Gabriel Lucian Radu
@incdsb.ro
Centre of Bioanalysis
INCDSB Bucuresti
RESEARCH, TEACHING, or OTHER INTERESTS
Analytical Chemistry, Bioengineering, Agricultural and Biological Sciences, Biomaterials
Scopus Publications
Scopus Publications
Camelia Albu, Ana Chira, Gabriel-Lucian Radu, and Sandra A. V. Eremia
MDPI AG
Cost-effective chemosensors have become an indispensable tool for sustainable monitoring in food safety and processing, where there is an urgent need for affordable, efficient, and real-time analytical solutions. This review discusses recent advances in low-cost chemosensor technologies, highlighting developments in materials, miniaturization, and integration into portable and accessible platforms. The focus is on applications for detecting contaminants, monitoring quality, and ensuring safety in food production and processing. This review also addresses the challenges related to sensor sensitivity, selectivity, and operational stability and provides insights into future directions and the role of low-cost chemosensors in supporting sustainable practices in these important sectors.
Georgiana Ileana Badea, Florentina Gatea, Simona Carmen Litescu-Filipescu, Andreia Alecu, Ana Chira, Celina Maria Damian, and Gabriel Lucian Radu
MDPI AG
The purpose of this study was to extract the lipophilic fraction from one of the largest source of waste in the industrial sector, namely, the tomato residue from processing the fruit. In order to make this process more environmentally sustainable, this study used a green extraction protocol employing natural deep eutectic solvents (NADESs) combined with a less energy-consuming technology, the ultrasound-assisted extraction (UAE) method, to simultaneously recover carotenoids and tocopherol from dried powder tomato waste. Two NADESs, one hydrophilic and one hydrophobic, were prepared and compared to support high extraction efficiency and increase the stability of the extracted compounds. The optimal extraction parameters were identified as choline chloride:1,3-butanediol (1:5)-based NADES, a solid-to-liquid ratio of 1:20 (w/v), time of extraction 12 min, temperature 65 °C, radiation frequency 37 Hz, and an ultrasound power level of 70%. The extraction process was intensified and resulted in extracts rich in lycopene (215.13 ± 4.31 μg/g DW), β-carotene (206.95 ± 3.27 μg/g DW), and tocopherol (130.86 ± 8.97 μg/g DW) content, with the highest antioxidant capacity 93.84 ± 0.18 mM Trolox equivalent. Incorporating NADESs for the extraction of bioactive compounds offers numerous benefits, such as improved sustainability, enhanced extraction efficiency, better protection of sensitive compounds, and reduced environmental impact. These advantages make NADESs a promising alternative to traditional organic solvents, especially in industries that require natural, green, and efficient extraction processes for valuable bioactive molecules.
Andreia Alecu, Camelia Albu, Georgiana-Ileana Badea, Aurelia Alionte, Alin-Alexandru Enache, Gabriel-Lucian Radu, and Simona-Carmen Litescu
MDPI AG
The extraction of bio-compounds from medicinal plants provides opportunities for using the plant extract for health benefits. Rosa canina L. is considered a “natural superfood”, and the valorization of its active compounds requires an extraction technique that ensures a suitable extraction yield while preserving the compounds’ activity. In our study, infrared laser irradiation (IRLIR) technology was used for the first time in the bioactive compound’s extraction from Rosa canina L. Different solvents (water–ethanol, hexane–ethanol) and different extraction times were tested to obtain a high extraction yield. Chromatographic and spectrophotometry methods were used to monitor the profile of bioactive compounds and the antioxidant activity of the extracts. The results obtained for IRLIR were compared with those obtained by accelerated solvent extraction (ASE), an advanced extraction method. The IRLIR technology proved to be a more reliable analytical tool for the extraction of (+)-catechin, gallic acid, and lutein. In addition, a richer extract formula was obtained by IRLIR extraction with respect to ASE, with the IRLIR process ensuring a short extraction time, low volume of the extraction solvent, low energy consumption, and a less expensive device.
Antoaneta Roman, Felicia Bucura, Oana Romina Botoran, Gabriel-Lucian Radu, and Marius Constantinescu
Informa UK Limited
Elena Neagu, Gabriela Paun, Camelia Albu, and Gabriel Lucian Radu
MDPI AG
In recent years, increased attention has been paid to the recovery of bioactive compounds from waste and by-products resulting from the agro-industrial sector and their valorization into new products, which can be used in the health, food, or agricultural industry, as innovative and sustainable approaches to waste management. In this work, two of these by-products resulting from the fruit-processing industry were used for the recovery of bioactive compounds (polyphenols), namely lingonberry pomace (Vaccinium vitis-idaea) and grape pomace (Vitis vinifera). Two green extraction techniques were employed to obtain hydroalcoholic extracts (solvent: 50% EtOH, 10% mass): ultrasound-assisted extraction (UAE) and accelerated solvent extraction (ASE). The extracts were subjected to micro- and ultrafiltration processes, and further analyzed to determine the bioactive compound content through spectrophotometric (UV-Vis) and chromatographic (HPLC-PDA) methods. Additionally, the extracts exhibited significant enzyme inhibition, particularly against α-amylase and β-glucosidase, suggesting potential anti-diabetic properties. The extracts characteristics, polyphenolic content, antioxidant capacity and enzyme inhibitory ability, were statistically compared, and significant differences were found between the two extraction methods. The grape pomace concentrated extracts showed a pronounced inhibitory activity on both analyzed enzymes compared to the lingonberry pomace concentrated extracts, closer to the standard used; e.g., IC50 α-amylase = 0.30 ± 0.01 µg/mL (IC50 acarbose = 0.3 ± 0.01 µg/mL), IC50 α-glucosidase = 0.60 ± 0.01 µg/mL (IC50 acarbose = 0.57 ± 0.02 µg/mL). These findings highlight the potential of agro-industrial residues as bioactive compound resources, with their valorization through application in food, nutraceutical, or pharmaceutical industries therefore contributing to the sustainable development and promotion of circular economy principles with the recovery of valuable inputs from plant by-products.
Daniel Preda, Gabriel Lucian Radu, Emilia-Elena Iorgulescu, Mihaela-Carmen Cheregi, and Iulia Gabriela David
MDPI AG
A new molecularly imprinted polymer (MIP)-based disposable electrochemical sensor for dipyridamole (DIP) determination was obtained. The sensor was rapidly prepared by potentiodynamic electrochemical polymerization on a pencil graphite electrode (PGE) using curcumin (CUR) as a functional monomer and DIP as a template molecule. After the optimization of the conditions (pH, monomer–template ratio, scan rate, number of cyclic voltammetric cycles applied in the electro-polymerization process and extraction time of the template molecule) for MIP formation, DIP voltammetric behavior at the modified electrode (MIP_PGE) was investigated. DIP oxidation took place in a pH-dependent, irreversible mixed diffusion-adsorption controlled process. Differential pulse voltammetry (DPV) and adsorptive stripping differential pulse voltammetry (AdSDPV) were used to quantify DIP from pharmaceutical and tap water samples. Under optimized conditions (Britton–Robinson buffer at pH = 3.29), the obtained linear ranges were 5.00 × 10−8–1.00 × 10−5 mol/L and 5.00 × 10−9–1.00 × 10−7 mol/L DIP for DPV and AdSDPV, respectively. The limits of detection of the methods were 1.47 × 10−8 mol/L for DPV and 3.96 × 10−9 mol/L DIP for AdSDPV.
Madalina-Petruta Bucur, Maria-Cristina Radulescu, Bogdan Bucur, and Gabriel Lucian Radu
Springer Science and Business Media LLC
Camelia Albu, Ana Chira, Alice Stoica, Gabriel-Lucian Radu, Antonio Radoi, Marius Stoian, Octavian-Gabriel Simionescu, and Sandra A. V. Eremia
MDPI AG
A nitrogen-doped nanocrystalline electrochemical graphite sensor for the sensitive determination of oleuropein (OL) from extra virgin olive oils (EVOOs) is presented. The sensor was developed by the deposition of nanocrystalline graphite (NCG) using plasma-enhanced chemical vapour deposition (PECVD) on silicon wafers. Scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX) and X-ray diffraction analysis (XRD) were used to characterise the microstructure and morphology of the developed materials. Cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and square wave voltammetry (SWV) were used to investigate the electrochemical properties of the material and the performance of the sensor. The developed sensor showed good analytical performance against OL over a concentration range of 5.00–500.00 µM, with a good detection limit of 3.93 µM and a good sensitivity of 0.057 µA µM−1. The reproducibility of the electrochemical sensor was excellent, with a relative standard deviation (RSD) of 8.56% for seven measurements.
Gabriela Paun, Elena Neagu, Camelia Albu, Andreia Alecu, Ana-Maria Seciu-Grama, and Gabriel Lucian Radu
MDPI AG
The present study evaluated three green extraction methods, accelerated solvent extraction (ASE), ultrasound-assisted extraction (UAE), and laser irradiation extraction (LE), for the polyphenolic compounds and vitamin C extraction of Cornus mas L. and Crataegus monogyna fruit extracts. The polyphenols and vitamin C of extracts were quantified using HPLC-DAD, and the total phenolic content, flavonoid content, antioxidant activity (DPPH and reducing power), and antidiabetic activity were also studied. The antidiabetic activity was examined by the inhibition of α-amylase and α-glucosidase, and in vitro on a beta TC cell line (β-TC-6). The results showed significant differentiation in the extraction yield between the methods used, with the ASE and LE presenting the highest values. The C. mas fruit extract obtained by ASE exhibited the best antioxidant activity, reaching an IC50 value of 31.82 ± 0.10 µg/mL in the DPPH assay and 33.95 ± 0.20 µg/mL in the reducing power assay. The C. mas fruit extracts obtained by ASE and LE also have the highest inhibitory activity on enzymes associated with metabolic disorders: α-amylase (IC50 = 0.44 ± 0.02 µg/mL for the extract obtained by ASE, and 0.11 ± 0.01 µg/mL for the extract obtained by LE at combined wavelengths of 1270 + 1550 nm) and α-glucosidase (IC50 of 77.1 ± 3.1 µg/mL for the extract obtained by ASE, and 98.2 ± 4.7 µg/mL for the extract obtained by LE at combined wavelengths of 1270 + 1550 nm). The evaluation of in vitro antidiabetic activity demonstrated that the treatment with C. mas and C. monogyna fruit extracts obtained using ASE stimulated the insulin secretion of β-TC-6 cells, both under normal conditions and hyperglycemic conditions, as well. All results suggest that C. mas and C. monogyna fruit extracts are good sources of bioactive molecules with antioxidant and antidiabetic activity.
Sandra A. V. Eremia, Camelia Albu, Gabriel-Lucian Radu, Andreia Alecu, Alice G. Stoica, and Elena Brinduse
MDPI AG
In recent years, various studies have been carried out to increase the concentration of antioxidant active principles in red wines as a consequence of the effects of winemaking techniques on the polyphenols content. In this study, in order to obtain the most optimal wine in terms of content and efficiency of antioxidant activity, various winemaking technologies (punching-down and pumping-over maceration) were tried with diverse gradations (Feteasca Neagra and Cabernet Sauvignon wines) and the addition of different concentrations of melatonin in must. Suitable HPLC and spectrophotometric methods were used to follow the evolution of the antioxidant compounds from wines during aging (for 12 months). After comparing the acquired results, an increase was observed in the antioxidant compound concentrations, particularly in resveratrol (85%), peonidin-3-glucoside (100%) or cyanidin-3-glucoside (100%), and antioxidant activity (10–40%). The most enriched wine was obtained in the case of Feteasca Neagra by the addition of 0.5 mg of melatonin per 1 kg of must using the punch-down technology and, in the case of Cabernet Sauvignon, by the addition of 0.05 mg of melatonin per 1 kg of must using the pumping-over technique. This study can provide winemakers with an approach to enhance red wines with antioxidant compounds.
ANDREEA-CAMELIA HÎRJĂU
Societatea de Stiinte Farmaceutice din Romania
ELENA-CORNELİA TĂNĂSESCU, ALEXANDRA-GABRİELA ENE, ELENA PERDUM, OVİDİU IORDACHE, and LUCİAN GABRİEL RADU
The National Research and Development Institute for Textiles and Leather
The need to protect textile museum collections against pests has led to the use of pesticides. Pesticides can persist over time, thus leading to problems such as possible injury to museum staff. To address this problem, attempts have been made to obtain an overview of pesticide detection without destroying collections. In this paper, a nondestructive method for the extraction and detection of three pesticides was optimised. The selection of the main parameters of the method was carried out using statistical analysis of the obtained data by applying one-way ANOVA and the Tukey test. FPSE optimisation is performed by evaluating the following parameters: polymer selection (individual or mixture of polymers), acid catalyst (trifluoroacetic acid, acetic acid and hydrochloride acid), amount of polymer (1 g, 2.5 g or 5 g), polymerisation time (30 minutes, 120 minutes and 240 minutes), ultrasonic bath temperature (40°C and 70°C), type of bath used to obtain the sol-gel (ultrasonic bath, water bath with stirring and mechanical stirrer) and influence of the last steps of the preparation of the sol-gel solution. After the extraction system was optimized, statistical analysis was conducted to assess the influence of pesticide extraction time on FPSE and desorption from FPSE in ethyl acetate.
Gabriela Paun, Elena Neagu, Andreia Alecu, Camelia Albu, Ana-Maria Seciu-Grama, and Gabriel Lucian Radu
MDPI AG
The present study evaluated the antioxidant and antidiabetic properties of Medicago sativa and Solidago virgaurea extracts enriched in polyphenolic compounds. The extracts were obtained by accelerated solvent extraction (ASE) and laser irradiation. Then, microfiltration was used for purification, followed by nanofiltration used to concentrate the two extracts. The obtained extracts were analyzed to determine their antioxidant activity using DPPH radical scavenging and reducing power methods. The antidiabetic properties have been investigated in vitro on a murine insulinoma cell line (β-TC-6) by the inhibition of α-amylase and α-glucosidase. M. sativa obtained by laser irradiation and concentrated by nanofiltration showed the highest DPPH• scavenging (EC50 = 105.2 ± 1.1 µg/mL) and reducing power activities (EC50 = 40.98 ± 0.2 µg/mL). M. sativa extracts had higher inhibition on α-amylase (IC50 = 23.9 ± 1.2 µg/mL for concentrated extract obtained after ASE, and 26.8 ± 1.1), while S. virgaurea had the highest α-glucosidase inhibition (9.3 ± 0.9 µg/mL for concentrated extract obtained after ASE, and 8.6 ± 0.7 µg/mL for concentrated extract obtained after laser extraction). The obtained results after evaluating in vitro the antidiabetic activity showed that the treatment with M. sativa and S. virgaurea polyphenolic-rich extracts stimulated the insulin secretion of β-TC-6 cells, both under normal conditions and under hyperglycemic conditions as well. This paper argues that M. sativa and S. virgaurea polyphenolic-rich extracts could be excellent natural sources with promising antidiabetic potential.
Elena Neagu, Gabriela Paun, Camelia Albu, Oana Teodora Apreutesei, and Gabriel Lucian Radu
MDPI AG
Recently, there has been increased interest in the discovery of new natural herbal remedies for treating diabetes and inflammatory diseases. In this context, this work analyzed the antidiabetic and anti-inflammatory potential of Artemisia absinthium, Artemisia vulgaris and Trigonella foenum-graecum herbs, which have been studied less from this point of view. Therefore, extracts were prepared and processed using membrane technologies, micro- and ultrafiltration, to concentrate the biologically active principles. The polyphenol and flavone contents in the extracts were analyzed. The qualitative analysis of the polyphenolic compounds was performed via HPLC, identifying chlorogenic acid, rosmarinic acid and rutin in A. absinthium; chlorogenic acid, luteolin and rutin in A. vulgaris; and genistin in T. foenum-graecum. The antidiabetic activity of the extracts was analyzed by testing their ability to inhibit α-amylase and α-glucosidase, and the anti-inflammatory activity was analyzed by testing their ability to inhibit hyaluronidase and lipoxygenase. Thus, the concentrated extracts of T. foenum-graecum showed high inhibitory activity on a-amylase—IC50 = 3.22 ± 0.3 μg/mL—(compared with acarbose—IC50 = 3.5 ± 0.18 μg/mL) and high inhibitory activity on LOX—IC50 = 19.69 ± 0.52 μg/mL (compared with all standards used). The concentrated extract of A. vulgaris showed increased α-amylase inhibition activity—IC50 = 8.57 ± 2.31 μg/mL—compared to acarbose IC50 = 3.5 ± 0.18 μg/mL. The concentrated extract of A. absinthium showed pronounced LOX inhibition activity—IC50 = 19.71 ± 0.79 μg/mL—compared to ibuprofen—IC50 = 20.19 ± 1.25 μg/mL.
Alexandra-Gabriela Oancea, Catalin Dragomir, Arabela Untea, Mihaela Saracila, Raluca Turcu, Ana Cismileanu, Ioana Boldea, and Gabriel Lucian Radu
MDPI AG
Brewer’s spent yeast (BSY) is a byproduct of the beer industry, rich in proteins and bioactive compounds. The effects of BSY were investigated through a 6-week feeding trial on 30 lactating dairy Blackhead sheep (54.7 ± 5.66 kg, 177.34 days in milk) distributed under a completely randomised design in two groups: a control group (with soybean meal and sunflower meal as protein sources), and a BSY group, where soybean meal was totally replaced by BSY (5.4% inclusion, DM basis). The inclusion of BSY led to a 25% decrease in ruminal propionate and in the acetate/propionate ratio. BSY influenced the milk fatty acid profile by significantly decreasing the omega 6: omega 3 ratio and increasing the contents of caproic, capric, and lauric acids. Also, the inclusion of BSY was associated with an increase in the milk’s total polyphenols. Consistently, determinations of the parameters of the milk fat’s oxidative stability revealed a decrease in conjugated diene contents. Moreover, the mineral contents of milk were influenced, with an increase in Ca content noted. Overall, these results indicate that BSY represents an alternative feedstuff for ruminants’ nutrition, which could have the potential to induce changes in ruminal fermentation and milk composition that are beneficial for consumers.
Daniel Preda, Maria Lorena Jinga, Iulia Gabriela David, and Gabriel Lucian Radu
MDPI AG
A new method for the determination of the antiplatelet drug dipyridamole (DIP) in pharmaceuticals using a molecularly imprinted polymer (MIP)-modified pencil graphite electrode (PGE) is proposed. The modified electrode was prepared simply and rapidly by electropolymerization of caffeic acid (CA) in the presence of DIP and subsequent DIP extraction with ethanol, resulting in a cost-effective, eco-friendly disposable modified electrode (MIP_PGE). Several working conditions (monomer and template concentration, number of voltametric cycles, scan rate extraction time, and solvent) for the MIP_PGE preparation were optimized. The differential pulse voltammetric (DPV) oxidation signal of DIP obtained at MIP_PGE was 28% higher than that recorded at bare PGE. Cyclic voltammetry emphasized DIP irreversible, pH-dependent, diffusion-controlled oxidation at MIP_PGE. Differential pulse and adsorptive stripping voltammetry at MIP_PGE in phosphate buffer solution pH = 7.00 were applied for the drug quantitative determination in the range of 1.00 × 10−7–1.00 × 10−5 and 1.00 × 10−8–5.00 × 10−7 mol/L DIP, respectively. The obtained limits of detection were at the tens nanomolar level.
Gabriel-Lucian Radu, Simona Carmen Lițescu, Alin Enache, Camelia Albu, and Sandra A. V. Eremia
MDPI AG
In recent years, new sensor-based technologies have been developed to meet the demand for rapid and accurate analysis of food and environment, as food safety and environmental monitoring are very important concerns nowadays. In this context, considerable attention has been paid to the development and design of electrochemical sensors, as these offer a number of advantages, such as portability, ease of use, low costs and fast response times. Molecularly imprinted polymers (MIPs) are robust synthetic polymers with special cavities designed for a target molecule, and they are used as selective tools through a mechanism of molecular recognition. Graphene is a 2D crystalline carbon that forms either a single or a coupled layer of hexagonally arranged carbon atoms and is referred to as a “wonder material”. The use of these two structures in the development of electrochemical sensors gives the newly created analytical tool enhanced properties, such as improved sensitivity and selectivity, low detection limit, good stability and reusability. This review presents an overview of the recent research regarding the use of MIPs and graphene in the development of electrochemical sensors for food and environmental analyses, critically discusses the pros and cons, and gives perspectives for further developments in this field.
Madalina-Petruta Bucur, Maria-Cristina Radulescu, Gabriel Lucian Radu, and Bogdan Bucur
MDPI AG
Ultrasound generates cavities in liquids with high-energy behaviour due to large pressure variations, leading to (bio)chemical effects and material modification. Numerous cavity-based treatments in food processes have been reported, but the transition from research to industrial applications is hampered by specific engineering factors, such as the combination of several ultrasound sources, more powerful wave generators or tank geometry. The challenges and development of cavity-based treatments developed for the food industry are reviewed with examples limited to two representative raw materials (fruit and milk) with significantly different properties. Both active compound extraction and food processing techniques based on ultrasound are taken into consideration.
Sandra A. V. Eremia, Camelia Albu, Gabriel-Lucian Radu, Andreia Alecu, and Elena Brinduse
MDPI AG
Until recently, the main antioxidant role among wine constituents was attributed to polyphenolic compounds, but once the presence of melatonin in wines was confirmed, an interesting new field of research opened up due to its possible synergistic effects with other antioxidants in the winemaking process, which may lead to a change in the profile of polyphenolic compounds and antioxidant activity. In order to investigate the evolution of active principles from the phenylpropanoid metabolism associated with the synergistic effects of melatonin, for the first time, a melatonin treatment was performed in the pre-stage of the different winemaking processes of Feteasca Neagra and Cabernet Sauvignon wines with different melatonin concentrations. After comparing the acquired results for the evolution of the polyphenolic compound profile and antioxidant activity of treated wines, we ascertained an increase in the antioxidant compound concentrations, especially in resveratrol, quercetin, and cyanidin-3-glucoside, directly proportional to the used melatonin concentration; an intensification in activity of PAL and C4H enzymes; and the modification in the expression of specific anthocyanin biosynthesis genes, especially UDP-D-glucose-flavonoid-3-O-glycosyltransferase. It was also shown that the application of melatonin in the pre-stage of the winemaking process can be successfully used to obtain red wines with increased antioxidant activity (almost 14%).
Elena Neagu, Gabriela Paun, Camelia Albu, Sandra Ana-Maria Victoria Eremia, and Gabriel Lucian Radu
MDPI AG
Lately, there has been increased interest in the development of phytochemical alternatives for the prevention and treatment of type 2 diabetes, the alternatives that are able to reduce or prevent glucose absorption by inhibiting digestive enzymes. In this context, this study aims to analyze the inhibitory α-amylase and α-glucosidase activities of Artemisia abrotanum and Symphytum officinale polyphenolic compound-rich extracts obtained by membrane technologies (micro- and ultrafiltration). Polyphenols and flavones content, HPLC-MS polyphenolic compounds profiling, antioxidant activity, and cytotoxic potential of these herbs were determined. Major phenolic acid compounds were chlorogenic acid, ellagic acid, caffeic acid, and rosmarinic acid. The flavone content was higher in the case of A. abrotanum extracts, and the major compounds were rutin and umbelliferone. The polyphenolic-rich extract of A. abrotanum had the highest quantities of polyphenols, 977.75 µg/mL, and flavones, 552.85 µg/mL, as well as a pronounced α-amylase inhibitory activity (IC50 1881.21 ± 1.8 mg/mL), a value close to acarbose inhibitory activity (IC50 1110.25 ± 8.82 mg/mL) that was used as the control for both enzymes. The α-glucosidase inhibitory activity was higher for both herb extracts, more pronounced for S. officinale polyphenolic-rich extract (IC50 291.56 ± 2.1 mg/mL), a value higher than that of acarbose (IC50 372.35 ± 3.2 mg/mL). These plants show potential as a complementary therapy for type 2 diabetes management.
Sandra A. V. Eremia, Camelia Albu, Gabriel L. Radu, and Marian Ion
MDPI AG
In recent years, the wine industry has shown a considerable degree of interest in the occurrence of melatonin in wines. Sample pretreatment may be the most important step in trace analysis. Since wine is a complex matrix and melatonin is present in low amounts (ppb), an adequate extraction technique is required. In this study, the effect of several extraction methods, such as solid phase extraction (SPE), Quick, Easy, Cheap, Effective, Rugged, and Safe extraction (QuEChERS), and dispersive liquid–liquid micro-extraction (DLLME) was studied and the variable parameters that can arise throughout the extraction process were optimized to obtain the best results. A high-performance liquid chromatography with fluorescence detector (HPLC-FL) method was adapted and validated, including measurement uncertainty, for the analysis of melatonin in wines and to assess the efficiency of the extraction yield. After comparing the acquired results, the DLLME method was optimized. Extraction recoveries values ranging from 95 to 104% demonstrated that the approach may be successfully applied for the extraction and concentration (enrichment factor of almost eight) of melatonin in wine samples prior to HPLC-FL analysis. The first report of melatonin levels in Feteasca Neagra wines has been made. The data obtained for Cabernet Sauvignon revealed that the final levels of melatonin in the wines are dependent on the winemaking process.
Emanuel Vamanu, Florentina Gatea, Ionela Avram, Gabriel Lucian Radu, and Sandeep Kumar Singh
MDPI AG
The administration of chokeberry extract in vitro in the GIS1 system was evaluated for the modulation capacity of the dysbiotic pattern resulting from the consumption of stevia. The microbial pattern determined by molecular method, the metabolomic one (fatty acids), the evolution of the antioxidant status, and the cytotoxic effect were determined comparatively for six months. This study presented for the first time that Aronia extract has a strong antimicrobial effect but also a presence of new organic acids that can be used as a biomarker. The functional supplement had the impact of a gradual increase in antioxidant status (DPPH scavenging activity) for up to three months and a subsequent decrease correlated with the reduction of the microbial load (especially for Enterobacteriaceae). The effect on metabolomic activity was specific, with butyric acid being generally unaffected (0.6–0.8 mg/mL) by the antimicrobial effect manifested after three months of administration. The pH was strongly acidic, corresponding to the constant presence of maximum values for acetic and lactic acid. The non-selective elimination of a part of the microbiota could also be correlated with a decrease in metabolomic efficiency. The results in the GIS1 system indicated for the first time that the controlled use of this extract had a pronounced antimicrobial and cytotoxic effect. This has helped to correct the dysbiotic pattern that results after the long-term use of sweeteners based on an increase of 0.2 log UFC/mL for favorable strains.