Food Engineering - The re-invention of the freezer?
July 2006
Perfect preservation of food over long periods of time is a food industry holy grail - is this possible with revolutionary freezing technology developed and commercialised in Japan, and only now finding interest elsewhere in the world? This report is by Graeme Glen of the Hokkaido International Business Association.
ALL conventional freezing systems suffer from the same basic flaw: as product freezes from the outside in, the ice formed insulates the centre against the cold. Over the years, freezers have become more and more powerful to overcome this phenomenon.Rather than trying to beat these physics, a Japanese technology company, ABI, has developed CAS or Cells Alive System that actually changes the physics of freezing. Using an oscillating electrical field, it causes water molecules to spin (as opposed to vibrate as in a microwave) and stops them from clustering and forming ice crystals that damage cell walls. This spinning motion also artificially lowers the freezing point of water to about -7ºC - when the product reaches this temperature, the electrical field is turned off and it freezes almost instantaneously from the inside out. With CAS freezing, power is no longer a major issue as uniform freezing is achieved. CAS uses 30% less power than conventional freezers, and can be uo to five times faster depending on the product.
After freezing, the rules of nature apply and lower temperatures reduce enzyme activity. But this can be done in an efficient and slow manner as the product is already perfectly frozen and ice crystal formation has been halted.
One very simple demonstration of CAS freezing and how it prevents ice crystal formation is that it can freeze a full glass bottle of water. The water level remains the same, the glass does not break, and the water is crystal clear except for a few bubbles.
The CAS freezer is backed up with a CAS stocker that operates on the same basic principal, and continually applies a low-level harmonic oscillating magnetic field to the food. The field works on the atoms within the food, aligning the magnetic moment of the electrons, and the magnetic flux attacks any bacteria present in the food and keeps them at manageable levels.
The CAS stocker has the ability to reduce oxidisation by 98% (product dependant) compared to a conventional stocker. And it does it at higher temperatures. For example, tuna stored at -60ºC in a conventional freezer has an expected shelf life of one year before oxidisation takes it toll on the fats. A CAS stocker operating at an economical -40ºC can store tuna for two years without loss to its original flavour, texture and aroma.
A freezing genius
The man behind CAS is 60-year old Norio Owada, an engineering genius and second-generation freezing equipment manufacturer who envisions a world where food can be stockpiled for years without going off or losing its nutritional value, where distance from markets is no longer a challenge. He plans to use his invention to build a multinational network of food exporters, shipping at reasonable cost, produce from safe environments to the tables of Tokyo, New York and London, and all in perfect condition.
Owada has heavily patented his invention and has no qualms about demonstrating, explaining or showing off his machine. His lab is located in the futuristic Tokyo University-affiliated Tokatsu Techno Plaza technology complex in Chiba. The CAS machine looks like a conventional closed-circuit freon freezing unit, with an LCD monitor showing an internal freezer temperature of -60ºC. Other engineering is also conventional, while the electronics that produce the oscillating fleld have an expected life span of 30 years.
To demonstrate the invisible oscillating field, a big magnet held up inside the freezer gently vibrates, increasing as the power is turned up. The system poses no health risks as it operates at 30 gauss, the same as the earths’ magnetic field, and generates the same amount of energy as a cellular phone.
ABI has been selling its systems in Japan for over ten years and it has recently started marketing abroad. CAS freezers can be retrofitted into existing infrastructure for the same price as conventional freezing equipment, with the benefits of reduced energy costs and superior preservation at higher temperatures.
CAS freezing is not just some techno-fantasy of things that could be. It’s earning hard currency competing in the competitive tuna fish market in Japan and is being used in Alaska to preserve cod roe and milt, a product that’s impossible to freeze and maintain market value using conventional freezing. In France, ingredient suppliers are preserving delicate doughs, foie gras, duck meat, and truffles etc. Other products being tested, tried and marketed include sushi, cream, milk, ready meals, green mangos, sea urchin, sashimi-grade seafood, and many others.
It has other applications, too, with five Japanese unlversities investigating it for human organ freezing. Progress so far indicates that although the CAS freezing process freezes to a high degree of perfection, the secret is in defrosting the organ as this is where some damage occurs. If this research is successful it will change the medical transplant business forever.