Smoking is one of the oldest methods of preserving foodstuffs, and it involves exposing food to smoke from burning or smoldering material, most often wood). The process of smoking helps prevent bacterial and fungal growth by removing moisture from food, which would otherwise ruin stored foods. Smoke is an antimicrobial and antioxidant, but smoke alone is insufficient for preserving food in practice, unless combined with another preservation method. The drying action of the smoke tends to preserve the meat, though many of the chemicals present in wood smoke are natural preservatives as well. Smoking is also a method of drying that imparts flavor to the food, usually meat items, and smoke helps keep bacteria-carrying-insects away during the drying process. Smoke dehydrates food and also gives it a distinctive color and aroma. There are two types of traditional smoking: cold smoking, where the temperature of the smoke stays below 30°C, and hot smoking, where smoke reaches 80°C in successive stages. Nowadays, new techniques are being used, such as injecting smoke extracts or spraying smoke flavors over food.