CHAPTER 1 INTRODUCTION 1.1 Backgroundof the Study. Steviaplants, is a genus from the Asteraceae family, whereby it is a plant that ismostly related to the sunflower family. Specifically, Stevia rebaudiana (Bertoni) is a species of plant that produces naturalsweeteners that are natively growing in Paraguay by the Guarani Indians (Ahmedet al.
, 2011). It was widely used by the natives to sweeten foods or medicinalpurposes for centuries (Mishra et al., 2010). S. rebaudiana has many names, the native Guarani Indians used tocall it as “ka’a he’e” (sweet herb), as for the common names are ‘candy leaf’sweet leaf’ or ‘sugarleaf’.
Morphologyof S. rebaudiana is that the leavesare green and grows in pairs, the flowers produced are normally white in color.The shoots tend to be softer at the beginning but becomes harder as time passes. S. rebaudiana produces roots that aresuperficial and the seeds are small with black and brown color and it eventuallyturns black as it matures. Usually the seeds are not viable and it ispollinated through insects or hermaphrodite in nature. Stevia rebaudiana,is said to have phytochemical compounds that allows the control of certainhealth issues.
Native Guarani Indians believed that stevia allowed them to havemuch softer skin, healthier digestive system, control the blood sugar levels,and also certain healing purposes. These days, people believe that stevia helpsmaintain sugar levels in blood as well as control blood pressure and lowercholesterol levels. Researches have proven that stevia does not have caloriesand is recommended to be used by diabetic patients. The properties in the leafis said to be approximately 150-300 times sweeter than conventional sugar. Steviarebaudiana was indigenous to the northern part of Americas and eventually dueto the sweetening property of the plant it has been widely cultivated. It arrivedin the Asia region since 1984 and since then have been cultivated at Korea,Thailand, Philippines, Indonesia as well as Malaysia.
It could be also found inColombia, Uruguay and Israel to say the least. Stevia plant enjoys humid andmoist climate. The best areas to cultivate stevia is around the equatorregions. Thewhole plant of stevia does not produce the sweet property. Since the commonname is ‘sweet leaf’ hence, the sweetening property arises from the leaf. Thedesired component in the leaf is called ‘Stevioside’ or ‘Steviol glycosides’.Rebaudioside C, dulcoside, and rebaudioside A is present in the leaves of wildlygrown S.