Total Flavonoid Research Articles

In vitro antimicrobial and antioxidant activities of bioactive compounds extracted from Streptomyces africanus strain E2 isolated from Moroccan soil

This study aimed to isolate Streptomyces sp. from Moroccan terrestrial ecosystems and identify bioactive compounds through GC–MS analysis. Antimicrobial activity was assessed against various pathogenic microorganisms including Staphylococcus aureus ATCC 25923, Pseudomonas aeruginosa ATCC 27853, Escherichia coli ATCC 25922 and Candida albicans ATCC 60193, and multi-drug resistant strains comprising Listeria monocytogenes, Klebsiella pneumoniae 19K 929, Proteus sp. 19K1313, Klebsiella pneumoniae 20B1572, Proteus vulgaris 16C1737, and Klebsiella pneumoniae 20B1572. Based on the results of the gene sequencing of gene 16S rRNA and phylogenetic analysis, the E2 isolate belongs to the genus Streptomyces with the highest degree of resemblance (97.51%) to the Streptomyces africanus strain NBRC 101005 (NR_112600.1). The isolate exhibited broad-spectrum antibacterial activity, with maximum efficacy against Klebsiella pneumoniae 20B1572 indicated by an inhibition zone diameter of 22.5 ± 0.71mm and a minimum inhibitory concentration (MIC) of 0.0625 mg/mL. The in vitro antioxidant potential of E2 strain was determined through screening of its ethyl acetate extract against sets of antioxidant assays. The results were indicative of E2 strain displaying strong antioxidant activity against ABTS, DPPH free radicals, and FRAP. Furthermore, there was a high significant correlation (p < 0.0001) between the total phenolic and flavonoid content and antioxidant activities. The GC–MS analysis of the extract identified six volatile compounds, with Eugenol (96%) and Maltol (93%) being the most prominent. Additionally, the HPLC–UV/vis analysis revealed six phenolic compounds: gallic acid, chlorogenic acid, vanillic acid, trans-ferulic acid, ellagic acid, and cinnamic acid. Overall, the study highlights Streptomyces sp. strain E2 as a potential source of potent antimicrobial and antioxidant metabolites, offering promise in addressing antibiotic resistance and oxidative stress-related conditions.

Investigating the effect of fermentation byLactobacillus reuteri on biochemical properties of Ceylon Cinnamon

Abstract Introduction Fermentation is an important biotechnological process that improves the biochemical properties of natural raw materials by transforming high molecular compounds into more beneficial low molecular compounds through microbial biotransformation. Ceylon cinnamon (Cinnamomum zeylanicum Blume), globally recognized as 'true cinnamon', contains high molecular weight, complex compounds that are responsible for its renowned antioxidant, antibacterial, and therapeutic properties, making it a vital component in medicinal applications1. Aims The present study aimed to investigate the effect of fermentation by Lactobacillus reuteri on selected phytochemical contents, antioxidant, and antibacterial properties of bark extracts of Ceylon cinnamon (Cinnamomum zeylanicum Blume) and to determine the optimum conditions for fermentation of Cinnamon bark extract by L. reuteri. Method Authenticated Ceylon cinnamon bark (CCB) was extracted into water using the decoction method. The water extract was fermented by L. reuteri under controlled conditions (pH 6, incubation at 35 ºC) and optimized using two parameters; the inoculum density (1.5×108 cfu/ml and 7.5×108 cfu/ml) and incubation time (2 and 4 days). After fermentation, total polyphenolic content (TPC), total flavonoid content (TFC), DPPH free radical scavenging activity and antibacterial activity of non-fermented extracts (NFE) and fermented extracts (FE) of CCB were evaluated. Antibacterial activity was determined using the agar well diffusion method against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. Ethical approval was not required since no human or animal study was done during the study. Results The extract fermented with an inoculum density of 7.5×108 cfu/ml and incubated for 4 days showed the highest TFC (19.3 ± 0.3 mg RE/g) and antioxidant activity (IC50: 97.2 ± 0.8 µg/ml) in comparison to that of NFEs (TFC:13.3 ± 0.3 mg RE/g and DPPH activity: IC50: 233.7 ± 12.8 µg/ml). Moreover, the fermented samples showed a reduction in TPC, indicating possible biotransformation of compounds. and no significant change in the antibacterial activity in comparison to the non-fermented samples. Discussion and Conclusion This study was mainly focused on investigating the effect of fermentation of Ceylon cinnamon bark aqueous extract by Lactobacillus reuteri. The increased antioxidant activity and total flavonoid content are notable and could be attributed to chemical transformations of some complex flavanols including catechin gallate and epicatechin gallate present in aqueous cinnamon to catechin and epicatechin monomers by the action of enzymes secreted by L. reuteri during the fermentation process2. Hence, this study suggests that fermentation using L. reuteri has a considerable positive impact on certain biochemical properties of cinnamon water extract. Cinnamon bark is a complex matrix containing various phytochemicals that could interact with bacterial strains in ways that are not fully understood. These interactions could lead to unexpected effects or limitations during fermentation.

Functionality of Semolina Pasta Supplemented with Grapefruit Flavedo Byproduct: Effect on Phytochemical, Functional, Textural, Cooking, and Sensorial Quality

Background: Pasta is consumed worldwide and can be an excellent food matrix for supplementation. Grapefruit (Citrus paradisi) flavedo byproduct is reported to contain considerable amounts of bioactive compounds, which represent a valuable and sustainable source of phenolics. So far, there is limited information available about the utilization of grapefruit flavedo byproducts for supplementation of pasta. Methods: The present study aimed to investigate the effect of freeze-dried grapefruit flavedo powder (GFP) incorporation at various concentrations (3, 6, 9, and 12%) on the phytochem-ical, functional, textural, microstructural, and sensory quality of the developed pasta. Results: Fortification with GFP significantly (P&lt;0.05) enhanced antioxidant activities rela-tive to DPPH and FRAP and increased the total phenolic and flavonoid content from 73.20–96.83 mg GAE/100g and 132.41–211.63 mg GAE/100g, respectively. Supplementation with GFP significantly (P&lt;0.05) reduced the optimum cooking time of pasta, while cooking loss increased up to 6.32% with 12% GFP incorporation, which was still under the acceptable limits (&lt;8%). The addition of GFP decreased the L* value, while the a* and b* values in-creased for the pasta. SEM analysis presented that GFP incorporation in pasta affected the structural integrity attributable to the enhanced fiber levels, inducing a weaker matrix, as ascertained by textural profile analysis (TPA) with a decline in hardness attribute with in-creasing GFP concentration. Sensory analysis divulged overall acceptability scores of 8.4 for the pasta with 6% GFP, while further increments in GFP levels led to decreased sensory scores. Conclusion: Grapefruit peels are typically discarded as waste, the outer layer of which, i.e., flavedo, could be used to enrich pasta. The present research divulged that pasta supplemen-tation with freeze-dried flavedo powder could provide total phenolic content, flavonoid con-tent, and antioxidant potential without compromising on the technological and sensory qual-ity of pasta. Utilization of this citrus waste as a bioactive food ingredient with promising effects represents a valuable byproduct valorization strategy.

Study on the Mechanism of Flavonoid Enrichment in Black Soybean Sprouts by Abscisic Acid/Melatonin Under Slight Acid Treatment

Plant hormones play a critical role in the physiological and biochemical mechanisms of plants, with functions such as regulating the metabolic pathways of secondary metabolite production and alleviating external stresses. In this study, the synthesis of flavonoids in black soybean sprouts was induced by slight acid combined with the plant hormones abscisic acid (ABA) and melatonin (MT). The results indicated that the contents of daidzin, genistin, daidzein, and genistein in black soybean sprouts treated with slight acid were increased by 10 μM ABA and 75 μM MT, and the total flavonoid content was significantly enhanced. Compared with the slight acid treatment, the H2O2 and malondialdehyde (MDA) contents in black soybean sprouts were increased after ABA treatment, and the black soybean sprouts were further stressed. However, the H2O2 and MDA contents in black soybean sprouts were significantly decreased after MT treatment, indicating that the stress of black soybean sprouts can be alleviated by MT. Under slight acid stress, the genes related to flavonoid synthesis in black soybean sprouts were induced by exogenous ABA, promoting the accumulation of flavonoids; under exogenous MT treatment, the activity of phenylpropanoid metabolism enzymes was significantly increased, the genes related to flavonoid synthesis were upregulated, and flavonoid synthesis was induced. These results suggest that the combination of slight acid and plant hormone treatments promotes the accumulation of flavonoid substances during the germination of black soybeans. This research lays the foundation for improving the growth conditions of black soybeans and promoting the enrichment of flavonoid substances in black soybeans.

The combination of nanoparticles and endophytes boosts Thyme (Thymus vulgaris L.) resistance to drought stress by elevating levels of phenolic compounds, flavonoids, and essential oils

BackgroundAs climate change and water scarcity increasingly threaten agricultural productivity, enhancing plant resilience to drought has attracted great attention. This study explored the potential of combining Fe2O3 nanoparticles (FeNPs), endophytic bacteria (EB), and endophytic fungi (EF) to boost drought tolerance in Thymus vulgaris. The research aimed to assess how these combined treatments affect the plant’s physiological responses and chemical composition under drought stress.ResultsA factorial experiment was designed using completely randomized design (CRD) method, incorporating four irrigation levels [100%, 75%, 50%, and 25% field capacity (FC)], four FeNPs concentrations (0, 0.5, 1, and 1.5 mg L−1), and three endophyte types (control, bacteria, and fungi). After extracting, purifying, identifying, and screening EB and EF from nine Lamiaceae species, the endophytes Azospirillum lipoferum and Aspergillus oryzae isolated from Salvia mirzayanii exhibited the highest drought resistance. The highest amounts of TFM (45.45 g) and TDM (21.56 g) were obtained using the combination of EB and FeNPs at 1 mg L−1 under irrigation with 100% FC. At 25% FC, EB treatment increased the activities of polyphenol oxidase (PPO) and phenylalanine ammonia-lyase (PAL) by 62.12% and 18.23% compared to the control, respectively. In addition, under optimal humidity conditions, FeNP concentrations were higher than 0.5 mg L−1 leading to a decrease in PPO activity. At 25% FC, the highest content of total phenols was observed with a 37.5% increase under EB treatment using 1 mg L−1 of FeNPs, while the highest content of total flavonoids showed a 62.72% increase under EF treatment with 0.5 mg/L of FeNPs. The highest level of p-coumaric acid was obtained under EF (34.27% compared to control). At 25% FC, EB and FeNPs (1 mg L−1) increased the level of caffeic acid in thyme plants by 24.70% and 10.08%, respectively. In addition, inoculation with EB increased (11.9%) the content of ferulic acid in plants and the application of FeNPs as a foliar spray decreased the level of ferulic acid in thyme plants. The highest essential oil percentage at 25% FC was observed after inoculation with EF and FeNPs (0.5 mg L−1), resulting in significant increases of 14.7% and 82.12%, respectively, compared to the control. A decrease in irrigation level led to an increase in the percentage of essential oil in thyme plants while decreasing dominant essential oil compounds, thymol, and carvacrol. The levels of thymol and carvacrol in the essential oil were not affected by the interaction effects of drought stress, endophytes, and FeNPs. EF and FeNPs (1.5 mg L−1), respectively, caused significant increases of 17.44% and 29.87% compared to the control in the amount of thymol and significant increases of 13.75% and 31.01% in the amount of carvacrol. All FeNPs concentrations decreased the concentrations of ferulic acid, FeNPs (1.5 mg L−1) and PPO; these particles act as abiotic stressors at sub-toxic levels and become phytotoxic at higher concentrations.ConclusionsIt seems that combining endophytes with FeNPs showed promise in enhancing drought tolerance in T. vulgaris. These treatments have significantly contributed to the production of enzymatic antioxidants, flavonoids, and phenolic compounds, leading to a reduction in the amounts of oxidants. At the same time, they have improved both the quality and quantity of essential oils. This highlights the importance of establishing an effective antioxidant system in response to environmental stresses.Graphical

Heterologous Expression of MYB Gene (Rosea1) or bHLH Gene (Delila) from Antirrhinum Increases the Phenolics Pools in Salvia miltiorrhiza

Phenolic acids have health-promoting properties, however, but their low concentrations in Salvia miltiorrhiza limit broader medicinal applications. MYB and bHLH transcription factors activate multiple target genes involved in phenylpropanoid metabolism, thereby enhancing the production of various secondary metabolites. We introduced the MYB transcription factor Antirrhinum Rosea1 (AmROS1) or Delila (AmDEL) into S. miltiorrhiza and observed that antioxidant activity in transgenic plants increased by 1.40 to 1.80-fold. The total content was significantly higher in transformants compared to the controls. Furthermore, heterologous expression of AmROS1 or AmDEL triggered moderate accumulations of rosmarinic acid and salvianolic acid at various growth stages. Levels of total phenolics, total flavonoids, and anthocyanins were significantly elevated. These biological and phytochemical alterations were correlated with the upregulated expression of genes involved in phenolic acid biosynthesis. Our findings demonstrate that AmROS1 and AmDEL function as a transcriptional activator in phenolic acids biosynthesis. This study offers further insights into the heterologous or homologous regulation of phenolics production, potentially enabling its engineering in S. miltiorrhiza.

Assessment of Bioactive Compounds and Physiological Activities of Ethanolic and Aqueous Extracts from Black Rice, Black Rice Bran, and Milled Black Rice

Black rice (BR) is considered one of the healthiest foods worldwide. This study assessed the bioactive compound contents and antioxidant activities of the distilled water (DW) and 80% ethanol (EtOH) extracts of BR, black rice bran (BRB), and milled black rice (MBR). In addition, their anti-obesity, anti-obesogenic, and anti-muscle atrophy effects were comparatively evaluated. The results revealed that the 80% EtOH extract of BR contained higher contents of β-glucan, total flavonoids, and total phenolics (26.97 ± 0.70 mg gallic acid equivalents (GAE)/g and 16.58 ± 0.37 mg quercetin equivalents (QE)/g, respectively) and showed higher antioxidant activity than those of the BRB and MBR extracts. On the other hand, BRB contained the highest content of γ-oryzanol, which was 15.12 ± 0.03 mg/g. Moreover, the 80% EtOH extract of BR exhibited a stronger anti-obesogenic effect by downregulating adipogenesis-related proteins (PPAR-γ, C/EBP-α, and FAS) and upregulating lipolysis-related proteins (PGC-1α and CPT-1), while the BRB extract effectively increased myotube diameter and fusion index. Overall, these findings indicate that the 80% EtOH extracts of BR, BRB, and MBR, particularly the BR extract, have high potential as natural antioxidants and anti-obesity agents, with BRB showing promise in preventing muscle atrophy.

Assessment of Pudding Formulations Using Lyophilized Apricot, Plum, and Plum–Apricot Powders: Texture, Bioactivity, and Sensory Quality

The food sector is constantly responding to consumers’ increased demands concerning healthy nutrition and beneficial ingredients. This study presented the development of three pudding alterations using lyophilized fruit (apricots, plum–apricots, and plums) powders. The same concentrations of fruit powder fully substituted the sugar in each formulation. The results showed that each new formulation formed a thick gel consistency and had full water-holding capacity at 24 h of storage. The color differed according to the established CIE-lab data. The lightness varied from 42.57 ± 1.97 (pudding formulation using plum powder) to 81.91 ± 1.18 (control sample). The total soluble solids and titratable acidity showed that the control sample was different from each new formulation. The water activity was similar in all studied samples varying from 0.978 ± 0.003 to 0.989 ± 0.001, and the plum and plum–apricot formulations had a pH near the control samples, at 6.54 and 7.23, respectively. The antioxidant activity, total polyphenol content, and total flavonoid content were also evaluated. The ABTS assay revealed the highest results compared to the other three applied methods. The sensory evaluation showed that it is necessary to further improve the recipes for better consumer perception.

Influence of temperature, solvent and extraction procedure on the content of phenolic compounds and antioxidant activity of &lt;i&gt;Aloysia citriodora&lt;/i&gt; Palau leaves

Introduction: The leaves of Aloysia citriodora Palau are a source of phenolic compounds that have antioxidant properties. Objective: The objective of this study was to compare the effects of temperature, type of solvent, maceration, and ultrasound processes in the extraction of phenolic compounds from A. citriodora Palau leaves that allow for maintaining the highest antioxidant capacity. Methods: In this study, phenolic compounds were extracted from A. citriodora by two methods, maceration, and ultrasonic treatment, using water and 80% ethanol as solvents and extraction temperatures of 25 °C, 45 °C, and 65 °C. Total phenolic compounds (TPhen), total flavonoid compounds (TFlav), and antioxidant capacity, evaluated by DPPH and ABTS assay, were characterized and reported as inhibition concentration (IC50). Results: The highest CPhen content was obtained with ethanolic extract using the ultrasonic method at 65 °C, with a value of 15.32 mg EAG/mL at 65 °C. For TFlav, the highest value was obtained with the ultrasonic treatment at 45 °C using ethanol as solvent, obtaining a value of 6.52 mg EQ/mL. The best antioxidant capacity was shown by the sonication with ethanol at 65 and 45 °C, with IC50 values of 27.10 µg/mL and 20.40 µg/mL, respectively. Conclusion: Ultrasound extraction at higher temperatures (45°C and 65°C) proved more effective than maceration, yielding greater amounts of phenolic and flavonoid compounds and exhibiting better antioxidant capacity.”. Keywords: Aloysia citrodora, phenolic compounds, antioxidant activity, inhibitory concentration IC50.

Influence of altitudes and development stages on the chemical composition and antioxidant capacity of Andean blackberries (Rubus glaucus Benth)

BackgroundThe Andean blackberry (Rubus glaucus Benth), locally known as “Mora de Castilla,” is a high-altitude fruit rich in phytochemicals, mainly anthocyanins, with potent antioxidant properties. Although its chemical composition has been studied, the influence of altitude on its phytochemical profile and antioxidant capacity is still unclear. This research aimed to investigate the effects of development stages and altitude on the phytochemical profile and antioxidant activity of this fruit.MethodsAndean blackberry fruits were collected at different altitudes and development stages in the central Andean region of Ecuador. An hydroalcoholic extraction was used to quantify the compounds and determine the total antioxidant activity, while solid phase extraction (SPE) was performed to separate anthocyanins from other compounds. Ultra-high-performance liquid chromatography coupled to a triple quadrupole mass spectrometer (HPLC-DAD/ESI-MSn) was used to identify anthocyanin and non-anthocyanin phenols, while total antioxidant capacity, total polyphenols, total flavonoid content, and total anthocyanin content were quantified spectrophotometrically.ResultsFlavonols and anthocyanins constitute the majority of the flavonoids identified in the Andean blackberry extracts, both in terms of peak areas and number of identified compounds, followed by ellagic and gallic acid derivatives, as well as phenolic acids, mainly hydroxycinnamic acids. Quercetin was identified as the predominant flavonol in unripe berries, where anthocyanins were not significantly present. On the contrary, in ripe berries, cyanidin and its glycosides stood out as the main anthocyanins and predominant compounds. We observed that in the early stages of ripening, the total polyphenol content predominates in the berries and is mainly responsible for their antioxidant capacity. However, as the fruit ripens, the total anthocyanin content increases, becoming the most prominent bioactive compounds in fully ripe berries.ConclusionThe results suggest that higher altitude environmental conditions may improve the composition, concentration of phenolic compounds, and antioxidant activity of Andean blackberries. Overall, our findings highlight the high functional value of this fruit, supporting its health-protective effects when consumed regularly, either as fresh fruit or in nutraceutical form.

Bioactive Properties of Campomanesia lineatifolia: Correlation Between Anti-Helicobacter pylori Activity, Antioxidant Potential and Chemical Composition

Helicobacter pylori is found in the stomach of patients with chronic gastritis and peptic ulcers, infecting approximately half of the world’s population. Current treatment for H. pylori infection involves a multi-drug therapeutic regime with various adverse effects, which leads to treatment abandonment and contributes to the emergence of resistant strains of H. pylori. Previously, we demonstrated that the essential oil of Campomanesia lineatifolia leaves exhibited an anti-H. pylori activity. In this study, we aimed to evaluate the phenolic content of the phenolic-rich ethanol extract (PEE) from C. lineatifolia and its anti-H. pylori and antioxidant properties. Additionally, the anti-H. pylori activity was assessed in polar and non-polar fractions from PEE, isolated myricitrin (MYR) and a mixture of myricitrin and quercitrin (MYR/QUER) from polar fractions, and aqueous extract (tea) to correlate the responsible fractions or compounds with the observed activity. Broth microdilution assays were performed to assess the anti-H. pylori activity using type cultures (ATCC 49503, NCTC 11638, both clarithromycin-sensitive) and clinical isolate strains (SSR359, clarithromycin-sensitive, and SSR366, clarithromycin-resistant). The antioxidant activity was evaluated using the DPPH assay. The total tannin and flavonoid contents were determined using the hide-powder method, the Folin-Ciocalteu reagent, and the aluminium chloride colourimetric assay, respectively. The tea (MIC 1:100), PEE, polar and non-polar fractions, MYR, and MYR/QUER inhibited the growth of H. pylori strains tested (MIC values ranging from 0.49 to 250 μg/mL). The antioxidant assays revealed that PEE exhibited a higher antioxidant activity (EC50 = 18.47 μg/mL), which correlated to the high phenolic content (tannin and flavonoid, 22.31 and 0.15% w/w, respectively). These findings support the traditional use of C. lineatifolia as a multitarget medicinal plant for treating gastric ulcers and reinforce the potential use of the species as a coadjuvant in therapeutic regimes involving patients with resistant H. pylori infection.

Optimization of microwave-assisted extraction using response surface methodology and HPLC-DAD phenolic compounds quantification from Hylocereus undatus peel and pulp cultivated in Tunisia

The present study aimed to optimize the microwave-assisted extraction process for both the peel and pulp of Hylocereus undatus (white dragon fruit) cultivated in Tunisia, using response surface methodology. Total phenolic content, total flavonoid content, FRAP (ferric reducing antioxidant power), and DPPH (1,1-diphenyl-2-picrylhydrazyl) antioxidant activities were optimized. A central composite design (CCD) was applied, considering three key variables: extraction time, extraction temperature, and liquid-to-solid ratio. The optimized extraction parameters for Hylocereus undatus peel and pulp were determined respectively (9.57 min, 42.20 °C and 27.79 mL/g) and (10.08 min, 40.84 °C and 31.52 mL/g). The main phenolic compounds identified in Hylocereus undatus peel and pulp extracts using HPLC-DAD were chlorogenic and caffeic acids and rutin, quercetin, luteolin-7-O-glucoside as flavonoids. Therefore, this research has revealed the potential of a sustainable and eco-friendly process hold promise a directional option and encouraging a circular economy approach for industrial production of antioxidant-rich Hylocereus undatus extracts.

Changes in Postharvest Quality and Physiological Attributes of Strawberry Fruits Influenced by L‐Phenylalanine

ABSTRACTStrawberry (Fragaria × ananassa) is a popular fruit with rich nutrients and a delicious taste. But this fruit is very vulnerable to diseases and decay. Therefore, L‐phenylalanine (Phe) (0, 4, 8 mM) was considered to improve biochemical characteristics and activity of antioxidant enzymes in strawberry fruit cv. Sabrina under cold storage (5, 10, 15 days). After treatment and storage, traits including weight loss, total phenol (TP), antioxidant capacity, ascorbic acid, total anthocyanin (TA), total flavonoid (TF), malondialdehyde (MDA), soluble protein content and antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), and guaiacol peroxidase (POD) and phenylalanine ammonialyase (PAL) were evaluated at 5‐day intervals. Our findings showed that the treatment of L‐phenylalanine in different concentrations prevented the weight loss of the fruit compared to the control and maintained and increased TP, antioxidant capacity, ascorbic acid, TA, TF, soluble protein and SOD, CAT, APX, POD, and PAL enzymes activity. Also, Phe decreased the MDA content and peroxidation of lipid. The results showed that 4 mM Phe is the best treatment for improving phytochemical characteristics and maintaining fruit quality. The findings indicated that Phe treatment may be useful to improve quality and increase postharvest shelf life in strawberry fruits.

Biostimulant effect of Cladophora glomerata extract on garden cress plant growth

Biostimulants that improve agriculture's productivity and environmental responsibility are widely favored and used. Algae has emerged as a viable option for sustainable agriculture. In the present study, the effects of the Cladophora glomerata (L.) Kütz. aqueous extract in three concentrations (2.5, 5, and 10 mg extract per mL of tap water) was tested on the growth and productivity of garden cress (GCR) Lepidium sativum L., plants over 12 days, and the results were compared with those of the control group (irrigated only with tap water). The effect of the algae extract was studied by assessing the changes in phenolic compounds using HPLC–DAD and determining the chlorophyll content as well as the total antioxidant capacity of the GCR using DPPH and ABTS tests. Total phenolics, as well as total flavonoids, were measured. The potential role of algae extract in promoting cress plant growth was attained when compared to the control, mainly at a concentration of 2.5 mg/mL, which exhibited the highest yield growth after 12 days and presented the highest antioxidant capacity at 13.53 ± 1.16 mg Trolox equivalent (TE)/g dry weight (DW), compared to 10.44 ± 0.33 mgTE/g DW for the control. The total phenolic content significantly increased (p < 0.05) from 14.34 ± 0.84 mg gallic acid equivalent (GAE)/ g dry weight (DW) to 23.14 ± 0.55 mg GAE/g DW. Eleven phenolic compounds were identified in different tested samples of GCR, whether treated or not treated with algae extracts. Chrysin was only identified in the treated plants. Therefore, the use of algae (C. glomerata) presents promising potential as a biostimulant in agriculture, contributing to increased plant growth and improved resistance to environmental stress.

Foliar Application of Methyl Jasmonate and Chitosan Improve Growth, Yield, and Quality of Guar (Cyamopsis tetragonoloba L.) Under Water-Deficit Stress

Guar (Cyamopsis tetragonoloba L.), a summer legume, is becoming increasingly important as an industrial crop due to its high gum and viscosity content. This study investigated the effects of methyl jasmonate (MeJA), chitosan (CH), and their combination on the growth, yield, and quality of guar under irrigation regimes. A greenhouse experiment was conducted using a factorial design to evaluate the effect of foliar spraying with MeJA (5, 25, and 50 µM), CH (100, 150, and 200 mg/L), their combination (25 µM MeJA + 150 mg/L CH), and control on two commercial guar varieties (RGC-986 and BR-2017) under different irrigation regimes (100%, 70%, and 40% field capacity). The results showed that the exogenous application of MeJA and CH, individually and in combination, significantly enhanced various morphological traits and yield components in guar, including plant height, pod characteristics, seed yield, and root development. Additionally, the combination treatments improved seed quality parameters, such as gum percentage and viscosity content. Leaf analysis revealed increased levels of total phenolic content, total flavonoid, and anthocyanin contents. The BR-2017 variety showed superior performance in most morphological and qualitative traits, demonstrating greater resistance to irrigation regimes. It maintained yield and quality characteristics under water-deficit conditions, particularly when treated with 25 µM MeJA and 150 mg/L CH. The highest gum percentage (33.67%) and viscosity (4768.5 cP) were observed in the RGC-986 variety, along with enhanced levels of secondary metabolites. This study provides new insights into how MeJA, CH, and their combination can improve the yield and quality of guar under water deficit stress conditions. The results suggest that the use of these elicitors, especially in combination, represents an innovative strategy for improving guar production and quality, with potential variety-specific responses to water-deficit stress.

Roasted and Unroasted Cocoa Nibs: Bioactive Compounds Analysis and Application in Cereal Bars

Cocoa beans contain a variety of nutritional compounds and are rich in biologically active substances. The aim of this study was to utilize cocoa nibs (roasted and unroasted) as the main ingredient in the development of an attractive and convenient product. The produced nibs were analyzed for total phenolics, flavonoids, and antioxidant capacity using DPPH, ABTS, and FRAP methods. The primary phenolic compounds and methylxanthines were analyzed by LC/MS. Subsequently, cereal bars were developed, including a control sample (without nibs) and five formulations containing 41% nibs, using various proportions of roasted and unroasted nibs. The influence of the origin of the beans on the product characteristics was also evaluated. The results showed that the roasting process led to a reduction in epicatechin, caffeine, and caffeic acid. Furthermore, the reduction in total phenolics, flavonoids, and antioxidant capacity after roasting was more pronounced in beans from Bahia compared to those from Espírito Santo. Regarding the cereal bars, the results demonstrated that using cocoa from Bahia, the formulation with a higher proportion of unroasted nibs (F80) significantly increased the total phenolic content (1968.85 mg of gallic acid/100 g) and total flavonoids (39.26 mg of quercetin/100 g). This initial study suggests that the use of cocoa nibs as a functional ingredient in cereal bars may be a viable and advantageous option for creating a product with greater antioxidant potential.

Effect of vermicompost on the nutraceutical quality of tender cladodes of Opuntia ficus-indica

The consumption of tender cladodes knows as “nopalitos” (Opuntia ficus-indica L. Miller.) has increased worldwide. That is because it is an important nutritional source in the human diet given its content of fiber, minerals, vitamins, phenolic compounds and secondary metabolites (antioxidants, phenols and flavonoids), which are essential for human health. The objective of this study was to evaluate the effect of doses of vermicompost (0, 5, 15 and 25 t ha-1) on the yield and nutraceutical quality of tender cladodes of O. ficus-indica. The measured variables were tender cladodes production and nutraceutical quality. The results showed no significant effect on the content of total phenolic compounds, total flavonoids and antioxidant capacity. However, the application of vermicompost showed significant effects on the yield, in which higher estimates were achieved for the highest dose with up to 100% compared to the control. The data obtained indicate that the dose of 25 t ha-1 of vermicompost promotes and increase in yield without compromising the nutraceutical quality of “nopalitos”.

The Utilization of Vegetable Powders for Bread Enrichment—The Effect on the Content of Selected Minerals, Total Phenolic and Flavonoid Content, and the Coverage of Daily Requirements in the Human Diet

The aim of this study was to evaluate the content of selected minerals and total phenolic and flavonoid content of wheat bread and bread enriched with varying amounts of carrot powder (CP) and pumpkin powder (PP). In addition, the coverage of daily requirements of selected minerals was evaluated after the consumption of 100 g of each type of bread. The research included seven types of bread: wheat bread (WB) and bread enriched with 10%, 20%, and 30% CP and PP. The vegetable powders were obtained by freeze-drying. The concentrations of minerals—sodium (Na), potassium (K), calcium (Ca), magnesium (Mg), iron (Fe), zinc (Zn), copper (Cu), and manganese (Mn)—were determined by atomic absorption spectroscopy (AAS) method. Coverage of daily requirements after consumption of a serving of bread was determined based on Recommended Daily Allowance (RDA) and Adequate Intake (AI) ratios for minerals, according to the nutritional standards for the Polish population. The addition of 10% PP led to a greater increase in Na, K, Mg, and Cu in the bread compared to CP, while for Ca, Fe, Zn, and Mn a greater increase was observed with the addition of 10% CP than PP. Among macronutrients, the greatest changes in content were recorded for Ca—the addition of 10 and 20% CP and PP resulted in increases of 66, 113, 51 and 59%. Among micronutrients, the addition of CP and PP to wheat bread caused the largest changes in Cu (46–150% increase) and Mn (25–99% increase) content. Additionally, there was a tenfold increase in total phenolic content (TPC) when 30% CP was added to the bread. Consuming 100 g of bread with CP and PP provided the greatest coverage of K (41–60%), Cu (8–17.5%), and Mn (6–17%). These findings suggest that fortification of bread with vegetable powders has the potential to be a useful method of enriching the mineral composition and increasing the proportion of selected minerals in the human diet.

Qualitative and quantitative analysis of major components in Abelmoschus manihot flowers treated with different drying methods using UHPLC Q-exactive MS and HPLC-PDA

The flowers of Abelmoschus manihot (L.) Medic are commonly used in clinical practice in China to cure forms of chronic kidney disease. Despite a long history of traditional use, the flowers obtained by different drying technologies have never been fully chemically characterized, and the ranges of constituents between different drying methods have not been comprehensively reported. To establish a quality control and chemical characterization method, a total of 14 batches of samples corresponding to 14 postharvest treatments were studied. Seven flavonoids were quantified using a HPLC-PDA method. The method was validated in terms of linearity (r > 0.999), precision (intra- and inter-day: 0.7–1.4 %), accuracy (99.90–100.7 %), detection limit (0.34–0.46 µg/mL) and quantification limit (1.15–1.52 µg/mL). The contents of total flavonoids in manihot flowers were as follows in descending order: Infrared Drying (50.96 mg/g) > Microwave Drying (41.84 mg/g) ≈ Hot-air Drying (39.58 mg/g) ≈ Fresh (39.35 mg/g) ≈ Primary Drying (38.95 mg/g). Principal component analysis showed that samples processed with Fresh, Primary Drying, and the investigated three modern drying methods were well classified into three domains, indicating an important difference between drying methods. For the purpose of saving the flavonoids contents, infrared drying under 80–100 °C would be most acceptable. Furthermore, using UHPLC Q-Exactive Orbitrap MS data with targeted and non-targeted approaches, 28 compounds were identified in Abelmoschus manihot samples. Flavonoids were the main group of compounds found in Abelmoschus manihot flowers. The study could provide the scientific evidence for the selection and optimization of appropriate drying method for manihot flowers, and also provide the reference for the formation of generic primary drying processing technology for medicinal flowers containing flavonoids.

Comprehensive honey authentication in Bangladesh: Profiling physicochemical and bioactive compounds to distinguish floral sources and detect adulteration

This study aims to advance honey authentication in Bangladesh by developing a reliable, cost-effective, and user-friendly system capable of distinguishing floral sources and purity. We analyzed various physicochemical parameters and bioactive compounds in honey samples from diverse floral sources across Bangladesh during different floral seasons, including deliberately adulterated samples. Results showed clear distinctions among the tested parameters. Notably, moisture content exhibited considerable variability, with the highest levels found in kholisha (24.07%–24.99 %) and the lowest in black cumin honey (17.80%–27.46 %). Jujube honey exhibited the highest protein content at 10 % adulteration, whereas mustard honey showed the least at 20 % adulteration. Generally, adulterated honey samples showed a considerable deviation in protein content compared to known standards for pure honey, suggesting adulteration significantly impacts protein levels. Black cumin honey showed the highest electrical conductivity, followed by jujube. Antioxidant levels were highest in litchi honey, followed by ayurvedic and kholisha. Multivariate analysis revealed that two principal components explained 65 % of total variances and could separate the various clusters of honey samples. The pH values, total phenolic, total flavonoid, protein content, electrical conductivity, color intensity at 360 nm and 635 nm, and antioxidant properties of all tested honey samples showed a strong positive correlation. Overall, the manuscript strategically combines experimental findings with detailed analyses to explore the complex nature of honey composition, adulteration issues, and the significance of authenticating honey to maintain quality and ensure consumer trust in the market. This study is the first to employ a comprehensive set of physicochemical and bioactive indicators with multivariate analysis for honey authentication in Bangladesh, offering a novel and systematic approach to identifying purity and floral sources.