Leybold supports vacuum technology as a key means for improving food packing and processing, thus reducing food waste. With vacuum technology, it is possible to:
Have food stay fresh for longer
Efficiently cool produce
Preserve fresh fish and meat
With increased implementation of these three strategies, it should be possible to significantly reduce the amount of food wasted in the future.
1. Vacuum packaging keeps food fresh for longer periods of time
Oxygen is one of the primary culprits for food spoiling. This is due to micro-organisms present on the food’s surface using the oxygen as they break down food.
Vacuum sealing assists with food preservation in two ways. First, it prevents micro-organisms such as bacteria and fungi from reaching the food. Second, any micro-organisms that were already present on the food are starved of oxygen after the seal is applied.
The most common types of vacuum pumps used for sealing food are rotary vane pumps and dry screw pumps. Dry screw pumps have the advantage of a longer maintenance interval due to their lack of an oil seal. Find out what users had to say about dry vacuum pumps in our summary of the 2020 Vacuum user survey.
Related: Find out how much you can save when switching to Leybold's DryScrew Vacuum technology from typical rollstock configurations, in our short comparison guide.
2. Vacuum cooling more efficiently preserves product freshness
Rapidly cooling fruits and vegetables is one of the best ways to guarantee a long shelf-life. The cold temperatures are able to aggressively slow the growth of micro-organisms on the food’s surface. Ideally, this cooling is done immediately after harvest.
Vacuum cooling is one of the quickest and most efficient means of cooling produce today. A container can be cooled and ready for shipping in under half an hour. Rotary vane and dry screw pumps are most commonly used for this application.
Generally speaking, the vacuum generated is somewhere between 6 and 23 mbar. Evacuation levels below 6 mbar must be avoided when vacuum cooling produce, as this will cause the water to freeze. The freezing process will damage the cell structure of the food and may affect taste and texture.
3. Vacuum drying prevents fish and meat decay
Drying fish and meat has been a practical food preservation strategy for millennia. In antiquity, sun and smoke were the most popular methods used. These days, vacuums can achieve an improved effect with greater precision in far less time.
There are two different processes employed to dry food with a vacuum pump:
Vacuum Microwave Drying (VMD)
Freeze Drying or Lyophilisation (FD)
VMD involves heating the food with microwaves to between 35 and 60 degrees Celsius. Simultaneously, a vacuum pump keeps the pressure around 10 mbar.
FD involves cooling the products to between -20 and -40 degrees Celsius. After the freezing is complete, a vacuum is pulled until pressure is below -1 mbar. This causes the water to sublimate out of the food.
Both of these processes work with rotary vane pumps, though VMD uses single-stage and FD uses double-stage. The same effects can also be achieved with dry screw pumps.
Related: Curious to learn more about the evolution of vacuum pumps and freeze-drying? Check out our resource page, on Vacuum Pumps and Freeze-Drying Technology, for a whirlwind tour of historical methods, all the way to today's cutting edge solutions.