Royal Duyvis Wiener B.V.

24/7 Technical Support Hotline: +31 756 126 133

+31 756 126 126

Koog aan de Zaan (NL)

Pasteurization Installation

  • Proven 5-log reduction on nuts and seeds, without discernible impact on the original product quality
  • Excellent for treatment of sensitive products (for example walnut halves)
  • Compact well-proven design, using limited floor space for high capacities
  • Continuous flow and full traceability
  • High production reliability based on fully automated process
  • Integrated solutions possible for roasting and pasteurization
Specifications / USP's
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Product Information

What makes LOG5 AwCP unique
Combining effective pathogen reductions without having an effect on the original product quality is challenging, especially for dry products such as nuts, seeds, herbs and spices. Log5 offers the unique combination of effective log reductions while maintaining original product quality.

Contrary to popular belief, pathogenic microorganisms such as salmonella will exist and survive in very dry environments. They will not multiply, but will survive under these dry conditions. As soon as moisture is present again, the pathogens will start to proliferate rapidly. By treating the product with warm, moist air and uniformly controlling parameters such as temperature, relative humidity, time, and air flow, we are able to effectively pasteurize the product while maintaining its original characteristics. In overview, the pasteurization treatment consists of the following steps:
1. Conditioning (pre-heating)
2. Pasteurization
3. Cooling
The implementation of these process steps can vary depending on the capacity of the system.
Trials with your own product can be performed in our fully validated PLC-controlled pilot plant.

The product is fed from the top of the treatment unit, and is gently transported down and mixed while passing through multiple treatment levels. Warm air (heated in a separate air treatment unit) is injected in the bottom of the system and flows upward (counter-current flow to the product movement). This ensures the lowest air inlet and outlet temperatures (mild for product and high energy yield).
The product is gently mixed from one tray to the other creating uniform conditioned product.

The product is treated in an environment where the water activity, temperature, relative humidity, airflow, air quantity, and dwell time are controlled. The conditioning process prevents excessive water uptake. Only the water activity level on the surface of the nuts is higher during treatment. Pathogens can therefore be inactivated with a 5-log reduction (lower and higher reductions also possible).
Pasteurization treatment is continuous and takes place in the same unit as conditioning.
The product is gently mixed while traveling from one tray to the other creating uniform pasteurized product.

After pasteurization, the product is cooled immediately to maintain the original product characteristics.
Cooling is performed using our very efficient vertical counter-flow cooling technology: the product in this system is charged from the top and moves to the bottom for discharge while the cold air is blown in from the bottom and discharges through the top.

An integrated solutions can be supplied for roasting and pasteurization (in which the roasting degree is completely independent from 5-log reduction pasteurization), in which conditioning and pasteurization is performed before roasting the product.
Product can be evenly roasted to any degree of color, taste, and texture because a dry, pasteurized product enters the roaster. A very high total process energy yield is achieved, because no drying is needed after pasteurization.


Dry Roasting, Nut Powder Processing, Oil / Butter Processing, Paste processing, Raw / Pasteurized Processing


AwCP N Pilot: 50-120 kg/hr, AwCP 10 N: 1000-2200 kg/hr, AwCP 23 N: 2200-5000 kg/hr, AwCP 35 N: 5000-7600 kg/hr

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