions as a curing, pickling and leavening agent. It also has the ability to control pH by increasing the acidity of the product. From a nutritional standpoint, GDL is completely metabolized in the body like any other carbohydrate, providing 4 kcal/g.
GDL is commercially manufactured from renewable carbohydrate sources by microbial fermentation followed by downstream processing. During the process, GDL is produced along with gluconic acid by glucose fermentation. The resulting product is a fine, white, crystalline powder freely soluble in water. GDL is practically odourless and has a slightly sweet taste.1
The delayed or slow rate of reaction of glucono delta lactone makes it ideal for:
- Refrigerated or frozen dough products
- Premium cookies
- Cake doughnuts
- Quick bread type products (e.g. canned dough and scones)
Using GDL can be cost-prohibitive in some applications. This weak organic acid has a low neutralizing value (45 grams of sodium bicarbonate neutralized by 100 g of the acid) implying that higher amounts of GDL are required to neutralize the baking soda completely and release optimum amounts of gas.
During conversion to gluconic acid, GDL becomes only slightly tart or acidic (about 33% of the sourness of citric acid). Therefore, it does not change the flavor profile of the formulated baked goods. The acidification effect also provides a preservative effect through pH drop, extending the mold-free shelf-life of the product.
Characteristics of GDL and other leavening acids
|Leavening acid||NV||ROR / CO2 release (%)|
|2 min||10 min||Baking (upon heating)|
|Potassium acid tartrate (cream of tartar)||45||70.0||5.0||25.0|
|Sodium aluminum sulfate (SAS)||104||5||5||95|