Authors:L. Varga, R. Engel, K. Szabó, L. Abrankó, B. Gosztola, É. Zámboriné Németh, and S. Sárosi
, Z. , Liang , Z. , Xie , C. , Zhao , M. , Yu , X. , Yang , M. , Huang , J. & Xu , X. ( 2014 ): Separation and purification of rosmarinic acid and rutin from Glechoma hederacea L . using high-speed counter
Authors:K. Berković, S. Kovač, and J. Vorkapić-Furač
The compounds of interest in the present study were the natural compounds rutin and quercetin, which are strong antioxidants and have beneficial effects on human health (Myake & Shibamoto, 1997). They are present in everyday foods and beverages and in this way they are used as an integral part of human diet. Therefore, it seemed interesting to investigate the influence of these valuable natural compounds on corrosion processes of aluminium, an ambalage material often used in food industry (Jovanovic et al., 1994). All the investigations were performed in 3% solution of sodium chloride, in aqueous rutin and quercetin solutions as well as in rutin and quercetin solutions in 3% sodium chloride solution. Concentrations of rutin and quercetin solutions used ranged from 10-2 to 10-5 mol dm-3, and investigations involved electrochemical methods. The results obtained showed that rutin and quercetin previously dissolved in 0.1 M NaOH and added to the 3% sodium chloride solution at concentrations of 10-4 and 10-5 mol dm-3 acted as aluminium corrosion inhibitors, while at higher concentrations (10-2 and 10-3 mol dm-3) their effects were opposite. The efficiency of the corrosion inhibition of aluminium by rutin and quercetin solutions was the result of forming protective film on the metal surface. Therefore, the diluted rutin and quercetin solutions could be used as corrosion inhibitors of aluminium.
Authors:A. Dvaranauskaite, P.R. Venskutonis, and J. Labokas
Ethanol extracts from 41 raspberry leaf accessions were studied. The plants of
L. were collected in different natural habitats of Lithuania located in 26 districts and replanted in the experimental field of the Institute of Botany, Lithuania. The total amount of phenolic compounds in leaves varied from 0.3 to 2.2 mg of gallic acid equivalents (GAE) in 1 g of dry leaves. Quercetin glucuronide, quercetin-3-glucoside and quercetin glucosylrhamnoside (rutin) were identified in the extracts by HPLC/UV/MS. Remarkable differences in the composition of the extracts were observed indicating that herbal tea preparations containing
leaves, which are used for phytotherapeutic purposes need more detailed examination in order to standardise their possible functional properties and pharmacological effects.
Authors:D. Radványi, R. Juhász, Sz. Kun, B. Szabó-Nótin, and J. Barta
Elderberry pomace, by-product of juice pressing procedure, is still rich in biologically active compounds, especially antioxidants and phenolic compounds. The aim of the present study was to investigate whether elderberry pomace could be utilized as a source of natural colourings and preservatives. By a simple solvent extraction a proper food colouring could be produced from elderberry pomace characterized by similar colour values as pressed elderberry juice. A solvent ratio of 1:20 with 50% ethanol proved to be the optimal solvent extraction method to produce an extract rich in antioxidants showing inhibitory effect against Lysteria monocytogenes and Enterococcus faecalis. In elderberry pomace extract three main phenolic compounds: chlorogenic acid, rutin and coumaric acid have been identifed by HPLC analysis. Based on our results, elderberry pomace, a by-product of fruit processing technologies, seems to be suitable for developing natural food additives after appropriate clarifcation processes.
Phenolic extract from banana peel was extracted with 95% ethanol and characterized by LC-TOF-MS/MS. Epicatechin, rutin, 3,4-dihydroxybenzaldehyde, 3,4-dihydroxybenzoic acid, myricetin, ferulic acid, chlorogenic acid, and gallic acid were detected in the extract. Cholate test was performed for the initial examination of the hypolipidemic effect of the dietary fibres. The dietary fibres prepared by sequential treatment with sulphuric acid then sodium hydroxide (SST) and sodium hydroxide treatment (SHT) had high water-holding capacities (7.48 and 6.91 g g−1) and swelling capacities (4.8 and 4.3 ml g−1). The dietary fibres prepared by sequential treatment with trypsin then sulphuric acid (TST) and sulphuric acid treatment (SAT) had high oil-holding capacities (5.52 and 5.10 g g−1) and enhanced capacities for sodium cholate adsorption. Results indicated the potentials of banana peel as functional ingredient in food applications.
Authors:A. Mikulajová, Z. Kohajdová, K. Németh, and E. Hybenová
Kreft, S., Štrukelj, B., Gaberščik, A. & Kreft, I. (2002): Rutin in buckwheat herbs grown at different UV-B radiation levels: comparison of two UV spectrophotometric and an HPLC method. J. Exp. Bot. , 53 , 1801
Authors:F.J. García-Alonso, I. Navarro-González, G. Ros, and M.J. Periago
The aim of this research was to assess the total antioxidant activity (TAA) of lipophilic (Lextr) and hydrophilic (Hextr) tomato extracts using in vitro chemical tests and cell-based assays, focusing on possible synergistic actions between tomato antioxidants. Both Hextr and Lextr were HPLC analysed for their carotenoids, phenolic compounds, and ascorbic acid contents. For the evaluation of TAA, extracts were assayed alone or in combination using in vitro chemical tests (TEAC, FRAP) and cell-based (CAA) assays using human hepatoma (HepG2) and human histiocytic lymphoma (U937) cells. The only carotenoid detected in Lextr was lycopene, while a mixture of phenolic compounds (chlorogenic acid, caffeic acid, and rutin) was identified in Hextr. Ascorbic acid was not found either in Hextr or in Lextr. Upon extract combination (1:1, v/v), the FRAP assay revealed additive action between Lextr and Hextr, whilst a slight synergistic action was observed in TAA as measured by the TEAC assay. Synergistic action was better revealed when TAA was analysed using either U937 or HepG2 cells. This could be explained by the presence of a multiphase media (cell membrane and extra- and intracellular media) that might facilitate the distribution and interaction of antioxidants with different polarities and different mechanisms of action.
Authors:E. Ivanišová, K. Meňhartová, M. Terentjeva, L. Godočíková, J. Árvay, and M. Kačániová
The aim of the present study was to determine the microbial composition, antioxidant activity, and content of phytochemicals in prepared kombucha tea beverage. Microbiota was identified by MALDI-TOF mass spectrometry, antioxidant activity of beverage was tested by ABTS and phosphomolybdenum method, the total content of phytochemicals (polyphenols, flavonoids, and phenolic acids) was measured by colorimetric methods. The major phenolic acids, flavonoids, and methylxanthines were detected by high performance liquid chromatography (HPLC). Candida krusei, Sphingomonas melonis, Sphingomonas aquatilis, Brevibacillus centrosporus, and Gluconobacter oxydans were the most abundant microorganisms. Antioxidant activity of kombucha tested by ABTS and phosphomolybdenum method was 1.16 mg TEAC/ml and 2.04 mg TEAC/ml, respectively, which values were higher than in black tea 0.67 and 0.81 mg TEAC/ml, respectively. Also, content of total polyphenols (0.42 mg GAE/ ml), flavonoids (0.13 mg QE/ml), and phenolic acids (0.19 mg CAE/ml) was higher in kombucha than in black tea (0.18 mg GAE/ml; 0.02 mg QE/ml; 0.05 mg CAE/ml, respectively). Gallic, chlorogenic, syringic, and protocatechuic acids, and rutin and vitexin from flavonoids were dominant in kombucha beverage detected by HPLC. Strong difference in caffeine contents, 217.81 µg ml−1 (black tea) and 100.72 µg ml−1 (kombucha beverage), was observed. The amounts of theobromine were similar in black tea and kombucha, but theophylline was detected only in black tea in trace amount (0.52 µg ml−1).