- Informed changes and enhancements in the production process
- Controlled additions of fat and/or emulsifiers
- Greatly improve both process control and product quality
Viscosity plays a crucial role in chocolate manufacturing as it affects many aspects of the final product, including texture, flavour, and the overall quality. Precise control of viscosity is therefore essential to meet consumer expectations and uphold strict quality standards.
Chocolate measurement is traditionally conducted offline, where samples are removed from production and analysed under laboratory conditions. Whilst this is an accepted method of viscosity measurement by the International Office of Cocoa, it is not sufficient for providing fine control of the production process. This limitation is particularly evident with tempered chocolate, where viscosity is significantly affected by processing temperatures and fat crystal formation.
As a result, there is growing interest in the application of inline viscosity measurements as a tool for both process optimisation and quality assurance. Robust, real-time measurements that provide meaningful process information enable manufacturers to reduce production errors, align with consumer preferences, and minimise waste. The latter becoming increasingly valuable in the face of rising commodity prices.
Advantages of Inline Viscosity Monitoring
Confectionary giant Nestle installed a Hydramotion XL7 into their chocolate process and determined several key advantages:
a. The ability to monitor the process, gaining a better understanding of the production system and ultimately improving the process control
b. Better understanding of the process, leading to more informed changes and enhancements to the production process
c. Adjusting the viscosity by the controlled addition of fat and/or emulsifier
Nestlé found that the viscosity of melted chocolate is primarily influenced by its fat content and the degree of tempering, with tempered chocolate showing higher viscosity due to lower processing temperatures (around 30°C) and the increased dispersed phase volume from fat crystal formation.
The XL7 viscosity sensor provides a single point viscosity value, and the noise-free trace responded well to process changes. This provided actionable insight into the process. The inline viscosity measurements also correlated well with the Casson plastic viscosity values measured off-line.
Conclusion
The researchers determined that integrating inline sensors is critical for the chocolate manufacturing process. These sensors play a pivotal role in error-proofing by actively monitoring and verifying key production steps in real time. Leveraging inline monitoring ensures that each stage contributes to producing chocolate that consistently meets quality standards and customer expectations.
Read the full Nestle whitepaper here: