Food - controlling the temperature at each step of production

Modern processes used today in the production of foodstuffs and pet food are varied, highly automated and complex. Alongside producing the actual food product, process chains also consist of packaging and labelling processes. Maintaining hygiene standards throughout the entire process is of highest importance. The food production industry faces similar challenges to those faced in the pharma and chemical industries. The properties of the food itself must also be considered, e.g. chocolate bloom due to sugar crystallisation. Success and failure of production methods depends on how effectively production temperatures are controlled. However, it is not necessary to rely on expensive specialist solutions.

Our standard applications can be adapted to the needs of your production process since functions such as exceptional control precision, ability to respond to quickly changing temperature gradients and ramp control are included as standard.

Heating - cooling - maintaining: Successful food production with Tool-Temp

Extrusion for producing foodstuffs and pet food
Extrusion technology plays an important roll in the food industry. This is true for the production of meat alternatives with fibre textures, the production of breakfast cereals, and in the production of animal feed.
Heating and steaming processes are integrated into the preconditioning phase both the animal feed and food industries in order to make the processed materials easy to digest. Using hot extrusion, an aqueous material is heated under high pressure in a compression screw. The screw cylinder has a constant heat supply to help heat the product. Tool-Temp temperature control units support such applications with their high-precision solutions. The pressure drops off at the outlet nozzle, the water evaporates and the product loosens up. The gelatinised starch prevents the product from falling apart. In this production methods, the product typically passes through further drying and roasting stations. A wide range of products are produced in this way: pasta products, snack foods, breakfast flakes, bread, textured vegetable proteins, and dry and semi-dry food for animals.

The use of double-walled containers, mixers and reactors in the food industry
The food industry makes use of a variety of double-walled containers, mixers and reactors. For example, beer production uses bioreactors and fermenters to cultivate microorganisms or cells. Organisms have an optimum temperature range in which they can best grow. Exceeding this temperature range can cause irreversible damage to proteins, whilst a temperature that is too low can lead to slower metabolisation and longer process times. Temperature control is implemented using heating and cooling circuits.
Whether temperature control for double-walled containers, mixers or reactors, Tool-Temp is able to deliver control units that are tailored to your processes. Requirements such as splash-water protection or fully stainless steel constructions can also be implemented, as well as the integration of interfaces to a control station. We have created a special line of units for temperature control in double-walled containers and reactors. These units regulate temperatures between -25°C to +240°C directly from the product. The units are designed for maximum process safety. They feature a pressure regulation system that prevents damage to the container as well as a digital flow indicator. Monitoring of inlet and return temperatures is a standard feature of our products designed for these demanding production processes.

Different packaging concepts
Each food product has its own packaging concept. The production methods used for packaging are just as varied and differ depending on the product. Whether for injection moulding or thermoforming packaging items, Tool-Temp delivers perfectly precise temperatures.

Food production - preconditioning - processing - mixing - pressing - cooling - hot extrusion - packaging

Vegetable oil: multi-step temperature controlled process
Refining vegetable oils involves removing unwanted components from the raw oil. This includes substances such as fatty acids, fat soluble substances such as lecithin and unpleasant aromas. The process involves several steps. One or two steps can be left out depending on the product. In order to reliably achieve a specific high quality, however, strict temperature controls are essential.
The first step is to press out or extract the raw vegetable oil. This can then be degummed in an acidic environment (temperature >100°C) to remove and collect phospholipids in the aqueous phase which then drain off (physical separation).
The remaining organic phase is neutralised with an alkaline lye which also works to remove fatty acids from the oil. They form into an aqueous alkaline salt and can be physically separated.
The refined oil is then washed with water. Heat is applied during this step. Finally, the water used for washing is physically separated.
To prevent the waxes still contained in the oil from crystallising in the consumer’s fridge at home and thus causing mistrust in the product, these are removed using a special crystallisation process with targeted cooling followed by filtering.
In the next step, fuller’s earth is added to eliminate various associated materials including dye pigments. The oil is thereby heated in a vacuum. By vacuum distillation at high temperatures of up to 270°C, various unpleasant smelling aromas and bad tasting substances are removed (known as deodourising).

What remains at the end is refined oil without any unpleasant taste or smell that can be stored for long periods of time. In each of the processes described here, ensuring the correct temperature is of high importance. It is ultimately oriented towards obtaining the desired product with its special properties. Even the separated components (e.g. lecithin, fatty acids, waxes) can be used. Further processing of these byproducts also relies heavily on temperature control.

From cooking oils to fats – and on into a very special creation: chocolate. Chocolate production is a true art. Much of the reason for this is the sheer variety of cocoa butter fats available. Believe it or not, six different forms of butter fat can be crystallised out, but only one of these crystals is the what the manufacturer is looking for. It is the only one which glistens and melts so tenderly in the mouth.
It is fortunate that the unwanted crystal formations melt away at 27°C, whilst the good crystal formation melts at one degree higher (34.5°C in the case of dark chocolate). For the chocolatier this means: Melting the mass at over 34.5°C, then leaving it to cool so that a few good crystals can form. Once warmed up again, these crystals can be used as seeds for further crystal growth. This process needs to be repeated several times – melt and precrystallise, melt and precrystallise, and so on.

The exact temperature programme is one of the great secrets of chocolate making. And depending on the type of chocolate, the programming will always need to be slightly different.

An exact temperature profile also plays an important role in further steps of the chocolate production process (e.g. conching). Precise thermostats, intelligent control electronics and, increasingly common these days, digital process control systems play a role here. Taking advantage of the solid and comprehensive expertise of external experts in the field of temperature control is always a worthwhile investment. Ensuring a finely tuned overall design for the system in question will ensure consistent quality and make process automation possible.

Controlling the temperature in reactions, mixtures, extractions or crystallisation processes is subject to thermodynamic and kinetic principles. The design of processes for producing and working with foodstuffs is heavily influenced by the properties of the food items themselves, as well as various hygiene regulations.

Many components play a role when selecting a suitable temperature control system. We will be happy to advise you and discuss the ideal heating and cooling solution for your needs. Various temperature control solutions are available depending on the maximum operating temperature, the required cooling capacity, the size of the consumer and the required flow rate.

Our wide portfolio includes:

  • Water temperature control units / 90°C max. temperature / 9 – 96 kW heating power
  • Pressurised water temperature / 160°C max. temperature / 9 – 48 kW heating power control units
  • Oil temperature control units / 360°C max. temperature / 8 – 144 kW heating power

For temperature control in reactors and double-walled containers, we have developed our own range of units, the standard design of which easily covers all the requirements associated with these applications.

Three design sizes are available:

  • TT-407 Z / 8 kW heating power / reactor capacity up to 50 litres
  • TT-409 Z / 24 kW heating power / reactor capacity 50 – 150 litres
  • TT-410 Z / 48 kW heating power / reactor capacity 50 – 400 litres

These heating and cooling units can be used with a temperature range from -20°C to +240°C with a circulating liquid heat transfer medium.
These units feature two independent heat exchangers in order to regulate across this wide temperature range. So that temperatures down to -20°C can be achieved, the second cooling circuit must operate using brine.

Comprehensive safety features – pressure monitoring:
The units are fitted with three manometers that monitor the pump pressure, the pressurised air supply and the pressurised air inside the unit. A pressure reduction valve allows the pressurised air inside the unit to be adjusted. Reduced energy consumption is achieved through regulation and a controlled consumption of pressurised air. The display allows the status of the pressurised air to be checked and makes adjustments easier.

Comprehensive safety features – temperature monitoring:
The MP-988 digital temperature controller with three sensor inputs. One sensor is used for regulating the temperature of the medium. This uses the temperature of the product in the container or the temperature of the oil in the unit’s tank as its reference point. Monitoring of the temperature difference between this and a measurement point in the inlet prevents the product surface from overheating.

Comprehensive safety features – inlet pressure regulation
The inlet pressure can be regulated in order to avoid damage to the double wall or reactor. The speed of the pump can be easily adjusted using the frequency converter and the inlet pressure read off from the manometer.

During production, foodstuffs and drinks or their individual ingredients must sometimes pass through complex temperature programs. They may need to be melted, crystallised, poured hot into moulds or extruded. The temperature must be precisely controlled from start to finish. For example, if the temperature is not just right, chocolate will crystallise, become crumbly and have a lacklustre or blotchy surface.

Customer-specific solutions – fast and cost-effective
Our catalogue comprises more than 60 different standard models which are produced exclusively in Sulgen, Switzerland. Regardless of size, all models are produced in cost effective batch sizes and kept in stock. Special units and customer-specific modifications can be integrated into the batch production process. This means that you benefit from being able to obtain specialised units with lead times similar to those of a standard unit. When developing special solutions, we rely heavily on proven components from our standard products that are in serial production. This allows us to offer worldwide replacement part availability, even for highly customised solutions.

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