Once only within reach of the larger international food manufacturing companies, cryogenic food freezing technology has steadily become more affordable to medium and even small food processors.
“As food consumers become more discerning and sophisticated in their food choices, constantly seeking new products and better quality, local food manufacturers are confronted with an increasingly competitive marketplace,” says Afrox’s Ruben Chetty. “Being able to meet these demands means inventing new food products and using the best technology for processing them and keeping them fresh, tasty and healthy.
“Against this background, cryogenic technology has come to the fore, creating a diversity of possibilities for food companies to produce convenient, ready-to-eat meals with their original quality and taste fully preserved.
“The high cost of electricity also points away from the traditional mechanical freezing methods to other freezing technologies, such as cryogenics, which delivers improved temperature control and freezing methods, while minimising production costs.”
Liquid carbon dioxide and nitrogen can be stored at very low temperatures (CO2 at -78 °C, N2 at -196 °C). When these liquids vaporise in contact with warmer materials, they absorb a large amount of heat from them and turn into very cold gases. These gases can safely be released into the atmosphere. This method, known as cryogenic freezing and cooling, has been in industrial use for over 40 years and is well known for producing high-quality frozen and chilled goods.
Chetty says Afrox, through its parent company The Linde Group, offers the South African market a broad range of cryogenic freezing technology, backed up by a nationwide distribution, installation and after sales support network. “Through Linde, which is among the global leaders in this arena, we have access to global expertise, best practice and customer reference sites,” he says. “Cryogenic freezing and cooling is one of Linde’s main business fields. Apart from various models of proprietary freezing and cooling equipment, Linde has developed a number of associated services to help customers maximise the benefits of this technology.”
Slow freezing can damage food products
There are three steps to freezing any foodstuff. First, the temperature is reduced to freezing point, secondly the freezing process which then turns the water in the foodstuff into ice (this is also called the latent heat phase) and finally, the temperature is further reduced to the final freezing point (usually -18 °C).
“However, slow freezing can damage food products because the process destroys their cells,” says Chetty. “Therefore the freezing process must be accomplished as quickly as possible in order to reach high product qualities. By using fast cryogenic freezing, the water inside and outside the cells freezes at the same rate, ensuring that the cells remain intact and the food keeps its freshness, flavour and texture – just as if it hadn’t been frozen at all.
“The cryogenic machinery available through Afrox offers a high degree of flexibility, with different types of freezers available for a wide range of food products. And, because they usually have a small footprint, they need only very little space on the factory floor.”
The standard freezing and cooling equipment available through Afrox includes tunnel and cabinet freezers, as well as super contact, pellet, rotary, triple deck and spiral freezers.
“With access to this world class technology and equipment, Afrox is very well placed to play a pioneering role in the South African food market,” concludes Chetty. “Each freezing concept is tailored specifically to meet our customers’ requirements – offering standardised as well as customised solutions — and this applies to all industries and all companies regardless of their size.”