The Use of Sugar in Food Preservation

The Use of Sugar in Food Preservation

Sugar is one of the most important aspects of food preservation. Although, the steps are different depending on what kind of result you want.

A very common form of food preservation is jams. In many places this practice is used by housewives. In factories jam making is a rather complicated procedure. To people who work in factories the procedure is different because they care more about the quality to make sure they have an unchanging product, but essentially the assembled product is the same as ones made at home. (http://www.fao.org/teca/content/use-sugar-fruit-preservation-jams-jellies-marmalade-fruit-paste)

If you want to make jam the first step in preserving food with sugar is boil the fresh or pre-cooked food in a mix of cane sugar or beet sugar until the water is evaporated enough to make it a mixture. Then while it cools it will become a gel that has about 32-34% water.

The formation of gel Gel depends on the amount of pectin in the fruit. If it is at a pH of 3.2 -3.4 and has a lot of sugar, it can form a sticky half-solid mixture. It is a mixture because the two substances are not chemically united. (Food Science, Jean Miller)

Any micro-organisms are destroyed during the jam boiling because the boiling of water is constantly condensing their proteins. If it is filled while hot into a clean container, sealed, and then turned upside down so the hot jam is touching the bottom of the lid it will not spoil. Approximately 30% of the Vitamin C in the fruit is destroyed during the jam making because oxygen evaporates it, but what is left is substantial during the storing. (Food Science, Jean Miller)

Because there is so much moisture in the jam, mold damage is possible if the container is open and exposed to air. There should not be any problems with spoilage in a canned product, it is very unlikely because there is no exposure to air. (Food Science, Jean Miller)

Marmalade is another sugar preserve. It is a gel-like substance that is made from fruit ingredients together with another sweetener. It may contain acids and food pectins. The ingredients are concentrated by cooking to a point that the dissolvable solids of the finished product is not below 65%. (Food Science, Jean Miller)

Fruit paste is also another common sugar preserve. You make it the same way as marmalade that is not gelified, but with less water about 25% "total soluble solids" in fruit paste. Less water can be acquired by boiling the water longer or letting it dry naturally. (Food Science, Jean Miller)