Olive mill wastewaters create significant environmental issues in olive-processing countries. One of the most hazardous groups of pollutants in these wastewaters is phenolic compounds. Here, olive mill wastewater was used as substrate and treated in single-chamber air-cathode microbial fuel cells. Olive mill wastewater yielded a maximum voltage of 381 mV on an external resistance of 1 kΩ. Notable decreases in the contents of 3,4-dihydroxybenzoic acid, tyrosol, gallic acid and p-coumaric acid were detected. Chemical oxygen demand removal rates were 65 % while removal of total phenolics by the process was lower (49 %). Microbial community analysis during the olive mill wastewater treating MFC has shown that both exoelectrogenic and phenol-degrading microorganisms have been enriched during the operation. Brevundimonas-, Sphingomonas- and Novosphingobium-related phylotypes were enriched on the anode biofilm, while Alphaproteobacteria and Bacteriodetes dominated the cathode biofilm. As one of the novel studies, it has been demonstrated that recalcitrant olive mill wastewaters could be treated and utilized for power generation in microbial fuel cells.

A reliable, sensitive and effective method based on ultrasound-assisted emulsification-microextraction (USAEME) coupled to HPLC-DAD has been developed to identify and quantify several target phenolic compounds from extra virgin olive oils (EVOO). This approach is based on the emulsification of a microvolume of polar organic extractant in a non-polar liquid sample by ultrasound radiation and further separation of both liquid phases by centrifugation. The percentage of methanol/water (v/v) in the extractant, the volume of extractant, and the extraction time as three effective parameters on the extraction were optimised by a central composite design (Box-Behnken response surface) method. The optimised method presented recoveries in EVOO between 91% and 115% for the target analytes (except vanillin with 65%) and a satisfactory precision with relative standard deviations (RSD%) lower than 8.4% for repeatability and reproducibility. The method showed good linearity and limits of detection and quantification were in the range 0.001-0.14 and 0.004-0.47mg/kg, respectively. After method validation, it was successfully applied to the analysis of three EVOO samples. All target compounds were detected in all analysed samples. Tyrosol and hydroxytyrosol were the major phenolic compounds, followed by pinoresinol and luteolin.

A liquid chromatographic method with a coulometric electrochemical detector (ECD) and a fused-core column was developed for the quantification of the olive oil phenolics tyrosol, hydroxytyrosol, oleuropein, pinoresinol, and caffeic, ferulic, vanillic, and p-coumaric acid. The method was validated according to guidelines of the U.S. Food and Drug Administration. The selectivity, linearity, lower limit of quantification (LOQ), lower limit of detection (LOD), precision, accuracy, recovery, as well as the stabilities of the phenolic standards and quality control samples were determined. The separation of the eight phenolic compounds was achieved within 16 min and the total analysis time (35 min) was ca. 3-fold shorter than that of conventional HPLC methods. The LOQ range was 0.3-15.3 ng/mL, which is at least 5-fold lower than those of other methods. Recovery was between 75% and 101%. Overall the method has the advantages of being sensitive, selective, fast and provides simultaneous qualitative and quantitative analysis of phenolics.

Virgin olive oil samples stored in the light at ambient temperature, in the dark at ambient temperature, and at low temperature in the dark for 12 months both with and without headspace were separated into recognizable patterns with stepwise linear discriminant analysis. The discrimination with variables volatile and phenolic compounds, free fatty acid (FFA), peroxide values, K232, and K270 revealed a departure of stored oil from freshness and showed significant (p < 0.01) differences between storage conditions. Virgin olive oil stored at low temperature had characteristics closest to fresh oil while oil stored in the light showed the largest departure from freshness. Parameters that exclusively and significantly (p < 0.01) discriminated storage conditions were identified as potential markers of the storage condition. In the presence of oxygen, hexanal was a marker of storage in the light, FFA was a marker for dark storage, and markers of low-temperature storage were acetic acid and pentanal. In the absence of oxygen, octane was the marker for storage in the light whereas tyrosol and hexanol were markers of virgin olive oil stored in the dark, with no marker indicative of low-temperature storage. E-2-Hexenal, K232, and K270 were identified as markers of virgin olive oil freshness.

The present study was designed to assess the agreement between analytical methodologies based on 1H and 31P NMR spectroscopy and conventional analytical methods (titration, gas chromatography, and high performance liquid chromatography) for measuring certain minor and major constituents (free acidity, fatty acids, iodine value, and phenolic compounds) of olive oil. The standard deviations of the NMR method were comparable to those of the conventional methods, except perhaps those of the total hydroxytyrosol and total tyrosol. Linear regression analyses showed strong correlations between NMR and conventional methods for free acidity, total hydroxytyrosol, total tyrosol, total diacylglycerols, (+)-pinoresinol, (+)-1-acetoxypinoresinol, and apigenin; good correlations for linoleic acid, free hydroxytyrosol, and free tyrosol; and weak correlations for oleic acid, linolenic acid, saturated fatty acids, and luteolin. Furthermore, a method comparison study was conducted and the agreement between NMR and conventional methods was evaluated by using the Bland and Altman statistical analysis. The distribution of the data points in the bias plot showed that 96.4% and 100% of the measurements of free acidity and iodine value, respectively, were within the limits of agreement of the two methods. For the remaining constituents of olive oil, the percentage of measurements, located within the limits of agreement, ranged from 94% to 98.5%.

In this study, the naturally debittered table olives cv Bella di Cerignola were studied in order to (i) characterize their phenolic composition; (ii) evaluate the polyphenols bioaccessibility; (iii) assess their absorption and transport, across Caco2/TC7. LC-MS/MS analysis has confirmed the presence of hydroxytyrosol acetate, caffeoyl-6'-secologanoside, and comselogoside. In vitro bioaccessibility ranged from 7% of luteolin to 100% of tyrosol, highlighting the flavonoids sensitivity to the digestive conditions. The Caco2/TC7 polyphenols accumulation was rapid (60 min) with an efficiency of 0.89%; the overall bioavailability was 1.86% (120 min), with hydroxytyrosol and tyrosol the highest bioavailables, followed by verbascoside and luteolin. In the cells and basolateral side, caffeic and coumaric acids metabolites, probably derived from esterase activities, were detected. In conclusion, the naturally debittered table olives cv Bella di Cerignola can be considered as a source of bioaccessible, absorbable, and bioavailable polyphenols that, for their potential health promoting effect, permit inclusion of table olives as a functional food suitable for a balanced diet.

Extra virgin olive oil (EVOO) samples, of five Greek olive varieties, were stored in dark glass bottles (headspace 0.5%) in a basement without central heating for 24 months. Quantitative variations of the phenolic compounds and their degradation products were monitored over time. The differences observed in the initial total phenolic compounds concentration (ranging between 250.77 and 925.75 mg/kg) were attributed to extraction system, olive variety, and maturity stage. Even after 24 months, the degree of reduction in total phenolic compounds did not exceed 31%. The reduction was more pronounced in dialdehydic forms of oleuropein and ligstroside aglycones (DAFOA and DAFLA), indicating a more active participation in the hydrolysis and oxidation processes of the more polar secoiridoids. The initial total phenolic content was the main factor correlated to the degradation rate of the phenolic compounds. The decrease in secoiridoid derivatives, gave rise to hydroxytyrosol and tyrosol content and to the formation of four oxidized products.

BACKGROUND

Many pathological mechanisms are involved in the development of arterial hypertension; disturbance of the rheological properties of blood and microvascular rarefaction are among those mechanisms.

OBJECTIVE

The effect of p-tyrosol (Tyr) on hemorheological parameters and microvascularization in the cerebral cortex of spontaneously hypertensive rats (SHRs) at the stage of blood pressure rising (5-11 weeks) was studied.

METHODS

Blood viscosity (BV), plasma viscosity (PV), hematocrit, erythrocyte aggregation and deformability, the oxygen transport capacity index (OTCI), and the capillary network in the cerebral cortex after the course of treatment of Tyr (50 mg/kg daily i.g. for 6 weeks) were studied. Control normotensive Wistar-Kyoto (WKY) rats and control SHRs received an equivalent amount of 1% starch mucilage.

RESULTS

In comparison with WKY rats, disturbances of rheological blood parameters and a decrease in OTCI were revealed in control SHRs at the 11 weeks of life. By the end of the experiment, brain microvascular rarefaction was observed in the control SHRs (the average density of the capillary bed was reduced due to a decrease in the number of capillaries with a diameter of 3-7 μm). In SHRs rats treated with Tyr, BV and PV, the indices of erythrocyte aggregation were lower, and OTCI was higher in comparison with control SHRs. The density of the capillary network and the number of capillaries of 3-7 μm in the cerebral cortex of SHRs rats receiving Tyr were significantly higher than the corresponding values in control SHRs.

CONCLUSIONS

When Tyr is administered to young SHRs during the development of hypertension, it limits the development of hyperviscosity syndrome, improves the oxygen transport capacity and eliminates microvascular rarefaction in the cerebral cortex.

A novel mesophilic sulfate-reducing bacterium, EMSSDQ(4)(T), was isolated from olive mill wastewater in the semi-arid region of Morocco (Marrakech). Cells were Gram-negative, catalase-positive, straight rods that were non-motile and non-spore-forming and contained cytochrome c(3) and desulfoviridin. The DNA G+C content was 65.1 mol%. Phylogenetic analysis based on 16S rRNA gene sequences revealed that the isolate was a member of the genus Desulfovibrio with Desulfovibrio carbinoliphilus D41(T), Desulfovibrio alcoholivorans SPSN(T), Desulfovibrio fructosivorans JJ(T) and Desulfovibrio carbinolicus EDK82(T) as the most closely related strains with validly published names. In addition to the classical substrates used by Desulfovibrio species, the isolate oxidized 1,4-tyrosol, one of the most abundant phenolic compounds occurring in olive mill wastewater, to 4-hydroxyphenylacetate without ring cleavage. D. alcoholivorans SPSN(T) was also found to carry out this reaction. Under air, strain EMSSDQ(4)(T) exhibited limited growth on lactate and yeast extract in the absence of sulfate. On the basis of genotypic and phenotypic characteristics, it is proposed that the isolate represents a novel species, Desulfovibrio marrakechensis sp. nov. The type strain is EMSSDQ(4)(T) (=DSM 19337(T) =ATCC BAA-1562(T)).

Grapevine trunk diseases (GTDs) are one of the most serious biotic stresses affecting this important crop. Among them a range of diseases were identified and associated to a plethora of phytopathogenic fungi, including species of Diaporthe. Diaporthe eres was recently identified as one of the species involved in cane blight of grapevine. The ability of a strain of this fungus isolated from infected grapevine plant in Italy to produce in vitro phytotoxic metabolites was investigated. Five phytotoxic metabolites were identified by their physical and spectroscopic properties as 4-hydroxybenzaldehyde, 4-hydroxybenzoic acid, nectriapyrone, p-cresol and tyrosol. When tested on grapevine leaf disks and by leaf absorption, 4-hydroxybenzoic acid induced symptoms on both disks and leaves, 4-hydroxybenzaldehyde and p-cresol showed, respectively, phytotoxicity on leaf disks and on the leaf absorption bioassay.

In this study, tyrosol - a phenolic antioxidant that present in olive oil and olive mill wastes - was embedded in ethylcellulose microparticles by double emulsion solvent evaporation technique. The effect of loading content (5 % w/w and 10 % w/w) on the release behavior and bioaccessibility of tyrosol was evaluated. The polymer endowed efficient protection to tyrosol during the in vitro gastrointestinal digestion of loaded microparticles as the maximum release of tyrosol was observed during the simulated intestinal digestion, and the releases were kept outstanding low during the simulated salivary and gastric digestions. The bioaccessibility of tyrosol was improved when encapsulated. The best-fitting models of the release profiles of tyrosol were the first, and the zero-order models for formulations considering a loading of 5% w/w and 10 % w/w, respectively. The results of this study bring new perspectives for the design of loaded microparticles that will be further submitted to gastrointestinal digestion.

Keywords: Bioaccessibility; Encapsulation; In vitro release studies; Mathematical modeling; Release mechanisms; Tyrosol.

Intervertebral disc degeneration (IDD) is the major pathogenesis of lower back pain. Tyrosol is a polyphenolic compound that exhibits anti-oxidant, anti-apoptotic, and anti-inflammatory effects. Herein, we explored the effects and mechanisms of tyrosol on IDD progression in interleukin (IL)-1β-stimulated human nucleus pulposus cells (HNPCs). Cell viability and apoptosis were detected by CCK-8 and flow cytometry analysis, respectively. The production of tumor necrosis factor-α (TNF-α), IL-6, nitric oxide (NO), and prostaglandin E2 (PGE2) was examined to evaluate inflammation. The mRNA expression of matrix metalloproteinases (MMPs) (MMP-3/9/13), collagen type II, SRY-related high mobility group box 9 (SOX-9), and aggrecan was measured by qRT-PCR. Protein levels of silent information regulator 2 homolog 1 (Sirt1), phosphorylated protein kinase B (p-Akt), Akt, collagen type II, SOX-9, and aggrecan were determined by western blot. Results showed that tyrosol attenuated IL-1β-induced viability reduction, apoptosis, and caspase-3/7 activity in HNPCs. The increase in the production of TNF-α, IL-6, NO, and PGE2 in IL-1β-treated HNPCs was abolished by tyrosol treatment. Tyrosol treatment reversed IL-1β-induced upregulation of MMP-3, MMP-9, and MMP-13, and downregulation of collagen II, SOX-9, and aggrecan in HNPCs. Additionally, tyrosol treatment activated the phosphatidylinositol 3-kinase (PI3K)/Akt pathway in IL-1β-stimulated HNPCs. Sirt1 was upregulated by tyrosol, and Sirt1 silencing inhibited Akt phosphorylation in HNPCs. Sirt1 knockdown attenuated the effects of tyrosol on IL-1β-induced apoptosis, inflammation, and ECM remodeling in HNPCs. In summary, upregulation of Sirt1 by tyrosol suppressed apoptosis and inflammation and regulated ECM remodeling in IL-1β-stimulated HNPCs through activation of PI3K/Akt pathway.

Keywords: ECM remodeling; Intervertebral disc degeneration; PI3K/Akt pathway; Sirt1; Tyrosol.

Chronic hypoxic stress results in deposition of lipofuscin granules in the CA3 region of hippocampal neurons which contributes to neurodegeneration and accelerated neuronal aging. Oxidative stress and mitophagy during hypoxia are crucial to cause aggregation of these lipofuscin granules in hypoxic neurons. Salidroside, a glucoside derivative of β-Tyrosol, has been reported to protect hypoxic neurons through maintenance of mitochondrial activity. The present study is aimed at investigating the potential of Salidroside in preventing mitophagy during chronic hypoxia and identification of the molecular targets and underlying signaling mechanisms. In-silico analysis for interaction of salidroside with Bcl-xL was carried out using VLife MDS software. The prophylactic efficacy of Salidroside for amelioration of global hypoxia induced neuronal aging was studied in adult male Sprague-Dawley rats exposed to hypobaric hypoxia simulating an altitude of 7600 m for 21 days. Salidroside was supplemented at a daily dose of 25 mg kg-1b.w. p.o. during hypoxic exposure. Ultra-structural and immune-histological studies were conducted to study lipofuscin aggregation and mitophagy. In-silico findings on salidroside mediated stabilization of Bcl-xL were validated by investigating its effect on downstream signaling molecules involved in mitophagy. Administration of Salidroside reduced deposition of lipofuscin in hypoxic CA3 hippocampal neurons and prevented mitophagy. Salidroside stabilizes Bcl-xL in hypoxic neurons resulting in inhibition of PGAM5 phosphatase activity and maintenance of FUNDC1 in phosphorylated state. Salidroside mediated inhibition of pFUNDC1 dephosphorylation prevents FUNDC1-LC3 II interaction which is crucial for mitophagy. The present study demonstrates potential of Salidroside in preventing lipofuscin deposition during chronic hypoxic stress.

Previous studies in animals have shown an increase of hydroxytyrosol (OHTyr), a potent phenolic antioxidant and a minor metabolite of dopamine (also called 3,4-dihydroxyphenylethanol or DOPET), after ethanol intake. The interaction between ethanol and dopamine metabolism is the probable mechanism involved. The aim of the study was to establish the contribution of the dose of ethanol on OHTyr formation. 24 healthy male volunteers were included. Subjects were distributed in three different cohorts and each volunteer received two doses of ethanol or placebo. Doses of ethanol administered were 6, 12, 18, 24, 30 and 42 g. Study design was double-blind, randomized, crossover and controlled. Hydroxytyrosol, tyrosol (Tyr), 3,4-dihydroxyphenylacetic acid (DOPAC), and homovanillic acid (HVA) urinary excretion, ethanol plasma concentrations and drunkenness were evaluated along a 6-h period. Urinary excretion of OHTyr and Tyr increased with ethanol administered dose. A reduction in the ratio DOPAC/OHTyr from placebo to the highest dose was observed, compatible with a shift in the dopamine metabolism to preferently produce OHTyr instead of DOPAC. Also a dose-dependent increase in plasma ethanol concentrations and subjective effects was observed. This study demonstrates an endogenous production of OHTyr and Tyr in relation to ethanol administered dose in humans. Biological effects of both phenols from this source should be investigated in future studies.

The valorisation of food wastes is a challenging opportunity for the green, sustainable, and competitive development of industry. The recovery of phenols contributes to the sustainability of olive waste sector, reducing its environmental impact and promoting the development of innovative formulations of interest for pharmaceutical, nutraceutical, and cosmeceutical applications. In this work, olive mill wastewater was treated through a combination of microfiltration (MF), nanofiltration (NF), and reverse osmosis (RO) in a sequential design to produce polyphenol-enriched fractions that have been investigated for their chemical profile using ultra-high-performance liquid chromatography (UHPLC), and their potential antioxidant, hypolipidemic, and hypoglycaemic activities. RO retentate exhibited the highest content of hydroxytyrosol, tyrosol, oleuropein, verbascoside, vanillic acid, and luteolin. In particular, a content of hydroxytyrosol of 1522.2 mg/L, about five times higher than the MF feed, was found. RO retentate was the most active extract in all in vitro tests. Interestingly, this fraction showed a 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic) acid (ABTS) radicals scavenging activity with an IC₅₀ value of 6.9 μg/mL and a potential inhibition of lipid peroxidation evaluated by the β-carotene bleaching test with IC₅₀ values of 25.1 μg/mL after 30 min of incubation. Moreover, RO retentate inhibited α-amylase and α-glucosidase with IC₅₀ values of 65.3 and 66.2 μg/mL, respectively.

Keywords: antioxidants; integrated membrane processes; obesity; olive mill wastewater; polyphenols; ultra-high-performance liquid chromatography (UHPLC).

The dichloromethane fraction of the bark of Machilus thunbergii Sieb. et Zucc. (Lauraceae) significantly protected primary cultures of rat cortical cells exposed to the excitotoxic amino acid, L-glutamate. Through the activity-guided isolation from the CH(2)Cl(2) fraction, (+)-9'-hydroxygalbelgin (1), isogalcatin B (2), (7S,8S,8'R)-3',4'-dimethoxy-3,4,-methylenedioxylignan-7-ol (3), 1-hydroxy-7-hydroxymethyl-6-methoxyxanthone (4), 5,7-dimethoxy-3',4'-methylenedioxyflavan-3-ol (5), (+)-(3S,4S,6R)-3,6-dihydroxypiperitone (6), protocatechuic acid methyl ester (7) and tyrosol (8) were obtained. All of them had significant neuroprotective activities against glutamate-induced neurotoxicity in primary cultures of rat cortical cells at concentrations ranging from 0.1 microM to 10.0 microM and were comparable to MK-801, a well-known inhibitor of glutamate receptor.

Lipophenols such as tea polyphenol palmitate derivatives (palmitoyl esters of tea polyphenols) have been classified as non-toxic food additives due to their better protective effects on lipidic food matrices from oxidation, but their digestion and absorption have remained unexplored. In this study, the digestive stability of tyrosol acyl esters (TYr-Es) with fatty acids of different chain lengths and different degrees of unsaturation such as C12:0, C14:0, C16:0, C18:0, C18:1, C18:2, and C22:6 was evaluated using an in vitro simulated gastrointestinal tract model containing various digestive enzymes (pancreatin, pancreatic lipase and phospholipase A2). HPLC-UV measurements demonstrated that only pancreatin and pancreatic lipase, but not phospholipase A2, could hydrolyze TYr-Es to free TYr. The degree of TYr-E hydrolysis negatively correlated with the chain length but positively correlated with the degree of unsaturation of their lipid moiety. In addition, the fact that TYr in fatty acid ester forms could be absorbed by the intestinal lumen, at least partially in the form of free TYr, may explain a sustained release behavior of TYr-Es to TYr during the time-course following the digestion process.

Industry of table olives is widely distributed over the Mediterranean countries and generates large volumes of processing wastewaters (TOPWs). TOPWs contain high levels of organic matter, salt, and phenolic compounds that are recalcitrant to microbial degradation. This work aims to evaluate the potential of bioelectrochemical systems to simultaneously treat real TOPWs and recover energy. The experiments were performed in potentiostatically-controlled single-chamber systems fed with real TOPW and using a moderate halophilic consortium as biocatalyst. In conventional anaerobic digestion (AD) treatment, ie. where no potential was applied, no CH4 was produced. In comparison, Bio-Electrochemical Systems (BES) showed a maximum CH4 yield of 701 ± 13 NmL CH4·LTOPW(-1) under a current density of 7.1 ± 0.4 A m(-2) and with a coulombic efficiency of 30%. Interestingly, up to 80% of the phenolic compounds found in the raw TOPW (i.e. hydroxytyrosol and tyrosol) were removed. A new theoretical degradation pathway was proposed after identification of the metabolic by-products. Consistently, microbial community analysis at the anode revealed a clear and specific enrichment in anode-respiring bacteria (ARB) from the genera Desulfuromonas and Geoalkalibacter, supporting the key role of these electroactive microorganisms. As a conclusion, bioelectrochemical systems represent a promising bioprocess alternative for the treatment and energy recovery of recalcitrant TOPWs.

This paper presents the results of the study on the extraction, identification and quantification of a group of important phenolic compounds in virgin olive oil (VOO) samples, obtained from olives of various varieties, by liquid chromatography coupled to UV-vis and fluorescence detection. Sixteen phenolic compounds belonging to different families have been identified and quantified spending a total time of 25 min. The linearity was examined by establishing the external standard calibration curves. Four order linear ranges and limits of detection ranging from 0.02 to 0.6 μg mL(-1) and 0.006 to 0.3 μg mL(-1) were achieved using UV-vis and fluorescence detection, respectively. Regarding the real samples, for the determination of the phenolic compounds in higher concentrations (hydroxytyrosol and tyrosol) a simple liquid-liquid extraction with ethanol was used to make the sample compatible with the mobile phase. Recovery values close to 100% were obtained. However, a previous solid phase extraction with Diol cartridges was necessary to concentrate and separate the minor phenolic compounds of the main interferences. The parameters affecting this step were carefully optimized and, after that, recoveries near 80-100% were obtained for the rest of the studied phenolic compounds. Also, the limits of detection were improved 15 times. Finally, the standard addition method was carried out for each of the analytes and no matrix effect was found, so the quantification of the 16 phenolic compounds from different monovarietal VOO was carried out by using the corresponding external standard calibration plot.

Edible berries are considered to be among nature's treasure chests as they contain a large number of (poly)phenols with potentially health-promoting properties. However, as berries contain complex (poly)phenol mixtures, it is challenging to associate any interesting pharmacological activity with a single compound. Thus, identification of pharmacologically interesting phenols requires systematic analyses of berry extracts. Here, raspberry (Rubus idaeus, var. Prestige) extracts were systematically analyzed to identify bioactive compounds against pathological processes of neurodegenerative diseases. Berry extracts were tested on different Saccharomyces cerevisiae strains expressing disease proteins associated with Alzheimer's, Parkinson's, or Huntington's disease or amyotrophic lateral sclerosis. After identifying bioactivity against Huntington's disease, the extract was fractionated and the obtained fractions were tested in the yeast model, which revealed that salidroside, a glycosylated phenol, displayed significant bioactivity. Subsequently, a metabolic route to salidroside was reconstructed in S. cerevisiae and Corynebacterium glutamicum. The best-performing S. cerevisiae strain was capable of producing 2.1 mM (640 mg L-1) salidroside from glucose in shake flasks, whereas an engineered C. glutamicum strain could efficiently convert the precursor tyrosol to salidroside, accumulating up to 32 mM (9,700 mg L-1) salidroside in bioreactor cultivations (yield: 0.81 mol mol-1). Targeted yeast assays verified that salidroside produced by both organisms has the same positive effects as salidroside of natural origin.

Hydrothermal carbonization (HTC) is an emerging technology to treat wet biomasses aimed at producing a biochar material. Herein, olive mill wastewater (OMW) was subjected to HTC. Mass balance considerations provide evidence that the yield of biochar is low (~30%, w/w), which is associated with a low fraction of carbohydrates in OMW. The combination of different preparation schemes, pre-chromatographic derivatization reactions and GC/MS analysis for the analysis of organic compounds in aqueous HTC-solutions allowed to identify and quantify a wide array of analytes which belong either to intrinsic constituents of OMW or to characteristic HTC-breakdown products. Biophenols, such as hydroxyl-tyrosol (OH-Tyr), tyrosol (Tyr) account for the most abundant members of the first group. Most abundant breakdown products include phenol and benzenediols as well as short-chain organic acids. Secoiridoids, such as decarbomethoxy ligostride aglycon and decarbomethoxy oleuropein aglycon, all of them being typical components of OMW, are less abundant in HTC-solutions.

In this work, quinoa and buckwheat cooked seeds were fermented by two autochthonous strains of lactic acid bacteria isolated from the corresponding seeds, namely Lactobacillus paracasei A1 2.6 and Pediococcus pentosaceus GS·B, with lactic acid chemically acidified seeds as control. The impact of cooking and fermentation on the comprehensive phenolic profile of quinoa and buckwheat seeds was evaluated through untargeted ultra-high-pressure liquid chromatography coupled to quadrupole-time-of-flight mass spectrometry (UHPLC-QTOF-MS). Samples were analyzed also for in vitro antioxidant capacity (as FRAP and ORAC assays) and total phenolic content (TPC). The in vitro spectrophotometric assays highlighted that the microbial fermentation was more efficient in increasing (p < .05) the TPC and in vitro antioxidant potential in quinoa cooked seeds. However, an increase (p < .05) in TPC and ORAC radical scavenging was observed in both pseudocereals after the different cooking processes (i.e., boiling or toasting). The untargeted phenolic profiling depicted the comprehensive phenolic composition in these matrices. Raw seeds of both pseudocereals possessed a similar phenolic content (4.4 g kg^-1 equivalents; considering free and bound fractions). Besides, the metabolomics-based approach showed that all treatments (i.e., cooking and fermentation) induced the release of specific classes, namely phenolic acids and tyrosols. The PLS-DA multivariate approach identified in flavonoids the best markers allowing to discriminate the different treatments considered (i.e., cooking, chemical acidification and microbial fermentation). These findings support the use of cooking and microbial fermentation to ensure the health-promoting properties of non-wheat grains, such as buckwheat and quinoa.

A phytochemical investigation of the trunk bark ethyl acetate extract of Citharexylum spinosum L. has led to the isolation of four previously undescribed iridoid glycosides, tunispinosides A-D, and five known phenylethanoid glycosides, verbascoside, leucosceptoside A, martynoside, isoverbascoside and plantainoside C, together with 4-hydroxy-2,6-dimethoxyphenyl 6'-O-vanilloyl-β-D-glucopyranoside, two 8,3'-neolignan glycosides, plucheosides D1-D2, coniferyl aldehyde, vanillic acid, syringic acid, ferulic acid and tyrosol. All compounds were isolated for the first time from C. spinosum. Their isolation was carried out using silica gel column and high performance liquid chromatography (HPLC). Structures were established by spectroscopic means including 1D and 2D NMR experiments, and spectrometric ESI-HRMS analysis.

The effects of oenological agents, gum arabic, and oenological tannin, added at two different stages in the winemaking of rosé sparkling wines (addition to the base wine and to the sparkling wine after disgorging) on evolution of the phytochemical composition during aging on lees and commercial storage were studied for the first time. The sparkling wines were monitored during 12 months of aging on lees (sur lie, with lees) and commercial storage (bottle storage, without lees), in terms of the polyphenolics, color intensity and antioxidant capacity. It was observed that the stage of the addition of oenological agents influenced the changes in phytochemical polyphenols and antioxidant capacity of sparkling wines. The most notable effects on the polyphenolics were observed in the experiment with the addition of oenological agents to the base wine, which significantly increased the concentrations of trans-resveratrol, gallic and ellagic acids, catechin, quercetin, and myricetin. The addition of oenological agents after the disgorging stage had less influence on the phenolics of the sparkling wines. Caffeic acid, trans-caftaric acid, catechin, tyrosol, and gallic acid were the most abundant polyphenolics in rosé sparkling wines. The winemaking practices evaluated in this study comprise an interesting approach to the improvement and/or maintenance of the polyphenolics, according to winemaking practices, besides providing new knowledge on the evolution of rosé sparkling wines. PRACTICAL APPLICATIONS: Tannins and gum arabic are been described as oenological agents, however, are poorly explored in rosé sparkling wines. Many chemical modifications that occur during the winemaking process, especially due to the second in-bottle fermentation and the yeast contact in the case of sparkling wines, can be determinant of authenticity and quality of sparkling wines. The addition of oenological agents in different stages of the winemaking can provide new insights into the evolution of phytochemical constituents of rosé sparkling wines and draw perspectives for improving technological properties of these wines based on practical experience.