A vital ingredient

GdL, a natural and sodium-free leavening acid opens up new opportunities, explains Raphael Singer.

“Consumers are increasingly looking for products that are perceived to be natural, free from artificial preservatives, colours and flavours, and minimally processed”
-Raphael Singer

Glucono-delta-lactone (GdL) is the standard crystalline form of gluconic acid. When GdL is put in contact with water, it dissolves quickly and then hydrolyses progressively to gluconic acid, leading to a controlled acidification.

In a dough mix containing GdL and bicarbonate, the gluconic acid produced through the addition of water reacts with the bicarbonate, providing a slow, continuous release of carbon dioxide over time, thus leavening the dough. Roughly two parts by weight of GdL are needed to neutralize one part by weight of sodium bicarbonate. The dough rate of reaction (DRR) of GdL goes from slow to fast, making it a versatile leavening acid that can substitute several types of leavening phosphates, from the slowest sodium acid pyrophosphate (SAPP) types to the fast monocalcium phosphate (MCP).

Organic growth
Consumers are increasingly looking for products that are perceived to be natural, free from artificial preservatives, colours and flavours, and minimally processed. Organic and all-natural products have thus become one of the most dynamic areas of the food industry. The EU organic market is growing by 10-15 percent a year, five times faster than the general food market. In the bakery sector, product launches with the claim 'all-natural' or 'organic' climbed from five percent of all bakery product launches in the EU in 2005 to 10 percent in 2008.

The organic approval of GdL is still strived for in Europe, but GdL has been allowed for use in organic products in the USA for several years already.

While the organic field is extremely regulated, there is still no valid legal definition for the term "natural". Therefore, it is somewhat subjective and open to individual interpretation. Jungbunzlauer considers its GdL as natural because its dissolved form, gluconic acid, occurs naturally in high concentrations in honey and noble wines; it is made from natural, renewable and non-GM carbohydrates as raw materials and; It is made by a natural process, ie. a non-GM microbial fermentation.

Sodium and aluminium reduction
Western consumers eat 3-5g of sodium (equivalent to 7.5-12.5g of salt) per day, well over the daily upper limit of 2.4g and 2.3g recommended by the UK Foods Standards Agency and the US Dietary Guidelines respectively, in order to avoid hypertension, cardiovascular diseases and stroke.

In sweet baked goods, more than 95 percent of the sodium content comes from three sources: salt, sodium bicarbonate and SAPP. Salt is not easy to replace due to its taste and technological benefits. Sodium bicarbonate may be replaced by potassium bicarbonate but due to its cost and taste this is not a real alternative. Replacing SAPP with the sodium-free GdL reduces the sodium content by 25-35 percent while improving product quality because the typical soapy off-taste caused by the use of SAPP does not occur when using the mild tasting GdL. It thus enables bakers to label their products with the nutrition claims 'reduced sodium' or 'light in sodium' under the EU Nutrition and Health Claims Regulation.

The leavening acid sodium aluminium phosphate (SALP) is often preferred to SAPP in muffins in the USA and the UK because it produces better tasting and more appealing products than SAPP. SALP has however become a concern since Joint FAO/WHO Expert Committee on Food Additives (JECFA) and European Food Safety Authority (EFSA) reduced the Provisional Tolerable Weekly Intake of aluminium from 7 mg/kg bw to 1 mg/kg bw. As GdL offers the same benefits as SALP, it is a real alternative for bakers concerned by the aluminium content of their products.

Use restrictions of phosphates in organic products, questions about their naturalness, their high sodium or aluminium content, changed economics, all speak in favour of GdL today. Indeed it offers a unique combination of benefits on the naturalness, healthiness, taste, appearance and shelf life of baked goods. This makes GdL more interesting than ever as a natural leavening acid, especially for muffins, cakes and pancakes in their organic, all-natural, sodium-reduced, aluminium-free and gluten-free variations.

Raphael Singer graduated is Product Manager Gluconates for Junbunzlauer. His main responsibility is the sustainable growth of his product group, including the development of new applications.