Low Molecular Weight Phenolic Compounds Research Articles

Effects of Edaphoclimatic Conditions on Thymus hyemalis L. Essential Oil Yield and Composition

Thymus hyemalis Lange shrubs were grown in two different cultivation areas of the region of Murcia (southeast Spain) in order to determine how edaphoclimatic conditions affect the essential oil yield and chemical composition of this thyme species. Results showed that no statistically significant differences were detected among essential oil yields. However, chromatographic analysis of the oils by GC and GC/MS reported that, from a total of 101 volatile components identified, statistically significant differences among concentrations of several volatile components existed. At the qualitative level, oils from La Paca cultivation area (690 m above sea level) showed a volatile profile rich in low molecular weight components and phenolic compounds when compared to those obtained from Torre Blanca cultivation area (30 m above sea level).

Simultaneous determination of aging markers in sugar cane spirits

In this work a method for simultaneous determination of 10 representative compounds in sugar cane spirits is reported. The low molecular weight phenolic compounds: gallic acid; vanillic acid; syringic acid; vanilin; syringaldehyde; coniferaldehyde; sinapaldehyde and coumarin; and the furanic aldehydes: 5-hydroxymethyl-furfural and furfural were simultaneously quantified by high performance liquid chromatography with UV detection. These compounds, together with acids, aldehydes and tannins are responsible for the organoleptic properties of aged beverages and can assest product quality, as well as be used as aging indicators. Determination of this group of compounds is important, as they are characteristic of types and styles of aged beverages.

Rosa rugosa Thunb. ex Murray

Rosaceae, Rosoideae, Rosa L.; subgenus Eurosa Focke; section Cinnamomeae (DC.) Rehder. Japanese Rose. Rhizomatous multi-stemmed erect deciduous shrub, strongly suckering, mature clones forming impenetrable thickets. Rhizomes woody, with orange-brown cortex and triangulate scale leaves. Rhizome branches and suckers emerge from axillary buds subtended by scale leaves. In addition, suckers may arise from buds on the roots. Stems erect, sometimes arching, to 1.5( − 2) m, often much branched, tomentose when young, densely prickly. Cortex light yellowish brown. Prickles subulate, slender and straight, of all sizes down to acicles. Larger prickles tomentose, at least near the base, and usually glabrous in the apical part. Leaves alternate with (5–)7–9 leaflets contiguous on the rachis. Leaflets nearly equally sized, 2–5 × 1.5–3 cm, leathery and robust, widely elliptical, acute, with broadly cuneate or rounded base. Adaxial side dark green, conspicuously bullate or rugose, rather shiny. Abaxial side green-grey, tomentose to pubescent, with sessile pale glands, and with reticulate nervation. Leaf margin bluntly and simply crenate-serrate, involute, edge of teeth often deflexed. Petiole and rachis densely pubescent, and with many unequal subulate prickles. Stipules pale green, densely pubescent, 2.5 × 1–1.5 cm, divergent, the free part broadly ovate or deltoid. Flowers usually solitary or few together, 6–9 cm across, fragrant, nectarless. Sepals 2–3 cm, entire, with a broad, expanded tip, appressedly pubescent, aciculate and glandular (sometimes with stipitate glands), erect on the hip, persistent. Petals five, bright purplish-pink, sometimes white ( R. rugosa f. alba (Ware) Rehder). Stamens 200– 250 per flower, and styles often more than hundred. Styles pilose; stigmas in a large, domed head, sunk in the narrow, concave disc; disc 2.5–4 mm across; orifice large, at least half the diameter of the disc. A hypanthium (hip) encloses the achenes. It is depressed globose, 1.5–2 cm long and 2–2.5 cm wide, with a distinct neck below the sepals, dull green to orange when unripe, becoming glossy and brilliant red when ripe, most often smooth. Pedicel of the same length as the hip, tomentose, often with gland-tipped acicles, erect in flower, curved in fruit so that the hip points downwards. Achenes with a woody-bony pericarp enclosing the seed. Achenes broadly ovoid, obtusely angular, 4.0–6.0 mm long and 2.0–2.6 mm wide and 1.8–2.2 mm thick, with a distinct suture on both ventral and dorsal sides, hilum basal. Achene surface more or less lustrous, orange-brown. Mean seed (achene) mass is 6.6 mg. The albumen is oily. No subspecies of R. rugosa have been recognized in the British Isles. Despite the many cultivated varieties of the species, mainly forms close to the wild type are seen naturalized. However, naturalized clones may be confused with R. × hollandica (syn. R. × kamtchatica ). This taxon differs morphologically from R. rugosa by having soft-textured, dull leaflets, without prominent veins, less prickly stems, conspicuously glandular sepals, and smaller flowers and hips (Rutherford 1990). Taxonomic position: Rosa L., subgenus Eurosa Focke (syn. subgen. Rosa ), section Cinnamomeae (DC) Rehder (syn. sect. Rosa ; sect. Cassiorhodon Dumort.). Section Cinnamomeae is central in the subgenus Eurosa , which contains all but four of the approximately 150 Rosa species in the world. The diploid species of this section, including R. rugosa , are probably basal in the reticulate evolutionary series from diploid species to irregular polyploid species within this genus (Erlanson 1938; Grossi et al . 1998). Originally introduced as a garden and landscape ornamental, and widely used as rootstock for other cultivated roses, R. rugosa can be found in many different cultivated settings. Now a well-established naturalized alien occurring scattered throughout Britain and invasive in fixed dunes and other coastal habitats.

Effect of ripening stage of grapes on the low molecular weight phenolic compounds of red wines

Different red wines were elaborated to study the effect of the date of the grape harvest on the levels of individual low molecular weight phenolic compounds, which are chiefly responsible for the wine color. Two red grape varieties and two consecutive years were studied at three different harvesting stages of grapes, and the changes during the 18 months of wine aging (12 months in oak barrels and 6 months in the bottle) were also followed. The results showed that the wines made from grapes harvested 1 week later than the usual date generally had higher contents of some simple phenols, which can act as cofactors that can maintain the color intensity and violet tonalities in aged wines. Besides, these wines had lower levels of caftaric and coutaric acids, which are two of the main substrates for oxidation and browning processes.

Early effects of phenolic compounds, extracted from two forest litters, on ammonium uptake and assimilation in Pinus laricio and Pinus pinaster seedlings

The early effects of low molecular weight phenolic compounds, released by Pinus laricio and Pinus pinaster litter, on ammonium uptake and its assimilation in two Pinus species were studied. In Pinus laricio seedlings, the exposure to phenols extracted from Pinus laricio litter increased not only the ammonium uptake but also the activity of the main enzymes involved in its assimilation, whereas the phenols extracted from Pinus pinaster litter had a negative effect on these metabolic processes. In Pinus pinaster seedlings, the exposure to both phenols decreased the ammonium uptake and the activity of the main enzymes involved in its assimilation. Histological analysis carried out in Pinus laricio roots showed that phenols extracted from Pinus laricio litter induced the greatest growth of cortex, element through which occurs the ions uptake in plants, whereas phenol extracted from Pinus pinaster litter inhibited cortex development. On the other hand, in Pinus pinaster seedlings the observation showed that both phenols inhibited cortex growth indicating a strict correlation between cortex development and ammonium uptake and its assimilation.

Effect of Far-Infrared Irradiation on the Antioxidant Activity of Defatted Sesame Meal Extracts

To determine the effect of far-infrared (FIR) irradiation on the antioxidant activities of sesame meal, half of sesame seeds were FIR-irradiated and then oil was extracted from the seeds. The resulting defatted sesame meal (DSM) was extracted with methanol, and the antioxidant activities of methanolic extract were determined. FIR irradiation of sesame seeds for 30 min increased the total phenol content from 34.0 to 59.0 muM and radical scavenging activity of DSM extracts from 26.40 to 68.76%. The induction time of lipid oxidation of oil added to extracts was also retarded from 0.82 to 0.96 h. According to the gas chromatography-mass spectrometry analysis, several low molecular weight phenolic compounds, such as p-hydroxy benzoic acid, vanillic acid, p-coumaric acid, isoferulic acid, and o-coumaric acid, were frequently detected in FIR-irradiated DSM extracts as compared to unirradiated ones. These results indicated that FIR irradiation of sesame seeds increased the antioxidant activity of methanolic extracts of DSM.

Variation of sorghum phenolic compounds during the preparation of opaque beer

Phenolic compounds affect the rate of fermentation, quality and stability of opaque beer produced from sorghum. The levels of proanthocyanidins (PAs) were determined photometrically at various stages during the preparation of opaque beer from high polyphenol sorghum. Decreases in the levels of proanthocyanidins were 52 and 34% during the lactic and second alcoholic fermentation stages, respectively. Quantitative and qualitative changes in the low molecular weight phenolic compounds of sorghum during the preparation process of opaque beer were determined by gas chromatography coupled with mass spectrometric detection. The main low molecular weight phenolic compounds detected in sorghum malt were p-hydroxybenzoic acid, p-hydroxybenzaldehyde and p-hydroxybenzoyl alcohol. Levels of p-hydroxybenzaldehyde decreased during both lactic acid and alcoholic fermentation while the levels of p-hydroxybenzoic acid and p-hydroxybenzoyl alcohol increased during alcoholic fermentation. Protocatechuic acid, caffeic acid and p-coumaric acid were detected at relatively low levels at various stages of opaque beer preparation.

Analysis for low molecular weight phenolic compounds in a red wine aged in oak chips

The evolution of low molecular weight polyphenols in a red wine aging in different systems (barrels, oak chips and oak staves) made of different oak species was studied. All were placed under the same aging conditions in a wine cellar participating the Cigales Appellation of Origin programme (Spain). The wine aged in contact with oak chips experienced a quicker aging and loss of certain compounds, and a greater number of polymerisations than the wine aged in barrels. The discriminant analysis showed that samples of the same source wine aged in barrels, oak chips and oak staves tended to group together according to the aging system when wood from different botanical species is used (American, French or Hungarian).

Isolation of a yeast, Trichosporon cutaneum, able to use low molecular weight phenolic compounds: application to olive mill waste water treatment

AbstractThis study deals with the degradation of phenolic compounds in olive oil mill waste; a highly polluting material in olive oil‐producing countries because of its abundance and the toxicity of its phenolic compound content. This investigation confirms the ability of an isolated yeast, identified as Trichosporon cutaneum, to degrade phenolic compounds extracted from olive mill waste water (OMW). The yeast was adapted to the OMW by an enrichment culture. The results of this biotransformation were a decrease in the phenolic content and hence a reduction in the phytotoxic effects of the effluent after the yeast treatment. The kinetic growth of the isolated yeast on phenol over a range of concentrations (0.3–3.0 g dm−3) was studied. The ability of the strain to assimilate simple monomeric phenols and alkyl phenols, at a concentration of 1 g dm−3, in a synthetic liquid medium used as the sole carbon source was investigated in a batch culture. The aromatic ring cleavage pathway occurred in the yeast through catechol oxidation. Using various concentrations of ethyl acetate extract from OMW as the sole carbon source, the yeast exhibited growth on the substrate up to 7 g dm−3 equivalent of phenols. A significant reduction of COD after the treatment of the OMW extract by the yeast isolate was noticed. The removal of phenol and COD exceeded 80% of the original loading after 8 days of treatment, for extracts containing initial COD in the range 19 to 72 g dm−3. Copyright © 2004 Society of Chemical Industry

Solubility of Syringic and Vanillic Acids in Supercritical Carbon Dioxide

The solubility in supercritical carbon dioxide, at pressures from (10 to 50) MPa and temperatures from (40 to 60) °C, is reported for two nonflavonoid, low molecular weight phenolic compounds, 4-hydroxy-3,5-dimethoxybenzoic acid (syringic acid) and 4-hydroxy-3-methoxybenzoic acid (vanillic acid). Two types of models have been used for correlation of the experimental solubility data. First a rigorous thermodynamic method, with the Peng−Robinson equation of state, was used to determine the fugacity of the fluid phase. Second, two semiempirical density-dependent correlations were used: a linear correlation between the enhancement factor and the density of the solvent, as suggested by Schmitt and Reid, and the Chrastil correlation.

Effect of heat treatment on the antioxidant activity of extracts from citrus peels.

The effect of heat treatment on the antioxidant activity of extracts from Citrus unshiu peels was evaluated. Citrus peels (CP) (5 g) were placed in Pyrex Petri dishes (8.0 cm diameter) and heat-treated at 50, 100, or 150 degrees C for 10, 20, 30, 40, 50, and 60 min in an electric muffle furnace. After heat treatment, 70% ethanol extract (EE) and water extract (WE) (0.1 g/10 mL) of CP were prepared, and total phenol contents (TPC), radical scavenging activity (RSA), and reducing power of the extracts were determined. The antioxidant activities of CP extracts increased as heating temperature increased. For example, heat treatment of CP at 150 degrees C for 60 min increased the TPC, RSA, and reducing power of EE from 71.8 to 171.0 microM, from 29.64 to 64.25%, and from 0.45 to 0.82, respectively, compared to non-heat-treated control. In the case of WE from CP heat-treated at the same conditions (150 degrees C for 60 min), the TPC, RSA, and reducing power also increased from 84.4 to 204.9 microM, from 15.81 to 58.26%, and from 0.27 to 0.96, respectively. Several low molecular weight phenolic compounds such as 2,3-diacetyl-1-phenylnaphthalene, ferulic acid, p-hydroxybenzaldoxime, 5-hydroxyvaleric acid, 2,3-diacetyl-1-phenylnaphthalene, and vanillic acid were newly formed in the CP heated at 150 degrees C for 30 min. These results indicated that the antioxidant activity of CP extracts was significantly affected by heating temperature and duration of treatment on CP and that the heating process can be used as a tool for increasing the antioxidant activity of CP.

Analysis for low molecular weight phenolic compounds in a red wine aged in oak chips

The evolution of low molecular weight polyphenols in a red wine aging in different systems (barrels, oak chips and oak staves) made of different oak species was studied. All were placed under the same aging conditions in a wine cellar participating the Cigales Appellation of Origin programme (Spain). The wine aged in contact with oak chips experienced a quicker aging and loss of certain compounds, and a greater number of polymerisations than the wine aged in barrels. The discriminant analysis showed that samples of the same source wine aged in barrels, oak chips and oak staves tended to group together according to the aging system when wood from different botanical species is used (American, French or Hungarian).

Study of low molecular weight phenolic compounds during the aging of sparkling wines manufactured with red and white grape varieties.

Thirty-two phenolic compounds of low molecular weight were identified in 36 white, blanc de noir, and rosé sparkling wines by using HPLC with photodiode array and mass spectrometry detection. Some of the identified compounds, such as cis- and trans-ethylcaftaric, cis- and trans-ethylcaffeic, and cis- or trans-ethyl-p-coumaric acids, 2R,3R-dihydroquercetin, 2R,3R-dihydrokaempferol 3-O-beta-d-glucoside, and a lignan derivative are described for the first time in sparkling wines manufactured with grapes of red varieties. This is also the first time that cis- or trans-diethylfertaric acids have been identified in wines. When cluster analysis was applied to the data of 19 of the 32 identified compounds, the greatest differences found in the low molecular weight phenolic compounds in sparkling wines were due to the grape variety from which they were manufactured, whereas aging time did not significantly influence phenolic composition. Nine phenolic compounds, that is, trans-p-coumaric and trans-caftaric acids, trans-resveratrol glucoside, cis-coutaric, trans-coutaric, cis-p-coumaric, and cis-caftaric acids, tryptophol, and syringic acid, permit the wines to be classified correctly in accordance with the grape variety from which they were manufactured.

Phenolic compounds in a Spanish red wine aged in barrels made of Spanish, French and American oak wood

A red Rioja wine was aged in barrels made of Spanish oak wood for 21 months. The evolutions of colour percentage intensity, families of phenolic compounds and low molecular weight phenolic compounds were studied in these wines and compared with those of the same wine aged in barrels made of French and American oak. The analysis of chromatic parameters and total anthocyanins indicates that the wines aged in Spanish and French oak wood barrels have similar chromatic characteristics, but are significantly different to those of wines aged in barrels made of American oak wood, indicating a different degree of modification of the colour. The ageing process also had an important influence on the low molecular weight polyphenols composition of wine. The evolution of these components allowed the production of wines with different characteristics, in relation to the type of wood used in barrel making process. On the other hand, Spanish oak wood can be considered suitable for barrel production for quality wines, since a wine aged in barrels made of Spanish oak wood showed similar and intermediate characteristics to those of the same wine aged in French and American oak woods.

Aker Kvaerner wins evaporator contracts

Alternative technologies have been extensively investigated towards a more sustainable ageing of red wine, but few studies were made on wine spirits. Moreover, the effect of micro-oxygenation on wine spirits’ ageing is still unknown. This work examined the effect of micro-oxygenation and wood staves applied in 1000 L stainless steel tanks versus 250 L wooden barrels on the phenolic composition and chromatic characteristics acquired by the wine spirit over the first six months of ageing. Two different kinds of wood, Limousin oak and chestnut, were used. Significantly higher total phenolic content and individual contents of low molecular weight phenolic compounds (syringic acid, ellagic acid, vanillin, syringaldehyde, coniferaldehyde, sinapaldehyde and umbelliferone) were obtained with micro-oxygenation and staves than with barrels, for both kinds of wood. Accordingly, greater colour evolution (lower lightness, higher saturation and higher intensities of red, yellow and brown hues) was achieved in the former. These results were ascribed to a faster extraction and its balance with several phenomena involving the wood-derived compounds in the specific environment created by the direct supply of oxygen. A synergistic effect between the alternative technology and the chestnut wood was also observed.

Solubility of some phenolic compounds contained in grape seeds, in supercritical carbon dioxide

The solubility of some natural, low molecular weight phenolic compounds, 3,4-dihydroxy benzoic acid (protocatechuic acid), methyl 3,4,5-trihydroxybenzoate (gallic acid methyl ester or methyl gallate), and 3,4-dihydroxy benzaldehyde (protocatechualdehyde), in supercritical carbon dioxide (SC-CO 2) has been determined at pressures from 10 to 50 MPa and temperatures from 313 to 333 K. These phenolic compounds are contained in grape seeds and other natural substrates. The data presented in this work are valuable to know the possibility of separation from their natural matrices by supercritical extraction with carbon dioxide. Data modeling has been carried out by using the Peng–Robinson equation of state (PR-EOS) to describe the behavior of the supercritical fluid (SCF) phase. Two semiempirical density dependent correlations, specifically, the Chrastil model, and a model that assumes a linear correlation between the enhancement factor and the density of the solvent, have also been used for data correlation.

Glyoxylate cycle in germination of Pinus laricio seeds: effects of phenolic compounds extracted from different forest soils

Low molecular weight phenolic compounds, identified in two different soils with vegetative cover, Fagus sylvatica L. and Pinus laricio Poiret, spp. calabrica, were tested at different concentrations on seed of Pinus laricio. We determined the activity of catalase, responsible for degradation of fatty acid to provide substrates for gluconeogenesis and malate synthase, phosphoenolpyruvate carboxykinase and isocitrate lyase, enzymes of the glyoxylic pathway. The data obtained show that all the phenolic compounds bioassayed affected seed germination inhibiting catalase and glyoxylic enzymes. The results show that the inhibition of Pinus laricio seed germination by phenolic compounds is clearly linked to low utilisation of storage lipids with a consequent deficit in glucose, the main respiratory substrate.

Patterns in content of phenolic compounds in leaves of mountain birches along a strong pollution gradient

The contents of individual low-molecular weight phenolic compounds (LMWPs) in mountain birch, Betula pubescens ssp. czerepanovii, leaves collected during 1996–1998 in six plots 7–65 km south of the nickel–copper smelter at Monchegorsk, Kola Peninsula, NW Russia, were reported. A high-performance liquid chromatography–electrospray ionisation–mass spectrometry (HPLC–ESI–MS) was used for the rapid identification of low-molecular weight phenolics. Quantification was performed by the analytical high-performance liquid chromatography with UV-detection. Contents of (+)-catechin and some gallic acid derivatives decreased significantly, and contents of flavonol glycosides slightly increased with the distance from the smelter. Hydroxycinnamic acid derivatives remained unaffected. These changes in birch leaf phenolics are probably related to the effect of environmental contamination on the biosynthetic reactions both in the shikimate and phenylpropanoid pathways.

Changes in low molecular weight phenolic compounds in Spanish, French, and American oak woods during natural seasoning and toasting.

The evolution of low molecular weight polyphenols in Spanish oak heartwood of Quercus robur,Quercus petraea, Quercus pyrenaica, and Quercus faginea was studied by HPLC, in relation to the processing of wood in barrel cooperage. The polyphenolic composition of Spanish woods subjected to natural seasoning for 3 years and to the toasting process was studied in relation to those of French oak of Q. robur (Limousin) and Q. petraea (Allier) and American oak of Q. alba (Missouri), which are habitually used in cooperage. The concentrations of benzoic and cinnamic acids and aldehydes of Spanish woods increased during seasoning depending on the duration of this process and in the same way as those of French and American woods. The process having the main influence on the phenolic composition of wood was the toasting. It led to high increases in the concentration of phenolic aldehydes and acids, especially cinnamic aldehydes (sinapic and coniferylic aldehydes), followed by benzoic aldehydes (syringaldehyde and vanillin) and benzoic acids (syringic and vanillic acids). This polyphenolic composition in Spanish oak species evolved during toasting as in French and American oak, but quantitative differences were found, which were especially important in American species with respect to the others.

The effect of phenols on respiratory enzymes in seed germination Respiratory enzyme activities during germination of Pinus laricio seeds treated with phenols extracted from different forest soils

Low molecular weight phenolic compounds were identified in two soilswith different vegetative cover, Fagus sylvatica, L. andPinus laricio, Poiret, spp. calabrica, and were tested atdifferent concentrations on seed germination of Pinuslaricio, and on respiratory and oxidative pentose phosphate pathwayenzymes involved in the first steps of seed germination. The data obtained showthat there are marked differences in the phenolic acid composition of the twoinvestigated soils. All the phenolic compounds bioassayed inhibited seedgermination and those extracted from Pinus laricio soilwere particularly inhibitory. We also found that the non-germination of seedsisstrongly correlated to the inhibition of the activities of enzymes ofglycolysisand the oxidative pentose phosphate pathway.