E575 Glucono delta Lactone

Glucono delta Lactone is a food additive with the E-number E575 used as a sequestrant, an acidifier, or a curing, pickling, or leavening agent. 

Glucono delta lactone (GDL) is a natural constituent of many foods. 

It can be found in honey, fruit juices, wine, and many fermented products. 

EC / List no.: 202-016-5

CAS no.: 90-80-2

Mol. Formula: C6H10O6 

Molar mass: 178.140 g·mol−1

Melting point: 150–153 °C (302–307 °F; 423–426 K)

Assay:  Not less than 99.0% on the dried basis

Description: White, odourless or nearly odourless crystals or crystalline powder  

Functional Uses: Acidifier, raising agent, sequestrant 

Solubility: Freely soluble in water; sparingly soluble in ethanol 

It is a lactone of D-gluconic acid. 

Pure E575 Glucono delta Lactone is a white odorless crystalline powder.

In addition to its coagulation properties, E575 Glucono delta Lactone is used as an acidulant, leavening agent, and sequestrant in food products.

Synonyms of Glucono-delta-Lactone: 

GDL

GdL

D-glucono-1,5-lactone

D-(+)-Gluconic acid delta lactone

3,4,5-trihydroxy-6-(hydroxymethyl)tetrahydro-2H-pyran-2-one

GLUCONO-δ-LACTONE 

D-gluconic acid delta-lactone 

As a natural food acid, it contributes to the tangy flavor of various foods, and because it lowers the pH, it also helps preserve foods from deterioration by enzymes and microorganisms.

E575 Glucono delta Lactone is commonly found in honey, fruit juices, and wine. 

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 E575 Glucono delta Lactone is equivalent to one gram of sugar. 

In processed foods, E575 Glucono delta Lactone functions as a curing and pickling agent, a leavening agent, a pH control agent, and a sequestrant.

GdL (glucono-delta-lactone) is a widely used acidulant in meat products, especially for dry-cured sausages. 

It is used when a slow release of acid is required. 

In the presence of water, it reverts to gluconic acid. 

Lowering the pH inhibits bacterial growth and accelerates drying.

E575 Glucono delta Lactone is effective in preventing the growth of Listeria monocytogenes when used in combination with lactate in emulsion-type meat products. 

Lowering of pH by GdL together with lactate significantly improved the oxidative stability of the meat product and resulted in higher a-values (red colour)

In meat technology, E575 Glucono delta Lactone is predominantly utilized as an acidity regulator in fermented salamis and occasionally as a colour enhancer

Approximately, 1 g of GDL lowers the pH value within salami by 0.1 pH units. 

GDL itself is a whitish powder and is not sour. 

Once in contact with water, from the meat, the ring-shaped molecule opens up and hydrolyses to gluconic acid. 

This acid causes the decline in pH value within fermented salami and GDL is commonly applied at levels between 3 and 12 g per kilogram of salami.

E575 Glucono delta Lactone has been marketed for use in feta cheese.

E575 Glucono delta Lactone is pH-neutral but hydrolyzes in water to gluconic acid, which is acidic, adding a tangy taste to foods, though it has roughly a third the sourness of citric acid. It is metabolized to 6-phospho-D-gluconate; one gram of GDL yields roughly the same amount of metabolic energy as one gram of sugar.

Upon addition to water, E575 Glucono delta Lactone is partially hydrolysed to gluconic acid, with the balance between the lactone form and the acid form established as a chemical equilibrium. The rate of hydrolysis of GDL increases with heat and high pH.

Glucono-delta-lactone, a neutral cyclic ester of gluconic acid, is commonly used as a slow-release acidifier.

Glucono-delta-lactone is the cyclic 1,5-intramolecular ester of D-gluconic acid. In aqueous media, it is hydrolyzed to an equilibrium mixture of D-gluconic acid (55-66%) and the delta- and gamma-lactones. 

Glucono-delta-lactone (GdL) is a neutral cyclic ester of gluconic acid, originating from the fermentation of glucose. It is separated from the acid by crystallisation.

E575 Glucono delta Lactone is a fine, white crystalline powder, freely soluble in water. It is practically odourless and has a slightly sweet taste. 

Non-toxic, it is completely metabolised in the body like a carbohydrate.

When added to an aqueous solution, E575 Glucono delta Lactone rapidly dissolves and subsequently slowly hydrolyses to gluconic acid, thereby producing a gentle acidification, as with lactic acid-producing bacteria. 

In solution, both gluconic acid and E575 Glucono delta Lactone are always in balance. The equivalent point and the rate of transformation are related to concentration, temperature, and pH-value.

Two properties set E575 Glucono delta Lactone apart from other common acids and are the basis of its application range:

Through its slow hydrolysis to gluconic acid, it ensures a gradual, continuous decrease in pH toward equilibrium. 

So it is used as a slow-release acidifier.

During its hydrolysis, the initial sweet taste of E575 Glucono delta Lactone becomes only slightly acidic, making the final flavour of an aqueous solution of E575 Glucono delta Lactone much less tart than that of other acidifiers.

Functions

This ingredient offers you the following excellent functions.

Acidification agent

Buffering agent

Chelating agent

Coagulating agent​

Exfoliation​

Leavening agent​

Mild acidification​

Moisturising properties​

pH-regulation​

Phosphate replacement​

What is Glucono Delta-Lactone (GDL)?

Glucono delta lactone (GDL) is a natural organic acid used in chemical leavening systems. 

It reacts slowly but steadily with sodium bicarbonate and is fully activated by oven heat.

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, GDL hydrolysis results in lower tartness than that of other acidifiers.

In food, glucono delta lactone functions as a curing, pickling, and leavening agent. 

It can also control pH by increasing the product's acidity. 

From a nutritional standpoint, GDL is completely metabolized in the body like any other carbohydrate, providing 4 kcal/g.

Commercial production

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

Application

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 g of sodium bicarbonate neutralizes 100 g of the acid), indicating that higher amounts of GDL are required to neutralize the baking soda completely and release optimal 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.

GdL is available in food-grade, Personal Care-grade, and USP-grade forms.

For food and USP-grade applications, we offer granular and powder materials; for Personal Care-grade applications, we offer only granular material. 

Glucono-Delta-Lactone (GdL) is the inner lactone of the gluconic acid formed during the production process by crystallization of gluconic acid at elevated temperatures and removal of excess water. 

When GdL is added to an aqueous medium, the lactonisation is reversed, and the gluconic acid is released. 

Moreover, GdL, like sodium gluconate, has chelating and moisturizing properties. 

Specific Uses: Glucono delta-lactone is allowed for use in human food as a curing and pickling agent, a leavening agent, a pH control agent, and a sequestrant [21CFR184.1318]. The Merck Index cites use as a coagulant for tofu (Budavari, 1996). 

The TAP review will focus on use as a tofu coagulant, as per the petition’s example, but other uses will be discussed to illustrate some specific functions and other characteristics of the material relative to the OFPA and NOSB criteria. 

Other uses in food processing include: acid (acidulant), leavening agent, and sequestrant (Food Chemicals Codex, 1996). 

Glucono delta-lactone may be employed as a chemical leavening agent and has been used in instant bread that requires no proofing. Glucono delta-lactone is an inner ester of gluconic acid.  

In a water solution, GDL slowly hydrates, becoming acidic and acting as a leavening agent.  

Hydrolysis is slow at cold temperatures but accelerated by heat, making GDL ideal for refrigerated or frozen dough products.  

GDL’s cost makes its use prohibitive in most baked goods, except in some refrigerated or frozen dough formulations (Chung, 1992). 

Glucono delta-lactone is one of the less commonly used food acidulants. 

In conjunction with reducing compounds, GDL accelerates the development of cure color in smoked meats, thereby considerably reducing smoking time.  (Friedman and Greenwald, 1992). 

The main function of curing accelerators is to accelerate color fixing or to preserve the color of cured meat products during storage.  

Curing accelerators must be used only in combination with curing agents (Schmidt and Raharjo, 1992).