New technologies: Pasteurisation of dry foods

Traditional thermal methods are not designed for sanitation of dry (low a_w) foods due to the increase in moisture content required and alterations in the quality of the products. In recent years new commercial technologies have been developed for processing dry foods.

These new systems, which have been proven to be suitable for dry food products commonly, use heat with super heated steam, pressure, vacuum or a combination of these processes. The incorporation of movement is important for some of these technologies to ensure uniformity of treatment. Dry products such as: herbs, spices, nuts, seeds, grains, dried fruits and vegetables, cereal mixes and animal feed can be treated with these technologies. While these technologies are suitable for processing dry food products, not all products have been validated for each piece of equipment.

We currently have a Revtech unit onsite for the continuous heat treatment of herbs, spices, nuts, seeds and other dry ingredients. The system incorporates electrical heating with optional heated steam followed by a drying step to remove moisture before packing. The product is conveyed through the tubes of the machine via vibration. The option for re-circulating is available if roasting is required. This machine is specially designed for research on food safety and the development of new products.

Podcast

• Pasteurising dry ingredients

R&D report

• R&D344: Heat resistance determination of Salmonella in low a_w foods

RSSs

• Technologies for validation, best practice and development of low a_w food and environment decontamination
• Salmonella in low a_w products

Examples of Low a_w pasteurisation manufacturers

• Revtech | External link
• Imtech Steri | External link
• Bühler Barth AG | External link
• Norris Thermal Technologies | External link
• Napasol AG | External link
• Cosmed group | External link

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