Heat treatment puts ‘clean label’ within reach

An ever-growing number of consumers are opting for food products that do not contain E numbers – additives used by the processing industry to produce food with the desired characteristics. With the CPD dryer/mixer, Hosokawa Micron is introducing a reactor that can give powdered food products the desired characteristics through a special heat treatment, eliminating the need for additives.

All additives that are permissible in Europe as E numbers have been thoroughly tested before being allowed onto the market. One such E number is oxygen, so it is difficult to avoid E numbers altogether...! Nevertheless, there is a clear trend among consumers towards 'clean label' products, i.e. food that does not contain E numbers. When consumers can choose between two products of equal quality, one of which contains E numbers and the other which does not, they have a clear preference for the one without.

"If they want to avoid or reduce the addition of E numbers, manufacturers have to alter the characteristics of their ingredients in order to achieve the intended finished product," says Daan Goris, Team Manager Food at Hosokawa Micron in Doetinchem. "This can include things like swelling, viscosity, colour, flavour, shelf life and all kinds of other aspects. Additives are one way a manufacturer can create a reaction in a product, but a thermal process combined with pressure or a vacuum can work just as well in many cases. It's the same result, just a different approach."

One disadvantage is that a thermal process consumes more energy than the use of additives. Goris: "But the CPD uses less energy than many conventional technologies, plus the process can be controlled relatively easily and very effectively. Even though things can get fairly 'lively' in a process involving a vacuum, high pressure and steam, the CPD reactor is designed to be very robust and there are minimal maintenance risks. Therefore, when it's time to invest in new equipment, many customers are now opting for a solution that enables them to make 'clean label' products."

Conical Paddle Dryer

Such a process revolves around selecting the right combination of finely tuned processing parameters such as temperature, pressure, mixing speed, mixing time, oxygen level and humidity. Goris: "It's very important to have the correct settings, because any deviations will affect the product quality. Once you've found the optimum settings, you can treat and process a whole range of different powders in the reactor in various phases."

Conical Paddle Dryer (CPD)

Hosokawa Micron's newest reactor is the Conical Paddle Dryer (CPD). As the name implies, this is a dryer with a conically shaped base and central paddle rotor. The rotor blades are geometrically designed to mix/heat the product as quickly as possible after steam has been injected under high pressure for the heat treatment. Goris: "We build each CPD in line with customer specifications. The reactor volume can be just five litres or as much as 20,000 litres, and the pressure and temperature ranges are very broad too. Our maximum used to be 150 degrees as standard, but we recently raised that level even further. With pressures of up to 6 Bar and temperatures of up to 300 degrees Celsius, we now cover every conceivable kind of process."

The Conical Paddle Dryer can be used for a wide variety of batch processes. "It's easy to change a huge number of processing parameters. Most customers use the CPD for various products. They sometimes even run successive batches of the same product with different formulations."

Try before you buy

"If manufacturers think that heat treatment could be a good solution for their product, they can bring a batch of that product to our test centre in the Netherlands. Our motto is 'try before you buy'. It's very important that you can find out in advance which scale and processing parameters are needed to achieve the desired product quality."