Indulging in chocolate has become a festive staple, from advent calendars and selection boxes to bracing mugs of hot chocolate. There is a measure of subjectivity to our enjoyment of chocolate-based products, but there are numerous neurocognitive benefits of chocolate-consumption that go beyond personal perception. Material characterisation of the chemical relationship between chocolate and neurocognitive activity has shown that chocolate-consumption stimulates the neurotransmitters phenylethylamine and serotonin. The former often causes a sense of alertness or excitement while the latter is commonly referred to as the happiness hormone. This is the primary chemical explanation for why chocolate and cocoa-based products have developed such a wholesome reputation.
In truth, quantitatively demonstrating the enjoyment of chocolate through material characterisation is barely necessary. Humankind has been consuming it in one form or another since 1900 B.C.E. and it is currently a $50 billion-a-year worldwide industry. The festive season is an enormous factor in this booming success.
Limited edition chocolate bars, novel hot chocolate mixtures, and entirely new recipes are often launched on the market in the build-up to Christmas. Each of these new products must be subjected to material characterisation to ensure that batches are compliant with regulations, and to determine thermodynamic stability under varying conditions. Even the nation’s favourite chocolates must undergo routine material characterisation during quality control (QC), particularly when product output reaches its highest volumes.
Material Characterisation of Chocolate: Viscosity & Particle Size
Viscosity is a critical characteristic at several stages of chocolate production. In the first instance, it is important for monitoring the consistency of the liquor that is refined from cocoa bean nibs. Grinding mechanisms are used to reduce the pulpy cocoa mass into a smooth liquid phase that is subsequently mixed and blended with cocoa butter and sugar. The flow characteristics of this raw material may be indicative of its performance during moulding, and the texture of the end-product.
Particle size is also a key factor in the texture and flavour of chocolate products. The size of particles in chocolate pastes and the particle size distribution (PSD) of mixed cocoa and milk recipes are indicative of the consistency of the final product.
Manufacturers may also measure the viscosity of blended mixtures to assess the formability and mouldability of specific chocolate recipes. Higher chocolate viscosities are desirable for moulding shapes and coating products with a thick and rich shell. Lower chocolate viscosities, by comparison, are used for more delicate coatings and liquid chocolate applications. It is unfeasible to use a chocolate of low viscosity in a chocolate fountain, for example. These two types can be mixed into a compound recipe, but this may impact flavour and texture.
Rheological material characterisation is often performed to determine both the applications and shelf-life conditions of limited edition chocolates or newly released products. Chocolates formed into the shape of Santa Claus, for example, are likely to have been subjected to viscosity measurements to ensure the end-product can hold its iconic shape. Particle size analysis is used in conjunction with such measurements to ensure that the properly-formed product has an appropriate taste and texture.
Christmas Materials Characterisation with Meritics
Meritics supplies an extensive range of analytical instruments for R&D and QC applications in the food and beverage industry. We have already demonstrated the unique potential for chocolate viscosity measurements using the RM200 Plus rheometer and have introduced chocolate materials characterisation capabilities with the LS 13 320 XR. This industry-leading particle size analyser can qualitatively assess the ‘mouth feel’ of chocolate products and eliminate particles that would contribute towards a gritty, unpleasant texture.
If you have any more questions, please do not hesitate to contact us directly. Otherwise, have a very merry Christmas and check back with us in the New Year for more posts about innovative material characterisation.