All Science Fair Projects

Food preservation

Food additives are normally added as preservatives to food in order to prevent and inhibit the growth of bacteria, fungi and mold in the food. Some of the commonly used food preservatives include sodium nitrate, calcium propionate and sulfides.

Natural substances like salt, vinegar, alcohol and sugar have been used traditionally through the ages, to help preserve food. Pickling, smoking and salting are some of the methods that have been traditionally used to preserve food for later use. Certain enzymes that are found in fruits can also be used to preserve food. For example, ascorbic acid found in lemons can be used to prevent a cut apple from turning brown.

Baked foods like bread are very vulnerable to mold and bacterial growth. These microbes will thrive at pH levels between 6.5 and 7.5. Adding natural preservatives like prunes, raisins, vinegar and spices like cinnamon can help to control the growth of microbes on bread. Using citric fruits in the bread will help to reduce the pH level and increase its shelf life.