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A vacuum pump is an essential piece of equipment that pushes gas or air molecules out of a substance or unit, leaving behind a low-pressure vacuum. This displacement concept has proved vital for industrial as well as scientific purposes. The food and beverage industry has reaped the most benefits by applying this displacement aspect.

The most important application is the element of food preservation. This is important in the modern-day era, where a reported 1.3 billion tons of food is wasted every year across the globe. Farm products typically go bad a few hours after harvesting if not immediately consumed.

Indeed, technology has brought new and improved ways of preserving foods, such as freezing which, when used along with other traditional ways such as drying and canning, ultimately improves longevity. However, these methods don’t entirely retain the vital properties of food, such as flavor and texture; freezing food for more extended periods technically damages its cell structure.

Moreover, a fast-growing population creates the need to preserve as much food as possible in its best state of freshness and flavor.

Photo by Алекке Блажин: https://www.pexels.com/photo/fish-preserved-in-vacuum-pack-plastic-8254505/

Vacuum Drying

Food can be preserved with vacuum pumps in two main ways; Vacuum Microwave Drying (VMD) or Freeze Drying (FD). Vacuum Microwave Drying involves using microwaves to heat food to temperatures of 35°C and 60°C with the vacuum pump maintaining a pressure of 10 millibar. On the other hand, freeze drying involves cooling the food substances at -20°C and -40°C, after which pressure is brought to below -1 millibar.

Vacuum Packaging 

Vacuum packaging is all about completely removing air molecules from a pack of a unit of food before dispatching it for sale or storage. The vacuum pump is used to suck the air off the food item creating a sealed vacuum around the unit. This creates an environment that is devoid of oxygen and other reactant elements.

Why Is This Important?

As long as the food comes into contact with oxygen, it is bound to deteriorate. If fresh products are released in a package that allows air molecules in, noticeable changes in food quality and appearance will be noticed. This is because oxygen creates pathways for the growth of bacteria responsible for the deteriorating aspect of food substances.

When you deprive these kinds of bacteria of oxygen, you create what is known as an anaerobic environment which also prevents the multiplication as well as the sprouting of new bacteria. This means food remains fresh for longer and reduces the chances of poisoning. The most common types of pumps used for this process are the rotary vane pumps and the dry screw pumps.

Vacuum-sealing food has some other benefits apart from the oxygen factor. It also preserves the original food moisture, which would have otherwise been lost to the environment. The food unit, therefore, doesn’t dry out or lose its moisture content.

This sealing also preserves the food’s original taste and quality by ensuring it doesn’t lose its natural oils and flavor. This also plays a role in the food maintaining its structure since its moisture and oils make it favorable to consume compared to others stored differently. In this way, the flavor is also largely maintained.

Vacuum sealing also prevents freezer burn. This is when moisture is lost from food that has typically been in the freezer for some time and ends up looking discolored and dry when thawed. By vacuum packaging a food unit, you protect it from cold dry air, which causes the freezer burn effect.

Freezing After Packaging

While most bacteria is taken care of when you suck the oxygen off the food substance, the resulting environment is a perfect breeding ground for anaerobic bacteria. A good example is clostridium botulinum which produces dangerous toxins in anaerobic environments. This problem is common in perishable foods.

In order to combat this, experts advise that perishable, vacuum-packaged foods be frozen. The low-temperature conditions eliminate any chances for the growth of harmful microorganisms.

Depending on the type, vacuum-sealed foods have been known to last up to four times longer, with frozen-sealed food lasting 2 to 3 years.

What Foods Can’t Be Vacuum-Sealed?

Almost all kinds of foods, from fruits and vegetables to meats, fish, cheese, and pasta, can be preserved for longevity through vacuum sealing. An exemption is only placed for foods containing anaerobic bacteria that can survive in certain conditions. Foods such as mushrooms are also only advised to be vacuum sealed only when cooked and not in their fresh nature, which would otherwise cause them to decay faster.

Experts also advise that you blanch vegetables before vacuum sealing them since they emit some natural gasses which, if produced in a vacuum, could cause them to go bad. Apples also undergo a process where they are sliced and coated with lemon juice before being vacuum sealed to avoid color discoloration.