Vacuum sealing food in specially designed plastic bags or pouches before storing them in the fridge or the pantry can increase their shelf life dramatically, or so goes the consumerist saying. But, in reality, a badly prepared vacuum package is no better than a normal package. In fact, you could be inviting more problems than solving a few if you are not careful. That said, here is a look at tips on how you should really go about vacuum sealing fresh produce.
The Problem With Vacuum Sealing Whole Fruits And Vegetables
Ideologically, vacuum sealing whole fruits and veggies and storing them in the refrigerator would seem like a sensible enough concept. But, it’s all right if you plan to consume them within 8-12 days. However, the same vegetables when stored in an oxygen reduced atmosphere (read vacuum sealed bag) and kept at low temperatures, release certain gases which interfere with the integrity of the bag’s seal thus making it porous.
An even more serious concern is the presence and slow growth of anaerobic bacteria in these foods when they are vacuum sealed and stored in the fridge without prior preparations. These bacteria can be found in the soil and therefore be transferred on to fruits and vegetables. Furthermore, when these same veggies are vacuum sealed, it only allows more room for these bacteria to grow and flourish.
Preparing Fruits And Veggies Before Vacuum Sealing
Start by skinning or peeling larger fruits and vegetables and cut into smaller portions while smaller produce like berries, plums etc can be left whole. Then clean them thoroughly under running water. Additionally for veggies, they’ll need to be ‘quick’ blanched and placed in a bowl of ice water immediately after.
This method of blanching will require you place the vegetable pieces in boiling water for a very short time (1-4 minutes). The high temperature will kill any surviving surface bacteria and stop the ripening process in them whereas the short time period will ensure they retain their natural rigidity. Immediately putting them in ice water will kill any ensuing cooking process that might be taking place within the vegetables.
But before you can vacuum seal the cut fruits and veggies, drain the water from them by wrapping in blotting paper. Soon after, vacuum seal the vegetables in separate batches. Here, it’s advisable to store similar veggies in a pack e.g. cruciferous vegetables in one, carrots, beets etc in another and so on.
Flash Freezing Vegetables And Fruits
If you are planning to store vegetables for an even longer period ( 2 years or more), then consider flash freezing them before following up with the vacuum sealing process. Contrary to normal process of freezing, all the juices and nutrients are locked inside the food in the form of minute ice crystals with flash freezing. So, upon rehydration, they taste very much like the original product.
As a scientific process, flash freezing or drying is carried out in laboratories using expensive equipment and super cooled gases. But, with some improvisations, you too can reproduce the same effect to a large extent in the comfort of your home.
Basically, what you do is spread the prepared bits of veggies or fruits evenly on a large cookie sheet to form a single layer where none of the pieces are sticking together. This tray then goes into the freezer and left in there for a certain period of time. An even better approach is to cover the fruit or veggie bits with ice and then put in the freezer, which further evens out the freezing process. If you are unsure about the progress, then pick out a piece from the tray and thaw it to check if it re-hydrates with the right consistency.
Vacuum sealed, flash dried fruits and veggies can last for several years without losing their flavor or nutrients. When you are ready to reuse them, simply remove the constituents from the bag, and reheat them in a microwave or steamer with some water. In fact, they will taste much like they did when they were freshly plucked!