Total Phenolics Research Articles

Impact of Water Stress on Metabolic Intermediates and Regulators in Broccoli Sprouts, and Cellular Defense Potential of Their Extracts.

Drought and flood (water stress) alter plant metabolism, impacting the phytochemical content and biological effects. Using spectrophotometric, HPLC, and electrophoretic methods, we analyze the effects of water stress on broccoli (Brassica oleracea L. convar. botrytis (L.) Alef. var. cymosa Duch.) sprouts. Drought and flood differently influenced chlorophylls, carotenoids, and porphyrins, with drought having a stronger inhibitory effect on chlorophyll a, total chlorophyll, and porphyrins. Carotenoids and glucosinolates increased under drought but decreased with flooding, suggesting that these compounds play a crucial role in drought tolerance. Nitrate increased with drought from 13.11 ± 1.05 mg/g dw to 22.41 ± 1.20 mg/g dw but decreased under flooding to 5.17 ± 1.03 mg/g dw, and oxalic acid was reduced by drought only (from 48.94 ± 1.30 mg/g dw to 46.43 ± 0.64 mg/g dw). Flood reduced proteins by 29%, phenolics by 15%, flavonoids by 10%, flavonols by 11%, tannins by 36%, and proanthocyanidins by 19%, while drought decreased flavonoids by 23%. Total phenolics and proanthocyanidins were increased by drought by 29% and 7%, respectively, while flooding decreased hydroxycinnamic acids by 13%. Both stress types influenced individual polyphenols differently: drought diminished ferulic acid by 17% and increased sinapic acid by 30%, while flooding reversed these effects and enhanced kaempferol by 22%. These compounds, along with proline (which increased by 139% under drought), emerged as biomarkers of water stress. Flood impacted antioxidant capacity more significantly, while drought-stressed broccoli extracts better protected plasmid DNA against oxidative damage. These findings underline the metabolic plasticity of broccoli sprouts and their potential in targeted crop management for water stress resilience.

Seasonal Phenolic Profile, Antioxidant, and Photoprotective Activities of Psidium guajava L. Leaves.

This study aimed to evaluate the phytochemicals from extracts of Psidium guajava L. leaves (P. guajava extract [PGE]) and its antioxidant and photoprotective effects. PGE showed constant production of total phenolics and maintained high antioxidant capacity across seasons and years. Liquid chromatography-mass spectrometry (LC-MS/MS) analysis revealed the phenolic compounds quercetin, catechin, gallic acid, epicatechin, vanillic acid, and syringic acid, as well as two new compounds, syringaldehyde and ferulic acid. The high sun protection factor (SPF) was observed in all seasons. The phytochemicals ferulic acid, syringic acid, and quercetin were correlated with cloudiness and humidity. Antioxidant activity was correlated with vanillic acid, ascorbic acid, flavonoids, and tannins, and SPF with temperature, antioxidant activity, flavonoids, vanillic acid, gallic acid, and catechin. The formulations containing UVA/UVB filters or not, plus aqueous autumn extract, showed an increase in SPF. Therefore, the results suggested that PGE has potential photoprotective and antioxidant agents for the production of new sunscreen formulations with environmental and health benefits.

Effect of crude extract and polysaccharides derived from Fucus spiralis on radish plants Raphanus sativus L. agrophysiological traits under drought stress

Drought is a significant environmental stressor that induces changes in the physiological, morphological, biochemical, and molecular traits of plants, ultimately resulting in reduced plant growth and crop productivity. Seaweed extracts are thought to be effective in mitigating the effects of drought stress on plants. In this study, we investigated the impact of crude extract (CE), and polysaccharides (PS) derived from the brown macroalgae Fucus spiralis (Heterokontophyta, Phaeophyceae) applied at 5% (v/v) and 0.1% (w/v) respectively on radish plants Raphanus sativus L. subjected to varying levels of drought stress, specifically 80% of field capacity (FC) for no stress, 60% FC for moderate stress, and 40% FC for severe stress. Our examination of growth parameters, along with physiological and biochemical characteristics, revealed that both CE and PS increased the fresh weight over the control by 47.43% and 64% at 40% FC and 12.5% and 38% at 60% FC respectively. Under stress (40% FC), the application of CE and PS decreased proline content of radish leaves by 23.45% and 6.46% respectively in comparison with the control. Furthermore, PS treatment caused an increase of the alkaline phosphatase and urease activity in the soil by 182.5% and 34.6% respectively. CE and PS treatments led to decreased sugar content and total phenolics levels. Notably, lipid peroxidation was reduced in stressed plants treated with both CE and PS, with PS treatment yielding lower concentrations (3.75 nmol MDA.g− 1 FW at 40% FC). Overall, F. spiralis extracts interacted through several mechanisms using various compounds to mitigate the negative effects of drought stress on radish plants. These results demonstrate that seaweed extracts could be adopted in integrated production systems to boost food productivity under harsh climatic conditions.

Phytochemicals Analysis and Antioxidant (IC50) Value of Dried and Fresh Mangrove (Rhizopora racemosa) Leaves Extract for Herbal Drink Base

The use of mangrove leaves as a functional ingredient is associated with secondary metabolites such as steroids, saponins, tannins, phenols, flavonoids, antioxidants, magnesium, sodium, potassium and calcium. This research determined the total phenol content (TPC), total flavonoid content (TFC) and antioxidants (IC50) in dry and fresh mangrove leaf infusion extracts. The method used was infusion extraction. The materials used are fresh mangrove leaves and dried leaves (dried in the oven). The data obtained then discussed descriptively based on the average obtained in the calculations. The research results showed that the type or condition of leaves used has an influence on TPC, TFC and Antioxidants (IC50). Oven drying can produce higher levels of secondary metabolites compared to fresh leaf infusion (TPC, 36 mg GAE/g; TFC 4.12 mg QE/g; IC50 225,706 ppm). Dried leaf extraction has better potential in producing secondary metabolic compounds and antioxidants. The choice of extraction method and type of solvent is highly recommended for further research objectives, because it suits research interests. It is recommended that when making functional drinks (tea) from mangrove leaves, to add other sources of ingredients such as dried lemon or mint leaves so that the resulting flavor is fresher and provides a better linking assessment of preferences.

Impact of the Extraction Method and Solvent on the Phenolic Compound Content and Antioxidant Potential of the Aerial Part of Ephedra altissima: In vitro and In silico Studies

Background: Despite the widespread use of Ephedra altissima plant in traditional Algerian medicine, the biological potential of this species has still not been well explored. Objective: This study, for the first time, focused on determining the effect of extraction methods and solvents on the phenolic content and antioxidant ability of the aerial part of Ephedra altissima. Methods: Extraction was carried out by maceration and Soxhlet using the solvents H2O, Methanol/ H2O and Petroleum ether. The chemical profile of E. altissima was determined by a qualitative HPLC/UV–Visible, and the antioxidant potential was evaluated by in vitro and in-silico studies. Results: The aqueous extract obtained by maceration exhibited the greatest total phenol content, while the petroleum ether prepared by Soxhlet extraction demonstrated the highest total flavonoid and condensed tannin contents. The HPLC profile showed the presence of a variety of phenolic compounds. The in-vitro assay results indicated good antioxidant potential. Gallic acid and sinapic acid were highlighted as the most potent antioxidants in the Soxhlet hydro-methanolic and petroleum ether extracts, respectively, according to the machine learning model. Molecular docking predicted the possible antioxidant potential of E. altissima phytocompounds by the interaction with human peroxiredoxin 5, and epicatechin was the most effective ligand. Molecular dynamics simulations confirmed the stability of the epicatechin-Prdx5 complex. Multivariate analysis was used to categorize the Ephedra altissima extracts into three groups according to their phenolic compound content and in vitro antioxidant ability. Conclusion: Overall, the results of the present study revealed that the choice of solvent and extraction technique directly influence the biomolecule content and bioactivity of Ephedra altissima aerial part extracts.

CISTUS CRETICUS L.: ANTIOBESITY, ANTIMICROBIAL AND ANTIBIOFILM PROPERTIES

Objective: Cistus creticus L. is widespread in the coastal regions of Türkiye. In this study, we investigated the cytotoxic, antiobesity, antimicrobial and antibiofilm properties as well as the total phenolic and flavonoid content of both aqueous and ethanolic extracts in vitro. Material and Method: Two different extracts were prepared from the flowering aerial parts of Cistus creticus using ethanol and water. The total phenolic content and total flavonoids were determined by the Folin-Ciocalteu method and the aluminum chloride colorimetry, respectively. The effect of extracts on the cell viability of 3T3-L1 was determined by methyl thiazole tetrazolium (MTT), and the evaluation of differentiation and the effects of the plant extracts on lipid accumulation in 3T3-L1 adipocytes was performed by Oil-Red O staining. In addition, MIC values and antibiofilm activities were also investigated. Result and Discussion: The total phenol content of the EtOH and water extract was determined to be 134.2849 mg GAE/g and 96.1803 mg GAE/g, respectively. The total flavonoids in the water and EtOH extracts were found to be 33.1942 mgQE/g and 22.8338 mgQE/g, respectively. The lowest MIC values were determined for the strains Bacillus subtilis DSM 1971, Bacillus licheniformis DSM 13 and Bacillus amyloliquefaciens DSM 7, while the highest MIC concentration was found for the strains Escherichia coli and Eenterococcus gallinarum. The MIC/16 concentration of Pseudomonas aeruginosa ATCC 27853 and Escherichia coli ATCC 25922 also proved to be effective in inhibiting biofilm formation. We observed that noticeable but not strong effects on lipid accumulation were observed in 3T3-L1 adipocytes treated with EtOH extract.

Deficit Irrigation Response and Climate Resilience of Mediterranean Tomato Landraces

Vegetable production worldwide is heavily influenced by climate change. We aimed to determine the responses of some local tomato landraces from Mediterranean countries pre-selected as drought tolerant according to previous screening tests at an early stage. Three irrigation approaches were applied: Full irrigation (Ir-Full), Deficit 1 (Ir-Def1), and Deficit 2 (Ir-Def2) irrigation. Drought stress was simulated via controlled irrigation deficit, reducing the amount of water applied by 35% and 50% in Ir-Def1 and Ir-Def2, respectively. Plant growth, yield, some fruit physicochemical properties, water consumption, and water use efficiency were measured. The results revealed that water deficit adversely affected total and marketable yields, plant growth, and biomass while enhancing some specific quality parameters. Landrace responses varied across different levels of water deficit. Among the tested tomato landraces, ‘Valldemossa’, ‘Chondrokats’, and ‘TR62367’ exhibited strong yield performance, with up to 4 kg m−2 under water-limited conditions, whereas ‘Cherry-INRAE 1’, ‘Cherry-INRAE 3’, and ‘Cherry-INRAE 4’ excelled in fruit quality attributes, reaching up to 9.3% Brix, 14.07 mg 100 g−1 vitamin C, 7.77 mg GAE 100 g−1 total phenols, and 75.74 µmol TE g−1 antioxidant activity. The amount of water could be reduced by 35% without compromising yield or quality in the most drought-tolerant landraces.

Replacing milk fat with pumpkin seed oil in yogurt

This study explored the potential of pumpkin seed oil (PSO) in enhancing the health benefits of yogurt by partially replacing milk fat. Yogurt was produced with varying amounts of PSO—0.0, 1, 2, 3, and 4%—to replace milk fat. Yogurt with 2% PSO showed higher levels of unsaturated fatty acids, conjugated linoleic acid, total phenols, and antioxidants, while also showing reduced amounts of free fatty acids and peroxide values. Although the texture remained unchanged, we observed significant differences in color, flavor, and overall acceptability between treated yogurt and control group. As the PSO content increased, color, flavor, and the overall acceptability of yogurt decreased.

The assessment of chemical composition and biological activity of faba bean pods as a potential feed additive utilized in piglets nutrition

The study addresses the utilization of food waste by-products from faba bean (Vicia faba L.) pods (FBP) as an alternative feed supplement to promote sustainable piglet growth by reducing antimicrobial use. Objectives include evaluation of FBP in terms of nutritional components (proximate composition, fibres, minerals), phytochemical composition (total phenols, HPLC-MS profiling), and in vitro biological activities. Air-dried FBP from the cultivar ‘Bizon’ contained high levels of crude protein (144 g/kg), dietary fibre (413 g/kg), potassium (27.8 g/kg), and iron (126 mg/kg). Phytochemical analysis of methanolic extract from FBP revealed significant levels of polyphenols, including vestitol, piscidic acid, hydroxyeucomic acid, quercetin, and kaempferol glycosides with no detectable tannins. The extract showed negligible activity against porcine digestive enzymes (α-amylase, lipase, and trypsin) (IC50 > 4 mg/mL) and demonstrated a dose-dependent antibacterial activity against Escherichia coli and Salmonella enterica in concentrations of 1–8 mg/mL. The extract had low cytotoxicity (IC50 = 432.6 µg/mL) against IPEC-J2 – cells derived from porcine jejunal epithelium. The results indicate that FBP ‘Bizon’ is a valuable source of bioactive compounds with antibacterial properties, without adverse effects on porcine enzymes or IPEC-J2 cells, supporting its potential as a sustainable feed in piglet nutrition, in line with circular economy concepts.

Plant Factory in a Restaurant: Light Quality Effects on the Development, Physiology, and Quality of Three Baby-Leaf Vegetables.

Plant factories with artificial lighting (PFALs) are a notable choice for urban agriculture due to the system's benefits, where light can be manipulated to enhance the product's yield and quality. Our objective was to test the effect of light spectra with different red-blue combinations and white light on the growth, physiology, and overall quality of three baby-leaf vegetables (green lettuce, kale, and pak choi) grown in a restaurant's PFAL. Leaf mass per area was lower under the most blue-containing treatments in all species. The performance indices (PIabs and PItot) of the photosynthetic apparatus were lower under more red light with the exception of PIabs in pak choi. Total soluble solids accumulation was diminished under most of the blue-containing LEDs, while total phenolics and antioxidant activity were induced by red-blue environments rich in blue light. Moreover, chlorophyll and carotenoid accumulation was also enhanced under blue-rich light treatments. Nitrate content was the lowest under monochromatic blue in all species. Finally, the employees were asked about their views on the PFAL within the restaurant's compounds and they expressed positive opinions. Overall, a light environment including red and blue wavelengths proved beneficial for baby leafy vegetable production in terms of yield and quality.

Comparative bioactivity analysis of latex and water extract of Euphorbia gaillardotii: chemical profile, antioxidant capacity, effects on water quality, in vitro antimicrobial-cytotoxic activities, and in silico molecular docking studies.

The genus Euphorbia, belonging to the family Euphorbiaceae, represents a significant ethnobotanical heritage due to the diverse bioactive properties exhibited. In this study, the phytochemical composition and biological activities of latex and aerial parts of the water extract of Euphorbia gaillardotii were investigated. Phytochemical analyses were performed using gas chromatography-mass spectrometry and high-performance liquid chromatography techniques and total antioxidants, phenolics, sugars, organic acids, and aroma components were quantitatively determined. The effects of the test compounds on physicochemical parameters in aqueous media were evaluated by electrical conductivity, dissolved oxygen concentration, and pH measurements. Antimicrobial activity was evaluated on Gram-positive and Gram-negative bacteria and yeast strains using the disk diffusion method. The cytotoxic activity on the MCF-7 human breast cancer cell line was measured spectrophotometrically using the Cell Counting Kit-8 proliferation/apoptosis detection kit. The results showed that E. gaillardotii latex and aerial parts water extract significantly affected the physicochemical parameters of aqueous media, especially at high concentrations. The test substances displayed antimicrobial activity, with the latex-impregnated disks demonstrating larger inhibition zones than the aerial parts extract. The results showed that both the latex and extract treatments exhibited concentration-dependent effects on MCF-7 cell viability (P < 0.001). Furthermore, in silico docking analyses revealed a robust binding affinity of succinic acid, the most prevalent bioactive compound in the extract, towards the B-cell lymphoma 2 (Bcl-2) molecule, with a binding energy of -6.16 kcal/mol. This may be associated with the observed cytotoxicity. These results suggest that E. gaillardotii may be a valuable source for potential pharmacological applications.

Comparison of Secondary Metabolite Extraction Methods in Hamelia patens Jacq. and Their Inhibitory Effect on Fusarium oxysporum f. sp. radicis-lycopersici.

Background: Hamelia patens Jacq. (HP) is widely recognized in traditional medicine for its antimicrobial properties, which are attributed to secondary metabolites such as phenolic compounds, alkaloids, and terpenes. Fusarium oxysporum f. sp. radicis-lycopersici (Fo), a phytopathogenic fungus affecting economically important crops, is managed with fungicides like benzimidazoles and azoles. Excessive use of these compounds has led to resistance and environmental contamination, highlighting the need for sustainable alternatives. This study aimed to optimize the extraction of secondary metabolites from HP leaves and flowers, evaluate their antifungal activity, and assess the impact of extraction methods and plant parts on chemical composition and efficacy. Methods: Three extraction methods were employed: consecutive maceration (CM) using solvents of ascending polarity; total maceration (TM), which is a single-step methanol-based method; and ultrasound-assisted maceration (UAM) employing ultrasonic waves with methanol. Extracts were characterized by quantifying total phenols (TP), condensed tannins (TC), flavonoids (Fl), alkaloids (TA), sterols (TS), and saponins (S) using colorimetric assays and UPLC-MS. Multivariate analyses, including PCA, PLS-DA, OPLS-DA, and Pearson correlation, evaluated the relationships between the chemical profiles and antifungal activity. Results: Leaf extracts exhibited higher flavonoid and tannin contents than flower extracts. CMML showed the highest antifungal activity (IC50 3.7% w/v), which was associated with elevated levels of these compounds. Significant correlations linked antifungal activity with rutin (HP21) and kaempferol-3-O-β-rutinoside (HP29). Conclusions: Methanolic extracts of HP exhibited significant antifungal activity against Fo. These findings highlight the importance of optimizing extraction methods and selecting specific plant parts to enhance bioactive compound efficacy, offering a sustainable approach to pathogen management.

The antioxidant content and activity of lemongrass [Cymbopogon citratus (DC. ex Nees) Stapf] under the combination of drought stress and nano-silica treatments

The study aimed to determine the effect of a combination of drought stress and nano-silica treatments to increase the content of antioxidant compounds and antioxidant activity of lemongrass [Cymbopogon citratus (DC. ex Nees) Stapf] and determine the optimal combination. The research used a Completely Randomized Design (CRD) with two factors with 5 replications. The first factor was the level of drought stress (without drought stress, moderate, and severe). The second factor was the nano-silica dose, (0 mg/L, 125 mg/L, and 250 mg/L) with a volume of 10 mL per plant. The parameters measured were carotenoid content, proline content, total phenolics content, and antioxidant activity. Data were analyzed using Analysis of Variance (ANOVA) and Duncan’s Multiple Range Test (DMRT). The results showed that there is a specific combination of drought stress and nano-silica which can increase the content of carotenoids, proline, total phenolics, and antioxidant activity in lemongrass. The treatment of moderate and severe drought stress with 125 and 250 mg/L nano-silica increased the carotenoid and proline content maximally. Higher total phenol content and antioxidant activity were obtained from the combination of 250 mg/L nano-silica without drought stress. The highest chlorophyll content was recorded from the combination of severe drought stress and 250 mg/L nano-silica. Drought stress treatment with 250 mg/L nano-silica could increase the antioxidants of lemongrass plants, but maximum production of antioxidants required different combinations of drought stress and nano-silica treatments. Nano-silica treatment at a dose of 250 mg/L in conditions of sufficient water or lack of water can be an optimal combination treatment in lemongrass cultivation.

Preliminary Data on Silybum marianum Metabolites: Comprehensive Characterization, Antioxidant, Antidiabetic, Antimicrobial Activities, LC-MS/MS Profiling, and Predicted ADMET Analysis.

Silybum marianum extract, obtained via microwave-enhanced extraction, was evaluated for its antioxidant, antidiabetic, and antimicrobial activities to explore its therapeutic potential. The extraction was performed using microwave-enhanced techniques, and LC-MS/MS was employed to profile the metabolites in the extract. Total phenolic and flavonoid contents were quantified using spectrophotometric methods. Antioxidant activity was assessed using DPPH, ABTS, CUPRAC, Phenanthroline, and FRAP assays. Enzyme inhibition assays were conducted to evaluate antidiabetic activity against α-glucosidase and α-amylase. Antimicrobial activity was determined using the disc diffusion method, and in silico ADMET and drug-likeness analyses were performed for key metabolites. The extract contained 251.2 ± 1.2 mg GAE/g of total phenolics and 125.1 ± 1.6 mg QE/g of total flavonoids, with 33 metabolites identified, including phenolic acids, tannins, flavonoids, and flavolignans. Strong antioxidant activity was observed, with IC50 values of 19.2 ± 2.3 μg/mL (DPPH), 7.2 ± 1.7 μg/mL (ABTS), 22.2 ± 1.2 μg/mL (CUPRAC), 35.2 ± 1.8 μg/mL (Phenanthroline), and 24.1 ± 1.2 μg/mL (FRAP). Antidiabetic effects were significant, with IC50 values of 18.1 ± 1.7 μg/mL (α-glucosidase) and 26.5 ± 1.3 μg/mL (α-amylase). Antimicrobial activity demonstrated inhibition zones of 8.9 ± 1.1 mm (Bacillus subtilis), 12.6 ± 1.6 mm (Escherichia coli), 8.2 ± 1.2 mm (Fusarium oxysporum), and 9.2 ± 1.1 mm (Aspergillus niger). In silico analyses showed high absorption, favorable metabolism and excretion, and minimal toxicity, with no hERG channel inhibition or hepatotoxicity. The comprehensive results highlight the significant antioxidant, antidiabetic, and antimicrobial activities of S. marianum extract, suggesting its potential for therapeutic and preventive applications.

Phytochemicals and Biological Properties of Azorean Camellia sinensis Black Tea Samples from Different Zones of Tea Plantation.

Camellia sinensis tea has received considerable attention due to its beneficial effects on health, particularly due to its antioxidant properties that are affected by several factors, which have a high influence on the final quality of black tea. The objective of this study was to investigate the biological properties of Azorean C. sinensis black tea from five different zones of tea plantation in order to select specific areas to cultivate tea rich in targeted compounds beneficial to human health. The free radical scavenging activity (FRSA), ferric reducing antioxidant power (FRAP), ferrous ion chelating (FIC) activities, total phenolic content (TPC), total flavonoid content (TFC), and tannins were determined by colorimetric methods, and catechin and theaflavin contents were analyzed by high-pressure liquid chromatography. The results indicated that samples from Zone E (341 m above the sea level) presented higher values of FRSA (EC50 = 7.22 µg/mL), FRAP (EC50 = 9.06 µg/mL), and FIC activities (79.83%) and higher values of total phenolics (264.76 mg GAE/g DE) and almost all catechins. For TFC, the values were very similar between zones, and for theaflavins content, Zone A showed the best levels, followed by Zone E. In general, these results clearly highlight that altitude plays a significant role in enhancing certain compounds of tea, thereby influencing its quality.

Guadua angustifolia biochar/TiO2 composite and biochar as bio-based materials with environmental and agricultural application

Globally, the companies that make commercial use of bamboo culms produce different kinds of solid waste rich in lignocellulosic biomass, which in some cases is not used and is discarded in landfills or incinerated in the open air; losing the possibility of recovering them and using them in other productive sectors. The research objective were to produce a biochar from Guadua agustifolia Kunth sawdust, evaluate its potential environmental and agricultural use, obtain a biochar/TiO2 composite to inactivate Escherichia coli and use the biochar as a soil conditioner in medicinal plants producing phenolic compounds and flavonoids. Biochar composite (produced at 300 °C for 1 h) involved TiO2 at 450 °C for 1 h for inactivation of E. coli (initial concentration: 6.5 ± 0.3 Log10 CFU mL− 1). For agriculture, 2% biochar was used to evaluate B. pilosa L. and G. angustifolia plant growth for 90 days. The biochar/TiO2 composite had a high photocatalytic activity on E. coli, generating a final count of 1.97 ± 0.2 Log10 CFU mL− 1 after 60 min. Biochar (2%) increased the total phenol and flavonoid content in the medicinal plant B. pilosa L. and total phenols in G. angustifolia, tested at the nursery stage. This study provides new information on the conversion and use of G. angustifolia sawdust as an alternative for new bio-based materials with environmental and agricultural applications. In addition, obtaining biochar and composite could positively impact the bamboo production chain in Colombia because of renewable and globally accepted alternatives that help capture gaseous emissions causing the greenhouse effect.

Effects of ultrasound-assisted plasma-activated water pretreatment combined with electrohydrodynamics on drying characteristics, active ingredients and volatile components of yam (Dioscorea opposita).

This paper explores the effect of ultrasound (US) assisted plasma-activated water (PAW) or deionized water (DW) pretreatment combined with electrohydrodynamics (EHD) on the drying of yam. The activity characteristics of four pretreatments (plasma activated water combined with ultrasound (PAW+US), plasma activated water (PAW), deionized water combined with ultrasound (DW+US), and deionized water (DW) (control)) and their effects on drying characteristics, rehydration rate, color, reducing sugars, total phenols, infrared spectra, and volatile compositions of yam under EHD drying process were investigated. The results showed that the media pretreaded by ultrasound (US) combined with plasma-activated water (PAW) has lower media of pH (53.84% lower than that of US+DW), higher nitrite ion concentration (311 times over US+DW), higher oxidation reduction potential (50.58% higher than that of US+DW), and higher electrical conductivity (99.29 times over US+DW). And ultrasonic pretreatment (US) combined with plasma-activated water (PAW) drying resulted in faster drying, better rehydration rate, higher brightness L * (18.35% higher than that of US+DW) and whiteness (1.1% higher than that of US+DW), and retention of more reducing sugars (10.96% higher than that of US+DW) and total phenols (14.04% higher than that of US+DW), and a higher variety and content of volatile components. This provides an experimental and theoretical basis for the application of ultrasonic (US) combined with plasma-activated water (PAW) pretreatment to electrohydrodynamic drying.

Evaluating the Andean blueberry (Vaccinium meridionale Swartz) powder in the preparation of ice cream: Improving the antioxidant capacity and the total phenolic content

This study evaluated the content of total phenolic compounds, antioxidant capacity, and functional properties of an ice cream formulated from Andean blueberry (Vaccinium meridionale Swartz) powder. The antioxidant capacity of pulp and powder from Andean blueberry was performed by using ABTS*+ and DPPH methods. The blueberry powder was obtained by convection drying, and the rheological and thermal properties of the ice cream were determined by rotational rheology and differential scanning calorimetry (DSC), respectively. The stability of ice cream was evaluated at -15 °C during storage for 30 days, measuring color, texture, antioxidant capacity, and phenolic compounds. The results showed a moisture content of 77.64% (w.b), 13.59 °Brix, pH of 3.0, and titratable acidity of 1.35% for the Andean blueberry pulp. The color parameters L*(10.2), a*(3.5), and b* (7.4) indicated the typical dark purple color of this fruit. Andean blueberry powder shows a moisture content of 5.20% (w.b), solubility of 58.24% in water, and color parameters’ values of L*(16.0), a*(16.9) and b*(8.1), with 1.43 mg GAE g-1 of total phenol, while, for the pulp, it was 4.31 GAE g-1. The antioxidant capacity ranged between 200 and 161 μmol TEs g-1 dry mass for pulp and from 56 to 49 μmol TEs g-1 dry mass for powder. Adding powder from Andean blueberry in the ice cream decreases overrun and delays the melting time. Finally, the ice cream showed good stability during storage time, keeping the color, and texture properties such as hardness, total phenolic compounds, and antioxidant capacity.

Fabrication of Algogenic Zinc Nanoparticles and Assessment of Their Biomimetics Attributes and Potential Antibacterial Efficacy Against Fish Pathogens

This study investigates the fabrication of algogenic zinc nanoparticles (ZnNPs), examining their biomimetic properties and potential antibacterial effectiveness against fish pathogens. The rising incidence of antibiotic resistance in aquaculture demands innovative strategies for disease management, highlighting the importance of developing biocompatible and effective antimicrobial agents. In this context, ZnNPs were synthesized using Pediastrum boryanum microalgal extract as the reducing and capping agent. Transmission electron microscopy (TEM) revealed spherical and tetragonal particles with sizes ranging from 32.84 to 26.87 nm. Fourier transform infrared spectroscopy (FTIR) demonstrated distinctive functional groups in the algal extracts and ZnNPs. X‐ray diffraction (XRD) showed pure crystallinity of the fabricated ZnNPs with an average crystalline size of 57.97 nm. The algal extract had high total phenolic (TPC) and flavonoid (TFC) contents (TPC: 53.83 and TFC: 12.44 mg QE/g, respectively). The obtained ZnNPs retained a considerable amount of TPC and TFC (7.92 and 5.31 mg/g, respectively). The microalgal extract and ZnNPs exhibited considerable antioxidant capacity in the 2,2‐Diphenyl‐1‐picrylhydrazyl (DPPH) radical scavenging assay. In addition, they elicited antibacterial efficacy against several bacterial pathogens in fish in a minimum inhibitory concentration (MIC) assay. Brine shrimp lethality assay (BSLA) revealed higher potential cytotoxicity of biosynthesized ZnNPs at 29.28 μg/mL compared to that of the algal extracts at 51.56 μg/mL. These findings highlight the potential of P. boryanum as a green factory for the nanofabrication of metallic nanoparticles (NPs) and as a promising clinical candidate for fish medicine.

Optimization of the green synthesis of gold nanorods using aqueous extract of peeled sour guava as a source of antioxidants.

Obtaining gold nanorods (AuNRs) through biosynthesis is an alternative that replaces the traditional use of ascorbic acid with chemical compounds such as polyphenols, owing to their notable antioxidant properties. Therefore, we developed an AuNR biosynthesis method using an aqueous extract of sour guava (Psidium araca). Initially, a study was conducted to determine the antioxidant capacity of different parts of the fruit (pulp and peel) over 14 days. Four colorimetric techniques were used: total phenol, ABTS (2,2-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid), FRAP (ferric reducing antioxidant power (FRAP), and DPPH (1,1-diphenyl-2-picrylhydrazyl). Subsequently, in stage 2, the selected aqueous extract was used, and two response surface designs were performed. The objective of this study was to find a model equation that would indicate the optimal parameters for obtaining AuNRs with a surface plasmon band at 808 nm, with possible applications in the health field. The results of the antioxidant capacity experiments were analyzed in Minitab® using a multilevel factorial design, and the peel exhibited the highest antioxidant capacity. Subsequently, the biosynthesis of AuNRs proceeded using a 5-factor response surface experimental design as input variables (concentration in mM of gold, silver, extract, NaBH4, and reaction time in hours) and longitudinal plasmon (LSPR) as output variables. The AuNRs were approximately 30 nm in size with an LSPR between 700 and 800 nm. Statistical model evaluation revealed a dependence between gold and time and gold-silver factors. Finally, antioxidant capacity was used to select the part (peel or pulp) of sour guava that could be used as a weak reducing agent. Moreover, the utility of surface-response methodology was explored to optimize the synthesis of AuNRs using green agents.