Search Results (259)

Background: The aim of the present study is to compare the potential of a high-fat diet, a high-carbohydrate diet, and a high-fat, high-carbohydrate diet to induce liver injury and visceral obesity within a period of five weeks, identify the pattern and degree of hepatic changes at the tissue level, identify the earliest metabolic markers of specific liver changes induced by each type of diet, and to test the possible beneficial effects of steviol glycosides in a rat experimental model. Methods: Wistar rats (n = 56) were divided into seven groups as follows: group BD (before diet), group SD (standard diet), group HFD (high-fat diet), group HCHD (high-carbohydrate diet), group HFHCHD (high-fat high-carbohydrate diet), group SDS (standard diet supplemented with Stevia extract), and group HFDS (high-fat diet supplemented with Stevia extract). Results: Total cholesterol concentrations (2.02 ± 0.22 mmol/L) increased in the HFD group (2.56 ± 0.82 mmol/L) and in the HFDS group (2.89 ± 0.48 mmol/L). The VLDL values before diets were 0.27 ± 0.11 mmol/L and increased most significantly in the HFHCHD group—1.14 ± 0.62 mmol/L. The baseline ALT values (88.4 ± 10.6 U/L) increased in the HFD group (128.13 ± 19.5 U/L) and the HFDS group (127.00 ± 17.74 U/L). Similar increases were registered in the AST/ALT ratio and ALP. Total bilirubin (7.10 ± 1.39 μmol/L) increased in HFD group (27.86 ± 17.01 μmol/L). Serum NO had the lowest values in groups fed diets supplemented with steviol glycosides. All high-calorie diets induced hepatocellular injury. The mass of the perirenal fat depot and cross-sectional area of adipocytes were highest in HFD, HFHCHD, and HFDS groups. Conclusion: High-calorie diets have the potential to induce visceral obesity and hepatocellular injury within a very short period of time, which produces characteristic histological changes and specific biochemical profile. Steviol glycosides may alleviate some aspects of the inflammatory response, but findings about lipid profile parameters and liver enzymes are controversial. Full article

This study investigates the impact of light exposure on the biotransformation of chalcones in yeast cultures. 4′-Hydroxychalcones, with a hydroxyl group in the A-ring, are characteristic substrates efficiently converted into 4′-hydroxydihydrochalcones—compounds naturally occurring in medicinal plants such as Glycyrrhiza glabra (licorice), Stevia rebaudiana, and Angelica keiskei (ashitaba). These compounds are valued for their bioactivity and are relevant to natural product research. In this research, we present the outcomes of the selective microbial reduction of chalcones to dihydrochalcones using the yeast Yarrowia lipolytica KCh 71, cultivated under both light and dark conditions. The aim was to determine whether light exposure affects the efficiency or selectivity of the transformation. Furthermore, the effect of substrate photoisomerisation induced by light was investigated, as the trans–cis isomerisation of chalcones may affect their availability and affinity toward enzymatic systems. The resulting metabolites were analysed using chromatographic and spectroscopic methods. No significant differences in transformation efficiency were observed between light and dark conditions. In all tested conditions, the 4′-hydroxydihydrochalcones were obtained with high yield, typically exceeding 90% conversion. Additionally, the selective bioreduction of the α,β-unsaturated bond in selected 4′-hydroxychalcones by the studied yeast culture is an exceptionally efficient process. The primary factor influencing the reaction rate is the structure of the substrate, particularly the number and distribution of methoxyl groups on the B-ring. In addition, we establish biocatalytic access to three target dimethoxy dihydrochalcones—4′-hydroxy-2,4-dimethoxydihydrochalcone (5a), 4′-hydroxy-2,5-dimethoxydihydrochalcone (6a), and 4′-hydroxy-3,5-dimethoxydihydrochalcone (7a)—under mild conditions using Yarrowia lipolytica KCh 71. Under preparative-scale conditions (7-day incubation), a minor additional product (≤10%) was detected only for the 4′-hydroxy-2,5-dimethoxydihydrochalcone transformation and identified as 4′,5-dihydroxy-2-methoxydihydrochalcone (6b); no such side reaction was observed in short-term experiments. Full article

This manuscript provides an in-depth review of both artificial and natural sweeteners, including polyols and plant-derived alternatives, examining their sweetening potency, glycemic index, modes of action, and applications in the food sector. The rising demand for sugar substitutes, fueled by health concerns such as obesity and diabetes, has prompted significant research into low-calorie and non-nutritive sweeteners. This work categorizes sweeteners into synthetic options (such as aspartame, sucralose, saccharin) and naturally occurring ones (such as stevia, monk fruit, and polyols like sorbitol, xylitol, erythritol), focusing on physico-chemical characteristics, relative sweetness (ranging from 100 to 220,0000 times sweeter than sucrose), and glycemic index, important for their use in diabetes-friendly food products. The current manuscript examines how these sweeteners interact with taste receptors to induce sweetness perception without contributing significant calories. It also discusses their health implications and controversies and limitations regarding healthy and safety data, process feasibility, market application trends, environmental stability, and commercialization challenges. The review also addresses challenges in scaling production and ensuring the economic viability of plant-based sweeteners, offering a forward-looking perspective on their commercialization in the food industry. Full article

Extensive research is underway on a variety of functional foods that support consumer health. A promising combination is milk (a drink with high nutritional value), fortified with spices (naturally rich in antioxidant compounds) and supplemented with low-calorie, health-promoting sweeteners. The aim was to analyze the antioxidant activity (AA), total polyphenol content (TPC), and mineral composition of milk beverages fortified with a mixture of spices and sweeteners and to verify the interactions between these ingredients. Twenty-four variants of milk drinks were prepared with the addition of three types of spice mixtures (1:1) of clove (Cl), cinnamon (Ci), and turmeric (Tu) with the shares of 2.5%, 5%, 7.5%, and 10%, and two types of sweeteners—erythritol (E) and stevia (S)—as well as six control samples, including three 10% aqueous solutions of spice mixtures. AA was measured using the ABTS, FRAP, and DPPH methods. TPC was determined using the Folin–Ciocalteu method. Mineral content (Ca, Mg, Fe, Cu, and Zn) was assessed using the FAAS/FAES method. The highest AA was demonstrated for beverages with Cl-Ci and Cl-Tu, whereas the highest TPC was found in those with Cl-Tu. AA and TPC values increased with the increase in the share of spices in the beverages, and both measurements were significantly higher in beverages with erythritol compared to those with stevia. Despite the 4–5 times lower TPC, 3–8 times higher AA was demonstrated in beverages with the addition of 10% spice mixtures than their corresponding control samples (aqueous solutions with the addition of 10% spice mixtures), which suggests the great role of interactions between nutrients in food. For beverages with 10% Cl-Ci/Cl-Tu mixtures, significantly higher ABTS, FRAP, and DPPH were observed than would result from the simple sum of AA of the components (synergistic effect). The opposite (antagonistic) effect was observed for beverages with Ci-Tu. AA was positively correlated with the content of Fe, Mg, and Cu; negatively with Ca; and not correlated with Zn. The results suggest that the most health-promoting properties are exhibited by the milk drink with the addition of 10% Cl-Tu and erythritol, demonstrating the highest AA and TPC, the strongest synergistic effect of the components, and the highest content of Mg and Zn. This study highlights the importance of carefully selecting and combining ingredients to maximize the antioxidant properties of functional beverages. However, further research is needed to expand knowledge on this issue. Full article

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

In this study, Stevia rebaudiana biomass was hydrothermally carbonized (HTC) at 215 °C for 60 min with acrylic acid (AA) as a catalyst at concentrations of 0.25, 0.50, and 1.00 mol L⁻¹. The maximum hydrochar yield (48.5%) was obtained at 0.25 mol L⁻¹ AA, while fixed carbon contents ranged from 20.79% to 34.27%. Higher heating values (HHV) varied between 26.95 and 36.61 MJ kg⁻¹, with the highest catalytic HHV (32.20 MJ kg⁻¹) achieved at 1.00 mol L⁻¹ AA (HC15). Acrylic acid addition significantly promoted deoxygenation, reducing the O/C ratio from 0.67 in raw biomass to 0.21, thereby improving fuel quality. FT-IR and XRD analyses indicated enhanced aromatization and partial graphitization with increasing acid concentration, while SEM images revealed carbon microspheres and porous morphologies. Thermogravimetric analysis showed that HC15 exhibited the lowest mass loss and highest residual carbon, indicating superior thermal stability. GC-MS analysis demonstrated that acrylic acid markedly increased phenolic derivatives, with phenol content rising from 19.47% (without catalyst) to 40.92% (1.00 mol L⁻¹ AA). The aqueous phase contained TOC values of 14,280–28,728 mg/L and COD values of 43,227–113,920 mg/L. Overall, acrylic acid-assisted HTC enhances both the energy-related properties of hydrochars and the chemical diversity of liquid products, providing a sustainable route for valorizing Stevia rebaudiana waste into value-added fuels and chemicals. 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

Stevia rebaudiana leaves and extracts need to be promptly dried after harvest to prevent microbial activity and preserve their bioactive compounds, including glycosides, flavonoids, and essential oils. Effective drying also reduces moisture and volume, which lowers packaging, storage, and transportation costs. Therefore, innovative drying methods are necessary to maintain stevia’s physicochemical, sensory, and nutritional properties for functional food formulations. This review evaluates various drying technologies for stevia leaves and extracts, including convective hot air, infrared, vacuum, microwave, freeze, and shade drying, and their impacts on product quality and energy efficiency. It also explores the growing applications of dried and extracted stevia in food products. By comparing different drying methods and highlighting the benefits of stevia in these food formulations, this investigation aims to identify future research directions and optimization strategies for utilizing stevia as a natural sweetener and functional ingredient. Convective hot air drying at higher temperatures was found to be the most energy-efficient, though several studies have reported moderate degradation of key bioactive compounds such as stevioside and rebaudioside A, particularly at elevated temperatures and extended drying times. Infrared drying enhanced antimicrobial activity but resulted in lower levels of polyphenols and antioxidants. Vacuum drying effectively preserved anti-inflammatory compounds like flavonoids. Microwave drying presented strong protection of antioxidant activity and superior particle morphology. Freeze drying, while less energy-efficient, was the most effective at retaining antioxidants, polyphenols, and volatile compounds. Shade drying, though time-consuming, maintained high levels of polyphenols, flavonoids, and essential oils. Advanced techniques like spray drying and electrospraying have been reported to enhance the sensory qualities and stability of stevia extracts, making them ideal for food applications such as dairy and baked products, confectionery, syrups, snacks, jams, preserves, and meat products. Overall, stevia not only serves as a natural, zero-calorie sweetener but also contributes to improved health benefits and product quality in these diverse food formulations. 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

Stevia rebaudiana Bertoni, a semi-perennial herb from the Asteraceae family, is native to the Paraguay–Brazil border region. The growing industrial interest in this species is due to its natural sweetening properties, such as steviol and its derivatives, which offer sweetness without adding calories. Morphological traits are crucial for assessing genetic variability and ensuring distinctness, homogeneity, and stability (DHS) for cultivar protection. This study characterized 19 elite Stevia genotypes from Embrapa Cerrados’ Active Germplasm Bank (BAG) using 21 morphological descriptors from Brazil’s Ministry of Agriculture, Livestock, and Supply (MAPA). Genetic distances were calculated using the simple coincidence index complement method, and clustering was performed via the Unweighted Pair-Group Method with Arithmetic Mean (UPGMA). The results showed that 17 of the 21 descriptors (>80%) effectively differentiated the genotypes, revealing significant genetic variability. Dendrogram analysis identified at least four major similarity groups, highlighting the potential of these genotypes for Stevia breeding programs. These findings underscore the suitability of these elite genotypes for developing superior varieties adapted to Cerrado conditions, supporting future cultivation and genetic improvement efforts. Full article

This study aimed to investigate the effect of the type of sweetener used (xylitol, stevia, cane sugar) on the quality of liqueurs made from Vaccinium myrtillus L. and Vaccinium corymbosum L. fruits. The quality assessment was performed based on selected organoleptic and physicochemical features, with particular emphasis on the health-promoting potential of the produced beverages. The liqueurs were assessed in terms of their physicochemical parameters: pH, total acidity, density, total soluble solids, color, ethanol and polyphenol contents, and redox potential. Antioxidant capacities were determined by a 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging capacity assay and ferric reducing antioxidant power (FRAP). The Qualitative Descriptive Analysis method was employed for their sensory assessment. The sensory profiling method was used to determine the intensity of the flavor sensations. The study results showed that the type of sweetener did not affect the antioxidative properties of the liqueur. The ABTS test yielded values from 1081.88 to 1238.13 μmol Tx/100 mL, the DPPH test from 348.8 to 367.88 μmol Tx/100 mL, and the FRAP test from 594.20 to 653.20 μmol FeSO₄/100 mL. However, the sweetening substrate affected the content of polyphenolic compounds in the resulting products, but by no more than 15%. The liqueur sweetened with xylitol had a comparable extract content to that sweetened with cane sugar. All three variants of liqueurs were accepted by the evaluation panel, and their overall qualities were comparable in the sensory assessment. It is, therefore, possible to produce a high-quality liqueur with a reduced caloric value, which will potentially increase its attractiveness for consumers. Full article

This Technical Note presents the design and implementation of a low-cost modular growth chamber developed to keep mother plants under controlled environmental conditions for vegetative propagation. The system was conceived as an accessible alternative to expensive commercial equipment, offering reproducibility and adaptability for small-scale and research-based cultivation. The proposed chamber integrates thermal insulation, LED lighting, forced ventilation through the implementation of extractors, a recirculating irrigation system with double filtration, and a sensor-based environmental monitoring platform operated via an Arduino UNO microcontroller. The design features a removable tray that serves as a support for the mother plant, an observation window covered by a movable dark acrylic that prevents the passage of external light, and a vertical structure that facilitates optimal space utilization and ergonomic access. Functionality was conducted using a Stevia rebaudiana Bertoni mother plant maintained for 30 days under monitored conditions. Environmental parameters—temperature, relative humidity, and illuminance—were recorded continuously. The plant showed vegetative development through new shoot emergence and the growth in height of the plant, and despite a loss in foliage expansion, it confirmed the chamber’s capacity to support sustained growth. Although no statistical replication or control group was included in this preliminary evaluation, the system demonstrates technical feasibility and practical utility. This chamber provides a replicable platform for future experimentation and propagation studies. Complete technical specifications, schematics, and component lists are provided to enable replication and further development by other researchers. The growth chamber design aligns with the goals of open-source agricultural innovation and supports knowledge transfer in controlled-environment plant propagation technologies. Full article

In Mexico and worldwide, the increased prevalence of both weight gain and obesity is associated with the consumption of sugary drinks. Mexico implemented a tax of one peso per liter on sugary drinks in 2014, and in response, the industry reformulated these beverages; however, the health effects are relatively unknown. Male and female Wistar rats consumed caloric sweeteners (CS: dextrose, saccharose, and HFCS at 7%) and non-caloric sweeteners (NCS: sucralose and stevia at 0.3%) for 16 weeks to determine the impact on metabolic and adiposity indicators. The weight, food intake (AIN93M diet), and beverage intake of the rats were recorded weekly. At the end of the treatment, the gonadal (GAT), mesenteric (MAT), and retroperitoneal (RAT) adipose tissue were dissected, and serum metabolic indicators were quantified. No differences were observed in weight gain, but there were higher beverage and energy intake, mainly in female rats. All groups with CS and NCS increased 2.0–2.4 or 1.3–1.9 times their intake of beverages, respectively, compared to the control groups (p < 0.01). With dextrose intake, male rats showed a significantly greater amount (mg/g body weight) of GAT (3.7 ± 0.6 vs. 2.3 ± 0.3), MAT (2.8 ± 0.8 vs. 1.7 ± 0.3), and RAT (4.6 ± 0.6 vs. 2.7 ± 0.2) in the stevia group, p < 0.05. Additionally, male rats in both CS and NCS groups presented elevated triglyceride concentrations (mg/dL), and the dextrose (299.7 ± 62.3) and sucralose (352.4 ± 36.2) groups registered the highest means, compared to the control group (122.3 ± 51.2, p < 0.05). The consumption of CS and NCS of beverages has effects on the volume ingested, as well as metabolic and adiposity indicators; therefore, they should not be considered innocuous. Full article