Highest Radical Scavenging Capacity Research Articles

Antioxidant and antimicrobial extracts from grape stalks obtained with subcritical water. Potential use in active food packaging development

In order to valorise winemaking grape stalks, subcritical water extraction at 160 and 180 °C has been carried out to obtain phenolic-rich extracts useful for developing active food packaging materials. Red (R) and white (W) varieties (from Requena, Spain) were used, and thus, four kinds of extracts were obtained. These were characterised as to their composition, thermal stability and antioxidant and antibacterial activity. The extracts were incorporated at 6 wt% into polylactic acid (PLA) films and their effect on the optical and barrier properties of the films and their protective effect against sunflower oil oxidation was analysed. Carbohydrates were the major compounds (25–38%) in the extracts that contained 3.5–6.6% of phenolic compounds, the R extracts being the richest, with higher radical scavenging capacity. Every extract exhibited antibacterial effect against Escherichia coli and Listeria innocua, while PLA films with extracts preserved sunflower oil against oxidation.

Preventive Anti-inflammatory Effects of Apocynin on Acetic Acid-Induced Colitis in Rats.

Ulcerative colitis is an inflammatory bowel disease with a complex aetiology characterised by abnormal immune responses and oxidative stress-induced tissue injury. Inflammatory cells play an important role in the progression of this pathology through the overproduction of reactive oxygen species (ROS) from various sources including the NADPH oxidases (NOXs). The aim of this study was to investigate the preventive effect of apocynin, a natural antioxidant molecule and a selective inhibitor of NOXs, on acetic acid (AA)-induced ulcerative colitis in rats. Our results first confirmed that apocynin has a high free radical scavenging capacity as well as a potent iron chelating ability. Oral pretreatment of rats with apocynin (200mg/kg and 400mg/kg) for 7days prior to AA-induced colitis suppressed the increase in pro-oxidant markers in colonic homogenates and preserved colonic cytoarchitecture from acetic acid-induced damage. Oral administration of apocynin (200mg/kg and 400mg/kg) also reduced several systemic inflammatory markers such as alkaline phosphatase, iron, pro-inflammatory cytokines, C-reactive protein and myeloperoxidase. This study shows that apocynin protects rats from acetic acid-induced colonic inflammation and suggests that apocynin may have a promising beneficial effect in the prevention of ulcerative colitis.

LC-HRMS Metabolite Profiling of Lunasia amara Stem Bark and In Silico Study in Breast Cancer Receptors

L. amara is a medicinal plant used as an aphrodisiac. Several studies show it has a compound with biological activities such as inhibition of cell proliferation, one of the mechanisms leading to anticancer activities. This study aimed to profile the metabolites and predict activity against two breast cancer receptors (ERα (3ERT) and HER2 (3PPO)) with an in silico approach. Metabolite profiling of water and 80% ethanol extract was analyzed by UHPLC-Q-Orbitrap-HRMS. Also, we performed a radical scavenging activity by 1,1-diphenyl-2-picrylhydrazyl (DPPH). Putative identification of metabolite in L. amara showed the 46 metabolites (4 unknown) were identified and predominantly as quinoline alkaloids. Some of the compounds from glycosides and phenol groups were also identified. From the antioxidant capacity test results, the 80% ethanol extract had a higher radical scavenging capacity than the aqueous extract. Based on the molecular docking results, the highest affinity for the ERα receptor was found in the tested compound tetrahydropapaveroline and exceeded the native 4-OHT ligand. For the HER2 receptor, graveolinine has the highest affinity but is still below the native lapatinib ligand. Ligand interactions with the amino acids Leu 387 and Glu 419 on the active site of the ERα receptor and Phe1004 on the HER2 receptor are thought to play an important role in increasing the energy affinity. Overall, all compounds showed higher affinity for HER2 receptors than ERα. Alkaloids demonstrated anticancer activity. Further research should be conducted to determine the in vitro activity of these compounds on breast cancer cells.

Enhanced DPPH Radical Scavenging Activity and Enriched γ-Aminobutyric Acid in Mulberry Juice Fermented by the Probiotic Lactobacillus brevis S3

Mulberries, known for their high sugar content and rich bioactive compounds, have attracted attention for their potential health benefits. γ-Aminobutyric acid (GABA) is an amino acid with multiple physiological functions. To increase the GABA content and enhance the antioxidant capacity in fermented mulberry beverages, we screened a high-yielding strain, Lactobacillus brevis S3, known for its probiotic properties. L. brevis S3 demonstrated an excellent tolerance to simulated gastric acid, gastric juice, intestinal fluid, bile salts, osmotic pressure, and phenol, making it a safe and valuable probiotic candidate for mulberry fermentation. We attempted the addition of different nutritional components to enhance the GABA content in mulberry juice, including 1% yeast extract; 0.5% peptone; 0.01% metal ion complex (magnesium sulfate, manganese sulfate, and ferrous sulfate); combinations of yeast extract and peptone, and all three components. Mulberry juice supplemented with all three components reached a viable cell count of 1.2 × 1010 CFU/mL after 72 h. The antioxidant capacity and GABA titer were enhanced. The DPPH free radical scavenging capacity increased by 1.62 times, and the GABA content reached 7.48 g/L. By utilizing L. brevis S3 with excellent probiotic properties and supplementation with nutritional components, it is possible to produce low-sugar mulberry functional beverages with a high DPPH free radical scavenging capacity that are rich in GABA.

Phytochemical status and antioxidant capacity of selected hot pepper varieties cultivated in Tanzania

Hot pepper is one of the most important economic fruits with abundant of nutritional qualities. Thus, the consumption of foods of plant origin with high nutritional and bioactive compounds of high antioxidants capacity is a major concern nowadays. A study was conducted to determine and quantify concentrations of important bioactive compounds present in the nine selected hot pepper varieties cultivated in Tanzania. Hot peppers were grown in the field at Botany department research farm, University of Dar es Salaam from March to September, 2021. Then, ripe-fruit extracts were used to determine vitamin C, beta-carotene, lycopene, total phenolic content (TPC) and total flavonoid content (TFC)among the varieties quantitatively. The results indicated that there were very high significant variations on the nutrients and bioactive compound concentrations (p<0.0001) among all varieties of hot pepper evaluated. The highest amount of vitamin C was 948.30 ± 22.6 mg/100g recorded from orange bird eye variety. The high concentration of beta-carotene was 0.62 ± 0.006mg/ 100 ml recorded from orange bird eye. The highest concentration of lycopene was 0.55 ± 0.0003 mg/ 100 ml from Big red cayenne. The highest concentration of TPC was 454.247 ± 20.9mg GAE/ 100g obtained from Big red cayenne. The highest concentration of TFC was 8.92 ± 0.15 mg RE/ 100g obtained from Big red cayenne. High variability was observed among the hot pepper varieties; Big red cayenne variety with the highest concentrations of TPC, TFC and lycopene, showed to have the highest radical scavenging capacity. Big red cayenne can be a cheap source of natural antioxidants, therefore recommended for future development of nutraceuticals or healthy food products and conveying great benefits for food and pharmaceutical industries, consumers, and producers.

Virtual screening, identification, and potential antioxidant mechanism of novel bioactive peptides during aging by a short-chain peptidomics, quantitative structure–activity relationship analysis, and molecular docking

Antioxidant peptides have received a great deal of attention. However, only a few studies have been conducted on the antioxidant peptides originating from Baijiu. A total of 1490 features deemed potential short-chain peptides (the amino acid number between 2 and 4, SCPs) were screened and analyzed by a customized short-chain peptidomics approach in Feng-flavor Baijiu (FFB) during 14 years of aging, with an obvious discrepancy between FFB aged for 3 years and 6 years being observed. Thirty-nine characteristic SCPs in total were identified and accurately quantified by high-throughput parallel reaction monitoring-based synthetic standards, with the contents ranging from 0.16 to 279.33 μg L−1. Combined with the absorption, distribution, metabolism, excretion, and toxicity analysis model, PGRW, WK, SC, and PAW, four novel antioxidant peptides with high ABTS radical scavenging capacity, were obtained using a customized quantitative structure–activity relationship (QSAR) model based on a two terminal position numbering method, with satisfied coefficients of determination (R2), internal cross-validated R2 (Q2), and external R2 (R2pre) of 0.925, 0.808, and 0.665, respectively. Furthermore, these 4 antioxidant peptides could block the Keap-Nrf2 interaction and promote the accumulation of Nrf2 by molecular docking analysis, and the interaction energy between peptide PGRW and Keap1 was higher than that between epigallocatechin gallate and Keap1 based on CHARMm forced field. Overall, this study facilitated the discovery of functional peptides in Baijiu and the understanding of aging mechanisms.

Metabolome and Transcriptome Analyses Reveal the Differences in the Molecular Mechanisms of Oat Leaves Responding to Salt and Alkali Stress Conditions

Plant growth and production are more severely inhibited by alkalinity than by salinity. However, the metabolites responsible for the reduced growth caused by alkalinity are largely unknown. Here, the Illumina RNA-Seq analysis and targeted metabolome were used to identify the differentially expressed genes and metabolites responding to salt and alkali stresses. The expression levels of eight genes related to photosynthesis and some genes related to chlorophyll synthesis decreased under alkali stress, whereas no changes were detected under salt stress, which may explain the observed lower level of photosynthetic rate in alkalinity than in salinity. Under alkali stress, significant decreases in the relative abundances of cis-cinnamic acid and scopoline were observed, which correlated with the high levels of reactive oxygen species (ROS). The levels of protocatechuic acids decreased, correlating with the observed decrease in the chlorophyll content. Alkalinity markedly increased the production of o-coumaric acid, which contributes to growth inhibition. No significant changes in cis-cinnamic acid, scopoline, and o-coumaric acid were detected in salinity, which may be the reason for the stronger growth inhibition due to alkali stress than salt stress. The accumulation of citric acid, serotonin, pyroglutamic acid, L-citrulline, ferulic acid, and caffeic acid was detected under salt and alkali stress conditions, indicating high free radical scavenging capacity. The enhancement of mevalonic acid and salicylic acid levels was detected under alkali stress, which could have facilitated chlorophyll accumulation. Salt and alkali stress conditions also led to the accumulation of cyclic AMP related to inorganic ion regulation and betaine-related osmoregulation. Benzamide, phenethylamine, N-feruloyltyramine, chrysoeriol 6-C-hexoside, 1,3-o-di-p-coumaroyl glycerol, cordycepin, and 1-o-p-cumaroylglycerol were identified to be accumulated in response to alkali stress.

Impact of ultrasound on pumpkin seed protein concentrate hydrolysis: Effects on Alcalase, protein, and assisted reaction

Ultrasound (40 kHz, 23.8 W/L) was applied (pH 7.5, 25 – 60 °C, up to 300 min) to Alcalase (protease) and pumpkin seed protein concentrate (substrate) as a pre-process or during proteolysis aiming to improve the hydrolysis rate, the final concentration of hydrolysates, and its solubility and in vitro antioxidant activity. The pre-process applied in enzyme and substrate increased the relative activity of the enzyme by 10.3 and 50.1%, respectively (p<0.05). Moreover, pre-sonication of protein and ultrasound-assisted hydrolysis provided up to 280% increase in the proteolysis rate and resulted in up to 24% higher concentration of soluble peptides, compared to conventional hydrolysis (p<0.05). Consequently, the hydrolysates obtained with ultrasound intervention had greater solubility (≤148.1%, p<0.05) and higher radical scavenging capacity than those produced through conventional hydrolysis. From the overall evaluation of the results, and considering the operational costs and equipment wear, we concluded that pre-sonication of pumpkin protein is the best strategy to enhance the generation of hydrolysates with better multifunctional properties.

Bioactive Compounds, Antioxidant Activity and Sensory Properties of Northern Red Oak (Quercus rubra L., syn. Q. borealis F. Michx) Seeds Affected by Roasting Conditions

The nutritional value and health-promoting properties cause the fruits (acorns) of Quercus spp. to have great potential for use in the food industry as functional ingredients and antioxidants source. The aim of this study was to examine the bioactive compound's composition, antioxidant potential, physicochemical properties and taste characteristics of northern red oak (Quercus rubra L.) seeds subjected to roasting at different temperatures and times. The results indicate that the roasting markedly affects the composition of bioactive components of acorns. In general, the use of roasting temperatures greater than 135 °C causes a decrease in the total phenolic compound content of Q. rubra seeds. Furthermore, along with an increase in temperature and thermal processing time, a remarkable increase in melanoidins, which are the final products of the Maillard reaction, was also observed in processed Q. rubra seeds. Both unroasted and roasted acorn seeds had high DPPH radical scavenging capacity, ferric reducing antioxidant power (FRAP) and ferrous ion chelating activity. Roasting at 135 °C caused negligible changes in total phenolics content and antioxidant activity of Q. rubra seeds. Almost all samples had lower antioxidant capacity along with an increase in the roasting temperatures. Additionally, thermal processing of acorn seeds contributes to the development of the brown color and the reduction of bitterness, and the creation of a more pleasant taste of the final products. Overall, the results of this study show that both unroasted and roasted Q. rubra seeds may be an interesting source of bioactive compounds with high antioxidant activity. Therefore, they can be used as a functional ingredient of beverages or food.

Proximate Composition, Mineral Element Profile and Antioxidant Properties of the Edible Kenyan Mushroom, Auricularia polytricha

The indigenous Kenyan Auricularia polytricha is a known delicacy to the communities residing around Kakamega forest in Western Kenya. The objective of the present study was to carry out proximate analysis, determine selected mineral element levels and radical scavenging capacity of the fruiting bodies of Auricularia polytricha. Proximate analysis which included determination of total carbohydrates, crude protein, crude fibre, crude fat, ash and moisture contents was done according to the Association of Official Analytical Chemists (AOAC) methods. The minerals (Ca, Mg, Fe, Zn, Mn, Pd, Cd) in the dried mushroom sample were determined using an Atomic Absorption Spectrophotometer (AAS) while Na and K were determined by flame emission photometry. Phosphorus was estimated by spectrophotometric method. The antioxidant activity of the crude mushroom extracts was evaluated by measuring their scavenging capacity on the stable radical, DPPH (2,2- Diphenyl-1-Picrylhydrazyl) using UV-Vi’s spectrophotometer at 517 nm. The mushroom was found to contain 64.53% total carbohydrates, 43.12% crude fibre, 11.67% crude proteins, 4.75% crude fat and 4.69% ash content on dry matter basis. The moisture content of the mushroom was found to be 80.33% of the fresh weight, which is typical of fresh foods and vegetables. A methanol extract of the mushroom exhibited antiradical activity against DPPH in a dose dependent manner with the highest radical scavenging capacity (40.84%) obtained at a concentration 500 µg/mL. For the mineral profile, the variations and concentrations of the essential and trace elements under study decreased in the order K˃Na˃Mg˃Ca˃Fe&gt;P&gt;Zn&gt;Mn. The selected hazardous heavy metals Cd and Pb were not detected in the mushroom sample. Implications of the mineral concentrations on the nutritional value of the mushroom have been highlighted. In conclusion, the obtained results suggest that the mushroom, which has good amounts of the required proximate components, minerals and antiradical constituents, is a potentially healthy, safe and functional food.

Extraction of red pigment from Chinese jujube peel and the antioxidant activity of the pigment extracts

Abstract Chinese jujube is a delicious fruit with high antioxidant nutrients. The fruit peel, however, is always discarded due to its indigestibility. In the current study, the jujube peels were collected for red pigment extraction. Six extraction-related parameters (ethanol concentration, solid-liquid ratio, material granularity, enzyme concentration, enzymolysis time, and pH) were optimized for jujube peel pigment extraction using Plackett–Burman and Box–Behnken designs. When the fruit peels were treated with 1.18% cellulase and 73% ethanol at pH 3.15, optimization enhanced the pigment extraction efficiency by 29.7% compared with the control. Ultra-high performance liquid chromatography (UHPLC) assay revealed that delphinidin 3-O-galactoside and cyanidin 3-O-rutinoside chloride were the major components of the jujube pigment extracts. Additionally, the red pigment extracts exhibited high free radical scavenging capacity and strong Fe3+ reducing power. Finally, it also provides us a simple new method for efficient extraction of natural antioxidants from discarded jujube peels.

Preparation and characterization of a novel nanoemulsion consisting of chitosan and Cinnamomum tamala essential oil and its effect on shelf-life lengthening of stored millets

This study aimed to improve the stability of Cinnamomum tamala essential oil (CTEO) via encapsulating into chitosan nanoemulsion (CsNe) through an ionic-gelation technique and explore its food preservative efficacy against aflatoxigenic strain of Aspergillus flavus (AFLHPSi-1, isolated from stored millet), aflatoxin B1 (AFB1) contamination, and lipid peroxidation, causing qualitative deterioration of stored millets. The CTEO was characterized through gas chromatography–mass spectrometry (GC–MS) analysis that confirmed the presence of linalool as a major component occupying approximately 82.64% of the total oil. The synthesized nanoparticles were characterized through scanning electron microscopy (SEM), fourier transform infrared (FTIR) spectroscopy, and X-ray diffraction (XRD) analysis. The encapsulation efficiency (EE) and loading capacity (LC) of CTEO-CsNe were found to be 97.71% and 3.33%, respectively. In vitro release study showed a biphasic release pattern: with an initial burst release followed by a controlled release of CTEO. During investigation of efficacy, the CTEO-CsNe caused complete inhibition of A. flavus growth, and AFB1 biosynthesis at 1.0 and 0.8 μL/mL, respectively. The CTEO-CsNe exhibited its antifungal mode of action by altering fungal plasma membrane integrity (ergosterol inhibition) and permeability (leakage of important cellular constituents), and antiaflatoxigenic mode of action by inhibiting cellular methylglyoxal biosynthesis. CTEO-CsNe showed high free radical scavenging capacity (IC50 = 5.08 and 2.56 μL/mL) against DPPH•+ and ABTS•+ radicals, respectively. In addition, CTEO-CsNe presented remarkable preservative efficacy, inhibiting AFB1 and lipid peroxidation in model food system (Setaria italica) without altering their organoleptic properties. Based on overall results, CTEO-CsNe can be recommended as a novel shelf-life enhancer of stored millet samples.

Potential Use of Moringa oleifera Twigs Extracts as an Anti-Hyperuricemic and Anti-Microbial Source

Moringa oleifera (MO) grows throughout most of the tropics and has several industrial and medicinal uses. Besides the various uses of the plant parts such as its leaves, seed kernels, roots, or stem barks, the twigs (MT) of this plant are usually regarded as excessive parts. Although there have been few studies conducted to determine the value of this plant part, in fact, its potential uses—especially the pharmaceutical effects—of this biomaterial remains an up-to-date topic for scientists to discover due to the lack of interest so far. This study aims to identify the optimized fractions of different solvents for the extraction of antioxidants, for xanthine oxidase inhibition agents, and for anti-microbial activities. The two most active fractions obtained by column chromatography were the Hexane-Ethyl Acetate elution at a 9:1 (E1) and 8:2 (E2) ratio, respectively. With regard to antioxidant activity, E1 and E2 displayed relatively high DPPH radical scavenging capacity (IC50 = 87.7 and 99.0 µg/mL), which was only four times weaker than the control BHT (IC50 = 21.4 µg/mL). The highest inhibition activity against xanthine oxidase was also observed clearly in E1 and E2, which showed relatively low IC50 (54.7 and 42.0 µg/mL, respectively). These levels were inconsiderably higher than that of the positive control (IC50 = 20.8 µg/mL), proving that E1 and E2 exerted relatively strong antioxidant activity in terms of XOD inhibition. Regarding the antimicrobial test, E2 showed the highest inhibition activities against E. coli, K. pneumoiae, L. monocytogenes, B. subtilis, and P. mirabilis. The result indicates that (1) E1 and E2 were the strongest fractions for constraining free radical agents and several bacteria, and thus, (2) Moringa oleifera twigs are also a potential source for the prevention of gout-related symptoms.

Unexpected Antioxidant Efficiency of Chlorogenic Acid Phenolipids in Fish Oil-in-Water Nanoemulsions: An Example of How Relatively Low Interfacial Concentrations Can Make Antioxidants to Be Inefficient.

Selecting effective antioxidants is challenging since their efficiency in inhibiting lipid oxidation depends on the rate constants of the chemical reactions involved and their concentration at the reaction site, i.e., at the interfacial region. Accumulation of antioxidants at the interface of emulsions is key to modulate their efficiency in inhibiting lipid oxidation but its control was not well understood, especially in emulsions. It can be optimized by modifying the physicochemical properties of antioxidants or the environmental conditions. In this work, we analyze the effects of surfactant concentration, droplet size, and oil to water ratio on the effective interfacial concentration of a set of chlorogenic acid (CGA) esters in fish oil-in-water (O/W) emulsions and nanoemulsions and on their antioxidant efficiency. A well-established pseudophase kinetic model is used to determine in the intact emulsified systems the effective concentrations of the antioxidants (AOs). The relative oxidative stability of the emulsions is assessed by monitoring the formation of primary oxidation products with time. Results show that the concentration of all AOs at the interfacial region is much higher (20–90 fold) than the stoichiometric one but is much lower than those of other phenolipid series such as caffeic or hydroxytyrosol derivatives. The main parameter controlling the interfacial concentration of antioxidants is the surfactant volume fraction, ΦI, followed by the O/W ratio. Changes in the droplet sizes (emulsions and nanoemulsions) have no influence on the interfacial concentrations. Despite the high radical scavenging capacity of CGA derivatives and their being concentrated at the interfacial region, the investigated AOs do not show a significant effect in inhibiting lipid oxidation in contrast with what is observed using other series of homologous antioxidants with similar reactivity. Results are tentatively interpreted in terms of the relatively low interfacial concentrations of the antioxidants, which may not be high enough to make the rate of the inhibition reaction faster than the rate of radical propagation.

Multifunctional Bioactive Peptides from Germinated Soy (Glycin max) and Voandzou (Vigna subterranea) Beans: In-vitro Anti-Diabetic Potential through α-amylase α-glucosidase Inhibition, and Antioxidant Ability by DPPH Reducing

Legumes, protein-rich foods containing various peptides, offer the possibility of modulating both sugar absorption and free radical production, in order to prevent diabetes and oxidative stress diseases. This study aimed to reveal the antioxidant and anti-diabetic potential of peptides from germinated soy and voandzou beans by checking the efficacy of these beans peptides generated by germination and even after post-meal digestion. Thus, beans crude proteins were extracted and digested with pepsin and pancreatic enzymes. Digested proteins were fractioned by dialysis. Each type of proteins ability to inhibit α-amylase and α-glucosidase activity and to scavenge DPPH free radical, were tested. Total protein content determined by spectrophotometry at 241 nm and extraction yield evaluated showed no significant difference (p˂ 0.05) with an average of 88% (soy) and 86% (voandzou) and 64.43% (soy) and 60.30% (voandzou), respectively; as opposed to the soluble protein content assessed in the supernatant of protein isolates. Simulated digestion of isolate protein generated peptide extracts showed a better inhibitory capacity of α-amylase and α-glucosidase with the digested voandzou protein isolate D2 exhibiting optimum inhibition (72.39%) for α-glucosidase near to acarbose (75.99%) and the digested soy protein isolate D2 displaying the optimum inhibition (89.25%) for α-amylase better than acarbose (75.99%). Moreover, it is the external fractions of size inferior to 10 kDa which are endowed with this excellent capacity of inhibition of these enzymes involved in the regulation of postprandial glucose. Finally, the high DPPH free radical scavenging capacity of all germinated protein isolate between 64.72 (D0) and 72.27% (D2) for soy and 73.45 (D0) and 81.43 % (D4) for voandzou is practically maintained after digestion and dialysis. Germinated soy and voandzou seeds thus have shown promising potential for being used as nutraceutical or functional ingredients for treatment and prevention of diabetes and diseases related to oxidative stress.

Application of Commercial Plant Probiotics Improves the Berry Yield and Quality of Field-Grown Blackcurrant

The berries of blackcurrants are commercially important and rich in antioxidants and have a high free radical scavenging capacity. Four controlled fields 1 ha in size were set up in an organic farm to test two commercial plant probiotic products, ProbioHumus and NaturGel, and their combined impact on blackcurrant berry yield and quality. Spray applications of ProbioHumus, NaturGel, and their combination significantly increased fruit yields 38, 25, and 16%, respectively, versus the nontreated control. The berries from plants inoculated with probiotics had significantly higher contents of anthocyanins versus the nontreated control and tended to exhibit increased levels of ascorbic acid. The blackcurrant berries treated with both probiotics exhibited a fair ability to scavenge DPPH free radicals. This is the first study of the improvement of both the yield and the quality of blackcurrant berries by the application of commercial plant probiotics under field conditions.

In vitro antioxidant properties of 2-(4-(2-hydroxybenzylideneamino)benzylideneamino)benzoic acid

In recent years, it has attracted great attention to determine and appraise synthetic antioxidants with high free radical scavenging capacity associated with various disorders. Because synthetic antioxidants are widely used in place of native antioxidants as they are influential and less expensive. In this study, the antioxidant activity of the newly synthesized asymmetric diimine Schiff base was determined by using DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging, ferrous ion chelation (FIC) activity and total antioxidant activity (Phosphomolybdenum assay) methods. The effective concentration (IC50) values were calculated for the Schiff base and standards. According to the results of DPPH radical scavenging, ferrous ion chelation and total antioxidant methods, Schiff base showed a well antioxidant activity. It was determined that Schiff base is reactive towards DPPH radicals (IC50, 180.0 μM) and especially Fe+2 ions (IC50, 76.3 μM). It was also found that it actively reduces the Mo(VI) ion to the Mo(V) form (IC50, 121.5 μM). The our results indicate Schiff base, may be a fine candidate as a source of synthetic antioxidants and possibly strong drug.

Characteristics and Valorization Potential of Fermentation Waste of Greengage (Prunus mume)

Greengage wine is gaining increasing attention in Asia for its rich nutritional elements and medicinal value. However, the treatment of the fermentation waste after brewing is a problem that remains unsolved. This work proposed to valorize the fermentation waste extract by a simple centrifugation. The bioactive compounds of the fermentation waste were investigated, including total flavonoids, total phenols, specific phenols and volatile compounds. The antioxidant and antibacterial capacities of the waste extract were also evaluated. The results revealed that the total phenol (1.34 mg GAE/g EPW) and total flavonoid (1.17 mg RE/g EPW) of the fermentation waste extract were still considerable. The fermentation waste also showed high DPPH radical scavenging capacity (5.39 μmol TE/g EPW) and high ABTS radical scavenging capacity (9.80 μmol TE/g EPW). Both GC-MS and LC-MS analysis identified key bioactive compounds, such as linalool, terpineol, β-ionone, neochlorogenic acid and chlorogenic acid, which have high antioxidant capacity and strong, thermal-stable antibacterial capacity. All these characteristics show a promising future for valorized fermentation waste, for example, in food additives or mouthwash.

Soluble protein isolate from brewing by‐product (trub) using the Box‐Behnken design

Brewing by-products, as trub, can be exploited as new nutrients sources, especially proteins. The objective of this study was to optimize the protein extraction from trub using the Box-Behnken design and response surface methodology to obtain a protein isolate and verify its antioxidants properties and phenolic compounds. Optimal extraction condition was at a pH of 12.31, concentration of 5.37 g/L, with 51.78 min of extraction at 80℃ (fixed temperature). Under these conditions, a protein isolate from trub was obtained (94.56% protein; 19.89% yield), its presented high water solubility (63.09 to 93.22%) over a wide pH range (6 to 12), high free radical scavenging capacity (63.03 and 186.07 TEAC μmol/100 g for DPPH and ABTS, respectively) and 35.36 mg gallic acid equivalents (GAE)/g of phenolic compounds. These results brings new information about a vegetable protein from a by-product enabling its extraction and applicability in different food matrices. Novelty impact statement Alkaline solution was efficient to extract the proteins from the trub, a beer production by-product that has been little reused. Vegetable protein isolate showed phenolic compounds, antioxidant activity and solubility in water over a wide pH range; and can be used as new protein source.

Modification of heat-induced whey protein isolate hydrogel with highly bioactive glass particles results in promising biomaterial for bone tissue engineering

This study deals with the design and comprehensive evaluation of novel hydrogels based on whey protein isolate (WPI) for tissue regeneration. So far, WPI has been considered mainly as a food industry by-product and there are very few reports on the application of WPI in tissue engineering (TE). In this work, WPI-based hydrogels were modified with bioactive glass (BG), which is commonly used as a bone substitute material. Ready-to-use, sterile hydrogels were produced by a simple technique, namely heat-induced gelation. Two different concentrations (10 and 20% w/w) of sol–gel-derived BG particles of two different sizes (2.5 and <45 µm) were compared. µCT analysis showed that hydrogels were highly porous with almost 100% pore interconnectivity. BG particles were generally homogenously distributed in the hydrogel matrix, affecting pore size, and reducing material porosity. Thermal analysis showed that the presence of BG particles in WPI matrix reduced water content in hydrogels and improved their thermal stability. BG particles decreased enzymatic degradation of the materials. The materials underwent mineralization in simulated biological fluids (PBS and SBF) and possessed high radical scavenging capacity. In vitro tests indicated that hydrogels were cytocompatible and supported MG-63 osteoblastic cell functions.