The presence of aβ-hydroxyl group at C-11 of the aglycone is essential for the sweetness, whereas glycosides with an 11-keto group (e.g., 11-oxomogroside) are bitter. Moreover, mogrosides with fewer than three glycosyl units have not been found to be sweet. Mogroside V, the most abundant sweet constituent, was found in a sample of whole fruits at levels of 0.8-1.3 % w/w