Luo Han Guo (Siraitia grosvenori or Momordica grosvenori) is a venerable Chinese fruit making a big splash on these Western shores. A cousin of the cucumber, it's a member of the greater gourd family.
Cultivated in the Guangxi Province of Southern China, the green fruit turns brown when dried, and is covered with small pale and black hairs. The dried fruits are part of the daily life in the provinces where it is grown. They are stored and used for drinks, teas, soups, candies, cakes, and crackers that are consumed all year long.
Extract of Luo Han Guo has been favored in China as a sweet curative for centuries, used in traditional medicine as a remedy for colds, coughs, sore throats, gastrointestinal disorders and as a blood purifier. It is cultivated in parts of the Guangdong, Guangxi, and Guiahou provinces, though it mainly grows in the mountains of Guangxi near Guilin. Guilin supplies over 90 percent of the total commercial production and is considered the home of Luo Han Guo fruit production, with a tradition of processing the fruit that began in the late 19th century.
|Luo Han Guo photo courtesy of www.itmonline.org.
Yet its curative history is not what first brought it to the attention of food manufacturers in this country. Locked in the fruit extract are substances called mongrosides, which, as it happens, are about 300 times sweeter than sucrose. They contribute hardly any calories and have potentially healthful side effects to boot.
Mongrosides belong to a group of compounds called triterpene glycosides. Though glycosides tickle our sweet taste buds, the body handles them differently from carbohydrates: Insulin levels do not rise in response to their consumption; they aren't broken apart to produce energy and thus can't pack on the pounds.
Unlike artificial sweeteners that are engineered to perform one purpose, stimulate taste buds, glycosides are presently under investigation as potential tumor inhibitors, help manage diabetes and defend against heart disease.
Researchers at Nihon University, Japan, have identified nearly 20 compounds from Luo Han Guo with potential anti-tumor activities. Animal studies at the University of Hiroshima, Japan, have shown that two of the mongrosides can inhibit the growth of skin tumors initiated by known carcinogens.
Other promising studies demonstrated that mongrosides not only fail to raise blood sugar levels but may actually slow the entrance of sugar into the blood by inhibiting the enzyme maltase in the small intestines. Maltase splits maltose into its constituent glucose units. Mongrosides may even help to protect against heart disease by preventing the oxidation of LDL cholesterol, a known risk factor, especially for persons at risk for heart disease or with diabetes.
The extracted fresh and dried fruits is processed into a powder comprised of at least 80 percent mogrosides, the primary of which is mogroside-5, the sweetest and most potent. The powder dissolves in water with no sediment, is stable and the taste is unaffected by cooking, making it an ideal natural replacement for artificial sweeteners in beverages, baked goods, special diet foods or any low-calorie application.
We often hear of "miracle" foods and other trendy ingredients in the fad-filled world of nutrition and health. Luo Han Guo is one up-and-coming ingredient that could just merit every bit of the sweet talk surrounding it.