Nestle has proceeded with applying for a patent for a non-melting chocolate, despite the fact that rival chocolate maker Mondelez, which manufacturs for Cadbury, has also lodged a patent.

Nestle filed the application for patent in late 2012, and it was published online in June 2013. The product is a “chocolate product with a tropicalised shell” that has “improved heat-stability”, and the patent would also apply to a method for making such a product.

Background of non-melting chocolate

Conventionally, manufactured chocolate consists of sugars, cocoa solids and proteins (usually from milk) dispersed in fats and fatty substances from cocoa butter.

According to the patent application, cocoa butter typically starts to soften at about 28 degrees Celsius. This is a concern especially in tropical countries, according to Nestle, where high ambient temperatures cause chocolate to melt.

Nestle said methods used in the past to produce a heat-resistant chocolate have included the incorporation of high-melting point fats, or the creation of a “three-dimensional matrix or network of sugar crystals or protein particles that will act as a sponge and hold the fat, thus maintaining the structure of the product even on the melting of the fat”.

Nestle has identified two major drawbacks of using high-melting fats in chocolate. Food regulations in many countries restrict the use of cocoa butter substitutes in chocolate; secondly that high-melting point fats in chocolate products often give the product an unpleasant texture.

Methods used in the past have “various drawbacks”, according to Nestle. Adding water, glycerol or other humectant liquids to tempered chocolate can change the viscosity of the product and make it difficult to handle and mould. The addition of a humectant liquid can also make the texture of the final product “gritty”, and high water content in the final product increases the risk of microbiological contamination.

Australian Food News report on Brazilian heat-resistant chocolate study

In January 2013, Australian Food News reported that a study from the University of Campinas in Brazil had found that the use of hardfats in products containing cocoa butter may be sufficient to alter the chemical structure of chocolate so it would become heat-resistant.

In December 2012, Australian Food News had reported that Cadbury had filed a patent for chocolate that comprised more of a “sugar continuous system” than a “fat continuous system”, and was therefore less likely to melt.

Nestle’s non-melting chocolate

Nestle said its new product would solve the problems with adding humectants liquids to chocolate products by being made up of a tropicalised shell and a non-tropicalised core. The tropicalised shell will be comprised of chocolate and a humectants liquid, but the core would not have any humectants liquid added.

“When exposed to temperatures above the usual melting temperature of chocolate, only the core of the product will soften and above a certain temperature even become liquid, but the shell will remain solid and thus the whole product will retain its shape,” Nestle said.

“Since the overall content of the humectants liquid can be kept very low, the negative side effects which are usually occurring when humectants are added – in particular grittiness or a waxy mouthfeel – can be avoided,” Nestle said.

Another advantage of its invention, Nestle said, is that it can be prepared with commercially available food ingredients, requiring “no expensive additives”.

Nestle’s application for patent details the ingredient content of its non-melting chocolate product, as well as two possible methods for making the product.

Using added glycerol

Nestle said that, depending on the thickness of the shell and dimension of the overall product, sufficient shape retention can already be obtained with a glycerol content of 0.3 per cent in the shell, but that a glycerol content of at least 1 per cent is preferred. The thinner the shell, the higher the glycerol content needs to be for the product to keep its shape. However, Nestle said it was desirable to keep the overall glycerol content as low as possible because of the effect it has on the product’s texture.

The optimum range strongly depends on the chocolate recipe, but Nestle said it had found than an ideal range for the glycerol content of the shell would be between 1.5 per cent and 4 per cent.

Using added water

Again depending on the thickness of the shell and dimensions of the overall product, Nestle said a sufficient shape retention could already be obtained with a water content of 0.5 per cent in the shell. Similar to glycerol, the thinner the shell, the higher the water content needs to be for the product to keep its shape.

Added water will have an effect on the texture of the finished product, but Nestle said a higher water content also increases the risk of microbiological contamination. Nestle said it found that an ideal range for water content in the product’s shell would be between 1 per cent and 2 per cent.

According to Nestle, the risk of microbiological contamination linked to added water can be lowered by the use of saturated sugar solutions, syrups or honey instead of plain water. As with water, Nestle said all these ingredients have the advantage that they are “natural and not perceived as ‘artificial’ additives by consumers”.

Shell thickness

Nestle said it found the ideal thickness of the tropicalised shell would be between 1 and 6mm, or between 5 per cent and 20 per cent of the thickness of the overall product.

The Company said thinner shells need a higher content of humectant liquid for the product to keep its shape, but have the advantage that the overall content of the humectant liquid can be kept low.

“This is especially an advantage when water or water-containing liquids are used as a humectant, because the resulting tropicalised chocolate may have a slightly gritty texture, a negative side effect which the consumer will hardly notice in the final product if the shell is very thin,” Nestle said.