Search Results (115)

Background: Potential advantages for improving plant growth, stress tolerance, and valuable metabolites generation are provided by the implementation of nanotechnology into plant biotechnology. A recently discovered technique with significant promise for agricultural practices is the use of biopolymer-based nanomaterials, like peptidomimetics, as insecticides, growth regulators, and nutrient carriers. This study explores the impact of biopolymer-based organic nanofibers—specifically peptidomimetics formed through the self-assembly of L-valine and nicotinic acid (NA) (denoted as M6) on Stevia rebaudiana in vitro propagation and specialized metabolite production. The central hypothesis was that such nanofibers, particularly when used as hormone carriers, can beneficially influence plant morphology, physiology, and biochemistry, thereby promoting the synthesis of antioxidant compounds with therapeutic potential. Methods: The nanofibers were tested either alone (M6) or as carriers of the plant hormone indole-3-acetic acid (IAA) (M6+IAA), supplemented to the cultivation MS medium at variable concentrations (0, 1, 10, and 50 mg L⁻¹). Results: The results revealed that treatment with 10 mg L⁻¹ M6 significantly enhanced shoot growth parameters, including the highest fresh weight (0.249 g), mean shoot height (9.538 cm), shoot number (1.95), and micropropagation rate. Plants treated with M6 alone outperformed those treated with M6+IAA in terms of shoot growth, total soluble sugars, and steviol glycoside content. Conversely, M6+IAA treatment more effectively promoted root initiation, the increased accumulation of mono- and dicaffeoylquinic acids, and boosted antioxidant enzyme activity. Conclusions: These findings highlight the potential of organic nanofibers, both with and without hormone loading, as novel tools for optimizing micropropagation and metabolite enhancement in Stevia rebaudiana. Full article

Stevioside, a natural high-intensity sweetener, is widely employed across the food, pharmaceutical, and daily chemical industries due to its intense sweetness and health benefits. However, traditional extraction and purification processes for steviol glycosides from Stevia rebaudiana are plagued by low efficiency, high energy consumption, substantial environmental impact, and inconsistent product quality. This study systematically optimized the extraction, decolorization, decontamination, and desalting processes to overcome these challenges. The extraction method was refined using 20% ethanol as the solvent, an optimal temperature of 50 °C, and a 1:10 material-to-liquid ratio, increasing the steviol glycoside yield from 32.0% to 49.1%. Decolorization employing a combination of resins D940 and T5 achieved decolorization rates of 89–92% with minimized steviol glycoside loss, surpassing the non-selective adsorption limitations of activated carbon. For decontamination, calcium hydroxide (Ca(OH)₂) outperformed diatomaceous earth, attaining a 98% protein removal rate while maintaining steviol glycoside loss below 20%. The desalting resin LXP-016 demonstrated superior performance at 40 °C, enhancing the ability of ionic impurity removal. These optimizations collectively improve the efficiency, sustainability, and quality of steviol glycoside production, offering a promising framework for industrial-scale applications. Full article

Monk fruit extract (Siraitia grosvenorii, MFE) is a natural, non-caloric sweetener known for its intense sweetness, antioxidant properties, and potential metabolic health benefits. While certain aqueous monk fruit decoctions are recognised as non-novel foods in the UK and Ireland due to significant pre-1997 consumption, the European Union (EU) has adopted a more cautious approach under the Novel Food Regulation (EU) 2015/2283. As of October 2024, only one specific aqueous extract of monk fruit has been authorised in the EU under Regulation (EU) 2024/2345, permitting its use in several food categories. However, highly purified mogrosides and non-aqueous extracts remain unapproved due to gaps in toxicological data and the absence of industry-led applications. This review systematically analyses the EU’s regulatory barriers, comparing MFE’s legal status with other approved non-caloric sweeteners such as steviol glycosides and erythritol, and examining regulatory frameworks in the EU, United States, United Kingdom, and China. Findings indicate that although 18 non-caloric sweeteners are currently authorised in the EU, regulatory constraints continue to hinder the broader approval of MFE, limiting innovation and the availability of natural sweeteners for consumers. Harmonising regulations, leveraging international safety assessments, and promoting industry engagement are recommended to advance MFE’s authorisation and support sustainable food innovation in the EU. Addressing these challenges is crucial to ensure that European consumers and industry can benefit from safe, innovative, and health-promoting alternatives to sugar, aligning food policy with broader public health goals and sustainability commitments. Full article

Objectives: The aim of this study was to investigate the effect of Rebaudioside A (RebA) on acetylcholinesterase (AChE) immunoreactivity in cortical neurons of the rat brain. RebA is a steviol glycoside commonly used in the production of sweeteners. Beyond its application as a food additive for diabetes management, steviol glycosides have been shown to influence memory and learning processes. Methods: RebA was administered to rats at two concentrations (1 mg/mL and 2 mg/mL of water) over both short-term (15 days) and long-term (45 days) periods. Indirect immunohistochemical peroxidase–antiperoxidase staining was performed on histological frontal sections of the brain cortex. Results: Acetylcholinesterase-positive neurons were analyzed both morphologically and morphometrically. The results of the experiment revealed no significant morphological changes in AChE-immunopositive neurons, indicating an absence of neurotoxic effects associated with the sweetener in these neurons. However, the analysis demonstrated a reduction in AChE immunoreactivity, particularly after 45 days of treatment. Conclusions: These preliminary findings demonstrates that RebA affects the immunoreactivity of neurons positive for AChE. Given the observed effects, further studies should be implemented to investigate the exact influence of this dietary supplement on the cholinergic nervous system. Full article

Background/Objectives: The growing interest of consumers in reducing their sugar consumption has led to an increase in the popularity of food products containing low- and no-calorie sweeteners as an alternative to sugar. The aim of this study was to comparatively analyze the presence of these substances in food products available on the Polish market. Methods: The analysis was performed on the labels of 1278 food products available on the Polish market in the second and third quarters of 2023. The products were divided into two groups: those with added sugar and those without added sugar. The presence of added sugars, intense sweeteners, polyols and steviol glycosides was assessed. Results: This study showed that 33.9% of the products without added sugar and 20% of the products containing sugar contained sweeteners. In sugar-free products, polyols dominated (22.9%), while in products with sugar, intense sweeteners were most often used, mainly sucralose (13.6%). Significant differences (p < 0.0001) were observed in the presence of polyols and intensive sweeteners between the analyzed groups. Conclusions: Products without added sugar more often contain low- and no-calorie sweeteners than products with sugar, which suggests their greater use in this category. Repeated use of the same sweeteners, in the absence of labeling, may lead to cumulative consumption, potentially causing acceptable levels to be exceeded. Further research is needed to assess this risk and develop strategies to reduce their excessive consumption. Full article

As a complex of enzymes α-l-rhamnosidase and β-d-glucosidase, naringinase catalyzes the deglycosylation of flavonoids. According to the PRISMA method, a systematic literature review was conducted analyzing peer-reviewed scientific articles from the Scopus and Web of Science databases. Recent reviews on naringinase have focused on its sources, production, and general applications, whereas the present study highlights its specific applications, its role in the deglycosylation of flavonoids, and the resulting improvement in their bioavailability. This review focuses on advances in modifying the glycosidic parts of various flavonoids using naringinase by selectively disconnecting the rhamnose or glucose moiety. Removing rhamnose from the flavonoid molecule but leaving the glucose allows more water-soluble compounds to be present and increases bioavailability. A necessary condition for such selective deglycosylation is removing or inhibiting beta-glucosidase, the second enzyme in the native naringinase molecule. The use of naringinase for preparing functional beverages with increased antioxidant activity and for preparing steviol sweeteners is also presented. Naringinase enables the desired sensory properties to be obtained, primarily the taste and aroma of food products, and can be used in combination with other enzymes, e.g., pectinase and tannase. Full article

Although enormous efforts have been made to prepare tasty and soluble steviol glycosides (SGs), the structure–property relationship of SGs still remains unclear, neither in experiment fact nor in the mechanism, such as the influence of linkage type and position of substituted glucosyl on physiochemical properties and sensory features of SGs. The favorable SGs, rebaudioside D (RD) and rebaudioside A (RA), possess good edulcorant quality, poor solubility, and other significantly different physical properties. This research chose two pairs of isomeric SGs, RA and its isomer rebaudioside E (RE) and RD and its isomer RA1G (a synthetic SG, α-1,6-mono-glucosylated RA), to conduct a comparative study, aiming to reveal the structure–property relevance on their solubility, sweetness, stability, and crystal structure. The RA1G presents an aqueous solubility 13 times that of RA and 137 times that of RD and exhibits better edulcorant quality than that of RA, similar to RD. The results indicate that the glucosyl linkage type and position have a stronger impact on the properties of the SGs than the number of glucosyl moieties. The underlying mechanism of their structure–property relevance was elucidated by analyzing the interaction energies between the SGs with solvent and human receptor proteins, respectively. Full article

In this study, the decomposition processes of tabletop sweeteners based on steviol glycosides were investigated to determine the kinetic parameters of activation energy (E_a) and the logarithm of the pre-exponential factor (ln A) based on the converted fraction (α). These parameters were assessed using the Friedman and Ozawa–Flynn–Wall isoconversion methods with the NETZSCH Kinetics Neo software and the Model Free package. This study also aimed to explore the probable mechanism of the thermal decomposition of these materials. The thermal degradation of the samples was carried out in a temperature range of 150 to 400 °C under nitrogen flow, with heating rates of 5, 10, and 20 °C min⁻¹. The results indicated that both stevioside and steviol glycoside (E3) samples require higher energy to initiate their decomposition. Furthermore, the samples based on steviol glycosides exhibited distinct probable decomposition mechanisms: a model of two consecutive reactions followed by two competitive reactions for stevioside (FnFnFnFn model), three consecutive stages for the steviol glycoside sample (FnCnFn model), two consecutive stages for the steviol glycoside + erythritol sample (FnCn model), and three consecutive stages for the steviol glycoside + xylitol sample (FnFnFn model). Full article

Extracts of Stevia rebaudiana are rich in sweet-tasting steviol glycosides (SG), which are widely valued as natural sweeteners. This study investigated the effects of different light conditions on stevia growth and SG production across growth stages using a controlled hydroponic system. Four light conditions were introduced at a low photosynthetic photon flux density of 50 μmol·m⁻²·s⁻¹. Stevia growth was divided into four stages, and leaf weight and SG yield were analyzed. Red light resulted in the highest leaf fresh weights at 23.53 g·plant⁻¹, whereas green light resulted in the lowest at 17.15 g·plant⁻¹, marking a difference of 37.2%. However, green light performed the highest total SG content (LSG) at 190.68 mg·g⁻¹ and total SG yield (YSG) at 39.24 g·m⁻², compared to the lowest LSG under red light at 108.68 mg·g⁻¹ and YSG at 24.76 g·m⁻², derived differences of 75.45% and 58.48%, respectively. These results suggest a trade-off between vegetative growth and SG synthesis. Red light is optimal for early-stage biomass accumulation, while green light and blue light treatments during the last two stages, respectively, may enhance overall SG production. Consequently, the results offered insights into commercial stevia cultivation and the production of SG. Full article

This study compared the effects of seed treatment with low-pressure cold plasma (CP) and atmospheric dielectric barrier discharge (DBD) plasma on morpho-biochemical traits in Stevia rabaudiana Bertoni plants cultivated by two methods: in soil and aeroponics. We investigated the impact of the treatments on the germination, plant growth, and content of secondary metabolites, namely steviol glycosides (SGs), rebaudioside A (RebA), and stevioside (Stev), as well as phenolic compounds and flavonoids. Seeds were treated for 2, 5, and 7 min with CP or DBD and 5 min with vacuum six days before sowing. All growth parameters in aeroponics exceeded the parameters of seedlings in the corresponding groups cultivated in soil. Seed treatments stimulated SGs biosynthesis in seedlings grown in soil, except for CP7. Although there were no stimulating effects of seed treatments on SGs in aeroponics, overall SG concentrations were considerably higher compared to plants cultivated in soil: the RebA+Stev concentration was 1.8–2-fold higher in the control, V5-, and CP-treated groups, and 1.3-fold higher in the DBD5 and DBD7 groups. Thus, aeroponic cultivation has the potential to improve the growth and synthesis of SGs in stevia, while a combination of aeroponics with seed treatments only increases the content of antioxidants and antioxidant activity. Full article

The use of in vitro cultures in plant breeding allows for obtaining cultivars with improved properties. In the case of Stevia rebaudiana Bert., genotypes with an appropriate rebaudioside A/stevioside ratio are desirable. The use of indirect organogenesis allows for the induction of somaclonal variation, which, consequently, results in obtaining variability within the regenerants. The Murashige and Skoog medium containing 4.0 mg × dm⁻³ 6-benzylaminopurine (BAP), 2.0 mg × dm⁻³ 1-naphthaleneacetic acid (NAA), and 2.0 mg × dm⁻³ 2,4-dichlorophenoxyacetic acid (2,4-D) resulted in obtaining plants that were biochemically and genetically diverse. The obtained regenerants were characterized by an increased content of rebaudioside A and a better rebaudioside A/stevioside ratio. Genetic analysis using SCoT (start-codon-targeted) markers showed their diversity at the molecular level. Moreover, this study showed that genotype multiplication through six subsequent re-cultures does not cause variability at the genotype level and does not affect the steviol glycoside profile. This study is the first report on obtaining genotypes with higher rebaudioside A content and a more attractive rebaudioside A to stevioside ratio through the use of in vitro cultures. The improved regenerants can be used as parents in hybridization programs or directly as valuable new genotypes. Full article

Several studies have explored the effects of single or binary mixtures of sweeteners on both healthy individuals and those with diabetes. However, there is limited research on the impact of a combination of four sweeteners supplemented with dietary minerals. Steviol glycosides, extracted from Stevia rebaudiana, offer a zero-calorie sweetness that exerts minimal influence on blood glucose levels. When combined with other sweeteners, they can reduce the required quantity of each component thus mitigating the potential side effects. Furthermore, the incorporation of chromium picolinate into sweeteners may enhance insulin sensitivity and glucose metabolism and diminish insulin resistance in both diabetic and non-diabetic individuals. This study aimed to evaluate the effects of commercial mixed sweeteners (acesulfame-K, sucralose, sorbitol, and steviol glycoside) supplemented with chromium picolinate (MSSC) on diabetes-related markers and complications in healthy and type 2 diabetic rats (T2D). Over six weeks, diabetic rats received daily oral administration of MSSC at a standard dosage. The results demonstrated that MSSC significantly reduced weight loss in diabetic rats, lowered fasting blood glucose levels, enhanced hexokinase activity, and improved pancreatic antioxidative capacities. Additionally, MSSC treatment led to notable reductions in serum triglycerides, cholesterol, malondialdehyde (MDA), and LDL cholesterol levels. The treatment also modulated specific renal function parameters, and moderately reversed the necrotic architectures of the liver and pancreatic β cells. These results indicate that long-term administration of MSSC may alleviate certain diabetic complications without adverse effects on non-diabetic individuals. Further clinical studies are strongly recommended to evaluate the safety and efficacy of MSSC in diverse populations. Full article

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. Full article

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. Full article

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. Full article