Spiral pasteurizer

electricsteamfor the food industry

What is pasteurization?
Pasteurization of dry foods is a controlled thermal treatment that reduces pathogenic microorganisms (e.g. Salmonella, E. coli) by heating product to a defined temperature for a defined residence time. This microbiological reduction step is often described as a "kill step" and is implemented to secure ready-to-eat ingredients without compromising typical organoleptic properties.

Overview of Revtech's pasteurization solution
Revtech supplies a continuous pasteurization system for low-water-activity ingredients. Product is conveyed into a vibratory tower where it is pre-heated by direct contact with a heated coil. A controlled quantity of wet steam (typically 2–10%) is then sprayed directly onto the product surface. Flow rate, temperature, residence time and steam dose are precisely regulated and adjustable to suit specific formulations. The system operates continuously, is fully automated and designed for compact integration.

Key process features

• Continuous operation using a vibratory tower for even product distribution
• Pre-heating by direct contact with a hot coil to stabilize inlet temperature
• Direct wet-steam injection to product surface (approx. 2–10% steam addition)
• Adjustable parameters: throughput, temperature, residence time, steam amount
• Short residence times (minutes) and low steam usage to preserve colour, texture and aroma
• Energy use on the order of ~100 W/kg (project dependent)
• Compact, turnkey systems delivered fully automated with low maintenance requirements

Validation and quality assurance
Systems can be validated to demonstrate up to a 5-log reduction of Salmonella following recognised international protocols. Revtech uses Enterococcus faecium as a surrogate organism for validation trials to simulate pathogenic behaviour. Validations are performed in partnership with independent third‑party laboratories and have been demonstrated on throughputs from ~100 kg/h up to 14 t/h.

Examples of concrete applications

• Grains — barley, corn, oats, rye, wheat; whole grains, bran, germ, flours; applications in bakery, cereals, snacks and beverage ingredients.
• Seeds — chia, flax, poppy, sesame, sunflower, hemp; used in ready-to-eat applications like puddings, smoothies, bars and seed butters.
• Nuts — almonds, hazelnuts, pistachios, cashews; pasteurization to control Salmonella risk and meet export/market specifications.
• Herbs & spices — parsley, oregano, coriander, cumin, fennel; chemical-free microbial reduction while preserving flavour and colour.

Support and services
Revtech delivers customised turnkey systems and provides process-engineering support for recipe adaptation, pilot trials and coordination of third‑party laboratory validations. Services include parameter tuning, FAT/SAT assistance and operational training to minimise labour and energy costs while maintaining product quality.

Technical specifications

• Equipment type: continuous vibratory-tower pasteurizer
• Steam injection: direct wet-steam to product surface, typical 2–10% (adjustable)
• Pre-heating: direct contact with heated coil
• Residence time: short, typically a few minutes (adjustable)
• Energy consumption: approx. 100 W/kg (project dependent)
• Validation capability: demonstrated up to 5-log Salmonella reduction (E. faecium surrogate)
• Validated throughput range: ~100 kg/h to 14 t/h
• Operation: continuous, fully automated, turnkey delivery
• Design: compact footprint, low maintenance
• Applications: dry ingredients with low water activity (grains, seeds, nuts, herbs & spices, flours, bran, germ)