Multivac announced that SFP Light is available with immediate effect for MULTIVAC thermoforming packaging machines. The company says the system packs hot products without a vacuum source. This is different from other solutions that contain some residual air when packaging hot food, which can adversely affect the shelf life.
When vacuum packing hot products, some residual air with 21% oxygen content always remains in the header space, which can reduce the shelf life of the food. “Many caterers and kitchens therefore let the hot food cool down before vacuum packing. Or they use active cooling. But by doing this, they lose either time or energy,” says Dominik Eberhard, product manager for thermoforming packaging machines at MULTIVAC. “In order to ease the burden on caterers and kitchens, we have launched a new steam flushing system for small to medium batch sizes onto the market, and this is called SFP Light.” SFP is an abbreviation for Steam Flush Packaging, and the steam flushing system enables hot food to be vacuum packed directly after cooking.
The thermoforming packaging machine first forms the pack cavities for the product from a plastic film—for packing five kilograms of goulash at a temperature of 60°C, for example. The portions then travel into a hermetically enclosed sealing station. Hot steam at a temperature of 180°C now flows through the station. Finally the upper web is sealed to the formed film, and the steam remains in the pack. The company says that the secret is that gases have a significantly greater volume than liquids. When the steam turns to water again during cooling, the pack automatically contracts.
“Thanks to SFP Light, it is possible to pack hot products without any significant residual air pockets. And all this without any vacuum source, which always has a limited effect due to the vapor pressure curve,” explains Eberhard. “There is also no danger of the products boiling or packs bursting, since there is no negative pressure in the product space.” Multivac adds that another beneficial side effect of the steam flushing system is that the hot gas at 180°C kills bacteria on the surface of the food, so that the shelf life is extended.