Natural Non-caloric Sweetener Research Articles

Protein rational design and modification of erythrose reductase for the improvement of erythritol production in Yarrowia lipolytica.

Erythritol is a natural non-caloric sweetener, which is produced by fermentation and extensively applied in food, medicine and chemical industries. The final step of the erythritol synthesis pathway is involved in erythritol reductase, whose activity and NADPH-dependent become the limiting node of erythritol production efficiency. Herein, we implemented a strategy combining molecular docking and thermal stability screening to construct an ER mutant library. And we successfully obtained a double mutant ERK26N/V295M (ER*) whose catalytic activity was 1.48 times that of wild-type ER. Through structural analysis and MD analysis, we found that the catalytic pocket and the enzyme stability of ER* were both improved. We overexpressed ER* in the engineered strain ΔKU70 to obtain the strain YLE-1. YLE-1 can produce 39.47 g/L of erythritol within 144 h, representing a 35% increase compared to the unmodified strain, and a 10% increase compared to the strain overexpressing wild-type ER. Considering the essentiality of NADPH supply, we further co-expressed ER* with two genes from the oxidative phase of PPP, ZWF1 and GND1. This resulted in the construction of YLE-3, which exhibited a significant increase in production, producing 47.85 g/L of erythritol within 144 h, representing a 63.90% increase compared to the original chassis strain. The productivity and the yield of the engineered strain YLE-3 were 0.33 g/L/h and 0.48 g/g glycerol, respectively. This work provided an ER mutation with excellent performance, and also proved the importance of cofactors in the process of erythritol synthesis, which will promote the industrial production of erythritol by metabolic engineering of Y. lipolytica.

Pharmacokinetic Analysis of Ethanol in a Human Study: New Modification of Mathematic Model.

In the pharmacokinetic analysis of ethanol after oral administration, only single- or two-compartment models are used, but their precision in estimating pharmacokinetic parameters might be insufficient. In a recent study, pharmacokinetic analysis using a modified Norberg three-compartment model was performed after oral administration of differently sweetened alcoholic solutions and compared to pharmacokinetic analysis using the classic Widmark model. On three occasions, eight male volunteers consumed differently sweetened alcoholic solutions: non-sweetened, sweetened with sucrose, and sweetened with steviol glycoside. Blood ethanol concentration was determined from samples obtained at t = 15, 30, 60, 90, 120, 180 min after consumption. Pharmacokinetic analysis was performed model independently, using the classic Widmarks model and using the modified Norberg model. Results showed that estimated pharmacokinetic parameters depend on the type of model used. The classic Widmark model in particular overestimated the fraction of absorbed ethanol from the gastrointestinal system to systemic circulation. Furthermore, the type of sweetener also affected pharmacokinetic parameters, although the difference was not statistically significant. In conclusion, the novel pharmacokinetic model, while being more physiological, fits experimental data better and hence is more suitable for modelling real-life alcohol consumption. In addition, the effect of natural non-caloric sweetener steviol glycoside on ethanol pharmacokinetics, analysed for the first time in the current research, might be different when compared to the common-used sweetener sucrose.

Lignocellulose-Derived Arabinose for Energy and Chemicals Synthesis through Microbial Cell Factories: A Review

The exploration of natural substrates for microbial conversion to synthesize industrial platform and fuel chemicals seems to be inevitable within a circular bioeconomy context. Hemicellulose is a natural carbohydrate polymer consisting of a variety of pentose (C5) sugar monomers such as arabinose, mannose, erythrose, and xylose. Among the C5 sugars, L-arabinose (L-Ara) is the second-most-abundant pentose sugar in the lignocellulosic biomass after xylose. L-Ara has been used as an industrial carbon source to produce several value-added chemicals such as putrescine, which is used to synthesize polymers in the textile industry; sugar alcohols that are used as sweeteners in diet foods; and amino acids such as L-lysine, L-glutamate, L-arginine, and L-ornithine, which are used in nutritional supplements, fertilizers, and other products in the food and beverage industries. L-Ara, a natural non-caloric sweetener, is used as a substitute in the food and beverage industry, when the risk of blood sugar and lipid levels could be reduced. Major use of L-Ara is also found in the medical and pharmaceutical sectors to treat several conditions, including mineral absorption disorder, constipation, and diabetes, among others. In recent years, there has been a rising interest in synthesizing various sugar alcohols and derivatives, including arabitol, xylitol, and 2,3-butanediol, through the modification of producer organisms either genetically or metabolically to produce value-added products. Understanding the current demand and the need to increase the diversified production of industrial green chemicals with the reduced waste of useful lignocellulosic resources, this review focuses on the background of L-Ara and its various sources, microbes that utilize L-Ara to produce high-value-added products, and the future prospects for strain improvements to increase the yield of high-value-added products.

The Content of Phenolic Compounds in Stevia rebaudiana (Bertoni) Plants Derived from Melatonin and NaCl Treated Seeds.

Stevia is a plant with many beneficial properties. It contains not only steviol glycosides, which are used as non-caloric natural sweeteners, but also a number of metabolites with antioxidant properties. This study examined the content of both phenolic acids and flavonoids in stevia leaves as an effect of treating seeds with melatonin and conducting germination in NaCl conditions. The results of our research indicated higher amounts of phenolic acids compared to flavonoids in stevia leaves. Among these acids, isochlorogenic, rosmarinic, and chlorogenic acids were accumulated in the largest amounts, regardless of the germination conditions. For 5 and 100 µM of melatonin treatments, the content of both phenolic acids and flavonoids increased. However, in salinity conditions (50 mM NaCl), 500 µM of melatonin had the most favorable effect on the synthesis of phenolic acids. The phenolic acids in that case reached a level three-times higher than that in the samples with the same melatonin concentration but without NaCl. We also found that the content of phenolic compounds varied depending on the age of the leaves. To the best of our knowledge, this is the first study to describe the effect of melatonin and NaCl on the synthesis on phenolic acids and flavonoids in stevia.

The Effect of Steviol Glycosides on Sensory Properties and Acceptability of Ice Cream.

There has been a challenge in overcoming the bitter aftertaste of stevia, a natural non-caloric sweetener. Recent research focuses on investigating various types of steviol glycosides, the sweet compounds in stevia leaves, as they exhibit different sensory characteristics. This study determined the sensory properties and acceptability of ice cream sweetened solely with three steviol glycosides, rebaudioside (Reb) A, D, and M (0.09% w/v), using sucrose-sweetened ice cream as a control (14% w/v). Ice cream consumers (n = 92) rated their overall liking, attribute liking, and sweetness and bitterness intensities and described the aftertastes of each sample using check-all-that-apply. The liking scores of Reb D- and M-sweetened ice creams were significantly higher than those of Reb A-sweetened ice cream. Among the three glycosides, only Reb M showed a sweetness intensity comparable with that of sucrose. Consumers perceived the aftertastes of Reb D and M ice creams as being more sweet, pleasant, creamy, and milky, while Reb A was more artificial and chemical. Reb D and M ice creams were also plotted close to sucrose in the correspondence analysis graph, meaning that their aftertaste characteristics were similar to those of sucrose. The present study clearly highlights that Reb D and M have better tastes and provide better perceptions to consumers than Reb A, which is the most widely used glycoside in food industry.

Formulation, Senso-chemical Analysis and Shelf-life Study of Biscuits using Stevia Leaf as the Substitute for Sugar

Background: Biscuits are the most popular cereal-based bakery and sugar is an important element of biscuits which provides unique taste, color and texture. However, the consumption of sugar is linked to potential health risks. Therefore, there is a scope to substitute sugar with natural non-caloric sweetener, maintaining all sensory and storage qualities of the biscuits. Methods: The present study was conducted to find an acceptable formulation to manufacture biscuits using stevia leaf. Dried leaf powder and fresh juice were used as a substitute for sugar in biscuit manufacturing. After baking, biscuits were tested for sensory qualities. In addition, biscuits were packaged with different packaging materials and organoleptic changes were assessed. Result: Biscuits made with 18 g stevia powder and 55 ml stevia juice per kg of flour showed the best results comparing all aspects of consumer preferences. The organoleptic and microbiological evaluations of stevia powder biscuit and stevia juice biscuit showed no significant changes and unsafe measures for one month of storage in glass, plastic jar and tin can. Therefore, sugar-free biscuits can be made following either stevia powder biscuit or stevia juice biscuit formulations and stored in either glass, plastic jar, or in tin can to remain safe for human consumption.

Mutation of Stevia glycosyltransferase UGT76G1 for efficient biotransformation of rebaudioside E into rebaudioside M

Rebaudioside M (RebM) is a desired natural non-caloric and high potency sweetener with very low content in the leaves of Stevia rebaudiana. In this study, based on the crystal structure of UDP-dependent glycosyltransferase UGT76G1, a key enzyme responsible for RebM production in S. rebaudiana, a computational strategy combining protein structure, molecular docking, and single-point saturation mutation was adopted to engineer UGT76G1 to promote the transformation of rebaudioside E (RebE) into RebM via a two-step continuous glycosylation. An S195Q mutant was verified to have better performance, with a catalytic efficiency 1.2-fold higher towards RebE and 2-fold higher towards rebaudioside D (RebD) than wild-type UGT76G1. RebM (12.8 ± 0.6 g/L) and RebD (10.5 ± 0.1 g/L) were generated from RebE (20 g/L) catalyzed by the S195Q mutant coupling with a sucrose synthase from Micractinium conductrix at 40 °C for 32 h. This work would expand the application of structure-based enzyme design for glycosyltransferase engineering.

Synthesis and characteristics of a rebaudioside-A like compound as a potential non-caloric natural sweetener by Leuconostoc kimchii dextransucrase

Stevioside (ST) is currently considered as a highly-demanded natural and zero-caloric replacer of sucrose with several health-promoting properties. Nonetheless, its bitter aftertaste limits its use in the food industry. Herein, glucosyl steviosides were synthesized using primarily a food-grade lactic acid bacteria, Leuconostoc kimchii dextransucrase and conversion yield (%) was 40.3%. A glucose moiety was transferred stereo-selectively to ST by α-1,6-linkage and this is the first report about obtaining rebaudioside A (Reb-A) like glucosyl stevioside-2 (STG-2). Glucosyl steviosides revealed greatly improved stability up to 120 °C and remained stable over 32.1% and 58.12% in the pH (1.4) compared with 30.55% of ST. Moreover, the glucosylated steviosides improved the stability, reaching 95% after 30 days and Reb-A like compound (STG-2) especially exhibited higher stability in commercial beverages. Furthermore, the glucosyl steviosides showed over 1.92- and 2.24-fold decreases than that of enzymatically modified ST in the glucose generation rate test.

Stevia rebaudiana LEAF EXTRACT REDUCES BLOOD GLUCOSE AND VISCERAL FAT ACCUMULATION IN ALLOXAN-INDUCED DIABETIC MICE

Diabetes is a major global epidemic currently affecting millions of people. Unfortunately, the present pharmacological approach for the management of this serious disease has still a lot of rooms for improvement and innovation, which behooves the exploration of newer and safer agents. S. rebaudiana has emerged as a natural non-caloric sweetener and it is reported to have several health benefits including its antidiabetic effects. Thus, an in-depth investigation of this plant is needed in order to elucidate further its antidiabetic properties and its influence on the histological integrity of the major organs involved in carbohydrate metabolism. Inbred ICR mice (n=36) were randomly into six groups – one group served as the negative control while other five groups were given intraperitoneally with alloxan to induce diabetes and divided into the following groups: positive control (untreated group), glibenclamide (0.2mg/20g) treated, and 100%, 60%, and 10% stevia leaf extract treated, respectively. The experiment was conducted for two weeks where the treatments were orally given once a day and the following were evaluated: changes in body weight, fasting blood sugar (fBGL), oral glucose tolerance test (OGTT), and gross and microscopic changes in the pancreas, liver, and kidney. Results showed that though stevia has no effect on the reduction of body weight, the different concentrations have comparable effects with glibenclamide in fBGL and OGTT. Furthermore, the different concentrations of stevia leaf extracts showed lesser visceral fat accumulation grossly, and lesser cellular degradation, microscopically.

Elicitor-induced in vitro shoot multiplication and steviol glycosides production in Stevia rebaudiana

Stevia rebaudiana, which produces the non-caloric natural sweeteners referred to as steviol glycosides (SGs), is a perennial herb native to South America. This study examines the effect of various biotic elicitors, including chitosan (CH) and yeast extract (YE), as well one abiotic elicitor, namely methyl jasmonate (MeJA), on in vitro shoot multiplication and the SGs content of S. rebaudiana. Different concentrations of these elicitors (50, 100, 200, and 300 mg/L) were added to Murashige and Skoog medium that had been supplemented with 2 mg/L 6-benzylaminopurine (BAP). The results showed that both biotic and abiotic elicitors increase shoot multiplication significantly when compared to the basal medium alone. Shoot length and shoot number increased by 70% and 94%, respectively, after adding 200 mg/L CH. Dry weight increased by 51%, 47%, and 36% after adding YE 50, CH 200, and MeJA 100 mg/L, respectively. Interestingly, total SGs content increased with the addition of MeJA 100, CH 200, and YE 50 (by 60%, 44%, and 40%, respectively). Stevioside (ST) and rebaudioside A (Reb A) concentrations, which are the final products of the SGs pathway, were both augmented by the addition of MeJA 100 and CH 200 mg/L. Moreover, these elicitors significantly enhanced the Reb A/ST ratio. Overall, the results indicate that elicitors— CH 200, MeJA 100, and YE 50 mg/L, in particular— can be effective stimulants for the production of biomass and the chemical composition of SGs content of in vitro S. rebaudiana.

Prediction of the sweetening effect of Siraitia grosvenorii (luo han guo) fruits by two-dimensional quantitative NMR

During the last decade, dried fruits of Siraitia grosvenorii (luo han guo), also known as monk fruit, have become popular food ingredients. Luo han guo extracts, which are promoted as non-caloric natural sweeteners, are now incorporated into dietary supplements, soft drinks, and energy shakes. The compounds responsible for the sweetening effect are glycosylated cucurbitane-type triterpenoids, the so-called mogrosides. However, of the more than 40 known mogroside compounds, only 11-α-hydroxy-mogrosides exhibit a sweetening effect, whereas the other triterpenoids are non- or bitter-tasting. We have used two-dimensional quantitative NMR to determine selectively the content of 11-α-hydroxy-mogrosides in these dried fruits and thus to predict their sweetening potential. Homonuclear (H,H COSY) and heteronuclear (HSQC) methods were developed, validated, and compared. Both techniques were found suitable for the quality control of luo han guo fruits and extracts, the COSY experiment being advantageous with regard to accuracy, precision, and limit of quantification.

Foliar fertilization with micronutrients improves Stevia rebaudiana tolerance to salinity stress by improving root characteristics

Stevia (Stevia rebaudiana Bertoni), a perennial crop of the family Asteraceae, is one of the most important sources of non-caloric natural sweeteners, but research on the impact of salinity on root parameters and steviol glycoside content is limited or does not exist. The objective of this study was to assess the effect of exogenous application of iron (Fe), boron (B), and selenium (Se) on root characteristics, growth, and yield of stevia under four levels of NaCl salinity (i.e., 0, 30, 60, and 90 mM). Root length (RL), root volume (RV), root area (RA), and root fresh and dry weight (RFW and RDW) were significantly decreased with increasing salinity. The highest values of all the above root traits were observed with foliar spraying B plus Se plus Fe. Foliar spraying B plus Se plus Fe resulted in 2.9 times greater RV and 2.8 times greater RFW than control. Furthermore, salinity significantly decreased plant height, branches number, leaves number, and biomass yield of stevia. However, foliar application of micronutrients, especially B and Se, reduced those adverse effects. Moreover, salinity decreased the relative water content (RWC) and increased relative water loss (RWL) in stevia tissues. The highest RWC and the lowest RWL were observed in foliar application of B plus Se. Foliar spraying of nutrients significantly improved root characteristics and water status of salt-stressed stevia plants, which in turn (i) helped plants to tolerate excessive Na levels and (ii) improved nutrient uptake under salinity stress. In light of the above, foliar treatment of stevia plants with micronutrients for improving growth under saline conditions could be considered, but toward that direction, studies under field conditions would be required to quantify the efficiency of these micronutrients in foliar applications.

Elimination of bitter-off taste of stevioside through structure modification and computational interventions

Stevioside is a natural non-caloric sweetener obtained from Stevia rebaudiana Bertoni plant. The major challenge in the commercialization of stevioside as a natural sweetener is its bitter-off taste. In this study, we prepared molecular models of potential taste receptors of stevioside, both sweet and bitter. With appropriate modifications on the stevioside backbone, we performed molecular docking of prepared ligands with both sweet and bitter taste receptors. Based on binding energy, we found that one of the potential substituents, Kamiya-8, shows a good affinity towards sweet taste and a weak affinity for bitter receptors. Further, we selected Kamiya-8 for molecular dynamics simulations to improve the prediction of binding energy and to check the binding strength of Kamiya-8 with taste receptors. Moreover, we also performed MM-PBSA calculation for calculating the end state free energies of molecules in solvent and found that Kamiya-8 gives a 2-fold effect as it interacts with sweet receptors (T1R2, T1R3) with lowest binding energy conformation (−285.265 kcal/mol, −571.481 kcal/mol). Secondly, it gives high binding energy (–273.319 kcal/mol, −355.500 kcal/mol) with bitter taste receptors (T2R4, T2R14) as compared to stevioside. Based on this study, we found that Kamiya-8 can be the potential substituent that can improve the palatability of stevioside.

Difference between natural and artificial sweeteners: Histopathological studies on male albino rat’s brain (hippocampus)

The present work is a trial to compare effect of short and long term administrations of sucrose as a natural widely used sweetener, aspartame as a synthetic non-caloric sweetener and stevia as a novel natural non-caloric sweetener on rats' brain hippocampus. This was achieved using 64 male albino rats. Rats were divided into four groups. The first group served as control group receiving distilled water. The second group represented the sucrose group receiving 10% sucrose solution (weight /volume). The third group served as aspartame group receiving aspartame (75 mg/kg body weight /day).The fourth group represented the stevia group and received (40 mg/kg body weight/day).Animals received different experimental treatments by oral gavage and they were dissected after a short duration of 30 days and long experimental duration of 90 days. Histological investigation of hippocampal sections of hippocampus revealed neuronal degeneration with pyknotic nuclei, dilatation and congestion in blood vessels and spongiform changes in the neuropil after both sucrose and aspartame treatments. On the other hand, stevia treatment to rats showed near to normal pattern of the granular and the neuropil. Histochemical, stained sections of Bromophenol blue stain to hippocampal tissue recorded significant decrease in protein content in hippocampus in sucrose group and aspartame groups respectively after 90 days compared with stevia and control rats. Staining hippocampus tissue of rats treated with sucrose or aspartame with Congo red stain revealed cellular homogenous pink deposits of amyloid throughout the hippocampus tissue. This was decreased and observed as limited or few amyloid depositions in stevia group compared to controls. In conclusion, Stevia, a non-calorific sweetener, is a better alternative to the synthetic sweetener aspartame because stevia has the potential to assist individuals in regulating their weights without any recognized side effects on hippocampus tissue besides its health benefits as a natural antioxidant.

Effects of N-Methyl-N-Nitrosourea on Seed Germination of Stevia rebaudiana

Stevia rebaudiana is a unique plant that contains non-caloric natural sweetener and has gained much interest among Malaysians. In this study, the effect of different concentrations of N‑methyl-N-nitrosourea (MNU) was assessed in inducing mutation in Stevia seeds to produce genetic variations, which is valuable for crop improvement. Stevia seeds were soaked in six concentrations of MNU (0.0, 0.13, 0.25, 0.38, 0.50, and 1.00 mM) for four different durations (15, 30, 45, and 60 min) at room temperature. As a result, application of MNU reduced the germination percentage and germination rate of Stevia seeds as compared to the control group. Prolonged exposure to the highest concentration of MNU recorded the lowest percentage of germination (2.5 ± 1.4%) and the lowest germination rate (0.21 ± 0.16). Tricots were observed among seedlings treated with 0.13, 0.38 and 1.0 mM of MNU for 30 min. Presence of seedlings with albino colour proved the mutagenic effect of MNU on Stevia genome. Based on the percentage of seedlings with chlorophyll mutation, the most effective and efficient mutagenic treatment to induce mutation was 60 min in 0.25 mM of MNU.

Assessment of steviol on pro-inflammatory cytokines release in human CD14+ cells

Steviol is a major metabolite of stevioside which is a natural noncaloric sweetener. The aim of this present study was to investigate an inhibitory activity of steviol on pro-inflammatory cytokines release from lipopolysaccharide (LPS)-stimulated human CD14+ cells. CD14+ cells were incubated with different concentrations of steviol in the absence or presence of LPS. TNF-α, IL-1β and IL-6 level were determined by using human enzyme-linked immunosorbent assay (ELISA) kits. Steviol at the concentration of 1-100 µM significantly inhibit (P<0.05) the release of TNF-α (966.0+66.0, 906.3+36.7 and 659.3+52.3 vs 1190.3+75.5 pg/ml) and IL-1β (2834.0+67.2, 2440.0+70.5 and 2181.3+143.3 vs 3226.7+106.6 pg/ml) in a dose dependent manner when compared to LPS-treated CD14+ cells. While the inhibition of IL-6 (P<0.05) was found at 10 µM and 100 µM (2171.7+44.3 and 1902.3+58.0 vs 2580.3+105.2 pg/ml). In conclusion, steviol, a major metabolite of stevioside, possess an anti-inflammatory activity in human CD14+ cell.

Consumer acceptance of natural sweeteners in protein beverages

Protein beverage consumption by Americans has increased in recent years. Coupled with this increased consumption is an interest in natural sweeteners. The objective of this study was to evaluate the sensory properties of naturally sweetened ready-to-mix (RTM) whey protein beverages using 3 temporal methods and to formulate a natural noncaloric sweetener blend that could be added to RTM protein beverages to provide sweetness while still appealing in flavor to consumers. Iso-sweet concentrations of sweeteners (sucralose, sucrose, fructose, stevia, monk fruit) in RTM vanilla whey protein beverages (25 g of protein/360 mL of water) were established using magnitude estimation scaling and 2-alternative forced-choice testing. Temporal sensory profiling was then conducted on each beverage by a trained panel using time intensity, temporal dominance of sensations, and temporal check-all-that-apply. These findings were used to formulate natural sweetener blends that closely matched the temporality of sucrose-sweetened RTM vanilla protein beverages for consumer testing. One sugar-free blend (25% stevia/75% monk fruit) and 1 reduced-sugar blend (25% stevia/25% monk fruit/50% fructose) were selected for consumer testing (n = 150 consumers) in addition to 3 control RTM beverages containing sucralose, stevia, or monk fruit. Two distinct consumer clusters were identified. The label-conscious segment of consumers preferred beverages sweetened with natural blends when primed. The flavor-driven segment of consumers conceptually preferred naturally sweetened beverages but preferred sucralose-sweetened beverages when primed. An all-natural label claim was most preferred across all consumers. Application of these findings to commercially produced RTM protein beverages aids in the development of naturally sweetened protein beverages with reduced calories and desirable sensory properties and highlights the importance of label claims to consumers overall but to a label-conscious segment of consumers in particular.

Business Roundup

BUSINESS Business Roundup ShareShare onFacebookTwitterWechatLinked InRedditEmail C&EN, 2017, 95 (37), p 13September 18, 2017Cite this:C&EN 95, 37, 13AbstractSolvay will start producing polyetherketoneketone (PEKK) at its site in Augusta, Ga., next year to meet growing demand from the aerospace industry. The firm already makes polyetheretherketone (PEEK) and other high-end polymers at the facility. Clariant has formed a joint venture with Tiangang Auxiliary to make ultraviolet light stabilizers in China’s Hebei province. A multi-million-dollar facility, to come on-line in 2019, will meet demand for the stabilizers from China’s textile and auto industries. Bayer has sold 19 million shares in Covestro, its former materials and plastics business, for $1.4 billion. The sell-off reduces Bayer’s stake in Covestro by 9.4% to 31.5%. MycoTechnology, a food technology start-up based in Aurora, Colo., has raised $35 million from undisclosed investors in a second round of funding. The company’s organic, powdered mushroom mycelium product is used to block bitter flavors of foods, beverages, and natural noncaloric sweeteners. Oxis Energy, a British lithium-sulfur battery materialsView: PDF | Full Text HTML

El cultivo de stevia en Veracruz: ¿un proyecto de desarrollo?

El programa “Prospera”, política social mexicana de transferencias condicionadas, recientemente incluyó la estrategia de “inclusión productiva” como una forma de posibilitar a las beneficiarias la obtención de ingresos mediante proyectos productivos. En el caso de la región de Los Tuxtlas, esta iniciativa tomó forma en la promoción de huertos de stevia, una planta cuyos componentes tienen alto poder endulzante y grandes posibilidades de mercado, incluso a nivel internacional, al ser considerados como endulzantes naturales no calóricos e inocuos para la salud humana. En este estudio, fundamentado en el análisis de los medios de vida de las familias de las beneficiarias del proyecto y el registro de las prácticas de cultivo, procesado y comercialización de la stevia, se observó cómo la rentabilidad del proyecto y sus beneficios sociales potenciales se desvirtuaron cuando fue manejado con fines político-electorales y se dejó de lado el seguimiento de las prácticas productivas.

In Vitro Callus Induction and Growth of Stevia (Stevia rebaudiana Bertoni M.) with Difference Concentrations of PEG (Polyethylene Glycol) and Light Conditions

Stevia (Stevia rebaudiana Bert. M.) is known as a natural non-caloric sweetener. This plants contain glycoside such steviosida type, mainly on the leave contain sweetness level between 200-300 cane sugar but the calorie is very low. This research was aimed to determine difference effects of PEG (Polyethylene Glycol) concentrations and the light conditions on Stevia (Stevia rebaudiana Bert. M.) callus induction in vitro. This research was conducted from April to June 2016 at Biotechnology Laboratory Faculty of Agriculture, Sultan Ageng Tirtayasa University. This research used a completely randomized design (CRD), which consisted of two factors with three replications. Concentrations of PEG as first factor consisted of four levels (0 mg/L, 5 mg/L, 15 mg/L, and 25 mg/L). Light conditions as second factor consisted of two levels (Dark and Light). The results showed that the concentrations of PEG (Polyethylene Glycol) did not significantly effect the time of callus appearance and diameter of callus on 4, 5 and 6 weeks after planting. Dark condition was the best conditions for callus induction of stevia. The texture of callus was compact on all treatments and the callus dominant color produced is golden brown.