Pasteurisation and sterilisation equipment

Although humans have put many micro-organisms to good use, the presence of many others in the environment, and particularly in food, is undesirable and even harmful.

The market demand for natural yet micro-biologically safe products and the requirements of modern food distribution logistics have forced the industry to investigate and develop new processes for the inactivation of micro-organisms and enzymes, capable of achieving these two apparently contrasting requirements: safe food with a long shelf-life and a fresh taste.

Sterilisation is the process of complete destruction of micro-organisms. The sterilisation process is generally carried out by submitting the product to drastic heat treatment (at least 121°C with long hold time). Due to the application of high temperatures and a relatively slow rate of conventional heat transfer to the centre of the product, there will be many changes in the food having a detrimental affect on quality.

Fortunately, many food products do not need to be completely sterile to be safe during their normal commercial consumption cycle. Pasteurisation is a relatively gentle heat treatment carried out at temperatures below the boiling point of water (generally in the range 75-85°C), with the aim of destroying pathogenic organisms that have public health significance and extending the shelf-life of food from the micro-biological and enzymatic point of view, causing limited degradation of sensorial and nutritional properties of the product.

Over the past 33 years STALAM has introduced radio frequency (RF) technology to many industrial drying and thermal processes. STALAM is the first company in the world to have developed continuous RF pasteurising equipment for packaged solid products and for pumpable liquids in the tube (in the latter case, the process can be extended until full sterilisation is achieved).

The use of RF heating for pasteurisation of fresh food combines the technical and economic advantages related to the success of this technology in other industrial applications.

The ability of radio frequency to heat volumetrically does not rely on the thermal conductivity of the substrate to transfer heat throughout its mass. Since the required processing temperatures are reached rapidly and accurately, degradation of the product is reduced to a minimum. The RF equipment requires less space compared to other machines based on conventional heating technology, that have long heating times and require large product volumes under processing at any given time. Because no thermal energy is wasted into the environment, the RF process is more efficient, economic and environmentally friendly providing significant reduction in the factory carbon footprint.

In other words, STALAM radio frequency equipment applies the so called “minimal thermal process” principle to food product sanitisation and can be considered the only real, technically proven and economically viable industrial alternative to conventional pasteurisation and sterilisation technologies presently available in the marketplace.