to kill many microorganisms.Salt[edit]Bag of Prague powder #1, also known as "curing salt" or "pink salt." It is typically a combination of salt and sodium nitrite, with the pink color added to distinguish it from ordinary salt.Main article: Curing (food preservation)Salting or curing draws moisture from the meat through a process of osmosis. Meat is cured with salt or sugar, or a combination of the two. Nitrates and nitrites are also often used to cure meat and contribute the characteristic pink color, as well as inhibition of Clostridium botulinum. It was a main method of preservation in medieval times and around the 1700s.Sugar[edit]Main article: SugaringThe earliest cultures have used sugar as a preservative, and it was commonplace to store fruit in honey. Similar to pickled foods, sugar cane was brought to Europe through the trade routes. In northern climates without sufficient sun to dry foods, preserves are made by heating the fruit with sugar.[2] "Sugar tends to draw water from the microbes (plasmolysis). This process leaves the microbial cells dehydrated, thus killing them. In this way, the food will remain safe from microbial spoilage."[3] Sugar is used to preserve fruits, either in an anti-microbial syrup with fruit such as apples, pears, peaches,apricots and plums, or in crystallized form where the preserved material is cooked in sugar to the point of crystallization and the resultant product is then stored dry. This method is used for the skins of citrus fruit (candied peel), angelica and ginger.Smoking[edit]Main article: Smoking (cooking)See also: List of smoked foodsSmoked ham in a smokehouse inSchleswig-Holstein, GermanySmoking is used to lengthen the shelf life of perishable food items. This effect is achieved by exposing the food tosmoke from burning plant materials such as wood. Smoke deposits a number of pyrolysis products onto the food, including the phenols syringol, guaiacol and catechol.[3] These compounds aid in the drying and preservation of meats and other foods. Most commonly subjected to this method of food preservation are meats and fish that have undergone curing. Fruits and vegetables like paprika, cheeses, spices, and ingredients for making drinks such asmalt and tea leaves are also smoked, but mainly for cooking or flavoring them. It is one of the oldest food preservation methods, which probably arose after the development of cooking with fire.Pickling[edit]Main article: PicklingPickling is a method of preserving food in an edible anti-microbial liquid. Pickling can be broadly categorized into two categories: chemical pickling and fermentation pickling.In chemical pickling, the food is placed in an edible liquid that inhibits or kills bacteria and other micro-organisms. Typical pickling agents include brine (high in salt), vinegar, alcohol, and vegetable oil, especially olive oil but also many other oils. Many chemical pickling processes also involve heating or boiling so that the food being preserved becomes saturated with the pickling agent. Common chemically pickled foods include cucumbers, peppers, corned beef,herring, and eggs, as well as mixed vegetables such as piccalilli.In fermentation pickling, the food itself produces the preservation agent, typically by a process that produces lactic acid. Fermented pickles includesauerkraut, nukazuke, kimchi, surstromming, and curtido. Some pickled cucumbers are