Perilla


 * ''This article is about the plant genus and its human use. For the spider genus see Perilla (zoological genus).

Perilla is a genus of annual herb that is a member of the mint family, Lamiaceae. In mild climates the plant reseeds itself. The most common species is ''Perilla frutescens var. japonica'' or shiso which is mainly grown in India and East Asia. There are both green-leafed and purple-leafed varieties which are generally recognized as separate species by botanists. The leaves resemble stinging nettle leaves, being slightly rounder in shape. It is also widely known as the Beefsteak plant. In North America, it is increasingly commonly called by its Japanese name, shiso, in addition to being generally referred to as perilla. Its essential oils provide for a strong taste whose intensity might be compared to that of mint or fennel. It is considered rich in minerals and vitamins, has anti-inflammatory properties and is thought to help preserve and sterilize other foods. In Nepal and parts of India, it is called silam. Its seeds are ground with chili and tomatoes to make a savoury dip/side dish.

It is sometimes known as purple mint, Japanese basil, or wild coleus (although it is not a mint, basil or coleus).

China
Perilla is traditionally used in Chinese medicine and has been shown to stimulate interferon activity and thus, the body's immune system.

Japan
The Japanese name for perilla is shiso (紫蘇). The Japanese call the green type aojiso (青紫蘇), aoba ("green leaf"), ōba (corruption of aoba, often written as 大葉, "big leaf") or aoshiso and often eat it with sashimi (sliced raw fish) or cut into thin strips in salads, spaghetti, and meat and fish dishes. It is also used as a flavorful herb in a variety of dishes, even as a pizza topping (initially it was used in place of basil). The purple type is called akajiso (赤紫蘇 "red shiso") and is used to make umeboshi (pickled ume), or combined with ume paste in sushi to make umeshiso maki. An inflorescence of shiso is called hojiso. Its young leaves and flower buds are used for pickling in Japan and Taiwan.



Vietnam
Vietnamese cuisine uses a variety similar to the Japanese hojiso but with greenish bronze on the top face and purple on the opposite face. The leaves are smaller and have a much stronger fragrance than hojiso. In Vietnamese, it is called tía tô, derived from the characters (紫蘇) whose standard pronunciation in Vietnamese is tử tô. It is usually eaten as a garnish in rice vermicelli dishes called bún and a number of stews and simmered dishes.

Indonesia
In Indonesia, Perilla is known as "Kemangi." The variety is similar to the one used in Thailand. The seeds collected from the flowers are known as "Selasih" and are often added to drinks.

Korea
The plant's Korean name is deulkkae or tŭlkkae (들깨). The same word is also used when referring to its seed, which has many uses in Korean cuisine, just as the leaves (kkaennip, 깻잎) do. The literal translations of deulkkae ("wild sesame") and kkaennip ("sesame leaf") are in spite of perilla's not being closely related to sesame, and Korean cookbooks translated to English sometimes use these translations. Cans of pickled kkaennip can be found in Korean shops all over the world, with some ground red pepper between every two leaves in the can. The leaves' essential oils provide for their strong taste. Fresh leaves have an aroma reminiscent of apples and mint and are eaten in salad dishes. The flavor is distinct from Japanese perilla, and the leaf appearance is different as well – larger, rounder, flatter, with a less serrate edge and often, a violet coloring on the reverse side. Perilla oil (deulgireum, 들기름) is extracted from the seeds; the cake can be used as animal food. Perilla oil has a rich taste and scent slightly resembling dark sesame oil (chamgireum, 참기름). Perilla seed can be cooked with meals, roasted, crushed to intensify its taste and/or mixed with sesame and salt.

Chemistry
The essential oil extracted from the leaves of perilla by steam distillation consists of a variety of chemical compounds, which may vary depending on species. The most abundant, comprising about 50–60% of the oil, is perillaldehyde which is most responsible for the aroma and taste of perilla. Other terpenes such as limonene, caryophyllene, and farnesene are common as well.

Of the known chemotypes of perilla, PA (main component: perillaldehyd) is the only one used for culinary purposes. Other chemotypes are PK (perilla ketone), EK (elsholzia ketone), PL (perillene), PP (phenylpropanoids: myristicin, dillapiole, elemicin), C (citral) and a type rich in rosefuran.

Perilla ketone is toxic to some animals. When cattle and horses consume purple mint (of the PK chemotype) while grazing in fields in which it grows, the perilla ketone causes pulmonary edema leading to a condition sometimes called perilla mint toxicosis.

Perilla oil is obtained by pressing the seeds of perilla, which contain 35 to 45 percent oil. In parts of Asia, perilla oil is used as an edible oil that is valued more for its medicinal benefit than its flavor. Perilla oil is a very rich source of the omega-3 fatty acid alpha-linolenic acid. As a drying oil similar to tung oil or linseed oil, perilla oil has been used for paints, varnishes, linoleum, printing ink, lacquers, and for protective waterproof coatings on cloth. Perilla oil can also be used for fuel.

The oxime of perillaldehyde (perillartin) is used as an artificial sweetener in Japan as it is about 2000 times sweeter than sucrose.