Bacterial fertilizers based on rhizobium laguerreae and bacillus halotolerans enhance cichorium endivia L. phenolic compound and mineral contents and plant development

[EN] Today there is an urgent need to find new ways to satisfy the current and growing food demand and to maintain crop protection and food safety. One of the most promising changes is the replacement of chemical fertilizers with biofertilizers, which include plant root-associated beneficial bacteria. This work describes and shows the use of B. halotolerans SCCPVE07 and R. laguerreae PEPV40 strains as efficient biofertilizers for escarole crops, horticultural species that are widely cultivated. An in silico genome study was performed where coding genes related to plant growth promoting (PGP) mechanisms or different enzymes implicated in the metabolism of phenolic compounds were identified. An efficient bacterial root colonization process was also analyzed through fluorescence microscopy. SCCPVE07 and PEPV40 promote plant development under normal conditions and saline stress. Moreover, inoculated escarole plants showed not only an increase in potassium, iron and magnesium content but also a significant improvement in protocatechuic acid, caffeic acid or kaempferol 3-O-glucuronide plant content. Our results show for the first time the beneficial effects in plant development and the food quality of escarole crops and highlight a potential and hopeful change in the current agricultural system even under saline stress, one of the major non-biological stresses.[ES] Hoy en día existe una necesidad urgente de encontrar nuevas formas de satisfacer la actual y creciente demanda de alimentos y mantener la protección de los cultivos y la seguridad alimentaria. Uno de los cambios más prometedores es la de los fertilizantes químicos por biofertilizantes, que incluyen bacterias beneficiosas asociadas a las raíces de las plantas. Este trabajo describe y muestra el uso de las cepas B. halotolerans SCCPVE07 y R. laguerreae PEPV40 como biofertilizantes eficientes para los cultivos de escarola, especies hortícolas ampliamente cultivadas. Se realizó un estudio genómico in silico en el que se codificaron genes relacionados con los mecanismos de promoción del crecimiento vegetal (PGP) o con diferentes enzimas implicadas en el metabolismo de compuestos fenólicos. También se analizó el proceso de colonización bacteriana de las raíces mediante microscopía de fluorescencia. SCCPVE07 y PEPV40 promueven el desarrollo de la planta en condiciones normales y estrés salino. Además, las plantas de escarola inoculadas mostraron no sólo un aumento en el contenido de potasio, hierro y magnesio, sino también una mejora significativa en el contenido de ácido protocatechuico, ácido cafeico o kaempferol 3-O-glucurónido. Nuestros resultados muestran por primera vez los efectos beneficiosos en desarrollo de la planta y la calidad alimentaria de los cultivos de escarola y ponen de manifiesto un cambio potencial y esperanzador en el sistema agrícola actual, incluso bajo estrés salino, uno de los principales estreses no biológicos. Traducción realizada con la versión gratuita del traductor www.DeepL.com/Translato

Color-copigmentation study by tristimulus colorimetry (CIELAB) in red wines obtained from Tempranillo and Graciano varieties

[EN] A study of the changes of copigmentation phenomenon in wines elaborated from different varieties has been undertaken. Colorimetric measurement of Tempranillo (T) and Graciano (G) monovarietal wines, and two 80:20 blend wines: M, (grape blending T and G, co-maceration) and W (wine blending T and G, co-vinification) was performed by spectrophotometry. Significant differences (p < 0.05) were found among the color of the wines. The Graciano cv. afforded somewhat darker and more colorful wines than the other wines. The color difference values, ΔE*ab suggested that co-vinification (W) led to wines being more similar to T than the co-maceration (M). The ΔE*ab[w − c] between untreated wines – whole wines, w – and the wines diluted to eliminate copigmentation – corrected wines, c – was 14.2 CIELAB units in the initial stages of winemaking and 6.7 in the final stages. M had a greater proportion of color due to copigmentation than the monovarietal wines. Evaluation of this parameter confirms the importance of copigmentation process into wine color during the early stages of the vinification. Also, through the full spectrum, quantitative data obtained allow a visual interpretation of the changes involved. In addition, with the aging in bottle, M wines had more stable color and more different color than W wines

Optimisation of an oak chips-grape mix maceration process. Influence of chip dose and maceration time

[EN] Oak chips-related phenolics are able to modify the composition of red wine and modulate the colour stability. In this study, the effect of two maceration techniques, traditional and oak chips-grape mix process, on the phenolic composition and colour of Syrah red wines from warm climate was studied. Two doses of oak chips (3 and 6 g/L) at two maceration times (5 and 10 days) during fermentation was considered. Changes on phenolic composition (HPLC–DAD–MS), copigmentation/polymerisation (spectrophotometry), and colour (Tristimulus and Differential Colorimetry) were assessed by multivariate statistical techniques. The addition of oak chips at shorter maceration times enhanced phenolic extraction, colour and its stabilisation in comparison to the traditional maceration. On contrast, increasing chip dose in extended maceration time resulted in wines with lighter and less stable colour. Results open the possibility of optimise alternative technological applications to traditional grape maceration for avoiding the common loss of colour of wines from warm climate

Application of differential colorimetry to evaluate anthocyanin-flavonol-flavanol ternary copigmentation interactions in model solutions

The combined effect of anthocyanin−flavanol−flavonol ternary interactions on the colorimetric and chemical stability of malvidin-3-glucoside has been studied. Model solutions with fixed malvidin-3-glucoside/(+)-catechin ratio (MC) and variable quercetin-3-β-D-glucoside concentration (MC+Q) and solutions with fixed malvidin-3-glucoside/quercetin-3-β-Dglucoside ratio (MQ) and variable (+)-catechin concentration (MQ+C) were tested at levels closer to those existing in wines. Color variations during storage were evaluated by differential colorimetry. Changes in the anthocyanin concentration were monitored by HPLC-DAD. CIELAB color-difference formulas were demonstrated to be of practical interest to assess the stronger and more stable interaction of quercetin-3-β-D-glucoside with MC binary mixture than (+)-catechin with MQ mixture. The results imply that MC+Q ternary solutions kept their intensity and bluish tonalities for a longer time in comparison to MQ+C solutions. The stability of malvidin-3-glucoside improves when the concentration of quercetin-3-β-D-glucoside increases in MC+Q mixtures, whereas the addition of (+)-catechin in MQ+C mixtures resulted in an opposite effec

Validation of a Mass Spectrometry Method To Quantify Oak Ellagitannins in Wine Samples

[EN] Detection and individual quantification of oak wood ellagitannins in oak barrel aged red wine samples are difficult mainly due to their low levels and the similarity between their structures. In this work, a quantification method using mass spectrometry has been developed and validated to quantify wine ellagitannins after sample fractionation with a previously reported method. The use of an internal standard is a requirement to correct mass signal variability. (−)-Gallocatechin, among the different tested compounds, was the only one that proved to be a suitable internal standard making possible the accurate and individual quantification of the main oak wood ellagitannins. The developed methodology has been used to detect and quantify these ellagitannins in different Spanish commercial wines, proving its usefulness

Flavanol-anthocyanin condensed pigments in plant extracts

Pigments resulting from the direct condensation of anthocyanins and flavanols are usually associated with reactions taking place during processing and storage of plant-derived foods and beverages and have been particularly studied in aged red wines. In this paper, small amounts of flavanol-anthocyanin condensed pigments are found in different plant extracts. Structures are suggested for 10 such condensed pigments detected in extracts of strawberry, runner beans, purple corn and grape skins, based on their MS" fragmentation patterns, following analyses by electrospray tandem mass spectrometry. All of them correspond to dimers containing a flavan-3-ol [either (epi)afzelechin, (epi)catechin or (epi)gallocatechin] as the upper unit carbon-carbon linked to a lower anthocyanin unit consisting of different delphinidin, cyanidin, pelargonidin, peonidin or malvidin derivatives. The detection of these pigments in plant extracts may suggest that they are natural pigments and not products exclusively formed during storage and ageing of processed foods and beverages, as was previously assumed.Comissão Europeia (Fundo Social Europeu) e Governo Português através do Programa PRODEP (III) - ref.ª 5.3/N/199.006/00-Doutoramento

Relationship between the Sensory-Determined Astringency and the Flavanolic Composition of Red Wines

[EN] The relationship between the proanthocyanidin profile and the perceived astringency was assessed in 13 commercial Tempranillo red wines. The concentration and compositional information were obtained by liquid chromatography with diode array detection coupled to electrospray ionization mass spectrometry after acid-catalyzed depolymerization of wine proanthocyanidins in the presence of excess phloroglucinol. Statistical analysis of the results showed significant correlations between sensory and chemical determinations. Astringency was more affected by the subunit composition than by the total concentration or the average degree of polymerization of wine proanthocyanidins. Higher proportions of epicatechin (EC) subunits in extension positions and gallocatechin (GC) subunits in terminal positions were shown to increase astringency. On the contrary, the amount of epigallocatechin (EGC) in both extension and terminal positions was negatively correlated with the perceived astringency

Determination by HPLC-DAD-ESI/MSn of phenolic compounds in Andean tubers grown in Ecuador

In this work, the phenolic compounds of four Andean tubers grown in Ecuador, such as yacon (Smallantus sonchifolius), mashua (Tropaeolum tuberosum), melloco (Ullucus tuberosus) and purple-sweet potato (Ipomea batatas) were analyzed by HPLC–DAD–ESI/MSn. Non-flavonoid compounds, such as hydroxycinnamic derivatives were identified in yacon, purple sweet potato and melloco samples, accounting for 100, 26 and 15% of the total of phenolic compounds, respectively. Mashua sample revealed the presence of flavan-3-ol monomers that were not found in the other samples, being (-)-epicatechin the most abundant (9.22 μg/g DM). Quercetin-3-O-rutinoside (40.6 μg/g DM), kaempferol-O-dirhamnosil-hexoside (29.5 μg/g DM) and kaempferol-O-dihexoside (46.22 μg/g DM) were the main flavonols present in mashua, melloco and purple sweet potato, respectively, being this last specie which presented the highest concentration in flavonols (89.32 μg/g DM). Purple sweet potato also had anthocyanins (157.16 μg/g DM), not detected in the other samples. The presence of these compounds and the consideration of the total phenolic content suggest the use of these Andean tubers as promising sources of natural antioxidants of wide use in the food industry. Therefore, these tubers could be considered as novel and inexpensive sources of bioactive compounds for their potential use in functional foods and nutraceuticals.This study is supported by MINECO-Spain (AGL2014-53445-R), the Community of Madrid (ALIBIRD-CM S-2013/ABI-272) and FEDER Interreg España-Portugal Programme (project ref 0377_IBERPHENOL_6_E). M.T.P. appreciates the support provided by the National Secretary of Higher Education, Science, Technology and Innovation of Ecuador (SENESCYT).Peer reviewe

Proanthocyanidine in den Fruchtschalen verschiedener Traubensorten

[EN] The proanthocyanidin composition of grape skins was studied and compared with that of grape seeds. Qualitative and quantitative differences in proanthocyanidin contents were observed between skins and seeds from the same variety. Grape seeds were found to have higher amounts of flavan-3-ol than skins; only procyanidins were found in the former, while in the skins prodelphinidins were also present, a predominance of (+)-catechin being found in their elemental flavan-3-ols.Die Proanthocyanidine der Schale von Weinbeeren wurden analysiert und mit denen der Kerne verglichen. Innerhalb derselben Sorte wurden qualitative und quantitative Unterschiede zwischen den Gewebearten gefunden. Die Gehalte der Samen lagen generell am höchsten. In den Samen konnten nur Procyanidine nachgewiesen werden, während die Fruchtschalen auch Prodelphinidine enthielten. Insgesamt dominieren jedoch Catechin-Grundeinheiten

Enological Tannin Effect on Red Wine Color and Pigment Composition and Relevance of the Yeast Fermentation Products

Enological tannins are widely used in the winemaking process either to improve different wine characteristics (color stability, among others) or to compensate for low tannin levels. In this work, the influence of the addition of two different enological tannins, mainly composed of hydrolysable (ellagitannins) and condensed tannins, on the evolution of color and pigment composition of two different types of model systems containing the five main grape anthocyanins was studied. In addition, the effect of the addition of an enological tannin on the color and pigment composition of red wines made from Vitis vinifera L. cv Tempranillo grapes was also studied by high-performance liquid chromatography with diode array detection coupled to mass spectrometry (HPLC-DAD-MS). Results showed that, in model systems, the addition of the enological tannin favored the formation of anthocyanin-derived pigments, such as A-type and B-type vitisins and flavanol-anthocyanin condensation products, provided that the yeast precursors were previously supplied. Moreover, model systems containing the enological tannins were darker and showed higher values of chroma at the end of the study than control ones. The higher formation of these anthocyanin-derived pigments was also observed in the red wines containing the enological tannin. Moreover, these wine also showed lower lightness (L*) values and higher chroma (C*ab) values than control wines, indicating a higher stabilization of color