Phenolic Profile, Antiradical and Antitumour Evaluation of Raspberries Pomace Extract from Serbia.

Raspberry waste, obtained from two cultivars, Meeker (ERM) and Willamette (ERW) was subjected to evaluation antioxidants and antitumour activities as a potential source of phenolics. Some phenolic acids and flavonoids were identified and quantified by HPLC. Antioxidant activity was tested by measuring ability to scavenge DPPH• and •OH by ESR spectroscopy. IC50DPPH• varied from 0.67 for ERM to 0.54 mg/mL for ERW, while IC50•OH values varied from 3.73 for ERM to 1.23 mg/mL for ERW. Cytotoxic activity was investigated using in vivo model of Ehrlich Ascite carcinoma cells (EAC) in mice. Pretreatment with extracts exhibited potent cytotoxic activity against EAC cells (up to 60%) and both extracts inhibited the tumour growth. Activity of xanthine oxidase (XOD) was extremely increased in pretreated animals, while the activity of enzyme complex glutathione reductase (GR) and glutathione peroxidase (GSHPx) was significantly increased. This study suggests that raspberry pomace could be used as nutraceutic resource and functional food ingredient.

Bioactive Compounds and Antioxidant Properties of Goji fruits (Lycium barbarum L.) Cultivated in Serbia.

OBJECTIVE: Goji fruit extracts, methanol (MGE) and hexane (HGE), were subjected to evaluation as potential source of phenolic antioxidants and antiradical activity. METHODS: Some phenolic compounds (gallic, protocatechuic, vanillic, chlorogenic, coumaric, caffeic and ferulic acid and catechin and rutin), vitamin C and carotenoids were identified and quantified by HPLC. Antioxidant activity was tested by measuring ability to scavenge DPPH and hydroxyl radicals. Also, reducing power of goji fruit extracts was determined. RESULTS: HPLC analysis results showed predominance of gallic acid (40.44 mg/g g.f). Vitamin C content in MGE was 716.91 mg vitC/100 g g.f. IC50DPPH· varied from 26.64 µmolTEAC/g for HGE to 62.15 µmolTEAC/g for MGE, while RP0.5 values varied from 952.23 µmolTEAC/g for MGE to 1360.48 mg/mL for HGE. IC50·OH for MGE was 1844.01 µmolTEAC/g. CONCLUSIONS: Our results support the use of goji fruits as rich sources of phytochemicals for further utilization in the food industry as supplements and functional food ingredients.

Encapsulation of Beetroot Pomace Extract: RSM Optimization, Storage and Gastrointestinal Stability.

One of the great problems in food production are surplus by-products, usually utilized for feeding animals and for preparation of dietary fibre or biofuel. These products represent potential sources of bioactive antioxidants and colour-giving compounds which could be used in the pharmaceutical industry and as food additives. In the present study beetroot pomace extract was encapsulated in soy protein by a freeze drying method. Process parameters (core: wall ratio, extract concentration and mixing time) were optimized using response surface methodology (RSM) in order to obtain the optimum encapsulate (OE) with the highest polyphenol encapsulation efficiency (EE) and radical scavenging activity on DPPH radicals (SA). Using the calculated optimum conditions, the EE (86.14%) and SA (1668.37 µmol Trolox equivalents/100 g) of OE did not differ significantly (p < 0.05) from the predicted ones. The contents of total polyphenols (326.51 mg GAE/100 g), flavonoids (10.23 mg RE/100 g), and betalains (60.52 mg betanin/100 g and 61.33 mg vulgaxanthin-I/100 g), individual content of phenolic compounds and betalains by HPLC, and the ability to reduce Fe(3+) ions, i.e., reducing power (394.95 µmol Trolox equivalents/100 g) of OE were determined as well. During three months of storage at room temperature, polyphenol retention was much higher (76.67%) than for betalain pigments, betacyanins (17.77%) and betaxanthins (17.72%). In vitro digestion and release of phenolics from OE showed higher release rate in simulated intestinal fluid than in gastric fluid. These results suggest encapsulation as a contemporary method for valorisation of sensitive bioactive compounds from food industry by-products.

Sour cherry pomace extract encapsulated in whey and soy proteins: Incorporation in cookies.

One of the potential sources of valuable bioactives is pomace, a by-product from fruit juice processing industry. In the presented study, bioactive compounds extracted from cherry pomace, encapsulated in whey and soy proteins, have been incorporated in cookies, replacing 10% (WE10 and SE10) and 15% (WE15 and SE15) of flour. Total polyphenols, anthocyanins, antioxidant activity and colour characteristics of enriched cookies were followed during 4 months of storage. Total polyphenols of WE10, SE10, WE15 and SE15 have shown a slight increase (23.47, 42.00, 4.12 and 1.16%, respectively), while total anthocyanins (67.92, 64.33, 58.75 and 35.91%, respectively) and antioxidant activity (9.31, 24.30, 11.41 and 12.98%, respectively) decreased. Colour parameters (L(∗), a(∗) and b(∗)) of cookies were influenced by the colour of encapsulates. Fortified cookies received satisfactory sensory acceptance as well. Encapsulated sour cherry pomace bioactives have positively influenced functional characteristics of fortified cookies and their preservation.

Bioactivity of Meeker and Willamette raspberry (Rubus idaeus L.) pomace extracts.

Taking into account the substantial potential of raspberry processing by-products, pomace extracts from two raspberry cultivars, Meeker and Willamette, were investigated. Total phenolic, flavonoid and anthocyanin contents were determined. Willamette pomace extract (EC50=0.042 mg/ml) demonstrated stronger 2,2-diphenyl-1-picrylhydrazyl DPPH radical-scavenging activity than did Meeker pomace extract (EC50=0.072 mg/ml). The most pronounced cell growth inhibition effect was obtained in the breast adenocarcinoma cell line, reaching EC50 values of 34.8 and 60.3 µg/ml for Willamette and Meeker extracts, respectively. Both extracts demonstrated favourable non-tumor/tumor cell growth ratios and potently increased the apoptosis/necrosis ratio in breast adenocarcinoma and cervix carcinoma cells. In reference and wild bacterial strains, minimal inhibitory concentrations (MIC) were achieved in a concentration range from 0.29 to 0.59 mg/ml, and minimal bactericidal concentrations (MBC) in a range from 0.39 to 0.78 mg/ml. The results indicate significant antioxidant, antiproliferative, proapoptotic and antibacterial activities of raspberry pomace and favour its use as a functional food ingredient.

Tomato waste: Carotenoids content, antioxidant and cell growth activities.

The carotenoid content, antioxidant and cell growth activities of tomato waste extracts, obtained from five different tomato genotypes, was investigated. High performance liquid chromatography was used to identify and quantify the main carotenoids present in tomato waste extracts. The antioxidant activity of tomato waste extracts was tested using spectrophotometric methods, 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity and reducing power assay. The highest DPPH scavenging activity (IC50 = 0.057 mg/ml) was obtained for Backa extract. The Knjaz extract showed the best reducing power (IC50 = 2.12 mg/ml). Cell growth effects were determined in HeLa, MCF7 and MRC-5 cell lines by sulforhodamine B test. Anti-proliferative effects were observed in all cell lines at higher concentrations (⩾ 0.125 mg/ml). The carotenoid contents exhibited a strong correlation with antioxidant and anti-proliferation activity. The results obtained indicated that tomato waste should be regarded as potential nutraceutic resource and may be used as a functional food ingredient.

Antioxidant and sensorial properties of linden honey with dried apricots.

The total phenol (TPh) and flavonoid contents (TFd), and antioxidant and sensorial properties of linden honey (LH) with dried apricots (20, 30, and 40%) were evaluated. TPh increased 4.3 times for LH40 (from 23.96 to 102.87 mg gallic acid equiv./100 g honey), while increase of TFd was slightly lower, ca. 2.9-fold for LH40 (from 18.11 to 51.72 mg rutin equiv./100 g honey). Based on HPLC analysis, the most dominant phenolic compound was gallic acid (11.14 mg/100 g honey in LH and 42.65 mg/100 g honey in LH40). In three different assays, the antioxidant activity increased with increasing concentration of apricots in honey. The values varied from 13.36 for LH to 7.06 mg/ml for LH40; the values ranged from 189.83 for LH to 11.23 mg/ml for LH40; the RP0.5 (reducing power) values ranged from 169.00 for LH to 27.60 mg/ml for LH40. Based on the correlation analysis, it is obvious that TPh and TFd were associated with the antioxidant activities of honey samples. A high degree of correlation existed between antioxidant activities of honey samples and TPh (R from 0.945 to 0.996) and TFd (R from 0.805 to 0.934). Obtained scores for individual sensory properties indicated very good quality of honey with dried apricots.

Free-radical scavenging activity and antibacterial impact of Greek oregano isolates obtained by SFE.

The antioxidant and antibacterial properties of Greek oregano extracts obtained by fractional supercritical fluid extraction (SFE) with carbon dioxide were investigated and compared with the properties of essential oil obtained by hydrodistillation. According to DPPH, hydroxyl radical and superoxide anion radical scavenging activity assays, the supercritical extracts expressed stronger antioxidant activity comparing to the essential oil. The most effective was the supercritical extract obtained by fractional extraction at 30 MPa and 100°C after the volatile fraction had been extracted at lower pressure. At the same time this extract showed strong antibacterial activity against staphylococci, including MRSA strain, but did not affect Escherichia coli of normal intestinal flora. The essential oil obtained by hydrodistillation showed stronger antibacterial activity against E. coli, Salmonella and Klebsiella pneumoniae, comparing to the supercritical extracts but at the same affected the normal gut flora.

Anthocyanin profiles and biological properties of caneberry (Rubus spp.) press residues.

BACKGROUND: The global interest in natural food colours shows increasing attention towards new product development to replace synthetic colourants, because of the strengthening of legislative rules and consumer 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 'Cacanska bestrna' (BC)) cultivars. RESULTS: Analysis by high-performance liquid chromatography-diode array detection-electrospray ionization-tandem mass spectrometry 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). CONCLUSION: This study has revealed the potential for valorization 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.

Antiradical, antimicrobial and cytotoxic activities of commercial beetroot pomace.

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.

Isolation, characterization and antioxidative activity of C-phycocyanin from Limnothrix sp. strain 37-2-1.

C-phycocyanin (C-PC) is a blue colored accessory photosynthetic pigment found in cyanobacteria. Some of the medicinal properties of Spirulina have been attributed to this pigment, which includes anticancer, antioxidant, and anti-inflammatory activity. We have screened cyanobacteria isolated from freshwater habitats in Florida for their high content of C-PC. Of 125 strains tested, one filamentous strain identified as Limnothrix sp. was selected for further research. This strain produced 18% C-PC of total dry biomass. Here we describe a simple method for obtaining C-PC of high purity without the use of ion exchange chromatography. The procedure is based on pigment precipitation from the cell lysate with an appropriate concentration of ammonium sulfate, then purification with activated carbon and chitosan, followed by a sample concentration using tangential flow filtration. We have shown that when the lower concentration of ammonium sulfate was used, C-PC with higher purity index was recovered. Characterization of C-PC from Limnothrix showed that it had an absorbance maximum at 620nm and fluorescence at 639nm. The molecular mass of intact C-PC was estimated to be ~50kDa with α and ß subunits forming dimmers. When C-PC content per unit biomass was compared to that of marketed Spirulina powder, we found that Limnothrix was superior. C-phycocyanin from Limnothrix had an antioxidative activity on DPPH free radicals similar to that found in a natural antioxidant - rutin.

Tomato waste: a potential source of hydrophilic antioxidants.

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.

Antioxidative and antiproliferative activities of different horsetail (Equisetum arvense L.) extracts.

In this study we investigated antioxidative and antiproliferative activity of different horsetail (Equisetum arvense L.) extracts. The antioxidative activity was measured by the electron spin resonance (ESR) spectroscopy-spin trapping method. The influence of different horsetail extracts during lipid peroxidation of (1) sunflower oil induced by the lipophilic azo-initiator 4,4'-azobis(4-cyanovaleric acid) and (2) soybean phosphatidylcholine liposomes induced by the hydrophilic azo-initiator 2,2'-azobis(2-amidinopropane) dihydrochloride was studied. Antiproliferative activity was measured using the sulforhodamine B colorimetric assay on the human cancer cell lines HeLa, HT-29, and MCF7. The results of ESR analysis confirmed that the extracts investigated suppressed the formation of lipid peroxyl radicals in both systems investigated in a dose-dependent manner. The results indicate that n-butanol, methanol, ethyl acetate, and water extracts had significant peroxyl radical scavenging activity. Extracts inhibited cell growth that was dependent on cell line, type of extract, and extract concentration. Ethyl acetate extract exhibited the most prominent antiproliferative effect, without inducing any cell growth stimulation on human tumor cell lines. The results obtained suggest that the horsetail extracts could be used as an easily accessible source of natural antioxidants and as potential phytochemicals.

Radical scavenging, antibacterial, and antiproliferative activities of Melissa officinalis L. extracts.

The aromatic herb Melissa officinalis L. can be used as an easily accessible source of natural antioxidants and as a possible food supplement and as a phytochemical. Radical scavenging, antibacterial, and antiproliferative activities of petroleum ether, chloroform, ethyl acetate, n-butanol, and water extracts of M. officinalis L. extracts were investigated. The results of antioxidative activity, obtained by electron spin resonance spectroscopy, confirmed that investigated extracts suppressed the formation of 2,2-diphenyl-1-picrylhydrazyl (DPPH), hydroxyl, and lipid peroxyl radicals in all investigated systems in a dose-dependent manner. The maximum DPPH and hydroxyl radical scavenging activities (SA(DPPH) = SA(OH) = 100%) were achieved in the presence of n-butanol extract at concentrations of 0.4 mg/mL and 0.5 mg/mL, respectively. The highest lipid peroxyl scavenging activity (93.20%) was observed at a higher concentration (5 mg/mL) of n-butanol extract in the lipid peroxidation system. The most effective antibacterial activities were expressed by petroleum ether and ethyl acetate extracts on Sarcina lutea. Chloroform extract showed the strongest antiproliferative effect with 50% inhibitory concentration values of 0.09 mg/mL and 0.10 mg/mL for HeLa and MCF-7 cell lines, respectively. The present study demonstrated the high phenolic content and radical scavenging, antibacterial, and antiproliferative activities of extracts of M. officinalis L. originating from Serbia.

Assessment of polyphenolic content and in vitro antiradical characteristics of apple pomace.

Apple pomaces, a by-product in the apple juice processing, were subjected to evaluation as potential sources of antioxidant phytochemicals on the basis of their total content of phenolics (from 4.22 to 8.67mg/g), total flavonoids (from 0.45 to 1.19mg/g) and total flavan-3-ols (from 2.27 to 9.51mg/g), and in vitro antiradical activities. Some individual phenolic compounds including caffeic and chlorogenic acids, (+)-catechin and (-)-epicatechin, rutin, quercetin glycosides and phloridzin were identified and quantified by HPLC. The antiradical activity of apple pomaces was tested by measuring their ability to scavenge DPPH and hydroxyl radicals by ESR spectroscopy. The highest DPPH (EC50(DPPH)=6.33mg/ml) and hydroxyl (EC50(OH)=26.11mg/ml) radical scavenging activities were obtained in the case of Reinders pomace. The regression analysis produced moderate to high correlation coefficients between the antiradical activities (1/EC50(DPPH) and 1/EC50(OH)), and total phenolics, total flavonoids, total flavan-3-ols, and some individual phenolic compounds.

Antimicrobial and free radical scavenging activities of Teucrium montanum.

The antimicrobial and free radical scavenging activities of petroleum ether, chloroform, ethyl acetate, n-butanol and water extracts of Teucrium montanum were investigated. Ethyl acetate, chloroform and n-butanol extracts expressed a wide range of inhibiting activity against both Gram (+) and Gram (-) bacteria. n-Butanol extract possessed potent DPPH free radical scavenging activity.