Food preservation prevents the growth of microorganisms such as yeasts, or other microorganisms although some methods work by introducing benign bacteria or fungi to the food, as well as slowing the oxidation of fats that cause rancidity. Food preservation may also include processes that inhibit visual deterioration such as the enzymatic browning reaction in apples after they are cut during food preparation. Many processes designed to preserve food involve more than one food preservation method. Preserving fruit by turning it into jam involves boiling to reduce the fruit’s moisture content and to kill bacteria, etc., and sugaring to prevent their re-growth and sealing within an airtight jar to prevent recontamination. Some traditional methods of preserving food have been shown to have a lower energy input and carbon footprint, when compared to modern methods. Maintaining or creating nutritional value, texture and flavor is an important aspect of food preservation.