Nestlé’s R&D subsidiary Nestec has developed temperature tolerant chocolate by adding little or no sugar or polyols to the chocolate core and instead adding the humectant liquids to a “tropicalized shell” for the product. Nestlé filed the patent in December last year and it was published online last week.
Shell retains shape and texture
“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 maintain its shape,” read the application.
“The chocolate product remains therefore dry to the touch and does not stick to its wrapper, or adopt the shape of the wrapper, even when exposed to temperatures above the melting range of the fat composition.”
When humectants are added they can produce grittiness or a waxy mouthfeel, but Nestlé said that this could be avoided since concentrations were so low.
Creating the shell
“Advantageously the product of the present invention can be prepared with commercially available food ingredients. No expensive additives are required,” said the company.
Suitable food grade humectant liquids include propylene glycol, polyethylene glycol and polyols such as glycerol. Sugar alcohols including sorbitol, xylitol, maltitol, mannitol may be used as well as sugars such as sucrose and fructose or any combination.
According to Nestlé, the tropicalized shell can be between 5-20% thicknesses of the product, but thinner shells require more humectant liquid.
The method can be used for chocolate using cocoa butter, as well as products containing vegetable fats in combination with cocoa butter or as a full replacement.
45°C melt temperature
The application said that cocoa butter usually starts to soften at 28°C. Nestec researchers said that chocolate made through its method could withstand 40°C and 45°C heat.
“This means that at the high ambient temperatures frequently encountered in tropical countries, chocolate becomes sticky or even runny. It tends to stick to the wrapper and fall apart when the wrapper is removed, leaving a semi-liquid mass that can often only be eaten with a spoon if cleanliness is desired.”
Other non-melt choc methods
Previous approaches to obtain non-melt chocolate have included using high melting point fats to substitute cocoa butter. However, Nestlé said that these fats were considered cocoa butter substitutes, which are restricted in many countries and in any case often give a waxy mouthfeel.
Other methods include altering the sugar matrix to hold fat, but Nestlé said this can rapidly increase viscosity making production processes such as enrobing or molding more difficult. It said adding water to the mix had the same effect.
Last year, Mondelez International-owned Cadbury filed a patent for temperature tolerant chocolate that was made by rerefining chocolate after the conching stage. This process shears sugar particles to produce a more continuous sugar matrix that reduces the amount of fat coated sugar particles, creating temperature tolerant chocolate.
Cadbury placed re-refined Dairy Milks in a 40°C incubator for 3 hours and found that bars did not melt and had the same mouthfeel as a traditionally processed bar.