Luo Han Guo
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Luo Han Guo ( Siraitia grosvenorii ) |
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| Siraitia grosvenorii | ||||||||||||
| ( Swingle ) C.Jeffrey ex AMLu & Zhi Y.Zhang |
Luo Han Guo ( Siraitia grosvenorii ), also monk fruit called, is a plant from the genus Siraitia in the family of the Cucurbitaceae (Cucurbitaceae). It is cultivated in China because of its extremely sweet fruit, it is used as a natural sweetener and as a remedy in traditional Chinese medicine , where Chinese 羅漢果 / 罗汉果 , pinyin luóhàn guǒ , also Luahanguo , Luo Han Kao or Lo Han Kao , Lo-Han is used -Kuo called.
description
Vegetative characteristics
Luo Han Guo is a perennial plant that sprouts from a succulent caudex every year . The caudex is a fleshy, elongated or egg-shaped rhizome 7 to 23 cm long and 6 to 12 cm in diameter. Young shoots are hairy with yellowish-brown trichomes , between which black glands stand. The tendrils are forked. The leaves are 12 to 25 cm long and 5 to 17 cm wide at the base, they are triangular-egg-shaped, provided with a pointed appendage towards the front and broadly heart-shaped at the base. The leaf margin is wavy or inconspicuously serrated. The leaf stalks are usually between 5 and 7 cm, rarely between 3 and 9 cm long.
Inflorescences and flowers
Siraitia grosvenorii is dioeciously segregated ( diocesan ). Both male and female plant specimens have yellow flowers 2.5 to 3.5 cm in diameter. The male flowers are in axillary, racemose groups of six to ten flowers. The inflorescence shafts are 7 to 13 cm long and the flower stalks 5 to 15 mm. The flowers have a cup-shaped flower cup (hypanthium) which is 4 to 5 mm long and 8 mm wide and has five lobes. These lobes are triangular-lanceolate, 3 mm wide at the base and pointed towards the front with a lanceolate appendix. The five-part crown consists of elongated, egg-shaped, pointed segments that are 10 to 15 mm long and 7 to 8 mm wide. The five stamens have individually standing stamens . Four of the stamens are in pairs, their anthers consist of two counters. The anthers of the fifth stamen has only one theka.
The female flowers are single or in zymose groups of two to five flowers. The sepals are linearly shaped. The crown is strongly divided into five pointed and anteriorly awl-shaped segments. The stamens are stunted to five clearly developed, 2 to 2.5 mm long staminodes , but occasionally also have pollen . They have a top permanent ovary , which is elongated ovoid, and 10 to 12 cm long and 5 to 6 mm wide. At the base it is rounded, the tip is slightly narrowed, densely hairy and glandular. The stylus is 2.5 mm long and has fleshy, bilobed scars .
Fruits and seeds
The berries are elongated, spherical or pear-shaped with a length of 5 to 8 cm and a diameter of 4 to 6.5 cm. The berries are tomentose, shaggy or velvety hairy, the surface is smooth or inconspicuously streaked or has six to eleven furrows extending from the fruit stalk. When dry, they turn light brown and have a thin and brittle shell 1 mm thick. The seeds are elongated, egg-shaped or almost spherical, the edge is thickened, rough and deeply furrowed.
ingredients
The fruit consists of 25 to 38% different carbohydrates , mainly fructose and glucose . However, the sweetness of the fruit is mainly determined by the mogrosides , a group of triterpene - glycosides ( saponins ). There are five different mogrosides, numbered from I to V. They are structurally related to the cucurbitacins . The main component is the mogroside V , which is also known under the name Esgosid.
Fresh fruits are also very vitamin C sustainably . A study showed a maximum of 461.12 mg vitamin C per 100 g in a wild plant, in cultivated varieties the proportion was between 339.68 and 389.31 mg per 100 g. Although the fruit loses around 90% of this vitamin through drying, it still contains almost as much vitamin C as fresh oranges.
The seeds of Luo Han Guo contain a wide variety of fatty acids , including 52.3% linoleic acid , 20.7% oleic acid , 14.7% palmitic acid , 7.1% stearic acid , 0.6% each of myristic acid and capric acid and 0.5% lauric acid .
Occurrence
Siraitia grosvenorii is likely native to the mountains in northeast China's Guangxi Autonomous Region . However, this plant species is rarely found in the wild, but it is grown in the south of China, mainly in the mountains around Guilin, on around 1,600 hectares . It grows mainly on shady slopes, which are often covered with fog and thus provide further protection from excessive solar radiation. However, the temperatures in the region are still warm.
history
Cultivation history
According to legend, the knowledge of the use of the Luo Han Guo fruit came from the Luohan monks who lived in Guilin in the 13th century. The oldest written description of the cultivation of the plants dates back to 1813. The cultivation of the plants has long been a secret of the Zhuang-Zu minority . However, the use of the fruit became more and more popular, so that the Zhuang Zu began selling more and more fruit in local markets. After 1900 the dried fruits were known in almost all of the Cantonese area of China and the cultivation resources were reaching their limits. In the Cantonese capital of Guangzhou , the fruits were very well known without any information about the appearance of the plant.
Taxonomy and Botanical History
A first mention of the fruit in botanical literature comes from George Weidman Groff , a professor of agriculture in Guangzhou. In 1932 he visited the Guilin area, from where he was sent some rootstocks of Luo Han Guo plants, which he then cultivated in Guangzhou. The plants formed vegetative shoots, but the different climate probably did not cause any flowers. Together with Walter Tennyson Swingle of the United States Department of Agriculture , Groff received a research grant from the National Geographic Society to study the plants further by means of an expedition to Guilin that began in August 1937. Based on these investigations, Swingle published the first description of the plant under the name Momordica grosvenorii in 1941 . The specific epithet honors Gilbert Grosvenor , then President of the National Geographic Society, as he was a long-time supporter of geographical and botanical expeditions in China and also approved the application for research support for the search for the Luo Han Guo plants.
After various material from the plants had been sent to Kew Gardens and examined there by Charles Jeffrey , among others , he saw the plant not belonging to the genus Momordica . Rather, he saw the species because of the shape of the tendrils within the genus Thladiantha and described it as Thladiantha grosvenorii . The now recognized classification in the genus Siraitia as Siraitia grosvenorii dates back to 1984 by Lu Anmin and Zhang Zhiyun from the Institute of Botany in Guangxi, which has been researching the species for a long time.
use
In Traditional Chinese Medicine (TCM), the fruit is used as a remedy for heat stroke , to moisten the lungs, against phlegm and cough and to promote digestion. The fruit is also added to various teas , which are then used, among other things, to prevent or relieve coughs or headaches and for detoxification. In the Guangzhou area, a small piece of the fruit is added to soups to improve the taste.
Because of its monosaccharides , some craft breweries in the United States have been experimenting with monk fruit as an ingredient since 2019 .
literature
- Walter Tennyson Swingle: Momordica grosvenori Sp. Nov. the source of the Chinese Lo han kuo . In: Journal of the Arnold Arboretum , Volume 22, 1941, pages 197-203.
- Shiu-ying Hu: Food Plants of China . The Chinese University Press, Hong Kong, 2005. ISBN 962-201-860-2 .
- Subhuti Dharmananda: Luo Han Guo - Sweet Fruit Used as Sugar Substitute and Medicinal Herb . In: ITM Online , January 2004, accessed November 21, 2008.
Web links
Individual evidence
- ^ Matthias F. Melzig: Monk fruit - sweetness without remorse? In: Deutsche Apotheker Zeitung. 158th Volume, No. 18, 2018, p. 44 f.
- ^ Charles Jeffrey: A new combination in Thladiantha (Cucurbitaceae) for a Chinese medicinal plant. In: Kew Bulletin. Volume 33, number 3, 1979, p. 393 f.
- ↑ Joe Strange: Special Ingredient: Monk Fruit. In: Craft Beer & Brewing. Craft Beer and Brewing Magazine, accessed May 26, 2020 .