Steviol Glycosides Research Articles

Intervention mechanism of amphiphilic natural sweeteners on starch chain dynamic behavior: Computational and experimental insights

Amphiphilic natural sweeteners (i.e. steviol glycosides (STE) and glycyrrhizic acid (GA)) have been adopted to improve the quality of various starchy products, which can fundamentally be characterized as the intervention of the former in the chain dynamic behavior of the latter. However, these phenomena and related mechanisms still lack systematic insights. Herein, dual-temperature molecular dynamic simulations combined with experimental analysis were used to tandemly investigate the intervention of sweeteners in six types of chain dynamic behaviors that are strongly correlated with starch properties, including unwinding, movement, long/short-term reassociation, rearrangement, and depolymerization. The results show that STE and GA both promoted the chain unwinding and movement, and also retarded the chain short/long-term reassociation and rearrangement. Besides, GA exhibited a greater role than STE in facilitating chain unwinding and movement. Peculiarly, GA (0 %–40 % w/w) collaborated with starch to form a new microstructure, especially at high content (≥ 20 % w/w), which endowed starch with exceptionally high hardness (15.50 gf→189.36 gf) and hardening rate (2.72 gf/d→17.76 gf/d), and also placed a physical barrier to retard starch depolymerization (slowly digestible starch: 11.26 %→20.62 %). This work contributes data and theoretical support for the development of starch/amphiphilic natural sweetener composite matrices.

Scientific opinion on the extension of the authorisation of use of the food additive steviol glycosides (E 960a-d) and the modification of the acceptable daily intake (ADI) for steviol.

The EFSA Panel on Food Additive and Flavourings (FAF Panel) evaluated the safety of proposed changes to the currently permitted uses of the food additive steviol glycosides (E 960a-d) and of a proposed modification of the current acceptable daily intake (ADI) from 4 mg/kg body weight (bw) per day to 6 or 16 mg/kg bw per day, expressed as steviol equivalents. Currently, steviol glycosides (E 960a-d) are authorised in the EU in 32 different food categories (FCs). An extension of use was proposed for four new uses within FC 7.2 'Fine bakery wares'. In addition, an increase of the maximum permitted levels (MPLs) for FC 14.1.3 'Fruit nectars' and for three uses within FC 14.1.4 'Flavoured drinks' was requested. Consequently, the Panel updated the exposure estimates using the protocol for assessing exposure to sweeteners, developed to consider the specificities related to consumers' exposure to this functional class of food additives. Considering the proposed extension of use and increase of the MPLs, together with the currently authorised uses (at the MPLs) of E 960a-d, the highest 95th percentiles of exposure are 4.1 and 6.9 mg/kg bw per day for infants and toddlers, respectively. Based on the currently available absorption, distribution, metabolism and excretion (ADME) dataset for steviol glycosides (E 960a-d), the Panel concluded that that there is insufficient justification to increase the current ADI of 4 mg/kg bw per day, expressed as steviol equivalents. With respect to the proposed extension of use and increase of the MPLs, the Panel concluded that the calculated, conservative, dietary exposure would result in an increased exceedance of the ADI for toddlers at the 95th percentile.

Boosting Stevia's sweetness: Growth regulators mitigate salt stress and enhance steviol glycosides

Stevia rebaudiana Bertoni is a plant species with sweet-tasting leaves that can be used as a natural, low-calorie sweetener with potential health benefits. Salt stress can reduce plant growth and productivity, but the application of growth regulators like salicylic acid (SA), methyl jasmonate (MeJ), and spermidine (Spd) can manage various plant abiotic stresses and improve plant growth and productivity. In this work, we investigated the role of exogenous SA, MeJ, and Spd in conferring salt stress tolerance in Stevia by analyzing plant growth, chlorophyll (Chl), total phenolic, total carotenoid content, antioxidant defense system and steviol glycosides. The aim of a recent study was to assess the effects of these regulators on Stevia plants under both individual and combined salt stress conditions. Foliar application of these regulators improved plant growth under salt stress, with moderate salinity stress increasing glycoside compounds. SA was most effective in increasing rebaudioside A (Reb A), while MeJ + Spd combination was best for increasing stevioside (Stv) content. Individual applications of Spd, MeJ, and SA significantly impacted plant growth and antioxidant content, although their combined use was less effective. Spd application under salt stress yielded the highest increases in total carotenoid and Chl a content, while MeJ and Spd together significantly boosted Chl b content. The study found that SA enhanced superoxide dismutase (SOD) activity and reduced catalase (CAT) activity under salt stress, whereas MeJ alone increased both CAT and SOD activity. The distinct responses to Spd, SA, and MeJ suggest varied mechanisms in oxidative stress-induced antioxidant production. Overall, the use of these growth regulators can improve the growth, yield, and nutritional value of Stevia under salt stress, offering significant implications for agriculture and food security.

Dietary exposure to high-intensity sweeteners by the Brazilian self-declared diabetic population and general Brazilian population

Due to an increasing use of high-intensity sweeteners in foods and potential health implications of high levels exposure, the intake of high-intensity sweeteners present in the diet of the Brazilian population and the self-declared diabetic population, based on national consumption data from the 2017-2018 Family Budget Survey (POF), was estimated. The occurrence of the high-intensity sweeteners was established by labeling foods obtained in physical stores and online, in two scenarios: average and maximum concentration. Food consumption data were derived for the self-declared diabetic Brazilian population and the Brazilian population for average consumers and consumers only, stratified by: sex, age, habitation, and regions from Brazil. For consumers only of the general Brazilian population, the intake of sodium cyclamate, steviol glycosides, and sucralose exceeded the Acceptable Daily Intake (ADI), mainly in adolescents (131.3%, 117.2, 123.0% of respective ADI). The estimated intake for the diabetic population was below ADI in all scenarios calculated. The most exposed diabetic population to sodium cyclamate and sucralose were female (69.6% and 59.4% of respective ADI) and the elderly (79.2% and 70.1% of respective ADI). The Brazilian population, mainly high consumers, was more exposed to high-intensity sweeteners than the self-declared diabetic population.

Urinary artificial sweeteners and breast cancer risk in women from the Moli-sani Study

Abstract Background Artificial sweeteners (AS) are chemical substances developed by the food industry to reduce sugar and calories while maintaining sweetness. Cohort studies suggested an increased risk of certain cancers, including breast cancer (BC), associated with AS intake, however evidence exclusively relied on self-reported dietary data rather than objectively measured AS. We examined the association of urinary biomarkers denoting AS intake with BC risk in women from the large Moli-sani Study. Methods Using a case-cohort design, a sample of 987 middle-aged women (mean age 55±12 y) was randomly selected as sub-cohort and compared with 273 women with incident BC (26 of them also belong to the sub-cohort). A total of 6 commonly used AS (i.e. aspartame, acesulfame, saccharine, sucralose, cyclamate, and steviol glycosides) were measured through liquid chromatography-mass spectrometry in urinary samples (creatinine-adjusted concentrations; µg/mg) collected at baseline (2005-2010). The multivariable hazard ratios (HRs) were estimated through Cox regression models using the Prentice method, where each AS was dichotomized as absence/presence, independent of concentrations. Results The main urinary AS was saccharine (E954), contributing to 71% of total AS, followed by steviol glycosides (E960;11%). During a median follow-up of 13.2 y we identified 38 premenopausal and 235 postmenopausal incident BC cases. In multivariable-adjusted Cox analyses, none of the individual AS was associated with overall BC risk, nor was the total urinary AS (HR = 0.93; 95%CI 0.63-1.37 for 1-unit increment). Compared to absence, presence of sucralose (E955) in urine was linked to premenopausal BC (HR = 4.23: 95%CI 1.23-14.51; p = 0.022). Conclusions Urinary artificial sweeteners were not associated with BC risk. However, sucralose presence in urine was linked to a higher risk of premenopausal BC. Prospective, dose-related studies with larger sample size are warranted to possibly confirm our findings. Key messages • The presence in the urine of commonly used artificial sweeteners was not associated with breast cancer risk. • Presence of urinary sucralose was linked to higher risk of premenopausal breast cancer.

Exploring yeast glucans for vaccine enhancement: Sustainable strategies for overcoming adjuvant challenges in a SARS-CoV-2 model

Vaccine adjuvants are important for enhancing vaccine efficacy, and although aluminium salts (Alum) are the most used, their limited ability to induce specific immune responses has spurred the search for new adjuvants. However, many adjuvants fail during product development due to manufacturability, supply, stability, or safety concerns. This work hypothesizes that protein-free yeast glucans can be used as vaccine adjuvants due to their known immunostimulatory activity and high abundancy. Thus, high molecular weight glucans with over 99% purity, comprising 64–70% β-glucans and 29–35% α-glucans, were extracted from a wild-type yeast and an engineered yeast to produce a steviol glycoside. These glucans underwent carboxymethylation to enhance solubility. Both water-dispersible and particulate glucans were evaluated as adjuvants, either alone or in combination with Alum or squalene stable emulsion (SE), for a SARS-CoV-2 vaccine. The study demonstrated that glucans triggered a robust immune response and enhanced the effects of Alum and SE when used in combination, both in vitro and in vivo. Water-dispersible glucans combined with Alum, and particulate glucans combined with SE, increased the production of specific antibodies against SARS-CoV-2 spike protein and enhanced serum neutralization titers against SARS-CoV-2 pseudovirus. Furthermore, the results indicated that larger molecular weight glucans from engineered yeast exhibited stronger immunogenic activity in comparison to wild-type yeast glucans. In conclusion, appropriately formulated glucans have the potential to be scalable, low-cost vaccine adjuvants, potentially overcoming the limitations of current adjuvants.

Identification and characterization of stevia (Stevia rebaudiana Bert.) lines with enhanced steviol glycosides derived from gamma ray-induced in vitro mutagenesis

Identification and characterization of stevia (Stevia rebaudiana Bert.) lines with enhanced steviol glycosides derived from gamma ray-induced in vitro mutagenesis

Comparative Metabolome and Transcriptome Analysis Revealed the Accumulative Mechanism of Rubusoside in Chinese Sweet Tea.

Terpenoids are important secondary metabolites in Rubus. Rubusoside is a relatively specific diterpenoid bioactive component in the leaves of Chinese Sweet Tea (Rubus suavissimus). However, the terpenoid anabolic pathway of Rubus and the molecular mechanism underlying the specific accumulation of rubusoside in R. suavissimus remain unclear. Here, metabolomics and transcriptomics analyses were performed on differences in terpenoid metabolism levels between R. suavissimus (sweet leaves) and Rubus chingii (bitter leaves). Steviol glycosides and goshonosides primarily accumulated in R. suavissimus and R. chingii, respectively. Three pairs of highly homologous glycosyltransferase genes (UGT85A57, UGT75L20, and UGT75T4) associated with rubusoside biosynthesis in the two Rubus species were identified. The three pairs of UGT proteins in both species could glycosylate steviol. Thus, the transcriptional regulation of UGTs in R. suavissimus appears to play a pivotal role in rubusoside accumulation. Our findings provide insights into the differences in terpenoid metabolism between R. suavissimus and R. chingii and reveal the molecular mechanism of rubusoside accumulation in R. suavissimus.

Steviol rebaudiosides bind to four different sites of the human sweet taste receptor (T1R2/T1R3) complex explaining confusing experiments.

Sucrose provides both sweetness and energy by binding to both Venus flytrap domains (VFD) of the heterodimeric sweet taste receptor (T1R2/T1R3). In contrast, non-caloric sweeteners such as sucralose and aspartame only bind to one specific domain (VFD2) of T1R2, resulting in high-intensity sweetness. In this study, we investigate the binding mechanism of various steviol glycosides, artificial sweeteners, and a negative allosteric modulator (lactisole) at four distinct binding sites: VFD2, VFD3, transmembrane domain 2 (TMD2), and TMD3 through binding experiments and computational docking studies. Our docking results reveal multiple binding sites for the tested ligands, including the radiolabeled ligands. Our experimental evidence demonstrates that the C20 carboxy terminus of the Gα protein can bind to the intracellular region of either TMD2 or TMD3, altering GPCR affinity to the high-affinity state for steviol glycosides. These findings provide a mechanistic understanding of the structure and function of this heterodimeric sweet taste receptor.

Comparison between bacterial bio-formulations and gibberellic acid effects on Stevia rebaudiana growth and production of steviol glycosides through regulating their encoding genes

Stevia rebaudiana is associated with the production of calorie-free steviol glycosides (SGs) sweetener, receiving worldwide interest as a sugar substitute for people with metabolic disorders. The aim of this investigation is to show the promising role of endophytic bacterial strains isolated from Stevia rebaudiana Egy1 leaves as a biofertilizer integrated with Azospirillum brasilense ATCC 29,145 and gibberellic acid (GA3) to improve another variety of stevia (S. rebaudiana Shou-2) growth, bioactive compound production, expression of SGs involved genes, and stevioside content. Endophytic bacteria isolated from S. rebaudiana Egy1 leaves were molecularly identified and assessed in vitro for plant growth promoting (PGP) traits. Isolated strains Bacillus licheniformis SrAM2, Bacillus paralicheniformis SrAM3 and Bacillus paramycoides SrAM4 with accession numbers MT066091, MW042693 and MT066092, respectively, induced notable variations in the majority of PGP traits production. B. licheniformis SrAM2 revealed the most phytohormones and hydrogen cyanide (HCN) production, while B. paralicheniformis SrAM3 was the most in exopolysaccharides (EPS) and ammonia production 290.96 ± 10.08 mg/l and 88.92 ± 2.96 mg/ml, respectively. Treated plants significantly increased in performance, and the dual treatment T7 (B. paramycoides SrAM4 + A. brasilense) exhibited the highest improvement in shoot and root length by 200% and 146.7%, respectively. On the other hand, T11 (Bacillus cereus SrAM1 + B. licheniformis SrAM2 + B. paralicheniformis SrAM3 + B. paramycoides SrAM4 + A. brasilense + GA3) showed the most elevation in number of leaves, total soluble sugars (TSS), and up-regulation in the expression of the four genes ent-KO, UGT85C2, UGT74G1 and UGT76G1 at 2.7, 3.3, 3.4 and 3.7, respectively. In High-Performance Liquid Chromatography (HPLC) analysis, stevioside content showed a progressive increase in all tested samples but the maximum was exhibited by dual and co-inoculations at 264.37% and 289.05%, respectively. It has been concluded that the PGP endophytes associated with S. rebaudiana leaves improved growth and SGs production, implying the usability of these strains as prospective tools to improve important crop production individually or in consortium.

Methyl jasmonate mitigates biochemical and phytochemical changes in salt stressed Stevia rebaudiana plants

This study explored the effects of salt stress on growth, oxidative stress, and steviol glycoside content in Stevia rebaudiana Bertoni plants cultivated in soil supplemented with methyl jasmonate (MeJA). Stevia plants were cultivated under normal and salt stress conditions, with and without MeJA supplements of 30 ?M, 60 ?M, and 120 ?M. Samples were harvested after the 1st, 3rd, 5th, 10th, and 15th day of treatment. The levels of chlorophyll (p<0.0001), carotenoids (p<0.0001), and antioxidant enzymes such as catalase (p<0.0001), superoxide dismutase (p<0.0001), APX (p<0.0001), and glutathione reductase (p<0.0001) were observed. The quantification of steviol glycosides, including stevioside (p<0.0001) and rebaudioside-A (p<0.0001), was studied by the most advanced hyphenated technique, LC-MS/MS. The study revealed that the oxidative stress responses were significantly improved in MeJA-treated plants compared to salt-stress control plants. The level of production of phenols (p<0.0001), flavonoids, total sugar, reducing sugar, and steviol glucosides was significantly altered in salt-stress plants. MeJA showed a dose- and time-dependent significant effect on the improvement of these factors over salt stress. In conclusion, MeJA not only improves the growth of plants but also reduces oxidative stress and enhances the level of phytochemicals under saline stress.

Identification of a 301 bp promoter core region of the SrUGT91D2 gene from Stevia rebaudiana that contributes to hormone and abiotic stress inducibility

BackgroundThe UDP-glucuronosyltransferase 91D2 (SrUGT91D2) gene is a crucial element in the biosynthetic pathway of steviol glycosides (SGs) and is responsible for creating 1,2-β-D glucosidic bonds at the C19 and C13 positions. This process plays a vital role in the synthesis of rebaudioside M (RM) and rebaudioside D (RD). The promoter, which regulates gene expression, requires functional analysis to understand gene expression regulation. However, investigations into the function of the promoter of SrUGT91D2 (pSrUGT91D2) have not been reported.ResultsThe pSrUGT91D2 was isolated from six S. rebaudiana lines, and subsequent multiple sequence comparisons revealed the presence of a 26 bp inDel fragment (pSrUGT91D2-B1188 type) in lines GP, GX, 110, 1114, and B1188 but not in the pSrUGT91D2 of line 023 (pSrUGT91D2-023 type). Bioinformatics analysis revealed a prevalence of significant cis-regulatory elements (CREs) within the promoter sequences, including those responsive to abscisic acid, light, anaerobic conditions, auxin, drought, low temperature, and MeJA. To verify the activity of pSrUGT91D2, the full-length promoter and a series of 5’ deletion fragments (P1–P7) and a 3’ deletion fragment (P8) from various lines were fused with the reporter β-glucuronidase (GUS) gene to construct the plant expression vector, pCAMBIA1300-pro∷GUS. The transcriptional activity of these genes was examined in tobacco leaves through transient transformation. GUS tissue staining analysis and enzyme activity assays demonstrated that both the full-length promoter and truncated pSrUGT91D2 were capable of initiating GUS expression in tobacco leaves. Interestingly, P8-pSrUGT91D2-B1188 (containing the inDel segment, 301 bp) exhibited enhanced activity in driving GUS gene expression. Transient expression studies of P8-pSrUGT91D2-B1188 and P8-pSrUGT91D2-023 in response to exogenous hormones (abscisic acid and indole-3-acetic acid) and light indicated the necessity of the inDel region for P8 to exhibit transcriptional activity, as it displayed strong responsiveness to abscisic acid (ABA), indole-3-acetic acid (IAA), and light induction.ConclusionsThese findings contribute to a deeper understanding of the regulatory mechanism of the upstream region of the SrUGT91D2 gene and provide a theoretical basis for future studies on the interaction between CREs of pSrUGT91D2 and related transcription factors.

Improving organoleptic and antioxidant properties by inhibition of novel miRstv_7 to target key genes of steviol glycosides biosynthetic pathway in Stevia rebaudiana Bertoni.

Stevioside (5-10%) and rebaudioside-A (2-4%) are well-characterized diterpene glycosides found in leaves of Stevia rebaudiana known to have natural sweetening properties with zero glycaemic index. Stevioside has after-taste bitterness, whereas rebaudioside-A is sweet in taste. The ratio of rebaudioside-A to stevioside needs to be changed in order to increase the effectiveness and palatability of this natural sweetener. Plant-specific miRNAs play a significant role in the regulation of metabolic pathways for the biosynthesis of economically important secondary metabolites. In this study inhibition of miRNA through antisense technology was employed to antagonize the repressive action of miRstv_7 on its target mRNAs involved in the steviol glycosides (SGs) biosynthesis pathway. In transgenic plants expressing anti-miRstv_7, reduced expression level of endogenous miRstv_7 was observed than the non-transformed plants. As a result, enhanced expression of target genes, viz. KO (Kaurene oxidase), KAH (Kaurenoic acid-13-hydroxylase), and UGT76G1 (UDP-glycosyltransferase 76G1) led to a significant increase in the rebaudioside-A to stevioside ratio. Furthermore, metabolome analysis revealed a significant increase in total steviol glycosides content as well as total flavonoids content. Thus, our study can be utilized to generate more palatable varieties of Stevia with improved nutraceutical values including better organoleptic and antioxidant properties.

Steviol glycosides, L-arginine, and chromium(III) affect trace element status in diabetic rats [pdf

Steviol glycosides, L-arginine, and chromium(III) affect trace element status in diabetic rats [pdf

Raman Spectroscopic Analysis of Steviol Glycosides: Spectral Database and Quality Control Algorithms

Besides all sharing an extraordinary high (i.e., up to ~450 times) sweetening power as compared to sucrose and while presenting strong similarities in their molecular structures, molecules belonging to the family of diterpene glycosides (i.e., the secondary metabolites of Stevia rebaudiana) differ in specific structural details that strongly impact on their levels of sweetness and bitter aftertaste. Given the nutritional and pharmacological benefits of steviol secondary metabolites as natural dietetic and anti-diabetic remedies, extraction and purification of steviol glycosides from plant material are nowadays widely spread among many countries. However, an unpleasant bitter aftertaste, which is linked to a genetic variation in human bitter taste receptors, hampers the full exploitation of such benefits and calls for a prompt improvement in organoleptic property control of stevia products. A deeper understanding of the molecular structure of different steviol glycosides and the consequent development of promptly measurable criteria for the organoleptic performance of their mixtures will support processing optimization and control of taste profiles within desired yields. The present research aimed at establishing Raman spectroscopic algorithms for quantitative characterizations of raw stevia-based sweetener products. First, a series of twelve high-purity diterpene glycosides were analyzed by high spectrally resolved Raman spectroscopy and their spectra analyzed in order to establish a complete Raman library of molecular structures. Then, quantitative spectroscopic parameters were built up and applied to characterize the organoleptic property of five different commercially available samples including the recently developed Rebaudioside M isoform. Raman spectroscopy was confirmed as a versatile analytical technique that could be used for quantitative quality control tasks on the production line and for prompt in situ characterizations of purchased products.

High-quality haplotype-resolved chromosome assembly provides evolutionary insights and targeted steviol glycosides (SGs) biosynthesis in Stevia rebaudiana Bertoni.

Stevia rebaudiana Bertoni is popular source of plant-derived low/no-calorie natural sweeteners (LNCSs), collectively known as steviol glycosides (SGs). Nevertheless, genetic predisposition for targeted biosynthesis of SGs is complex due to multi-substrate functionality of key uridine diphosphate glycosyltransferases (UGTs). Here, we created a high-quality monoploid assembly of 1.34 Gb with N50 value of 110 Mb, 55 551 predicted protein-coding genes, and ~80% repetitive regions in Rebaudioside-A (Reb-A) enriched cultivar of S. rebaudiana. Additionally, a haplotype-based chromosome assembly consisting of haplotype A and haplotype B with an overall genome size of 2.33Gb was resolved, harbouring 639 634 variants including single nucleotide polymorphisms (SNPs), indels and structural variants (SVs). Furthermore, a lineage-specific whole genome duplication analysis revealed that gene families encoding UGTs and Cytochrome-P450 (CYPs) were tandemly duplicated. Additionally, expression analysis revealed five tandemly duplicated gene copies of UGT76G1 having significant correlations with Reb-A content, and identified key residue (leu200val) in the glycosylation of Reb-A. Furthermore, missense variations identified in the acceptor region of UGT76G1 in haplotype resolve genome, transcriptional and molecular docking analysis were confirmed with resequencing of 10 diverse stevia genotypes (~25X). Gene regulatory network analysis identified key transcription factors (MYB, bHLH, bZIP and AP2-ERF) as potential regulators of SG biosynthesis. Overall, this study provides haplotype-resolved chromosome-level genome assembly for genome editing and enhancing breeding efforts for targeted biosynthesis of SGs in S. rebaudiana.

Effect of Processing and Storage of Very-Low-Sugar Apple Jams Prepared with Sugar Substitution by Steviol Glycosides on Chosen Physicochemical Attributes and Sensory and Microbiological Quality

Consumers have become more aware of the impact of nutrition on health, paying attention to the composition and origin of food and looking for natural products. There is a trend towards a “healthy” diet with low-energy foods and a preference for healthier alternatives. This study aimed to assess the technological quality and food safety of very-low-sugar apple jams with steviol glycosides substituting sugar in various quantities. Apple jam variants with SG substitution at concentrations of 30, 50, and 80% selected in preliminary studies were subjected to physicochemical, sensory, and microbiological analyses during storage for 3 and 6 months. The studied jams were sensorily acceptable, and no significant changes in the technological quality of the products were observed, apart from color darkening. The microbiological quality during storage for 3 and 6 months was also satisfactory. The use of a natural sweetener, steviol glycosides, in the production of apple jam was shown to be satisfactory. It resulted in a product with taste and odor similar to conventional jam but with a low energy value. This product is suitable for people with diabetes, people on a restrictive diet, or those who pay attention to a product’s natural features, in line with the clean-label trend.

Multi-Omics Analyses Uncover the Mechanism Underlying Polyploidization-Enhanced Steviol Glycosides Biosynthesis in Stevia rebaudiana.

Stevia rebaudiana (Bertoni) is a valuable sweetener plant whose sweetness primarily derives from steviol glycosides (SGs), especially rebaudioside A (RA). Polyploidization has the potential to enhance the content of active ingredients in medicinal plants, making this strategy a promising avenue for genetic improvement. However, the underlying regulatory mechanisms that contribute to the fluctuating SGs content between autotetraploid and diploid stevia remain unclear. In this study, we employed metabolic analysis to identify 916 differentially accumulated metabolites (DAMs), with the majority, specifically terpenoids, flavonoids, and lipids, exhibiting upregulation due to polyploidization. Notably, the content of stevia's signature metabolite SGs (including RA, steviolbioside, and rebaudioside C), along with their precursor steviol, increased significantly after polyploidization. Furthermore, a comprehensive analysis of the transcriptome and metabolome revealed that the majority of differentially expressed genes (DEGs) involved in the SG-synthesis pathway (ent-KAH, ent-KS1, UGT73E1, UGT74G1, UGT76G1, UGT85C2, and UGT91D2) were upregulated in autotetraploid stevia, and these DEGs exhibited a positive correlation with the polyploidization-enhanced SGs. Additionally, multi-omics network analysis indicated that several transcription factor families (such as five NACs, four WRKYs, three MYBs, eight bHLHs, and three AP2/ERFs), various transporter genes (four ABC transporters, three triose-phosphate transporters, and two sugar efflux transporters for intercellular exchange), as well as microorganisms (including Ceratobasidium and Flavobacterium) were positively correlated with the accumulation of RA and steviol. Overall, our results indicate the presence of a regulatory circuit orchestrated by polyploidization, which recruits beneficial rhizosphere microbes and modulates the expression of genes associated with SG biosynthesis, ultimately enhancing the SG content in stevia. This finding will provide new insights for promoting the propagation and industrial development of stevia.

Association between consumption of non-nutritive sweeteners and gestational diabetes mellitus in Chilean pregnant women: A secondary data analysis of the CHiMINCs-II cohort

ObjectiveTo evaluate the association between consumed non-nutritive sweeteners (NNS) and gestational diabetes mellitus (GDM) in a cohort of pregnant women from Santiago, Chile. MethodsThis secondary data analysis of a cohort.involved 1,472 pregnant women from the Chilean Maternal-Infant Cohort Study-II (CHiMINCs-II). These women received care at primary health care centers in Puente Alto county, South-Eastern Metropolitan Health Service of Santiago, Chile. NNS consumption was estimated using 24-h dietary recalls and linked to the packaged foods nutrition facts panel. Plasma glucose values were extracted from clinical records. GDM was defined according to national criteria: 1) fasting plasma glucose (FPG) ≥100 and <126 mg/dL at the first antenatal visit; 2) FPG ≥100 mg/dL or 2-hour plasma glucose ≥140 mg/dL in the 75 g oral glucose tolerance test at 24–28 weeks. Cases with a GDM diagnosis in their medical records were also considered regardless of test results. The association between each NNS and GDM was assessed using logistic regression models. ResultsA total of 77.8% of the participants consumed NNS. The most consumed was sucralose (66%), followed by acesulfame-K (43.6%), and steviol glycosides (41.1%). Beverages (82%), dairy (12.4%) and candy products (4.4%) were the primary dietary sources of NNS. The GDM incidence was 18.9%, higher among consumers of any NNS compared to non-consumers (20.3% vs. 14.2%, p < 0.05). The adjusted model showed a significant association between the consumption of any NNS and sucralose and the risk of GDM (OR for any NNS = 1.58; 95% CI: 1.10–2.26; P = 0.014; OR sucralose = 1.44; 95% CI 1.06–1.95; P = 0.020). ConclusionsThe consumption of NNS, particularly sucralose, is associated with an increased risk of GDM in pregnant women. Further studies are essential to validate these results in other contexts and to guide future recommendations for healthier dietary practices among pregnant populations.

Development of dark chocolate with inulin and sweetened with stevia extract obtained by pressurized hot water

Because of its taste, texture, and aroma, chocolate is consumed as a way to generate pleasant sensations. Due to its high caloric density, moderate consumption is recommended. Seeking to offer the benefits of this product to a more selective public, the aim of this research was to determine the chemical composition and sensory properties of a sugar-free dark chocolate added with inulin and sweetened with stevia extract obtained by pressurized hot water, which was compared with a commercial dark chocolate and accompanied by a sensory analysis of the samples. A completely randomized statistical experimental design was used to compare the properties of the alternative and commercial chocolates. The treatments were carried out in triplicate and the results obtained were analyzed by descriptive statistics and one-way analysis of variance with 95 % confidence level. The results showed that the treatment of stevia leaves with hot pressurized water allowed an extraction of 41.51 g of steviol glycosides for rebaudioside A and 6.76 g for stevioside per 100 g of leaves subjected to processing. The chemical analysis of the alternative and commercial chocolates indicated that the fat and total dietary fiber contents showed no significant difference (p &gt; 0.05) between the dark chocolates, unlike the other components. Moisture, ash, fat, and protein contents were slightly higher in the two types of chocolate, and carbohydrate content was 4.1 % lower than in the commercial chocolate. Both products had 0 % added sugars and high dietary fiber content (&gt; 37 %), and there was a reduction of 100 kcal/100 g compared to the commercial brand. Consumer sensory evaluation showed a higher level of liking (p &lt; 0.05) for the elaborated chocolate with respect to the commercial product in attributes such as appearance, color, and texture. These findings suggest the use of stevia extracts obtained by pressurized hot water as a non-caloric sweetener for healthy, alternative dark chocolates suitable for people with diabetes.