Μmol Trolox Equivalents Research Articles

Phenolic composition of tomato varieties and an industrial tomato by-product: free, conjugated and bound phenolics and antioxidant activity

The aim of this study was to isolate, identify and quantify soluble free phenolics, conjugated acid-hydrolysable phenolics (AHP) and alkaline-hydrolysable phenolics, and bound phenolics (BP) fractions from two tomato varieties (saladette and grape) and an industrial tomato by-product, as well as, to determine their antioxidant capacity. Phenolic composition was determined using Folin-Ciocalteu's method and HPLC-DAD. AHP were predominant in grape and saladette tomato extracts (91.47 ± 17.28mg gallic acid equivalents (GAE) per g dry extract (DE) and 57.41 ± 8.80mg GAE per g DE, respectively), while BP form was predominant in tomato by-product (51.30 ± 10.91 GAE per g DE). AHP extract of grape tomato presented the highest antioxidant capacity by DPPH assay (252.35 ± 42.55 μmol trolox equiv (TE) per g DE). In the case of ORAC assay, AHP fractions from both grape (1005.19 ± 138.52μmol TE per g DE) and saladette tomatoes (804.16 ± 131.45μmol TE per g DE), and BP fraction from by-product (852.40 ± 71.46μmol TE per g DE) showed the highest ORAC values. Caffeic acid was the most abundant phenolic acid and it was found mainly in its conjugated forms. Naringenin was the most abundant flavonoid and it was mainly detected in bound form. Our analysis allowed a better characterization of phenolic compounds in whole tomato and by-product, remarking the importance of the fractionation. The valorization of the industrial tomato by-product, through the use of its different fractions of phenolic antioxidant compounds, could generate additional income to the tomato industry and reduce the waste disposal problem.

Antioxidant Potential of Extracts Obtained from Macro- (Ascophyllum nodosum, Fucus vesiculosus and Bifurcaria bifurcata) and Micro-Algae (Chlorella vulgaris and Spirulina platensis) Assisted by Ultrasound

Background: Natural antioxidants, which can replace synthetic ones due to their potential implications for health problems in children, have gained significant popularity. Therefore, the antioxidant potential of extracts obtained from three brown macroalgae (Ascophyllum nodosum, Fucus vesiculosus and Bifurcaria bifurcata) and two microalgae (Chlorella vulgaris and Spirulina platensis) using ultrasound-extraction as an innovative and green approach was evaluated. Methods: Algal extracts were obtained by ultrasound-assisted extraction using water/ethanol (50:50, v:v) as the extraction solvent. The different extracts were compared based on their antioxidant potential, measuring the extraction yield, the total phenolic content (TPC) and the antioxidant activity. Results: Extracts from Ascophyllum nodosum (AN) and Bifurcaria bifurcata (BB) showed the highest antioxidant potential compared to the rest of the samples. In particular, BB extract presented the highest extraction (35.85 g extract/100 g dry weight (DW)) and total phenolic compounds (TPC) (5.74 g phloroglucinol equivalents (PGE)/100 g DW) yields. Regarding the antioxidant activity, macroalgae showed again higher values than microalgae. BB extract had the highest antioxidant activity in the ORAC, DPPH and FRAP assays, with 556.20, 144.65 and 66.50 µmol Trolox equivalents (TE)/g DW, respectively. In addition, a correlation among the antioxidant activity and the TPC was noted. Conclusions: Within the obtained extracts, macroalgae, and in particular BB, are more suitable to be used as sources of phenolic antioxidants to be included in products for human consumption. The relatively low antioxidant potential, in terms of polyphenols, of the microalgae extracts studied in the present work makes them useless for possible industrial applications compared to macroalgae, although further in vivo studies evaluating the real impact of antioxidants from both macro- and micro-algae at the cellular level should be conducted.

Changes in antioxidant status associated with haemodialysis in chronic kidney disease.

We evaluated the effects of one session of HD on the antioxidant capacity and lipid peroxidation in CKD patients. Thirty-six CKD patients requiring HD were recruited into this study. Participants were naïve to HD and each completed a session of three hours using polysulfone membrane dialyzers. Blood samples were collected before and after dialysis. Total antioxidant capacity (TAC) was measured by ferric reducing antioxidant power (FRAP) while malondialdehyde (MDA) was measured using thiobarbituric acid-reactive substance (TBARS). Comparison was made between pre-HD and post-HD values of TAC and MDA respectively, p value of <0.05 was taken as significant. Mean age and estimated glomerular filtration rate of subjects were 45 ±15 years and 6.3± 4.7mls/1.73m2 respectively. There was significant decrease in the mean TAC from 1232.2 ± 495.6 µmol Trolox equiv/ to 832.4 ± 325.7 µmol Trolox equiv/L post-dialysis (p< 0.001) while MDA values were similar before and after HD (11.8 ± 1.8 vs 11.8 ± 2.331)µmol/L (p> 0.05). There was no significant association between changes in antioxidant status following HD with blood flow rate, ultrafiltration volume nor dialyzer per size. A session of HD in patients with CKD is associated with significant reduction of the total antioxidants capacity; and no effect on MDA levels. No external funding received.

Supercritical CO2 Extracts and Volatile Oil of Basil (Ocimum basilicum L.) Comparison with Conventional Methods

Interest in new products from aromatic plants as medical and nutritional compounds is increasing. The aim of this work was to apply different extraction methods, including the use of supercritical carbon dioxide extraction, and to test the antioxidant activity of basil (Ocimum basilicum L.) extracts. In vitro efficacy assessments were performed using enzymatic assays. Essential oil obtained by hydrodistillation and volatile oil obtained from supercritical fluid extraction were analyzed by gas chromatography to quantify components. The total phenolic content in the extracts ranged from 35.5 ± 2.9 to 85.3 ± 8.6 mg of gallic acid equivalents and the total flavonoid content ranged from 35.5 ± 2.9 to 93.3 ± 3.9 micromole catechin equivalents per gram of dry weight of extract. All the extracts showed an antioxidant activity with 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid (ABTS), and the reducing power test. Extracts obtained from methanol had a higher antioxidant capacity per the DPPH test results (IC50 = 3.05 ± 0.36 mg/mL) and the reducing power test assay 306.8 ± 21.8 μmol of trolox equivalents per gram of extract (TE/g) compared with ethanolic or supercritical fluid extracts. However, using the ABTS assay, the extract obtained by supercritical fluid extraction had a higher antioxidant capacity with an IC50 of 1.74 ± 0.05 mg/mL. Finally, the examined extracts showed practically no acetylcholinesterase (AChE) inhibitory capacity and a slight inhibitory activity against tyrosinase.

Phenolic profiles and their contribution to the antioxidant activity of selected chickpea genotypes from Mexico and ICRISAT collections.

Chickpea (Cicer arietinum L.) genotypes, nine kabuli from Mexico and 9 desi from other countries, were investigated for their phenolic profiles and antioxidant activity (AA). Phenolics in methanol extracts (ME) were analyzed by ultra-performance liquid chromatography coupled to diode array detection and mass spectrometry (UPLC-DAD-MS), whereas the AA was measured as Trolox equivalents (TE) by ABTS, DPPH and FRAP methods. Twenty phenolic compounds were identified in the ME and their levels showed a great variability among the chickpea genotypes. Phenolic acids and flavonoids were the most abundant compounds in kabuli and desi genotypes, respectively. The AA values (μmol TE/ 100g dw) by ABTS (278-2417), DPPH (52-1650), and FRAP (41-1181) were mainly associated with the content of sinapic acid hexoside, gallic acid, myricetin, quercetin, catechin, and isorhamnetin, suggesting they are the main compounds responsible for the AA. The sum of the AA obtained for standards of these compounds evaluated at the concentration found in the extracts accounted for 34.3, 69.8, and 47.0% of the AA in the extract by ABTS, DPPH, and FRAP, respectively. In the AA by DPPH, most of the mixtures of these compounds resulted in synergistic interactions. Three desi genotypes with black seeds (ICC 4418, ICC 6306, and ICC 3761) showed the highest AA and flavonoids content, whereas the most promising kabuli genotypes were Surutato 77, Bco. Sin. 92, and Blanoro that showed the highest values of phenolic acids. These genotypes represent good sources of antioxidants for the improvement of nutraceutical properties in chickpea.

Protein extraction and bioactive hydrolysate generation from two microalgae, Porphyridium purpureum and Phaeodactylum tricornutum

Microalgae are a relatively underutilised source of valuable nutritional compounds and biochemicals. Their high protein contents make them an interesting target for the generation of bioactive peptides for the functional food industry. Here, the nitrogenous components of the red microalga Porphyridium purpureum and the diatom- Phaeodactylum tricornutum were quantified, and their SDS-PAGE profiles analysed. Proteinswere isolated from these species by solubilisation at alkaline pH followed by precipitation at acidic pH. The protein extracts were hydrolysed with the food-grade proteolytic preparations Alcalase 2.4 L and Flavourzyme 500 L. The P. purpureum and P. tricornutum hydrolysates were examined for their in vitroanti-diabetic and antioxidant properties. The microalgal-derived protein hydrolysates had dipeptidyl peptidase (DPP) IV inhibitory activity, with IC50 values of 2.28 ± 0.36 and 2.68 ± 0.19 mg/mL for P. purpureum and P. tricornutum, respectively. The oxygen radical absorbance capacity (ORAC) and ferric reducing power (FRAP) values were, respectively, 13.98 ± 0.97 and 478.94 ± 34.43 for P. purpureum, and 15.04 ± 0.54 and 155.74 ± 38.30 for P. tricornutum expressed in μmol Trolox Equivalent (TE) per gram of dry matter.The results suggest that protein hydrolysates from these microalgae have potential use as functional food ingredients.

Chemical characterization and biological activity of Onosma gigantea extracts

Onosma species have traditionally been used as laxative and anthelmintic agents as well as their uses in eye, blood diseases, bronchitis, abdominal pain, strangury, thirst, itch, leucoderma, fever, wounds, burns, piles, and urinary calculi. This study examines the investigation of biological activities of ethyl acetate, methanolic, and aqueous extracts from Onosma gigantea Lam. The extracts were evaluated for the antioxidant and enzyme inhibitory activities. Phenolic compounds in the extracts were also detected by RP-HPLC-DAD. The aqueous extract showed remarkable antioxidant activity in phosphomolybdenum [134.31 μmol trolox equivalents (TEs)/g air dry matter (adm)], chelating effect [32.97 μmol ethylenediaminetetraacetic acid (disodium salt) equivalents (EDTAEs)/g adm], radical scavenging [on DPPH (32.14 μmol TEs/g adm) and ABTS (58.68 μmol TEs/g adm)], and reducing power [CUPRAC (50.23 μmol TEs/g adm) and FRAP (40.96 μmol TEs/g adm)] assays. The aqueous extract also exhibited considerable inhibitory activity of tyrosinase (10.48 μmol kojic acid equivalents/g adm) and α-glucosidase [1320.53 μmol acarbose equivalents (ACEs)/g adm]. It has been determined that the methanolic extract showed significant AChE (31.57 μmol galanthamine equivalents (GALAEs)/g adm) and α-amylase (6.75 μmol ACEs/g adm) inhibitory activity. The ethyl acetate, which contains low polarity compounds, showed the highest BChE inhibitory activity (6.87 μmol GALAEs/g adm). In general, it is found that there is a positive correlation between the phytochemical contents of the extracts and their biological activities. The results indicate that O. gigantea extracts could be considered as a novel source of bioactive agents with functional connections.

Subcritical water extraction of phenolic and antioxidant constituents from pistachio (Pistacia vera L.) hulls

Pistachio hulls, important by-products of pistachio processing, were extracted using an environmentally friendly process with subcritical water (SCW) at a pressure of 6.9 MPa in the range of 110 and 190 °C, and a flow rate of 4 ml/min. Detailed HPLC-DAD-ESI/MSn analyses allowed the identification of 49 phenolic compounds in the SCW extracts. Total gallotannin yields up to 33 g/kg were reached at 150–170 °C, where gallic acid (22.2 g/kg) and penta-O-galloyl-β-d-glucose (9.77 g/kg) levels were 13.2- and 10.6-fold higher than those in the aqueous methanol extracts. Flavonols were also effectively extracted at 110–150 °C (4.37–5.65 g/kg), while anacardic acid recovery was poor (1.13–2.77 g/kg). Accordingly, high amounts of anacardic acids (up to 50.7 g/kg) were retained in the extraction residue, revealing that SCW extraction allowed selective extraction of gallotannins and flavonols. Antioxidant capacities ranged from 0.68 to 1.20 mmol Trolox equivalents (TE)/g for SCW extracts increasing with temperature up 190 °C.

ASSESSMENT OF DIETARY FIBER, ISOFLAVONES AND PHENOLIC COMPOUNDS WITH ANTIOXIDANT AND ANTIMICROBIAL PROPERTIES OF QUINOA (Chenopodium quinoa Willd.)

The consumption of quinoa (Chenopodium quinoa Willd.) has been steadily increasing due to its high nutritional value and health benefits associated with its high antioxidant capacity. The objective of this study was to determine the contents of dietary fiber, polyphenols, flavonoids and isoflavones, and how they contribute to the antioxidant and antimicrobial activity of six ecotypes of quinoa cultivated in three different zones of Chile. The ecotypes studied were: Ancovinto and Cancosa (Northern zone), Cahuil and Faro (Central zone), and Regalona and Villarrica (Southern zone). The results indicate that all Chilean quinoa ecotypes could be considered as good sources of dietary fiber (12.23 g 100 g-1 dry matter) and polyphenols (161.32 mg Gallic Acid Equivalents (GAE)100 g-1 dry matter). The North and Central ecotypes exhibited the highest isoflavone concentration. The Northern Cancosa was the ecotype that showed the highest flavonoid content (211.06 mg Catechin Equivalents (CAE) 100 g-1 dry matter). Based on the ORAC (Oxygen Radical Absorbance Capacity) assay, Ancovinto, Cancosa and Faro presented the highest antioxidant capacity (67.6 mmol Trolox Equivalents (TE) 100 g-1 dry matter). Regarding antimicrobial activity, Regalona ecotype showed the best performance against Saccharomyces cerevisiae and Listeria innocua. The bioactive compounds found in this study add new knowledge to the antioxidant and antimicrobial activity of Chilean quinoa seeds.

Phenolic profiles, antioxidant and antimutagenic activities of Solanum lycopersicum var. cerasiforme accessions from Mexico

ABSTRACTThe fruit of 18 Solanum lycopersicum var. cerasiforme accessions from Mexico were evaluated for total phenolics (TP) by the Folin-Ciocalteau assay, phenolic profiles by high performance liquid chromatography-diode array detection-mass spectrometry (HPLC-DAD-MS), antioxidant activity (AoxA) by 2,2´-azino-bis(3-ethylbenzothiazolin)-6-sulfonic acid (ABTS), 2,2-diphenil-1-pycrilhydrazyl (DPPH), and oxygen radical absorbance capacity (ORAC), and antimutagenic activity (AmuA) by the Ames assay. TP was measured as Gallic Acid Equivalents (GAE) and the AoxA as Trolox Equivalents (TE). TP varied from 37 to 86 mg GAE 100 g−1 fresh weight (fw). The AoxA by ABTS (568-1187 µmol TE 100 g−1 fw) and DPPH (157-350 µmol TE 100 g−1 fw) correlated with TP and the levels of caffeoylquinic acids and rutin. The AmuA did not correlate with the levels of phenolics. Some accessions had higher AoxA and AmuA than those reported for commercial cultivars and also showed high levels of caffeoylquinic acids and rutin; thus, their consumption could have good health promoting effects.

Biodegradable Films Based on Gelatin and Papaya Peel Microparticles with Antioxidant Properties

Biodegradable and bioactive films were prepared using gelatin from nutraceutical capsules wastes and natural antioxidants present in papaya peel. These films are intended to be an alternative to synthetic polyethylene packages in food preservation. Papaya peel was incorporated in the gelatin matrix as macroparticulate powder and in the form of microparticles, in different concentrations (2.5, 5, and 7.5%). The papaya peel powder microparticles were produced by spray drying with gelatin as wall material. The results indicated that microparticles of papaya peel powder originated a more continuous film matrix increasing the tensile strength and Young’s modulus. Films with 5 and 7.5% papaya peel macroparticulate powder showed the highest antioxidant activity with values of 0.94 and 1.44 μmol Trolox equivalents (TE)/g dried film, respectively, when compared to films with microparticles (0.63 and 0.84 μmol TE/g dried film). When applied as packaging material for lard, the films with microparticles (7.5%) were the most efficient as active barriers (higher antioxidant activity), as a lower content of peroxides (3.47 mEq/kg) quantified after 22 days. The addition of natural antioxidants through papaya peel microparticles is a promising strategy for the development of environmentally friendly packaging of food products with high-fat content and susceptible to oxidation.

In Vitro Bioaccessibility and Effect of Mangifera indica (Ataulfo) Leaf Extract on Induced Dyslipidemia

Cardiovascular diseases (CVDs) are the leading causes of death in the world, and epidemiological evidence points to dietary habits, stress, and obesity as major risk factors promoting pathological conditions like atherosclerosis, hypertension, and thrombosis. Current therapeutic approaches for CVDs rely on lifestyle changes and/or the use of drug agents. However, since the efficacy of such interventions is often limited by poor compliance and/or significant side effects, continued research on new preventive and therapeutic approaches is much needed. Our study is aimed to determine the bioaccessibility, total content of phenolic compounds, and antioxidant capacity (DPPH·, ABTS·+) of a methanolic extract from Mangifera indica L. leaves (MEM), and its lipid-lowering effect on an induced dyslipidemia model in Wistar rats. Our results showed that mangiferin is the main component of MEM. The extract showed a total content of polyphenol compounds of 575.28 gallic acid equivalents per dry matter basis (GAE/g db), antioxidant activity 77.68 μmol Trolox equivalents per gram (TE/g) db as measured by DPPH· and 20,630 μmol TE/g db by ABTS·+, and 12% of phenolic compounds were bioaccessible, and 100 mg/kg of MEM reduced hyperlipidemia levels induced in Wistar rats. Further study on the potential use of MEM as a nutraceutical to prevent CVDs in high-fat diet consumers is required.

Phenolic Content and Antioxidant Capacity Level in Commercial Mexican Lager Beers

The total phenols, total flavonoids, and antioxidant capacity by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical scavenging were evaluated in seven commercial Mexican lager beers. The range of total phenols was from 174 to 274 mg of gallic acid equivalents per liter, with lagers CB and ME being the lowest and highest, respectively. In total flavonoids, the lowest content was for lager ME with 14 mg of catechin equivalents (CatE) per liter, whereas the highest content was found in lager TT with 160 mg of CatE/L. For most of the samples, nonflavonoid compounds were the main phenolic group, with values ranging between 56.53 and 94.82%, except for lagers CB and TT, in which flavonoid compounds represented the majority of phenolics with 52.71 and 68.11%, respectively. The antioxidant capacity levels in DPPH and ABTS assays ranged from 432 to 520 μmol of Trolox equivalents (TE) per liter and from 143 to 233 μmol of TE/L, respectively, with lagers PA and TT as the lowest and highest, respectively, in both assays. Results of phenolic compounds content and antioxidant capacity levels found in Mexican beers were higher in comparison with most of the data on beers from different geographical origins available in the literature.

RED WINE EXTRACT OBTAINED BY MEMBRANE-BASED SUPERCRITICAL FLUID EXTRACTION: PRELIMINARY CHARACTERIZATION OF CHEMICAL PROPERTIES.

Abstract – This study aims to obtain an extract from red wine by using membrane-based supercritical fluid extraction. This technique involves the use of porous membranes as contactors during the dense gas extraction process from liquid matrices. In this work, a Cabernet Sauvignon wine extract was obtained from supercritical fluid extraction using pressurized carbon dioxide as solvent and a hollow fiber contactor as extraction setup. The process was continuously conducted at pressures between 12 and 18 MPa and temperatures ranged from 30 to 50oC. Meanwhile, flow rates of feed wine and supercritical CO 2 varied from 0.1 to 0.5 mL min -1 and from 60 to 80 mL min -1 (NCPT), respectively. From extraction assays, the highest extraction percentage value obtained from the total amount of phenolic compounds was 14% in only one extraction step at 18MPa and 35oC. A summarized chemical characterization of the obtained extract is reported in this work; one of the main compounds in this extract could be a low molecular weight organic acid with aromatic structure and methyl and carboxyl groups. Finally, this preliminary characterization of this extract shows a remarkable ORAC value equal to 101737 ± 5324 µmol Trolox equivalents (TE) per 100 g of extract.

Natural Variation and Genome‐Wide Association Study of Antioxidants in a Diverse Sorghum Collection

Consumption of polyphenol‐rich food is associated with decreased risk of oxidative stress‐related chronic diseases. Sorghum, a major food and feed cereal crop, has many polyphenol‐containing accessions with high antioxidant activity in the grain. However, many of these polyphenol‐containing accessions are not high‐yielding or food‐grade varieties. The natural variation in sorghum grain polyphenols can be used to develop high‐yielding, health‐promoting specialty food types through marker‐assisted breeding. To identify new antioxidant‐rich germplasm, we quantified antioxidant activity, total polyphenols, and condensed tannins in whole kernel flour in 266 accessions from the genetically and phenotypically diverse Sorghum Association Panel. Antioxidant activity, total polyphenols, and condensed tannins were in the ranges of 9.6–325.1 μmol of trolox equivalents (TE)/g, 0.8–18.8 g of gallic acid equivalents/kg, and 0–65.5 g of catechin equivalents/kg, respectively. Twenty‐three accessions were rich sources of antioxidant activity, with PI534144 (SC84; 325.1 μmol of TE/g) and PI534117 (SC991; 237.0 μmol of TE/g) possessing the highest values. To identify quantitative trait loci associated with sorghum grain antioxidant traits, we conducted a genome‐wide association study with 404,628 single nucleotide polymorphism markers. Many significant associations were identified, including two homologs of Arabidopsis (Arabidopsis thaliana) transparent testa (TT) genes TT10 and TT4. This study provides information that can help breeders incorporate health‐promoting traits into elite breeding lines.

Purification and Characterization of Antioxidative Peptides Prepared from Pea Protein with Strong Inhibitory Activity on Lipid Oxidation

This study was to evaluate the potential for developing superior antioxidative peptides derived from pea protein isolates that could be used to prevent meat lipid oxidation and improve its shelf-life. Pea protein isolate was hydrolyzed with individual microbial proteases and further fractionated by sequential ultrafiltration (molecular weight cut-off of 3 and 10 kDa) to a total of 12 hydrolysate fractions. Their antioxidant activities were evaluated and compared. The hydrolysate fractions exerted significant oxygen radical absorbance capacity ranging from 24.5 to 81.6 µmol Trolox equivalents /g dry weight and 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation (ABTS + ˙ ) scavenging activity ranging between 22.4 and 50.2 µmol TE/g dry weight. Three hydrolysate fractions with superior antioxidant activities were selected for further evaluation on the inhibition of lipid peroxidation using a food model (ground beef) during a 15-day storage period. At the end of the treatment, NP-F4 produced by neutral protease from Bacillus subtilis at both doses (250 and 500 µg/g beef) exerted significant inhibitory activities against lipid oxidization which were comparable to butylated hydroxyanisole (200 µg/g beef), a commonly used synthetic antioxidant with the thiobarbituric acid reactive substances reduced by 31.9%, 38.8%, and 45.7%, respectively, as compared to the negative control. Our results suggest that the specific antioxidative hydrolysates produced from pea protein with commercial proteases and ultrafiltration separation could be used to replace synthetic ones to inhibit lipid oxidation and improve shelf-life of lipid-rich food products.

Productivity, Physicochemical Changes, and Antioxidant Activity of Shiitake Culinary-Medicinal Mushroom Lentinus edodes (Agaricomycetes) Cultivated on Lignocellulosic Residues.

The effects of substrate and strain on productivity, physicochemical characteristics, and compounds with antioxidant activity were evaluated in basidiomes of the shiitake mushroom, Lentinus edodes. Strains IE-245 and IE-256 and the substrates oak wood shavings (OW), sorghum stubble (SS), and sugar cane bagasse (SC) were used. Productivity was evaluated by measuring biological efficiency (BE), production rate (PR), and yield. Total sugars, total soluble solids, pH, titratable acidity, color parameters, total phenolics, flavonoids, ascorbic acid, and antioxidant activity of the basidiomes were measured. BE, PR and yield were higher with the combination IE-256/SS, at 103.71%, 1.32%, and 34.57%, respectively. The largest amount of total sugars (17.61 mg glucose · g-1 dry weight) was found with combination IE-256/SS. Variation was observed in basidiome color; the lowest luminosity (L*) value (darkest color) was found in the IE-256 strain on the OW substrate (L* = 30.45), whereas that of the IE-245 strain on the SC substrate was the lightest in color (L* = 57.00). The largest amounts of total phenolics were recorded in the IE-256 strain on the OW (6.50 mg gallic acid equivalents [GAE] · g-1 dry weight) and the SS substrates (5.85 mg GAE · g-1 dry weight). The best antioxidant activity was obtained with IE-256-0.80, 0.65, and 0.59 μmol Trolox equivalents · g dry weight-1-on the OW, SC, and SS substrates, respectively. Based on the values of BE, PR, and yield, IE-256/SS was the most productive. Substrate and strain, and their interactions, influenced the physicochemical characteristics of the basidiomes and the amounts of compounds with antioxidant activity they contained.

Evaluation of the antioxidant activity of Betula pendula leaves extract and its effects on model foods

Context: Betula pendula Roth (Betulaceae) exhibits many pharmacological activities in humans including anticancer, antibacterial, and antiviral effects. However, the antioxidant activity of BP towards lipid degradation has not been fully determined. Objective: The BP ethanol and methanol extracts were evaluated to determine antioxidant activity by an in vitro method and lyophilized extract of BP was added to beef patties to study oxidative stability. Materials and methods: Antioxidant activities of extracts of BP were determined by measuring scavenging radical activity against methoxy radical generated by Fenton reaction 2,2′-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid (TEAC) radical cation, the oxygen radical absorbance capacity (ORAC) and the ferric reducing antioxidant power (FRAP) assays. The lipid deterioration in beef patties containing 0.1% and 0.3% (w/w) of lyophilized extract of BP stored in 80:20 (v/v) O2:CO2 modified atmosphere (MAP) at 4 °C for 10 days was determined using thiobarbituric acid reacting substances (TBARS), % metmyoglobin and colour value. Results: The BP methanol extract revealed the presence of catechin, myricetin, quercetin, naringenin, and p-coumaric acid. The BP ethanol (50% w/w) extract showed scavenging activity in TEAC, ORAC and FRAP assays with values of 1.45, 2.81, 1.52 mmol Trolox equivalents (TE)/g DW, respectively. Reductions in lipid oxidation were found in samples treated with lyophilized BP extract (0.1% and 0.3% w/w) as manifested by the changes of colour and metmyoglobin concentration. A preliminary study film with BP showed retard degradation of lipid in muscle food. Conclusion: The present results indicated that the BP extracts can be used as natural food antioxidants.

Preliminary study on antioxidant properties, phenolic contents, and effects of Aesculus hippocastanum (horse chestnut) seed shell extract on in vitro cyclobutane pyrimidine dimer repair

Aim: Human skin exposure to solar UV radiation induces cells to produce reactive oxygen species that directly cause DNA damage via the formation of cyclobutane pyrimidine dimers (CPDs), which are the primary UVB-induced DNA lesions. CPDs are responsible for cell death, mutation, and neoplastic transformation. Aesculus hippocastanum (horse chestnut) seed extract has traditionally been used for venotonic treatments and also as a raw material for cosmetics. This study aimed to characterize the antioxidant properties of the phenolic contents of extracts from A. hippocastanum seed shell and endosperm and to investigate their effects on CPD repair in UVB-exposed human dermal fibroblasts in vitro. Materials and Methods: Crude 60% aqueous ethanol extracts (v/v) were prepared, and their total polyphenol contents, antioxidant activities, and ORAC values were measured by Folin–Ciocalteu, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging capacity, and ORAC assays, respectively. The levels of CPDs induced by UVB irradiation were measured by cell-based immunoassays after 6-h treatment with the extract of A. hippocastanum seed shell at a concentration of 100-μg/ml and 9-h treatment with it at concentrations of 50, 100, and 200- μg/ml. Result: A. hippocastanum seed shell extract had 602 ± 1.6-mg gallic acid equivalent per gram of extract and exhibited 4990 ± 70.9 and 7140 ± 835 μmol Trolox equivalents per gram of extract as DPPH radical-scavenging activity and ORAC value, respectively; these values were comparable to those of extracts from green tea and Mallotus japonicus leaves. However, these values of the seed endosperm extract were relatively low. A 9-h treatment of cells with seed shell extracts at concentrations of 50, 100, and 200-μg/ml after UVB exposure significantly reduced CPD levels compared with those in UVB-exposed cells without treatment. Conclusion: This study indicated that A. hippocastanum seed shell extract possesses a potential to limit the harmful effects of human skin exposure to UVB and that this could be the first step toward identifying novel benefits of this extract.

Sprouts as potential sources of dietary antioxidants in human nutrition

Purpose: The present study evaluates antioxidant activity, as well as polyphenol and flavonoid contents in common sprouts, available on the Polish market. The aim of this study was to extend our already published food databases. Materials and methods: Ten seed species from four plant families were analysed. Total polyphenol content of sprout extracts was determined using the Folin-Ciocalteau method. Total flavonoid content was assessed by the aluminium chloride colorimetric method. Total antioxidant status was measured using FRAP and ABTS methods. Results: The FRAP antioxidant potential was 0.60- 2.53 mmol TE (trolox equivalents)/100 g FM (fresh mass), and arranged in descending order it was: white mustard&gt;cress&gt;radish&gt;broccoli&gt;chickpea&gt; sunflower&gt;mung bean&gt;wheat&gt;green lentil&gt;alfalfa), while the ABTS potential was 3.92-16.19 mmol TE/100 g FM (according to decreasing value: white mustard&gt;green lentil&gt;chickpea&gt;sunflower&gt;mung bean&gt;cress&gt; alfalfa&gt;wheat&gt; broccoli&gt; radish). The polyphenol content was 160-774 mg GAE (gallic acid equivalents)/100 g FM, and flavonoid content 15-53 mg QE (quercetin equivalents)/100 g FM. Conclusion: Our results suggest that sprouts in comparison to other foods, despite small weight can be powerful sources of antioxidants. Special attention in human nutrition should be paid to white mustard sprouts as they are excellent source of polyphenol and flavonoid and are characterized by tremendous antioxidant activity.