Catabolismo auxínico en las raíces de los cereales

Tesis inédita de la Universidad de Madrid, Facultad de Ciencias, Sección de Químicas, 1971.Universidad de MadridTRUEProQuestpu

Catabolismo auxínico en las raíces de los cereales

Tesis inédita de la Universidad de Madrid, Facultad de Ciencias, Sección de Químicas, 1971.Universidad de MadridTRUEProQuestpu

Phenolic Content of Blends of Tempranillo with Graciano or Cabernet Sauvignon Wines Produced in Spain

Utjecaj sorte Graciano (GRA, vrijedna španjolska sorta koja se proizvodi u malim količinama u mediteranskim zemljama) i sorte Cabernet Sauvignon (CS, svjetski poznata francuska sorta) na koncentraciju fenola (ukupnih polifenola (TP), ukupnih antocijanina (TA), katehina (CAT) i proantocijanidina (PRO)) u vinima Tempranillo (TEM-BASE, rasprostranjena španjolska sorta) istražen je u mješavinama s 26 i 10 % svake sorte nakon 4; 6; 9; 16,5 i 23 mjeseca čuvanja u bocama. Utvrđena je značajna razlika u koncentraciji katehina i ukupnih antocijanina u vinu (mješavinama i sortnom vinu), ovisno o faktoru miješanja. Osim toga, iako su tendencije razvoja različitih vrsta fenolnih spojeva tijekom starenja vina bile slične u mješavinama i u sortnom vinu, različite mješavine pokazale su bržu kinetiku razgradnje antocijanina od sortnih vina, vjerojatno zbog većeg udjela katehina, koji mogu pospješiti neke reakcije kondenziranja antocijanina tijekom starenja u boci. Taj je učinak nešto izraženiji u TEM-GRA nego u TEM-CS mješavinama. Daljnjim istraživanjem sastava fenola u jednosortnim vinima upotrijebljenim pri kupažiranju, a i u grožđu (kožici i sjemenkama) od kojih su vina dobivena, otkriveno je da se utjecaj kupažiranja na koncentraciju katehina može povezati s većom koncentracijom tih spojeva u sjemenkama grožđa Graciano i Cabernet Sauvignon nego u grožđu Tempranillo. Rezultati ovoga rada znanstveno potvrđuju da, što se tiče koncentracije fenola, vina Graciano imaju svojstva slična vinu Cabernet Sauvignon, a za kupažiranje s vinom Tempranillo.The effect of Graciano (GRA, Spanish valuable variety of limited production in Mediterranean countries) vs. Cabernet Sauvignon (CS, world-wide known French variety) on the phenolic content [total polyphenols (TP), total anthocyanins (TA), catechins (CAT) and proanthocyanidins (PRO)] of Tempranillo wines (TEM-BASE, a largely cultivated Spanish variety) was studied in blends prepared with 25 and 10 % of each variety after 4, 6, 9, 16.5 and 23 months of bottle ageing. Significant differences among wines (blends and base wine) according to the »blend« factor were observed for CAT and TA. Besides, although the evolution trend during wine ageing of different families of phenolic compounds studied was similar in the blends and base wine, different blends presented a faster anthocyanin disappearance kinetics than the base wine, probably due to their higher CAT content, which may favour the progress of certain anthocyanin condensation reactions during ageing in the bottle. This effect was slightly more pronounced in the TEM-GRA blends than in the TEM-CS ones. A further study of the phenolic composition of the monovarietal wines used for blending, as well as of the grapes (skins and seeds) from which these wines were elaborated, revealed that the blending effect on CAT could be associated with higher concentration of these compounds in Graciano and Cabernet Sauvignon grape seeds in comparison with Tempranillo. Finally, the findings of this work scientifically confirm that, in terms of the phenolic content, Graciano wines possess properties similar to Cabernet Sauvignon for blending with Tempranillo

Insights into the metabolism and microbial biotransformation of dietary flavan-3-ols and the bioactivity of their metabolites.

Flavan-3-ols, occurring in monomeric, as well as in oligomeric and polymeric forms (also known as condensed tannins or proanthocyanidins), are among the most abundant and bioactive dietary polyphenols, but their in vivo health effects in humans may be limited because of their recognition as xenobiotics. Bioavailability of flavan-3-ols is largely influenced by their degree of polymerization; while monomers are readily absorbed in the small intestine, oligomers and polymers need to be biotransformed by the colonic microbiota before absorption. Therefore, phenolic metabolites, rather than the original high molecular weight compounds found in foods, may be responsible for the health effects derived from flavan-3-ol consumption. Flavan-3-ol phenolic metabolites differ in structure, amount and excretion site. Phase II or tissular metabolites derived from the small intestine and hepatic metabolism are presented as conjugated derivatives (glucuronic acid or sulfate esters, methyl ether, or their combined forms) of monomeric flavan-3-ols and are preferentially eliminated in the bile, whereas microbial metabolites are rather simple conjugated lactones and phenolic acids that are largely excreted in urine. Although the colon is seen as an important organ for the metabolism of flavan-3-ols, the microbial catabolic pathways of these compounds are still under consideration, partly due to the lack of identification of bacteria with such capacity. Studies performed with synthesized or isolated phase II conjugated metabolites have revealed that they could have an effect beyond their antioxidant properties, by interacting with signalling pathways implicated in important processes involved in the development of diseases, among other bioactivities. However, the biological properties of microbe-derived metabolites in their actual conjugated forms remain largely unknown. Currently, there is an increasing interest in their effects on intestinal infections, inflammatory intestinal diseases and overall gut health. The present review will give an insight into the metabolism and microbial biotransformation of flavan-3-ols, including tentative catabolic pathways and aspects related to the identification of bacteria with the ability to catabolize these kinds of polyphenols. Also, the in vitro bioactivities of phase II and microbial phenolic metabolites will be covered in detail

Characterization of flavonoid glycosides from fenugreek (Trigonella foenum-graecum) crude seeds by HPLC-DAD-ESI/MS analysis

© 2014 by the authors; licensee MDPI, Basel, Switzerland. Fenugreek (Trigonella foenum-graecum) is a medicinal plant which is widely used for its pharmacological properties. In this study the phenolic composition of fenugreek crude seeds originating from Morocco has been investigated. Extraction was performed from defatted seeds by a hydromethanolic solution using an Accelerated Solvent Extractor. HPLC technique coupled to negative ion electrospray ionization mass spectrometry and diode array detection was employed to identify the polyphenol in the obtained extract. The obtained results allowed the detection of 32 phenolic compounds among which various flavonoid glycosides and phenolic acids have been tentatively identified on the basis of their UV and MS spectra, and comparisons with standards when available, as well as with literature data. A systematic study of the obtained MS spectra and the observed fragmentation showed that most of the identified compounds were acylated and non-acylated flavonoids with apigenin, luteolin and kaempferol as aglycons. Hydroxycinnamic acids mostly dominated by caffeic acid derivatives were also detected. The quantitative analysis of the identified compounds showed that the phenolic composition of the studied crude fenugreek seeds was predominantly acylated and non-acylated flavone derivatives with apigenin as the main aglycon.Peer Reviewe

Tryptophol content of young wines made from Tempranillo, Garnacha, Viura and Airén grapes

The characteristics of the tryptophol present in young wines made in the laboratory from Tempranillo, Garnacha, Airén and Viura grapes were determined by thin-layer chromatography (TLC). The concentration of this substance in the wines, obtained by means of high performance liquid chromatography (HPLC), was found to be statistically significant in both the red and white wines.Peer reviewe

Application of principal component analysis to simple determinations of brandies as a means of verifying quality

[DE]: Die phenolische Zusammensetzung der in Holzfässern gelagerten Destillate wurde studiert, um daraus verschiedene Standards zu erarbeiten, so daß daraus die Unverfälschtheit und Qualität abgeleitet werden kann.[EN]: Phenolic composition of distillates aged in wood has been widely studied, thus giving rise to different standards that establish their genuineness and quality. The present paper sets out the results for classification of Spanish brandies and cognacs according to quality by applying analysis of variance and principal component analysis to the results of simple chemical (pH, phenol content) and physical (colour) determinations and/or the relationships between them. Chemical changes that occur during the aging process are related to these parameters.Peer reviewe

Barley spent grain: release of hydroxycinnamic acids (ferulic and p-coumaric acids) by commercial enzyme preparations

Based on a paper presented at ferulate '98, IFR, Norwich, 8–11 July 1998.Barley spent grain is a residue from the brewing process. In this paper, four different commercial enzyme preparations (Viscozyme L, Ultraflo L, Termamyl and Lallzyme) were tested for their ability to release hydroxycinnamic acids, ferulic acid (FA) and p-coumaric acid (PCA), from barley spent grain. The cinnamic acid esterase activities of the enzyme preparations were measured against the model substrate methyl ferulate. Termamyl was the only enzyme preparation that showed no esterase activity. Incubation of Ultraflo L (1.3 U g−1 substrate, 24 h) with barley spent grain released 70% of the total alkali-extractable FA and 8% of the total alkali-extractable PCA. Under the same conditions, Viscozyme L and Lallzyme released, respectively, 33 and 55% of the total alkali-extractable FA, and 0.8 and 1.6% of the total alkali-extractable PCA. For FA release, enzyme concentrations higher than 1.3 U g−1 were saturating. However, for the release of PCA, a continuos increase was observed until 13 U g−1. The percentages of the FA released by Viscozyme L, Ultraflo L and Lallzyme were higher than those obtained by pure ferulic acid esterases. These three enzyme preparations could be employed for the effective release of hydroxycinnamic acids from barley spent grain.The authors grateful to the Comunidad de Madrid (Project 06G/ 042/ 96) for financial support.Peer reviewe

Influencia de las lías durante el proceso de envejecimiento en barrica y botella de un vino monovarietal de Vitis vinifera cv Tempranillo

Trabajo presentado al IX Congreso Nacional de Investigación Enológica (GIENOL) celebrado en Badajoz del 29 de mayo al 1 de junio de 2007.En vinos de Vitis vinifera cv. Tempranillo se valoraron por LC-ESI/MS, en procesos de envejecimiento durante 12 meses en barricas y 6 meses en botella, con (T+L) y sin (T) lías, seis tipos de compuestos: Acidos benzoicos (1), cinámicos y sus derivados (2); catequinas y procianidinas (3), flavonoles y sus derivados (4); alcoholes y compuestos relacionados (5) y estilbenos (6), estableciéndose las concentraciones en mg/L, siendo la suma de todos los grupos (To).Los autores agradecen la financiación del proyecto VINO3-006-CO2-1 y la beca predoctoral concedida a C. Pino por el Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA).Peer reviewe

Natural occurrence of alternariol and alternariol methyl ether in Spanish apple juice concentrates

A limited survey of 32 samples of apple juice concentrates, destined for the production of commercial juices, was carried out in order to evaluate the natural occurrence of the Alternaria metabolites alternariol and alternariol methyl ether. A high-performance liquid chromatographic method based on solid-phase extraction columns for extraction and purification of the toxins was used. Both mycotoxins were found as natural contaminants in 50% of the samples analyzed. Levels of alternariol were in the range 1.35–5.42 ng/ml. Alternariol methyl ether was present in most cases only at trace levels, and the highest amount detected was 1.71 ng/ml in one sample.We acknowledge the financial support from the Comision Interministerial de Ciencia y Tecnologia (Project ALI94-0054).Peer reviewe