Luo han guo (siraitia grosvenorii or luo han guo) is a herbaceous perennial vine of the Cucurbitaceae (gourd) family, native to southern China and northern Thailand. This fruit, which is about the size of an orange or large lemon, has a thin brown hard shell that holds multiple seeds, the plant is cultivated for its fruit, whose extract is nearly 300 times sweeter than sugar and has been used in China as a low-calorie sweetener for cooling drinks and in traditional Chinese medicine.
The sweet taste of the fruit comes mainly from mogrosides, a group of triterpene glycosides that make up about 1% of the flesh of the fresh fruit. Through solvent extraction, a powder containing 80% mogrosides can be obtained, the main one being mogroside-5 (esgoside). Other similar agents in the fruit are siamenoside and neomogroside.
Arguably, luo han guo fruit extract is popular nowadays as a natural zero-calorie sweetener. Luo han guo processors typically extract the natural sweetener from the fruit by crushing it and infusing it with water. While the extract is around 300 times sweeter than table sugar, it has zero calories and carbohydrates.