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Stevia: Non caloric natural sweetener
Abstract
Stevia rebaudiana Bertoni is a herbaceous perennial shrub native to the highlands of Paraguay and sections of Argentina and Brazil that are situated along the 25th Degree Line, South Latitude. It is widely diffused now in many parts of the world. Stevia leaves have been used for centuries by the Guarani Tribe of Paraguay, the Mestizos, and by other natives, that refer to Stevia as Caá-hê-é. They have used the herb to sweeten their bitter beverages (matè for example) since pre-Columbian times. Its use is nowadays approved in many countries, e.g. Brasil, Argentina, China, Japan. Stevia Rebaudiana contains six diterpenic glycosides that exhibit an intense sweet taste, the most importants being the Stevioside and Rebaudioside A, both about three hundred and four hundred times sweeter than saccharose, respectively. Minor components identified are Rebaudioside C, Dulcoside A, Rebaudioside E and Rebaudioside D. This work describes a new extraction procedure and the characterization of the Steviosides from leaves of the Stevia Rebaudiana and its possible use as non caloric natural sweetener in food preparations.
... Stevia rebaudiana Bertoni is a herbaceous perennial shrub native to the highlands of Paraguay and sections of Argentina and Brazil. The leaves of this plant are used by humans because they exhibit an intensely sweet taste due to diterpenic glycosides such as stevioside and rebaudioside A. Stevioside and rebaudioside A are approximately three hundred and four hundred times sweeter than saccharose, respectively (Santini et al., 2008). As described in a review by Soni et al. (2007), due to the pharmacological importance of S. rebaudiana and its specific chemical composition, many studies have focussed on different topics associated with this plant, such as methods for its in vitro cultivation (Sivaram and Mukundan, 2003;Hwang, 2006;Debnath, 2008;Patel and Shah, 2009); the chemical composition and therapeutic actions of both its crude extracts and isolated compounds (Chatsudthipong and Muanprasat, 2009); its biotechnological modification; and evaluations in the formulation of foods. ...
... As described in a review by Soni et al. (2007), due to the pharmacological importance of S. rebaudiana and its specific chemical composition, many studies have focussed on different topics associated with this plant, such as methods for its in vitro cultivation (Sivaram and Mukundan, 2003;Hwang, 2006;Debnath, 2008;Patel and Shah, 2009); the chemical composition and therapeutic actions of both its crude extracts and isolated compounds (Chatsudthipong and Muanprasat, 2009); its biotechnological modification; and evaluations in the formulation of foods. Recent studies have described new extraction procedures for the characterisation of steviosides from the leaves of S. rebaudiana and their possible use as a non-caloric natural sweetener in food preparations (Santini et al., 2008;Carakostas et al., 2008;Abdel-Salam et al., 2009). ...
Native polyacrylamide gel electrophoresis was used in the current study to identify polymorphisms in α- and β-esterase loci in the leaves of Stevia rebaudiana Bert. Bertoni. The esterases produced from the Est-2 and Est-4 loci were observed as strongly stained bands, and four alleles were detected at each of these loci from the 428 analysed S. rebaudiana plants. The observed and expected mean heterozygosity were higher in populations maintained by genetically breeding plants for higher glycoside production than in plant populations propagated by seeds or maintained by vegetative propagation. The esterase analysis employed in this study showed that the artificial selection of plant samples with specific uniform characteristics, such increased height and precocious flowering, may lead to the fixation of alleles and α/β-esterase phenotype patterns in S. rebaudiana populations. The uniform α/β-esterase phenotype may be applied in the monitoring of genetic stability in selected populations for specific traits of interest.
... Steviol glycoside (SG) sweeteners are extracted and purified from the stevia plant (Stevia rebaudiana Bertoni) of the Compositae family, native to South America, where it has been used as a sweetener for a long time. Stevia rebaudiana contains SGs such as stevioside (St), rebaudioside (Rb) A, B, C, D and E, dulcoside A and steviol biosides [2][3][4][5][6]. The flavor of rebaudioside A has been described as bitter, metallic, and astringent, with an unnaturally sweet aftertaste compared to 5% sucrose, which exhibits a high sweetness intensity [7]. ...
Lighting conditions are an important controller of plant growth and development, and they affect secondary metabolite synthesis. In this research, we explored the effect of additional UV irradiation of various ranges in addition to the main one at PPFD 160 µmol m⁻² s⁻¹ on the accumulation of some secondary metabolites of stevia (Stevia rebaudiana Bertoni). The fresh weight of leaves was slightly higher under additional UV-A and UV-B irradiation compared with the control variant, and the leaf surface area was significantly larger, respectively, by 23.3 and 20.7% than in the control variant, while the rate of photosynthesis did not decrease. Plants under additional UV-B and UV-C irradiation were under the greatest light stress, as evidenced by a decrease in antioxidant capacity by an average of 30% compared to the control and UV-A. The total flavonoid content was significantly higher (by 74%) under UV-B irradiation. The highest concentration of steviol glycoside was observed during budding and flowering under UV-B and UV-C irradiation (by 13.2 and 11.3%, respectively). Analysis of hyperspectral images, chlorophyll fluorescence, and vegetation indices showed light stress increasing under UV-C irradiation, which caused an increase in the relative chlorophyll content, scorches, leaf morphology changes, a CO2 absorption rate decrease, and plant growth inhibition. UV-B irradiation can be used as an optimal type of irradiation based on a set of indicators.
... Many countries like Thailand, Chine, Indonesia, Malaysia and Brazil grow stevia commercially for the production of sugars by various names such as rebiana, purevia and truvia commercially available in the market. Principle natural sweeteners present in S. rebaudiana are stevioside and rebaudiosides A, B, C, D, and E; dulcoside A; and steviolbioside which are synthesized in the leaves (Santini, Ferrara, Naviglio, Aragòn, & Ritieni, 2008). Amongst all stevioside is the major sweetener which gives a slightly bitter aftertaste however, it is about 250-300 times sweeter compared to sucrose. ...
Stevia leaves have been claimed to possess the highest antioxidant capacity among botanic foods, yet the antioxidant activity has been attributed to the polyphenols from Stevia leaves (PPS). However, most studies about the PPS were based on Stevia extracts that contain abundant polyphenols and flavonoids. The PPS excluded flavonoids were found to possess antioxidant activity similar to that of epigallocatechin gallate, demonstrating stronger hydrophilic antioxidant activity and stability than that of ascorbic acid (VC), vitamin E or chlorogenic acid under the assayed circumstances. Both of the PPS and their antioxidant activity are very stable in various physical environments, but less stable in the presence of potassium sorbate or sucrose. Moreover, the combination of PPS and VC could increase the antioxidant stability of either VC or PPS. Therefore, the PPS have the potential to be a natural, inexpensive and abundant antioxidant that can be utilizein the pharmaceutical and cosmetics.
The amount of the sweetener stevioside in leaves of Stevia rebaudiana (Bertoni) Bertoni was investigated with regard to the morphological characteristics of plants grown in the Minga Guazu region of East Paraguay. Seedlings were taken from the region of Yby Ya'u (northeastern Paraguay) which is considered one of the most productive areas of the country. The quantitative determination of stevioside was carried out on dried leaves from plants of 16 different plots, using a new analytical method based on an HPLC/ELSD (Evaporative Light Scattering Detector) coupled system. The average levels of stevioside varied from 43.6 to 98.9 g kg(-1). The results indicate that environmental and agronomic factors have more influence on stevioside production than the growth habit.
Aims Stevioside is a natural plant glycoside isolated from the plant Stevia rebaudiana which has been commercialized as a sweetener in Japan for more than 20 years. Previous animal studies have shown that stevioside has an antihypertensive effect. This study was to designed to evaluate the effect of stevioside in human hypertension.
Methods A multicentre, randomized, double-blind, placebo-controlled study was undertaken. This study group consisted of 106 Chinese hypertensive subjects with diastolic blood pressure between 95 and 110 mmHg and ages ranging from 28 to 75 years with 60 subjects (men 34, women 26; mean ± s.d., 54.1 ± 3.8 years) allocated to active treatment and 46 (men 19, women 27; mean ± s.d., 53.7 ± 4.1 years) to placebo treatment. Each subject was given capsules containing stevioside (250 mg) or placebo thrice daily and followed-up at monthly intervals for 1 year.
Results After 3 months, the systolic and diastolic blood pressure of the stevioside group decreased significantly (systolic: 166.0 ± 9.4–152.6 ± 6.8 mmHg; diastolic: 104.7 ± 5.2–90.3 ± 3.6 mmHg, P < 0.05), and the effect persisted during the whole year. Blood biochemistry parameters including lipid and glucose showed no significant changes. No significant adverse effect was observed and quality of life assessment showed no deterioration.
Conclusions This study shows that oral stevioside is a well tolerated and effective modality that may be considered as an alternative or supplementary therapy for patients with hypertension.
Stevioside, a diterpene glucoside from Stevia rebaudiana, belongs to the strongest natural sweeteners. Its potential widespread use requires an easy and accurate analytical method. A simple method for stevioside analysis based on the water extraction, hydrophobic chromatography (Sep-Pak C18cartridges) and HPLC using linear gradient of acetonitrile in water is described. The feasibility of this procedure was tested analyzing the stevioside level in Stevia leaves as well as in tea “Fruit tea with Stevia”. Stevioside content did not show statistically significant difference when a set of 20 tea bags randomly chosen from five boxes was determined (P<0.01). The mean value of stevioside content in fruit tea with Stevia was 8.14±2.71 mg/mL. The described method proved to be fast and friendly to the environment by minimization of organic solvent consumption.
Anti-human rotavirus (HRV) activity of hot water extracts from Stevia rebaudiana (SE) was examined. SE inhibited the replication of all four serotypes of HRV in vitro. This inhibitory effect of SE was not reduced on the prior exposure of SE to HCl for 30 min at pH 2. Binding assay with radiolabeled purified viruses indicated that the inhibitory mechanism of SE is the blockade of virus binding. The SE inhibited the binding of anti-VP7 monoclonal antibody to HRV-infected MA104 cells. The inhibitory components of SE were found to be heterogeneous anionic polysaccharides with different ion charges. The component analyses suggested that the purified fraction named as Stevian with the highest inhibitory activity consists of the anionic polysaccharide with molecular weight of 9800, and contains Ser and Ala as amino acids. Analyses of sugar residues suggest uronic acid(s) as sugar components. It did not contain amino and neutral sugars and sulfate residues. These findings suggest that SE may bind to 37 kD VP7 and interfere with the binding of VP7 to the cellular receptors by steric hindrance, which results in the blockade of the virus attachment to cells.
A sugar profile study of wheat-based, rice-based and oats infant cereals was conducted to determine changes produced during processing. Two extraction procedures were assayed. The fructose, glucose, sucrose, maltose, maltotriose, isomaltotriose and raffinose contents of the cereals were analysed by gas liquid chromatography. In untreated flours, sucrose was the main sugar; glucose, fructose, maltose and raffinose were also detected. During hydrolysis, there were increases in the maltose (2.1–7.6 g/100 g, depending on the sample), glucose and fructose contents and maltotriose and isomaltotriose were also increased. Roller-drying reduced the maltose content. Four commercial samples with rice or wheat were analysed: the sugar composition was 20 g/100 g sucrose and 3 g/100 g maltose. Other ingredients in the formulations were also analysed.
The natural sweetener stevioside, which is found in the plant Stevia rebaudiana Bertoni, has been used for many years in the treatment of diabetes among Indians in Paraguay and Brazil. However, the mechanism for the blood glucose-lowering effect remains unknown. To elucidate the impact of stevioside and its aglucon steviol on insulin release from normal mouse islets and the beta-cell line INS-1 were used. Both stevioside and steviol (1 nmol/L to 1 mmol/L) dose-dependently enhanced insulin secretion from incubated mouse islets in the presence of 16.7 mmol/L glucose (P < .05). The insulinotropic effects of stevioside and steviol were critically dependent on the prevailing glucose concentration, ie, stevioside (1 mmol/L) and steviol (1 micromol/L) only potentiated insulin secretion at or above 8.3 mmol/L glucose (P < .05). Interestingly, the insulinotropic effects of both stevioside and steviol were preserved in the absence of extracellular Ca2+. During perifusion of islets, stevioside (1 mmol/L) and steviol (1 micromol/L) had a long-lasting and apparently reversible insulinotropic effect in the presence of 16.7 mmol/L glucose (P < .05). To determine if stevioside and steviol act directly on beta cells, the effects on INS-1 cells were also investigated. Stevioside and steviol both potentiated insulin secretion from INS-1 cells (P < .05). Neither stevioside (1 to 100 micromol/L) nor steviol (10 nmol/L to 10 micromol/L) influenced the plasma membrane K+ adenosine triphosphate ((K+)ATP)-sensitive channel activity, nor did they alter cyclic adenosine monophosphate (cAMP) levels in islets. In conclusion, stevioside and steviol stimulate insulin secretion via a direct action on beta cells. The results indicate that the compounds may have a potential role as antihyperglycemic agents in the treatment of type 2 diabetes mellitus.