EW TRENDS in food processing are developing rapidly, with changes in technology and consumer demand impacting everything from packaging to nutritional content.
But while technology is leading the way with new techniques for maintaining freshness and nutrition, the mere thought of transgenic or irradiated food is still enough to put many people off their dinner.
Gordon Young, lecturer in food engineering and food technology at the University of Queensland, says the move towards nutraceuticals in the Australian market has been one of the more significant trends in food processing in recent years. Nutraceuticals, also commonly referred to as “functional foods”, are aimed at preventing or treating disease.
Nutraceutical categories include dietary supplements such as vitamins and minerals, foods such as prebiotics for the control of intestinal flora, or canola oil with lowered triglycerides for cholesterol reduction. This broad category may also cover transgenic plants and animals developed for nutritional enhancement, or even, potentially, as carriers of immunising agents. Currently, the functional foods sector most significantly covers such products such as health food bars, yoghurts or sports drinks with added nutrients or medications.
Young sees the local trend as a response to developments in overseas markets, particularly Japan, rather than as a response to strong public demand.
The term ‘irradiation’ generally refers to treating food using ionising radiation, such gamma rays, X-rays, or electrons. The use of ionising radiation has a direct effect at a molecular level, destroying organisms such as insects or bacteria.
Irradiation can also be used for other reasons, for example, to inhibit sprouting in potatoes. It can also have some negative effects on food quality, such as inhibiting even ripening of fruit, or accelerating rancidity in meat.
However, the greatest inhibition to using the technique is public perception of the dangers of radiation, despite the fact all foods exhibit a certain amount of radioactivity taken up from the environment.
While irradiation is widely used in a number of countries, including the Netherlands and South Africa, in Australia the process is mainly used in the local food industry to pre-sterilise packaging.
With the moratorium on food irradiation in Australia now lifted, companies may apply to the Australian and New Zealand Food Authority for permission to irradiate foods. Queensland-based company Steritech have announced plans for a plant at Narangba, north of Brisbane.
George West, general manager of Steritech, defends the practice of irradiating food, saying that there have been many “wrong, misleading and scare mongering statements.” There are other technology-driven food-preservation methods coming to the fore.
In-package product sterilisation is increasingly being extended to foods packaged in plastic pouches or glass jars. This process involves filling the food product into the container, vacuum sealing it, then heating it to destroy bacteria. High pressure steam may be applied with a device called a “retort”.
The increasingly popular in-flow food sterilisation process includes UHT milk and unrefrigerated fruit juices. In this process, the product is heated as it flows through a heat exchanger, then the product is filled into sterile packages under strictly sterile conditions. In-flow sterilisation allows much higher temperatures to be used, permitting a significantly shorter process time, while also purportedly retaining higher product quality.
“In recent years there’s been a trend towards aseptic rather than retort-type products, notably UHT milk,” said Young. “This is partly because you should be able to get better product quality through UHT to the equivalent retort, and also because of the increasing availability of the heat exchanges and packaging equipment to achieve it at more reasonable cost. While the cost of technology will continue to impact on the adoption of new processing and packaging trends, consumer perception is also playing a significant role in the adoption or rejection of technology-driven techniques. With acceptance of transgenic and irradiation foods far from certain, processing trends are sure to evolve in unexpected directions.