[Show abstract][Hide abstract] ABSTRACT: The global interest in natural food colours shows increasing attention for new product development to replace synthetic colourants, due to the strengthening of legislative rules and consumers' awareness of synthetic additives and chemicals in food. This study was designed to evaluate anthocyanin content and biological activities of press residues from four caneberries: two raspberry (Rubus idaeus, cv. 'Meeker' (RM) and 'Willamette' (RW)) and two blackberry (Rubus fruticosus, cv. 'Thornfree' (BT) and 'Čačanka' (BC)) cultivars.
HPLC-DAD-ESI/MSn analysis identified cyanidin glycosides in all press residues, cyanidin 3-glucoside being prevalent in BC (1360.6 mg kg(-1) ) and BT (1397.7 mg kg(-1) ), and cyanidin 3-sophoroside in RM (349.2 mg kg(-1) ) and RW (581.0 mg kg(-1) ). Antioxidant capacity (AC), evaluated by ABTS (2,2'-azino-bis(3-ethyl benzothiazoline-6-sulfonic acid) assay, reducing power (RP) and α-glucosidase inhibitory potential (α-GIP) was higher in blackberry press residues. Total anthocyanin content was in good correlation with AC (r = 0.953; P<0.05), RP (r = 0.993, P<0.01) and α-GIP (r = 0.852, P<0.15).
This study has revealed the potential for valorisation of juice-production byproducts for further industrial use as a rich source of bioactive compounds and natural colourants (mainly anthocyanins). Also, they can provide health-promoting effects beyond their general organoleptic acceptance in food product development.
Journal of the Science of Food and Agriculture 09/2014; 94(12):2393-2400. DOI:10.1002/jsfa.6564 · 1.71 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Abstract Crude extracts of two edible and two medicinal lignicolous mushroom species: Meripilus giganteus, Agrocybe aegerita, Fomes fomentarius and Xylaria polymorpha, growing wild in Serbia, were analyzed for their antioxidative and antibacterial potentials. Free radical scavenging capacity (RSC) on DPPH(•) and (•)OH was evaluated both by spectrophotometer and by Electron Spin Resonance (ESR) spectroscopy against DPPH(•). The highest antioxidant and antibacterial bioactivity was obtained with F. fomentarius extracts (IC50 ≈ 10.7 µg/ml in DPPH(•) assay; 136.6 mg ascorbic acid equivalents (AAE)/g dry weight (d.w.) for ferric reducing antioxidant power FRAP). It also showed the highest total phenol (TP) (82.54 mg gallic acid equivalents (GAE)/g dry weight (d.w.)) and total flavonoid (TF) content (76.8 µg rutin equivalents (RE)/g dry weight (d.w.)). A. aegerita showed the best antioxidant activity (IC50 = 0.87 mg/ml) against DPPH(•) in ESR analysis. Total redox potential of extracts was in direct positive correlation with TP content (r(2 )= 0.98) and TF content (r(2 )= 0.58). GC/MS analysis detected major constituents of extracts, confirming the presence of the following organic and phenolic acids: fumaric, succinic, mallic, 4-hydroxy benzoic, gentisic, protocatechuic, vanillic, gallic and p-coumaric acid.
International Journal of Food Sciences and Nutrition 12/2013; 65(3). DOI:10.3109/09637486.2013.860584 · 1.21 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Serbian soybean genotype Ana was gamma irradiated at doses of 1, 2, 4, and 10 kGy in order to evaluate the influence of gamma irradiation on isoflavone (genistein, daidzein, and their glycosides genistin and daidzin) contents and hydroxyl radical scavenging effect (HRSE). The increase in genistin and daidzin contents as well as antioxidant activities was observed especially at doses of 4 and 10 kGy. Results were also compared with our previous results relating to total phenol content (TPC), DPPH radical scavenger capacity (DPPH RSC), and ferric reducing antioxidant power (FRAP). Our results indicated that doses up to 10 kGy improve the antioxidant activities of soybean and also nutritional quality with respect to isoflavone content. All results were analyzed by multivariate techniques (correlation matrix calculation and autoscaling transformation of data). Significant positive correlations were observed between genistin, daidzin, DPPH RSC, and HRSE.
The Scientific World Journal 11/2013; 2013(2):383574. DOI:10.1155/2013/383574 · 1.73 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The by-product of food processing is often utilized as feed, and for the preparation of dietary fiber and biofuel. However, these products are also promising sources of bioactive antioxidants and color giving compounds, which could be used as additives in the food, pharmaceutical and cosmetic industry. The aim of this study was to investigate the phytochemical profile, and the antiradical, antimicrobial and cytotoxic activities of industrial beetroot pomace extract (BPE). The content of phenolics (45.68 mg gallic acid equivalents g(-1)), flavonoids (25.89 mg rutin equivalents g(-1)) and betalains (4.09 mg betanin g(-1); 7.32 mg vulgaxanthin I g(-1)) were determined spectrophotometrically. The antiradical activity on DPPH (EC(50)(DPPH)˙ = 0.0797 mg ml(-1)), hydroxyl (EC(50)˙(OH) = 0.0655 mg ml(-1)) and superoxide anion (EC(50)(O2)˙(-) = 1.0625 mg ml(-1)) radicals were measured by electron spin resonance (ESR) spectroscopy. The antimicrobial activity was determined using the agar-well diffusion method. Gram(-) bacteria (Salmonella typhimurium, Citrobacter freundii) and Gram(+) bacteria, (Staphylococcus aureus, Staphylococcus sciuri, Bacillus cereus) showed high susceptibility, while yeasts and moulds were resistant. BPE exhibits cytotoxic properties against Ehrlich carcinoma (EAC) cells in vivo due to induction of oxidative stress. The largest decreases in EAC cell numbers were observed in the pre-treated male (approximately 53%) and female (approximately 47%) mice, and also the EAC cell viability was decreased after administration of BPE. The activities of the antioxidant enzymes, xanthine oxidase (XOD) and peroxidase (Px), were significantly different between the untreated EAC control group and all other groups that were treated with BPE. The XOD and Px activities were very low in untreated malignant cells, but increased significantly after administration of BPE. Our results show that BPE holds promise in the food industry as a source of bioactive compounds.
[Show abstract][Hide abstract] ABSTRACT: Buckwheat (Fagopyrum esculentum Moench) is an alternative crop belonging to the Polygonaceae family. In comparison to antioxidant activity of frequently used cereals, buckwheat has been reported to possess higher antioxidant activity (AOA), mainly due to high rutin content. The objective of this work was to determine the main antioxidant compounds and AOA of buckwheat grain fractions (whole grain, hull, and groat). Buckwheat grain fractions were extracted with ethanol/water (80/20, v/v), followed by determination of total phenolic and flavonoid content. Quantification of phenolic compounds and tocopherols was performed by high-performance liquid chromatography (HPLC). The AOA was estimated by 2 direct electron spin resonance (ESR) and 4 indirect (spectrophotometric) tests. Significantly higher contents of total phenolics and total flavonoids were found in buckwheat hull than in whole grain and groat. Protocatechuic, syringic, and sinapic acid, rutin, and quercetin were found in all tested fractions, whereas vanilic acid was found in whole grain and hull. The content of total tocopherols in investigated samples ranged from 23.3 mmol/g for hull to 61.8 mmol/g for groat. Hull was superior in scavenging activity on 1,1-diphenyl-2-picrylhydrazyl (DPPH•), hydroxyl (•OH), and superoxide anion (O2•-) radicals, reducing activity, AOA by β-carotene bleaching method, and chelating activity on Fe2+ as evidenced by its lower IC50 value. Obtained results can broaden the utilization of buckwheat, especially a share of hull in whole grain flour production.
Practical Application: Obtained results suggest possibility to supplement the whole grain buckwheat flour with hull, which leads toward better usage of by-products in buckwheat production, and enhancement of antioxidant potential of the final product.
[Show abstract][Hide abstract] ABSTRACT: The kinetic behaviour of tomato waste extracts (obtained from six genotypes) and standard antioxidant compounds (ascorbic and caffeic acid) were investigated using the 2,2-diphenyl-1-picrylhydrazyl radical test. Based on the time required for the reaction to reach steady state, the investigated extracts showed very slow (steady state >= 180 min) antiradical behaviour, ascorbic acid acted as a rapid antioxidant (steady state < 5min) while caffeic acid is a rapid-intermediate antioxidant (5 min < steady state < 20 min). The efficient concentrations at different kinetic times EC50,t were determined for all extracts, as well as for ascorbic and caffeic acid. The EC50,t was used as a parameter to screen and compare antiradical activites of food extracts with slow kinetic action. Irrespective of the time considered, a comparison of the EC50,t values for extracts of tomato waste obtained from different tomato genotypes showed that their DPPH radicals-scavenging activity decreased in the order O-2 > Knjaz > Backa > Saint Pierre > Rutgers > Novosadski niski. The tomato waste extracts showed very slow kinetic action, which is probably the result of the different kinetic bevaviour of the phenolic compounds present in tomato waste, as well as other antioxidants (vitamins, carotenoids, etc.).
Journal of the Serbian Chemical Society 01/2012; 77(10):1381-1389. DOI:10.2298/JSC120410065S · 0.87 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Waste obtained from six genotypes of tomato was subjected to evaluation as potential sources of hydrophilic antioxidants on the basis of content of total phenolics (TPh; from 11.7 to 18.6 mg/g), total flavonoids (TFl; from 7.62 to 12.1 mg/g) and ascorbic acid (AA; from 0.51 to 1.89 mg/g), and antioxidant activities. The antioxidant activities of tomato waste extracts were evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, ferrous ion chelating activity (CA) and reducing power (RP) assay. The O(2) tomato waste extract was found to have the strongest antioxidant activity in scavenging DPPH radicals (effective concentration, EC(50) = 0.18 mg/ml). The Saint Pierre tomato waste extract showed the best performance in RP assay (EC(50) = 1.57 mg/ml). The Rutgers tomato waste extract exhibited a strongest CA (EC(50) = 1.49 mg/ml). The linear correlation analysis produced moderate-to-high correlation coefficients between the antioxidant activities and TPh, TFl and AA.
International Journal of Food Sciences and Nutrition 08/2011; 63(2):129-37. DOI:10.3109/09637486.2011.606211 · 1.21 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Apple pomace is an easily accessible source of bioactive compounds which can be used for various purposes in the food, pharmaceutical and cosmetic industry. Six types of apple pomace extracts were tested to study their health benefits, free radical scavenging and antiproliferative activities.
The radical scavenging activity was determined by electron spin resonance (ESR) spectroscopy. Antiproliferative action was measured using MTT [3-(4,5-dimethylthiazol- 2-yl)2,5-diphenyl tetrazolium bromide] colorimetric assay in cervix epithelioid carcinoma (HeLa) and colon adenocarcinoma (HT-29) human cancer cell lines.
All extracts suppressed the formation of 2,2-diphenyl- 1-picrylhydrazyl (DPPH○) and hydroxyl-free radical in a dose-dependent manner. In the presence of 12.5 mg/ ml Pinova, Reinders and Nectar pomace extract, the ESR DPPH○ signals vanished. The ○OH was completely scavenged in the presence of 45 mg/ml or higher concentration of the investigated extracts. Pinova and Braeburn pomace extracts showed the strongest antiproliferative activity against the investigated human cancer cell lines. Also, HeLa cells were found more sensitive than HT-29 cells to all extracts.
Although the relationship between radical scavenging activities and phenolic contents or flavonol glycosides (R(2)≥0.80) was high, there were no significant correlations between the total phenolic contents or individual phenolic compounds and the antiproliferative activity.
Journal of B.U.ON.: official journal of the Balkan Union of Oncology 06/2011; 16(1):147-53. · 0.74 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Free radicals are implicated in the aetiology of some gastrointestinal disorders such as gastric ulcer, colorectal cancer and inflammatory bowel disease. In the present study we investigated the antioxidant and genoprotective activity of some rotenoids (i.e. boeravinones) isolated from the roots of Boerhaavia diffusa, a plant used in the Ayurvedic medicine for the treatment of diseases affecting the gastrointestinal tract.
Antioxidant activity has been evaluated using both chemical (Electron Spin Resonance spectroscopy, ESR) and Caco-2 cells-based (TBARS and ROS) assays. DNA damage was evaluated by Comet assay, while pERK(1/2) and phospho-NF-kB p65 levels were estimated by western blot. Boeravinones G, D and H significantly reduced the signal intensity of ESR induced by hydroxyl radicals, suggesting a scavenging activity. Among rotenoids tested, boeravinone G exerted the most potent effect. Boeravinone G inhibited both TBARS and ROS formation induced by Fenton's reagent, increased SOD activity and reduced H(2)O(2)-induced DNA damage. Finally, boeravinone G reduced the levels of pERK(1) and phospho-NF-kB p65 (but not of pERK(2)) increased by Fenton's reagent.
It is concluded that boeravinone G exhibits an extraordinary potent antioxidant activity (significant effect in the nanomolar range). The MAP kinase and NF-kB pathways seem to be involved in the antioxidant effect of boeravinone G. Boeravinone G might be considered as lead compound for the development of drugs potentially useful against those pathologies whose aetiology is related to ROS-mediated injuries.
PLoS ONE 05/2011; 6(5):e19628. DOI:10.1371/journal.pone.0019628 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Four berry (bilberry, blackberry, strawberry and raspberry) fruits pomace, a waste product coming from juice production, were extracted with 80% methanol containing 0.05% acetic acid. The highest content of antioxidant components, total polyphenols, flavonoids and anthocyanins, was found in the bilberry pomace extract (1116.24, 1047.39 and 1279.49 mg/100g fresh pomace, respectively). The antioxidant activity of the four berry pomace extracts (BPE) was determined using DPPH free radical scavenging assay and reducing power. There was a high linear correlation between the IC 50 and content of anthocyanins (r 2 =0.98) and polyphenols (r 2 =0.85). Also, a good correlation was found between the IC 50 and the content of flavonoids. The strawberry pomace extract showed the highest (RP 0.5 =0.35 mg/ml), while the blackberry pomace extract showed the lowest (RP 0.5 =0.57 mg/ml) reducing power. The results showed that BPE can be a valu-able source of natural ingrediences of the products in the food, cosmetical and phar-maceutical industry.