Begin by washing and cleaning the fruit thoroughly. If the fruit is small, like berries, toss them all into a colander and hold them under cold running water to dislodge dirt and soil. If the fruits are larger, like peaches, you will need to wash them individually. After they have been washed, pick out and discard any bruised or rotten fruit, and remove items like twigs, leaves, etc.
Next, prepare the fruits for the preservation process. If the fruits are berries, leave them as they are, but if the fruits need to be peeled and sliced, do so. Take a large bowl, and pour in water and lemon juice – one-quarter cup of lemon juice per quart of water. Then drop any sliced fruits into this for around 10 minutes, before you take them out again – this will keep them from browning. Do not let the fruit sit in the mixture for long, otherwise they will absorb the sourness of the lemons, and become soggy.
Then, spread all the fruit out on a baking tray, and pat it dry. Make sure the fruit is arranged so that none of the pieces are touching each other. Cover the tray with cling film/plastic wrap, and slide it into the freezer, onto a cleared, flat freezer shelf. Let the tray stay in for 1 or 2 hours, or however long it takes for the fruits to freeze.
Once the fruits are completely frozen, remove the tray from the freezer, pick the fruits off the tray, and put them into the vacuum seal bags. There is no need to be too neat, as the fruits are frozen, but you will need to work quickly, to make sure the fruits stay frozen and do not begin to thaw.
Finally, seal the vacuum seal bags as per the instructions that come with the vacuum sealer. Once all the bags have been sealed, mark them – use a permanent marker to note down details on the bag, like the kind of fruit it contains, the quantity, and the date on which it was frozen. Then, put the bags in the freezer, and keep them there until you are ready to use the fruit. If sealed and frozen properly, the fruit will keep for roughly a year.