Ferric Reducing Antioxidant Power Research Articles

Spent coffee grounds as an alternative fertilizer: impact on bioaccessibility of antioxidants and commercial quality of lettuce.

During the processing of spent coffee grounds (SCGs) several residues are obtained, which are mostly disposed of in landfills. There is an urgent need for a comprehensive waste management strategy for these residues. This study evaluates the potential of SCGs as a biofertilizer by assessing their effects on lettuce leaves and the release of antioxidants following in vitro digestion and fermentation. Lettuce plants were grown with different amounts of SCGs (0-150 g kg-1) in the substrate. High SCG concentrations in the soil generated lighter colored tissues, a decrease in the green color, less root development, and lower dry weight of leaves (P < 0.05). The SCG levels also affected the release of antioxidants by the final product. This effect was more pronounced in the digested fraction: applying the Ferric Reducing Antioxidant Power (FRAP) method, the addition of SCGs from 10 g kg-1 to 125 g kg-1 increased the amount of antioxidant from 43.88 ± 4.81 to 105.96 ± 29.09 μmol Trolox g-1 of dry weight (P < 0.05). The Indigo Carmine Reducing Capacity (ICRED) method also showed a similar trend, but in this case the highest value was obtained with 150 g kg-1 of SCGs (16.41 ± 3.93 mmol catechin g-1 of dry weight) (P < 0.05). Moreover, in the fermented fraction a significant increase in the antioxidant released was found with low levels of SCG(P<0.05), while lettuces fertilized with intermediate amounts of SCGs (25 and 50 g kg-1) presented the highest amount of insoluble antioxidant (P < 0.05). A compromise should be found in order to achieve a product with a high antioxidant capacity and an acceptable visual quality. © 2024 Society of Chemical Industry.

Effect of Different Drying Methods on Colour, Total Phenolic Content, Flavonoid Content, and Antioxidant Activity Retention of Strobilanthes crispus Leaves

Strobilanthes crispus, a medicinal herb, is recognised for its abundant phytochemicals, notably in its leaves, contributing to its high antioxidant activity. However, the crucial step of drying, aimed at extending shelf life, can impact the stability of these bioactive compounds. This study evaluates the impact of different drying methods, which include oven, microwave, freeze drying, and air drying, on the colour, phenolic and flavonoid content, and antioxidant activities of S. crispus leaves. The colour analysis of the fresh and dried leaves was assessed using the chromameter. Total phenolic content (TPC) and total flavonoid content (TFC) were determined using Folin-Ciocalteu’s and aluminium chloride colourimetric assays, respectively. Antioxidant capacities were analysed via ferric-reducing antioxidant power (FRAP) and a 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay. The results showed that microwave-dried S. crispus leaves exhibited minimal alterations in colour attributes L*, a*, and b*, closely resembling the fresh leaves (p &gt; 0.05). Microwave drying significantly preserved TPC (145.42 ± 1.61 mg GAE/g), TFC (117.27 ± 5.10 mg QE/g), FRAP activity (258.92 ± 0.15 µg TE/g extract), and displayed the most potent DPPH scavenging half-maximal inhibitory concentration (7.58 ± 0.48 µg/ml) compared to other methods (p &lt; 0.05). Notably, the DPPH scavenging potency surpassed that of the synthetic antioxidant butylated hydroxytoluene. In conclusion, microwave drying appeared to be an efficient method for preserving the colour and antioxidant properties of S. crispus leaves. It highlights its potential as a favourable drying technique for conserving bioactive compounds in medicinal plant materials, offering promising applications in the nutraceutical and pharmaceutical fields.

Rapid discovery of natural antioxidants in Hypericum japonicum: Dual roles of the liquid phase mobile phase as extraction and separation solvent

Hypericum japonicum is a traditional folk medicine with various bioactivities such as hepatoprotective, antioxidant, and anti-tumorous. The antioxidant effect of H. japonicum is one of the most prominent effects due to its responsibility for many of its activities. To clarify active natural substance, the antioxidant properties of H. japonicum were preliminarily assessed by ferric reducing–antioxidant power (FRAP), 2,2-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid (ABTS) and Oxygen radical absorbance capacity (ORAC), as well as superoxide dismutase (SOD). Then, a straightforward and effective method named online liquid extraction-high performance liquid chromatography combined with ABTS antioxidant assay and mass spectrometry (OLE-HPLC-ABTS/Q-TOF-MS) was developed to swiftly and directly discover the antioxidants in H. japonicum. Using mobile phase as extraction and separation reagent, coupled with online activity analysis and compounds identification by high-resolution MS, the online system enables rapid screening of natural antioxidant bioactives from complex mixture. By using it, a total of 9 compounds including flavonoids and phenolic acids characterized by retention time, precise mass, and fragmentation ions in MS/MS spectra showed antioxidant action. Finally, the antioxidant and SOD activity of main found active compounds were validated by in vitro experiment assay and molecular docking. In summary, these results suggested that H. japonicum could be considered as a potential source of natural antioxidants, and the online integrated system might become a promising candidate for the natural antioxidants discovery in the future.

Antibacterial, antioxidant, and anti-giardia properties of the essential oil, hydroalcoholic extract, and green synthesis of the silver nanoparticles of Salvia mirzayanii plant

In this study, an environmentally-friendly, simple, and low-cost approach was developed for the production of silver nanoparticles (Ag NPs) accelerated by Salvia mirzayanii plant. The identification process involved ultraviolet-visible (UV-Vis) spectrophotometry, Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), and scanning electron microscopy (SEM). The UV–Vis spectrum exhibited a peak at 450 nm which is a characteristic surface plasmon resonance of Ag NPs. The XRD and EDS analyses confirmed the crystalline nature and the presence of silver element, while the SEM analysis displayed the production of almost spherical nanoparticles. The FTIR spectrum exhibited that the Ag NPs were functionalized with biomolecules found in the extract, which are involved in the production and stabilization of the NPs. The antibacterial activity of the essential oil, the hydroalcoholic extract and Ag NPs was examined against antibiotic-resistant bacteria, Staphylococcus aureus (S. aureus), and Escherichia coli (E. coli). The anti-Giardia activity was tested on Giardia lamblia cysts at different time intervals. The results exhibited that the MIC values for essential oil, hydroalcoholic extract and Ag NPs against S. aureus were 1.65 µL/mL, 75 mg/mL, and 0.125 mg/mL respectively. The MBC was attained 6.25 µL/mL, 300 mg/mL, and 0.25 mg/mL, for essential oil, hydroalcoholic extract and Ag NPs, respectively. The MIC values for essential oil, hydroalcoholic extract and NPs against E. coli were 3.12 µL/mL, 150 mg/mL, and 0.06 mg/mL, respectively. The MBC was determined to be 50 µL/mL, 300 mg/mL, and 0.25 mg/mL for essential oil, hydroalcoholic extract and Ag NPs, respectively. In addition, the antioxidant activity was determined using the ferric reducing antioxidant power (FRAP) test. The results indicated that the essential oil of this plant exhibited the highest antibacterial and anti-giardial properties, whereas its extract demonstrated the strongest antioxidant properties.

Comparative Analysis of Shelf-Life, Antioxidant Activity, and Phytochemical Contents of Australian-Grown and Imported Dragon Fruit under Ambient Conditions

Dragon fruit (Hylocereus spp.), renowned for its aesthetic appeal and rich antioxidant content, has gained global popularity due to its numerous health benefits. In Australia, despite growing commercial interest in cultivating dragon fruit, there is uncertainty for local growers stemming from competition with imported varieties. Notably, there is a lack of comparative research on the shelf-life, antioxidant activity, and phytochemical contents of Australian-grown versus imported dragon fruit, which is crucial for enhancing market competitiveness and consumer perception. This study compares the shelf-life, antioxidant activity, and phytochemical content of Australian-grown and imported dragon fruits under ambient conditions, addressing the competitive challenges faced by local growers. Freshly harvested white-flesh (Hylocereus undatus) and red-flesh (H. polyrhizus) dragon fruit were sourced from Queensland and the Northern Territory and imported fruit were sourced from an importer in Queensland. All fruit were assessed for key quality parameters including peel color, firmness, weight loss, total soluble solids (TSS), pH, titratable acidity (TA), total phenolic content (TPC), total flavonoid content (TFC), ferric reducing antioxidant power (FRAP), cupric reducing antioxidant capacity (CUPRAC), total betalain content (TBC), and total anthocyanin content (TAC). The results indicate that Australian-grown white dragon fruits exhibited average one day longer shelf-life with less color degradation, better firmness retention, and less decline in weight loss, TSS, and acidity compared to imported fruits. Australian-grown red dragon fruits showed similar shelf-life compared to fruits from overseas. Antioxidant activities and phytochemicals were consistently higher in Australian-grown fruits throughout their shelf-life. These findings indicate that Australian-grown dragon fruits offer better physical quality and retain more nutritional value, which could enhance their marketability.

Biological Activity, Cytotoxicity, and Phytochemical Content of Leaf Extracts of Matoa (Pometia pinnata) and Pulasan (Nephelium ramboutan-ake) From the Sapindaceae Family

This study sought to assess the leaf extracts of matoa (Pometia pinnata) and pulasan (Nephelium ramboutan-ake) for antimicrobial, antifungal, antioxidant, and cytotoxic activities, besides phytochemical content. Four extracts (hexane, ethyl acetate, ethanol, and water) were obtained from each plant via sequential extraction. The antimicrobial activities were evaluated using colorimetric broth microdilution methods. The antioxidant activities were studied using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and ferric-reducing antioxidant power (FRAP) assays. The cytotoxicity was examined using mouse fibroblasts NIH/3T3 while the phytochemical content was detected using various chemical tests. Among the extracts, only the water extract of matoa and ethyl acetate extract of pulasan exerted bactericidal effects on Bacillus cereus (minimum bactericidal concentration (MBC): 0.63 mg/mL) and Staphylococcus aureus (MBC: 1.25 mg/mL), respectively. In contrast, all extracts, except hexane extract, of both plants exhibited fungicidal effects with minimum fungicidal concentrations of 0.31-1.25 mg/mL. All extracts of matoa leaves displayed higher DPPH radical scavenging activity and FRAP than the extracts of pulasan leaves. Notably, the water extract of matoa showed the lowest half-maximal inhibitory concentration (IC50) value of 9.88 ± 1.70 µg/mL and the highest FRAP value of 6.11 ± 0.51 mmol Fe2+ equivalent/g extract (n=3). These antioxidant activities were significantly correlated (p&lt;0.01) with the amounts of phenolic compounds in the extracts. All extracts of both plants, except water extracts, showed significant toxicities (p&lt;0.05) towards NIH/3T3 cells. Alkaloids, terpenoids, saponins, and glycosides were detected in the leaves of both plants. The matoa and pulasan leaves contained bioactive compounds with antibacterial, antifungal, and antioxidant activities.

Antioxidant and anti-inflammatory potentials of the leaf extracts of Calotropis procera and Enantia chlorantha

Inflammation and oxidative stress are involved in the aetiology of numerous human diseases. The two processes are interconnected such that one may appear before or after the other, but as soon as one of them appears, the other will. Consequently, targeting the two conditions may aid in the prevention or treatment of associated human diseases, and plants capable of performing the two functions together are of great advantage. This study was aimed at evaluating the antioxidant and anti-inflammatory potentials of methanol and aqueous extracts of Calotropis procera and Enantia chlorantha. The leaves of the two plants were extracted separately in water and methanol using a cold maceration method. Antioxidant activity was evaluated using the Lipid peroxidation (LPO), 1,1-diphenyl-2-picrylhydrazyl (DPPH), and ferric reducing antioxidant power (FRAP), while the anti-inflammatory properties were evaluated using membrane stabilization and inhibition of protein denaturation assays. Qualitative phytochemical analysis was performed using standard methods. The results of the study showed that the aqueous extract of the two plants demonstrated better antioxidant activity than the methanol extracts. IC50 values of 61.60, 59.12, and 83.07 µg/mL were, respectively, for ascorbic acid, aqueous extracts of E. chlorantha and C. procera, while the methanol extracts of both plants recorded a value &gt;150 µg/mL for DPPH. For LPO inhibition, the IC50 values were 191.79 µg/mL, &gt;150 µg/mL for the aqueous, methanol extracts of C. procera and 228.25 µg/mL, 135.46 µg/mL for ascorbic acid and quercetin used as standards. The aqueous extract of E. chlorantha had a value of 161.95 µg/mL and the methanol extracts had a value &gt;250 µg/mL. For the two anti-inflammatory methods used, the IC50 values for the plant were &gt;250 µg/mL. Phytochemicals such as tannins, flavonoids, alkaloids, terpenoids, and phenols were identified in both plant samples. Overall, the results demonstrated the potential of the plant when used for the treatment of diseases related to inflammatory and oxidative stress.

Antioxidant analysis of protein from fresh and dry leaf of Orthosiphon aristatus (Blume) Miq.

Orthosiphon aristatus (Blume) Miq. is a folklore plant consumed as brewed tea for various health benefits. The white variety of the plants leaf and stem are predominantly sold in the market in dried form, blooming as a natural herbal product. To date, no proteomics and antioxidant studies are available on the fresh and dried leaf protein extract of O. aristatus since most studies take an interest in the crude extracts of plants. Thereupon, this study focuses on the One-dimensional (1D) electrophoretic pattern of the fresh and dry leaf determined via sodium dodecyl-sulphate polyacrylamide gel electrophoresis (SDS-PAGE). Additionally, antioxidant proteins are currently being focused on for their link to controlling disease through their potential to destroy free radicals that are present in excess. Hence, an antioxidant assay was conducted for the fresh and dry leaf protein extract using 2,2-Diphenyl-1-picrylhydrazyl (DPPH) free radical assay and ferric reducing antioxidant power (FRAP) assay. The electrophoretic pattern obtained resulted in approximately 16 and 10 bands for the fresh and dry leaves respectively. As for the antioxidant activity, the dry leaf had higher radical scavenging activity and higher reducing power compared to the fresh leaf. The findings obtained provides insight in to the protein content and antioxidant activity found in the protein extract of fresh and dry leaves of O. aristatus. Hence, further detailed study of the protein extracts could further unveil their therapeutic potential.

Evaluation of the proximate composition and antioxidant capacity of some seaweeds from the Konkan coast of India

Minerals, antioxidants, and other nutrients that promote health can be found in abundance in seaweeds. In this study, we evaluated the proximate composition and antioxidant capacity of some seaweeds from Konkan coast of India. There were notable differences in the proximate compositions between the species. The highest protein content was found in Pyropia vietnamensis (~49 mg. g−1 dw), whereas the highest carbohydrate (~83 mg. g−1 dw), lipids (56 mg. g−1 dw) and vitamins were found in Stoechospermum marginatum. Total phenolic content (TPC) and antioxidant activity were estimated from a Methanolic extracts. The antioxidant capacity of the seaweeds was evaluated using 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging, ABTS (2,2-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid), ferric reducing antioxidant power (FRAP) assay and hydrogen peroxide free radical scavenging activity assay. Folin-Ciocalteu method was used to quantify total phenolic content (TPC), and Ulva fasciata had the highest TPC (24.30 ± 3 mg GAE. g−1 dry weight). In U. fasciata, the antioxidant activity was ~62 %, with an IC50 value of 0.057 ± 0.01 mM. Acanthophora spicifera was found to have a strong reducing power, with an IC50 value 0.012 ± 0.002 mM. H2O2 scavenging activity (~79 %) with an IC50 value of 0.006 ± 0.001 mM and 67 % ABTS radical scavenging activity (IC50 = 0.005) was highest in S. marginatum. Analysis showed that TPC exhibited strong positive correlation with both the ferric reducing antioxidant potential and DPPH antioxidant activity. These results showed that these seaweeds have significant antioxidant capacity and rich nutritional properties, which suggest they could be useful sources of functional ingredients for dietary supplements and other food products.

In Vitro Inhibition of Enzymes and Antioxidant and Chemical Fingerprinting Characteristics of Azara serrata Ruiz &amp; Pav. Fruits, an Endemic Plant of the Valdivian Forest of Chile

The World Health Organization has emphasized the importance of consuming small fruits for the prevention of chronic health problems, including diabetes, cardiovascular diseases, cancer, and obesity, which are named chronic non-communicable diseases (NCDs). Azara serrata Ruiz &amp; Pav., commonly called “aroma de Castilla”, is a shrub endemic to Chile from the Salicaceae family that produces an underutilized blue-grey berry that grows wild in southern Chile. The species is widely used as a medicinal plant by the Andean communities of southern Chile. In this work, a high-resolution mass spectrometric analysis of the methanolic extract revealed several phenolic compounds for the first time in the edible berry of this endemic species. Furthermore, several glycosylated anthocyanins were detected and quantified using UHPLC coupled with UV/Vis detection and trapped ion mobility mass spectrometry (UHPLC-DAD-TIMS-TOF) for the anthocyanin-rich extract, which was prepared using an optimized anthocyanin extraction protocol. The extract proved to be active in the inhibition of several enzymes linked to NCDs, such as acetylcholinesterase, tyrosinase, amylase, lipase, and glucosidase (IC50 = 3.92 ± 0.23, 12.24 ± 0.03, 11.12 ± 0.10, 32.43 ± 0.0, and 371.6 ± 0.0 μg/mL, respectively). Furthermore, the extract concentrated in anthocyanins showed good antioxidant activity evidenced by the bleaching of the radicals DPPH and ABTS, ferric-reducing antioxidant power (FRAP), and oxygen radical absorbance capacity (ORAC). The results show that these neglected endemic small berries can be a source of healthy phytochemicals. These Chilean berries can be used as functional food and their extracts are candidates for use as functional ingredients in naturally healthy products.

Microencapsulation and characterization of pomegranate seed oil using gum Arabic and maltodextrin blends for functional food applications

AbstractPomegranate seed oil (PSO) is highly valued in the functional food industry due to its rich fatty acid content and associated health benefits. However, its high degree of unsaturation makes it susceptible to rapid degradation when exposed to oxygen and light. This study investigates the encapsulation of PSO at 15% w/w using different blends of gum Arabic (GA) and maltodextrin (MD) (1:0, 0:1, 1:1, 3:1, and 1:3) to determine optimal formulations for enhanced stability and functional quality. Characterization of the encapsulated PSO powders showed distinct particle morphologies, including flake‐like shapes and textures ranging from smooth to wrinkled and porous. The Fourier transform infrared (FT‐IR) spectra indicated shifts in functional groups from 2973.70 to 408.84 cm−1, revealing the presence of aliphatic, amine, aromatic, carboxylic acid, and hydroxyl groups. Although no single formulation achieved all desired outcomes, the GA:MD ratios of 1:0 and 1:1 were superior in enhancing color properties (yellowness and chroma), techno‐functional attributes (bulk density and solubility), and in preserving essential fatty acids, including stearic, cis‐oleic, α‐linolenic, arachidic, γ‐linolenic, linoleic, and punicic acids. Additionally, GA:MD (3:1) powders exhibited superior ferric‐reducing antioxidant power (FRAP) and 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) radical scavenging activities (RSA). In conclusion, formulations using solely GA or GA:MD ratios of 1:1 and 3:1 effectively preserve bioactive content in PSO, enhancing its antioxidant capacity. These findings suggest promising applications for these encapsulated powders in developing functional foods that meet industry demands.

The principal component analysis of antioxidant activities of Songgak, a traditional herbal drink in West Nusa Tenggara, Indonesia

Songgak is a traditional herbal tea of the Sasak Tribe in Lombok Island, Indonesia, formulated to strengthen people's stamina. Songgak is composed of seven kinds of roasted spices: Piper nigrum L., Coriandrum sativum L., Piper retrofractum Vahl, Myristica fragrans Houtt, Syzygium aromaticum, Elaeocarpus grandiflorus, and Helicteres isora. This study aimed to assess the benefits of Songgak and its constituent spices by evaluating their antioxidant activities, total phenolic content (TPC) and flavonoid content (TPC). Antioxidant activity tests were performed on the water extract of Songgak, ethanolic extract of Songgak, and ethanolic extract of seven spices of Songgak including 2,2′- diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging, Trolox equivalent antioxidant capacity (TEAC), and ferric reducing antioxidant power (FRAP) assay. The antioxidant activity using DPPH method showed that the water extract of Songgak has a strong categorisation of antioxidant activity with DPPH IC50 value of 63.78±4.29 µg/mL. The constituent species of Songgak with the strongest antioxidant activity was S. aromaticum. Total phenolic content (TPC) and total flavonoid content (TFC) of Songgak tea were 26.85±4.29 mg GAE/g and 6.99±0.29 mg RE/gram, respectively. The correlation between TPC, TFC, and antioxidant activities was determined using principal component analysis (PCA). The loading plot showed that TPC and TFC were strongly correlated with the antioxidant activity (FRAP method) of Songgak tea and its constituent spices. These results revealed that the presence of flavonoid and phenolic compounds in the seven herbal medicinal plants were responsible for the antioxidant properties of Songgak as a healthy herbal drink. Therefore, consuming Songgak every day can be beneficial for preventing various diseases involving free radicals.

Antioxidant Activity and Oxidative Stress Survival of Limosilactobacillus reuteri LR92 in Fermented Milk with Juçara Pulp

Fermented milk with probiotic bacteria is a functional food, and adding fruit can enhance its taste. Juçara, the fruit of the Euterpe edulis Martius palm tree, is known for its natural antioxidant properties. This study aimed to assess the antioxidant capacity of milk fermented by Limosilactobacillus reuteri LR92 with juçara pulp (JFM) over 30 days of storage at 4 °C and its protective effect on probiotic cells against reactive oxygen species (ROS). Phenolic compounds and antioxidant activities were measured using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric-reducing antioxidant power (FRAP) assays during storage. The resistance of L. reuteri to hydrogen peroxide, superoxide anions, and hydroxyl radicals was also tested. The results indicated that JFM maintained stability in its composition, except for color, which showed reduced brightness by the end of the 30 days. Although antioxidant activity measured by DPPH and FRAP decreased (83.92–67.03 µmol TEAC.g−1 and 1185.64–830 g TEAC.100 g.mL−1, respectively), it remained higher than the control (21.90–24.50 µmol TEAC.g−1 and 235.77–229.87 g TEAC.100 g.mL−1, respectively). Phenolic content remained consistent. In addition, juçara pulp significantly protected L. reuteri cells from ROS. Therefore, juçara-enriched fermented milk not only improved antioxidant properties but also shielded probiotics from oxidative stress, highlighting its potential as a functional food with added health benefits.

Antioxidant, membrane stabilizing and thrombolytic potentials of the leaves of erythrina fusca lour

Erythrina fusca (Family: Fabaceae) is famous for many traditional healing. In the present study, the leaves of E. fusca were collected, dried, powdered and then extracted with methanol. It was further partitioned into n-hexane, dichloromethane and aqueous soluble fractions. All the extracts were subjected to antioxidant, membrane stabilizing and thrombolytic assays. In case of free radical scavenging assay, the aqueous soluble fraction showed highest scavenging activity. In ferric reducing anti-oxidant power assay, the dicholoromethane extract showed highest reduction of ferric ion in a dose dependent manner. In total antioxidant assay, the methanol extract and dichloromethane extract showed stronger capacity as antioxidant. During the determination of total phenolic and flavonoid contents, the methanol extract and dichloromethane soluble fraction showed higher contents of phenolics and flavonoids, respectively. The erythrocyte membrane stabilizing assay revealed the capacities of methanol extract and its aqueous fraction to stabilize the RBC membrane in both hypotonic solution- and heat- induced hemolytic conditions. However, the clot lysis ability of the E. fusca leaf extracts was not so prominent. Bangladesh J. Bot. 53(3): 439-445, 2024 (September)

Stage of lactation, parity, breed, milk composition and minerals affect the non-enzymatic antioxidant activity of sheep milk

The aims of this study were to i) characterize sheep milk for non-enzymatic antioxidant activity via 2 different assays, namely the ferric reducing antioxidant power (FRAP) and the 2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH), and ii) investigate the effect of milk composition and animal-related parameters on these 2 assays by using Generalized Additive Mixed Model (GAMM) approach. A total of 740 ewes belonging to Massese and Comisana breeds were sampled once during the morning milking across 11 sampling sessions. All milk samples were analyzed for fat, protein, casein, and lactose, somatic cell score (SCS) and minerals (Ca, Mg, Na and Cl). The FRAP and DPPH assays were tested to measure the non-enzymatic antioxidant activity of milk, expressed as μM eq. ascorbic acid/mL of milk and % of inhibition, respectively. The GAMM model included the effect of parity and breed as parametric terms, and the effect of days in milk (DIM), milk yield and the interactions protein × fat, casein × SCS, Ca × Mg and Na × Cl as smooth terms. The sampling day was included in the model as random effect. Results revealed that the non-enzymatic antioxidant capacity of sheep milk, expressed as FRAP, was affected by DIM, potentially because of changes in milk composition over time. Conversely, parity and breed of ewes affected DPPH, suggesting that age- and breed-specific factors are related to specific components in milk acting as hydrogen donors. Milk fat and high casein percentages were found to significantly affect FRAP, while protein content was crucial for high DPPH levels. Additionally, Ca and Mg emerged as important non-enzymatic antioxidants for both FRAP and DPPH, highlighting their important role in antioxidant activity of sheep milk. On the other side, combinations of Na and Cl were particularly influential for FRAP, revealing the complex relationship between these minerals and non-enzymatic antioxidant activity of milk. These findings offer valuable insights into the factors affecting the antioxidative properties of sheep milk, highlighting the need for further exploration of other non-enzymatic antioxidants and their contribution to the total antioxidant activity.

Assessment of phenolic composition and antioxidant activity of fermented Andean blackberry beverage enriched with medicinal plants of Ecuador

In recent years there has been a great interest in functional beverages with antioxidant capacity that impart various health implications upon consumption due to the presence of various bioactive components, like phenols. Fruit juices are excellent matrices for the delivery of active components for these functional beverages. This research was focused on developing and testing the biological activity of a new fermented blackberry (Rubus glaucus Benth) beverage enriched with different plants as a new product on the functional food market. Several Ecuadorian species (spices, aromatic, and medicinal) have been tested for the highest antioxidant activity and phenolic content. Methods like Folin Ciocalteu, α-diphenyl-α-picrylhydrazyl free-radical-scavenging method (DPPH), free-radical-scavenging activity (ABTS), and Ferric reducing antioxidant power (FRAP) were used. Among the tested plants, arrayán (Myrcianthes hallii), plantain (Plantago major), ishpingo (Ocotea quixos), and ataco (Amaranthus quitensis) were selected. The study demonstrates the ability of medicinal plants to improve the total phenolic content and antioxidant capacity, but also the sensory properties of the functional drink compared to the blackberry fermented drink. The highest values of the analyzed characteristics (total phenolic content, antioxidant capacity, sensory evaluation), were obtained in the case of the treatment consisting of fermented blackberry beverage enriched with 4 g of medicinal plants.

The Antioxidant Activity of Atomized Extracts of the Leaves and Stems of Cnidoscolus diacanthus (Pax &amp; K. Hoffm.) J.F. Macbr. from Peru and Their Effect on Sex Hormone Levels in Rats

In this research, we aimed to determine the antioxidant activity of an atomized extract of Cnidoscolus diacanthus (Pax &amp; K. Hoffm.) J.F. Macbr., known in Peru as “huanarpo hembra”, and its effect on sex hormone levels. Its phytochemical profile was determined using liquid chromatography–mass spectrometry (LC–MS), while its total phenol content (TPC) and total flavonoids (TFs) were determined using the Folin–Ciocalteu method and the aluminum chloride method. Its antioxidant activity was determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH), the radical 2,2-azino-bis-3-ethylbenzthiazolin-6 sulfonic acid (ABTS), and ferric-reducing antioxidant power (FRAP). The biological activity of C. diacanthus and its effect on sexual hormones were determined in Holtzman rats of both sexes. Phytochemical analysis revealed the presence of flavonoids and phenolic compounds in its leaves and stems, mainly rutin, quercetin, chlorogenic acid, and genistein. However, the stem extract contained higher total phenol (464.38 ± 4.40 GAE/g) and flavonoid (369.17 ± 3.16 mg QE/g of extract) contents than the leaf extract (212.38 ± 3.19 mg GAE/g and 121.49 ± 2.69 mg QE/g). For DPPH, ABTS, and FRAP, the Trolox-equivalent antioxidant capacity (TEAC) was 597.20 ± 5.40 µmol/g, 452.67 ± 5.76 µmol/g, and 535.91 ± 1.56 µmol/g, respectively, for the stems, while for the leaves, it was 462.39 ± 3.99 µmol/g, 202.32 ± 5.20 µmol/g, and 198.13 ± 1.44 µmol/g, respectively. In terms of the values for hormonal levels, at a dose of 100 mg/kg of the extract, testosterone levels of 1.430 ng/mL (with the leaf extract) and 1.433 ng/mL (with the stem extract), respectively, were found in the male rats. Regarding estradiol levels, in the female rats, these were 10.425 ng/mL (leaf extract) and 8.775 ng/mL (stem extract), while their levels of luteinizing hormone were 0.320 mIU/mL (leaf extract) and 0.273 mIU/mL (stem extract). For the follicle-stimulating hormone, levels of 0.858 mIU/mL (leaf extract) and 0.840 mIU/mL (stem extract) were found in the female rats, and levels of 0.220 mIU/mL (leaf extract) and 0.200 mIU/mL (stem extract) were found in the male rats. It is concluded that the C. diacanthus stem extract had a greater antioxidant capacity than the leaf extract, while both extracts had a superior effect on the sex hormone levels in the female rats compared to the male rats.

Apple Pomace as a Potential Source of Oxidative Stress-Protecting Dihydrochalcones

Among fruits, the apple is unique for producing large amounts of the dihydrochalcone phloridzin, which, together with phloretin, its aglycone, is valuable to the pharmaceutical and food industries for its antidiabetic, antioxidant, and anticarcinogenic properties, as well as its use as a sweetener. We analysed the phloridzin concentration, total phenolic content, and antioxidant activity in the peel, flesh, seeds, juice, and pomace of 13 international and local apple varieties. In the unprocessed fruit, the seeds had the highest phloridzin content, while the highest total phenolic contents were mostly found in the peel. In processed samples, phloridzin and the total phenolic compounds especially were higher mostly in juice than in pomace. Moreover, the total phenolic content was much higher than the phloridzin content. Juice showed the highest antioxidant activity, followed by the peel and flesh. Across all samples, antioxidant activity did not directly correlate with phloridzin concentrations, suggesting that the antioxidant activity ascribed to phloridzin may need re-evaluation. In the Ferric Reducing Antioxidant Power (FRAP) assay, phloridzin only showed antioxidant activity at high concentrations when compared to its aglycone, phloretin. Considering the large amounts of apple juice produced by the juice industry, residual pomace is a promising source of phloridzin. For technical use, processing this phloridzin to phloretin would be advantageous.

Green synthesis of platinum nanoparticles using aqueous bark extract of Quercus sp. for potential antioxidant and antimicrobial applications

Oak bark, which is commonly used in the wood industry, has by-products often repurposed as fuel. Its extracts are rich in compounds with anticancer, antibacterial, antifungal, and anti-inflammatory properties. This study synthesized platinum nanoparticles (PtNPs) using aqueous extracts from Quercus dalechampii (QD), Q. frainetto (QF), and Q. petraea (QP). Key factors during nanoparticle formation included reaction time, metal ion concentration, pH, extract-to-metal ion ratio, and temperature. The PtNPs were characterized by dynamic light scattering, Fourier transform infrared spectroscopy, and transmission electron microscopy. The average diameters were 58.5 ± 7.6 nm for QD-PtNPs, 41.6 ± 5.4 nm for QF-PtNPs, and 41 ± 5.3 nm for QP-PtNPs. Antioxidant and antimicrobial activities were also analyzed. The QP-PtNPs had the highest DPPH (2,2-Diphenyl-1-picrylhydrazyl), FRAP (Ferric Reducing Antioxidant Power), and CUPRAC (Cupric Reducing Antioxidant Capacity) free radical scavenging activities, while QD-PtNPs excelled in ABTS (2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid)) scavenging. All PtNPs showed strong antimicrobial properties, particularly against Enterococcus faecalis, Escherichia coli, Candida krusei, and Candida auris. These findings suggest that Quercus-mediated PtNPs have significant potential for developing treatments against bacterial and fungal infections, with promising applications in medicine.

Characterisation of wild red raspberry ecotypes in Northern Anatolia: Insights into sensory, biochemical and antioxidant properties

ABSTRACT Red raspberries are among the most significant wild edible fruits (WEFs) in Türkiye, thriving in cold to warm temperate regions across the country. This study focuses on 11 wild red raspberry ecotypes sampled from the Northern Anatolia region, examining their sensory, biochemical and antioxidant properties. Sensory analysis was used to compare ecotypes based on aroma, taste and juiciness. Biochemical assessments included soluble solid content (SSC), vitamin C amount, organic acids, total anthocyanins (TA), total phenolic content (TPC), total flavonoid content and total antioxidant capacity. The Ferric Reducing Antioxidant Power (FRAP) assay measured antioxidant capacity. Despite similar growing conditions, significant variations were observed among ecotypes and across years. In the first year, fruit weights ranged from 1.04 g to 1.33 g, and in the second year, they ranged from 0.97 g to 1.27 g. Fruit chroma values ranged between 26.11 and 33.70 in 2021, and 23.17 and 30.19 in 2022. Vitamin C exhibited considerable variability, ranging from 29.3 mg · 100 g−1 to 44.4 mg · 100 g−1 across ecotypes and years. TPC, total anthocyanin content (TAC) and total flavonoid content ranged from 164 mg to 390 mg gallic acid equivalent (GAE) · 100 g−1, 17.3 mg to 33.2 mg cyanidin-3-glucoside equivalent · 100 g−1 and 10.3 mg to 17.6 mg quercetin equivalent (QE) · 100 g−1, respectively, in both years. Citric acid emerged as the dominant organic acid across all ecotypes. Notably, the ecotypes V-4, V-8, V-3 and V-10 showcased larger, more appealing fruits suitable for fresh consumption, whereas V-3 and V-5 presented sweeter fruits ideal for processing. Additionally, the ecotypes V-6, V-7 and V-11 displayed higher levels of health-promoting compounds, such as TPC and antioxidant capacity, suggesting their potential as functional foods and valuable sources of natural antioxidants in the future.