The chocolate industry is a dynamic and constantly evolving sector with many technological innovations. Let’s look at the advantages and disadvantages of these applications.

The industrial processing of chocolate is adapting to the continuous changes in the market and the demands for innovative products by a demanding consumer seeking hedonistic satisfaction and companies interested in using chocolate as a carrier of pharmaceutical and bioactive substances for health purposes.

3D PRINTING

3D printing has revolutionized many areas of the food industry: In chocolate processing, it uses different methods, which require pilot plant testing to assess safety and overall product quality. The advantages of these techniques include the ability to produce geometrically complex shapes so far non-replicable with molds, as well as the potential reduction of wastes and the enhancement of precision machining and customer-specific requirements.

Extrusion Printing

This method involves the cold extrusion of milk chocolate and melting at 18-28°C, through a nozzle by means of a pneumatic piston (advantage of controlled flow) or a screw.

Benefits:

• It is relatively simple to implement: The use of aids can facilitate gliding.
• It can produce shapes with accurate details and add ingredients for pharmaceutical purposes (especially useful in pediatrics, to make products appealing to children) or health.
• It is suitable for small-scale production.

Disadvantages:

• It may require controlled temperatures to prevent unwanted crystallization and pressures that vary depending on the grease content of the product and its lubricating effect.
• Production time can be long due to the need to create individual layers and cool them immediately afterwards.

Jet printing

This method uses nozzles to spray melted chocolate drops onto a surface, either on request or continuously: Dispensing occurs by thermal, electrostatic or piezoelctric (the most common) means by moving the support and not the nozzle.

Benefits:

• It can be fast and efficient for large-scale production.
• Allows greater flexibility in creating customized templates (e.g. cake decorations).

Disadvantages:

• It requires careful nozzle calibration to ensure even chocolate distribution.
• Chocolate with low viscosity must be used to make it easier to flow through the printer.

Powder-binding printing

In this method, a layer of chocolate granules or powder is deposited evenly on the printing surface and a liquid binder, such as molten chocolate, is applied layer by layer to join the particles together to form the desired object.

Benefits:

• It can produce complex objects with precise detail.
• Can be suitable for larger batch production.

Disadvantages:

• It may require post-processing to remove excess powder or binder.
• Production time may be longer than other methods due to stabilization and solidification processes.

Critical Printing Parameters

Compared to traditional polymers for this type of printing, 3D printing of a rheologically complex substrate such as chocolate obviously requires optimization of various parameters, including melting temperature, extrusion speed, filling density, and model geometry, depending on the type and quality of cocoa beans and the specific processing and composition conditions. The balance between these parameters is critical to ensuring quality and reproducibility.

COCOA DRYING TECHNOLOGIES

Drying cocoa beans is a decisive step in the final quality of chocolate, preserving the raw material from oxidation and keeping the bioactive compounds intact. The use of microwaves (300 MHz to 300 GHz) is a solution which, on the one hand, offers a rapid increase in temperature and better preservation of sensory characteristics, but is limited by industrial adaptability and energy consumption. The results due to the heat produced by molecular rearrangement and the level of humidity, pH, fat, colour and degree of moulding as qualitative parameters on the treated matrix are under study.

Similarly, solar drying uses heating of the air at a constant temperature by means of various engineering solutions (natural or forced convection by fans, heat storage systems and photovoltaic panels). An interesting option is hybrid drying, which combines different energy sources, such as solar, geothermal, wastewater or thermal waste, to optimize the process. This approach offers greater flexibility, allowing adaptation to the environmental conditions and available resources.

ULTRASOUND AND PRE-CRYSTALLIZATION

Pre-crystallization is a fundamental process in chocolate production for several reasons:

1. It facilitates the formation of a uniform and stable crystalline structure within the cocoa butter, which affects consistency, shine and stability.
2. Reduction of crystallization time with relative increase in productivity
3. Prevents cosmetic defects such as the coating formed by grease separation on the surface
4. It helps to control the rheological properties of chocolate, affecting its consistency, viscosity and flow capacity
5. It facilitates the development of creaminess in chocolate, thus improving the sensory experience of the consumer.

In this respect, ultrasound can be used to promote and accelerate the formation of cocoa butter crystals. The process can be divided into the following steps, if used at 20 kHz, as bibliography suggests:

1. Breakdown: Ultrasound crushes the lumps of cocoa butter crystals in the molten chocolate, helping to distribute the crystals evenly in the middle.
2. Nucleation: Collapse of cavitation bubbles could nucleate cocoa butter crystals, creating more numerous and homogeneous sites within the melted chocolate.
3. Stirring: Ultrasound energy ultrasound generates motion in molten chocolate, which promotes crystal formation and improves component rearrangement.

Benefits include:

• Increased efficiency: Ultrasound can significantly accelerate the pre-crystallization and tempering process, reducing overall production time.
• Greater control over the formation of cocoa butter crystals and the final structure of chocolate.
• More consistency: Ultrasound promotes the formation of smaller, smoother crystals, which develop a finer structure and better mechanical consistency even during storage.

However, there are also a few limitations to consider:

• Costs: Plants can be expensive to adapt and operate, especially for small and medium-sized companies.
• Technical requirements: Advanced technological and engineering expertise is required to optimize process parameters, such as maintaining chocolate temperature and managing the frequency and amplitude of pulses.
• Side effects: Improper use may cause overheating or damage the structure of chocolate, thus affecting the quality of the final product. Treatment should therefore be assessed based on the composition of the matrix (e.g. amount of fats and added ingredients).

PRECISION TEMPERING TECHNIQUES

Tempering is a critical phase in the production flow chart; it is aimed at obtaining the target consistency and gloss through greater control of time and temperature by means of new automatic machines equipped with sensors and digital controls that continuously monitor and adjust process parameters, thus ensuring optimal crystallization of the cocoa butter.

ARTIFICIAL INTELLIGENCE

Artificial Intelligence (AI) is an attractive solution for companies’ R&D to test innovative chocolate flavours. Machine learning algorithms analyze consumer preferences to create a customer profile and develop new ingredient pairings. Industry 4.0 uses the data of the machines used and uploads them to a server making control and analysis of the system much easier and dynamic, with the complex interaction of its different phases, facilitating real-time decision-making.

MIXED SYSTEMS

Last-generation models use a combination of simultaneous conching and grinding: The inner surface consists of a double-jacketed cylinder and optimally manages vapours and moisture. An alternative is the combined grinding and cutting of the raw product by means of steel balls that homogeneously mix the cream in the tanks.

CONCHING

The main innovations concern three areas. Accelerated conching: Some studies have looked at new approaches to speed up the process such as the use of multiple-hole extruders with interesting results in terms of reducing energy consumption.

Continuous conching: This is nothing new except for the important shift from batch to 5-roller systems, which on the one hand guarantee a more performing and adaptable type of processing on a large scale, where there is no need to change or replace product recipes. Ultrasound: The application can improve efficiency by helping to free air from the chocolate mass, thus reducing the overall time of the operation.