High resolution mass spectrometric analysis of secoiridoids and metabolites as biomarkers of acute olive oil intake - an approach to study inter-individual variability in humans

SCOPE: Phenolic compounds are minor components of extra virgin olive oil (EVOO). Secoiridoids are the major components contributing to the phenolic content of EVOO. {Silva, 2015 #95}Information is lacking regarding their potential as biomarkers for EVOO intake. METHODS AND RESULTS: Healthy volunteers (n = 9) ingested 50 mL of EVOO in a single dose containing 322 mg/kg total phenolic content (caffeic acid equivalents) and 6 mg/20g hydroxytyrosol and its derivatives. Plasma was collected before (0h) and at 0.5, 1, 2, 4 and 6h after ingestion. Urine samples were collected prior to ingestion (0h) and at 0-4, 4-8, 8-15 and 15-24h. Samples were analysed by UPLC coupled with an Exactive Orbitrap MS. Partial Least Squares Discriminant Analysis with Orthogonal Signal Correction was applied to screen for metabolites that allowed samples discrimination. Plasma biomarkers and urine biomarkers were selected although individual variability was observed among volunteers. Results are in accordance with in vitro experiments performed (in vitro digestion and hepatic microsomal activity assays). CONCLUSIONS: Plasma (elenolic acid + H2 ; p-HPEA-EA + H2 + glucuronide) and urinary (3,4-DHPEA-EA, 3,4-DHPEA-EA + H2 +glucuronide, methyl 3,4-DHPEA-EA + H2 +glucuronide) secoiridoid compounds were selected as biomarkers to monitor EVOO intake showing good predictive ability according to multivariate analysis

Phenolic Compounds Extraction of Arbutus unedo L.: Process Intensification by Microwave Pretreatment

Producción CientíficaArbutus unedo L., commonly known as the strawberry-tree fruit, is an endemic species of the Mediterranean flora. Microwave extraction technology has been considered as a fast and “green” method for the production of extracts rich in bioactive compounds, although the energy consumption is high. To overcome this bottleneck, microwave was used as a pretreatment procedure in short time periods. This technique promotes the burst of intracellular vacuoles leading to an increase in the lixiviation of phenolic compounds. Different approaches were tested, namely a solvent-free irradiation (SFI), a solvent-assisted irradiation (SAI) and a pressurized solvent-assisted irradiation (PSAI). After irradiation, a solid–liquid extraction procedure was performed using a mixture of water and ethanol. A kinetic evaluation of the total phenolic content (TPC) was performed using the Folin–Ciocalteu method. For the total anthocyanin content, a UV-spectrophotometric method was used. HPLC-UV and LC-MS were used for TPC and identification of present compounds. Microwave irradiation led to an increase in TPC of extracts after SAI (52%) and PSAI (66%) along with a reduction in time of extraction from 30 min to less than 2 min. The anthocyanin content also increased by 66% for the SAI and PSAI extractions.Fundação para Ciência e Tecnologia (fellowship SFRH/BD/52532/2014)Fundação para a Ciência e Tecnologia/Ministério da Educação e Ciência - Fondo Europeo de Desarrollo Regional (partnership PT2020)Portuguese National Mass Spectrometry Network (contracts RNEM—REDE/1518/REM/2005, ROTEIRO/0028/2013 and LISBOA-01-0145-FEDER-022125)Marie Curie Industry - Academia Partnerships and Pathways (project FP7-PEOPLE-2013-IAPP-612208

Phenolic characterization of aging wine lees: correlation with antioxidant activities

Aging wine lees are water-wastes produced during the wine aging inside wood barrels that can be considered as alternative sources of bioactive compounds. Phenolic characterization and antioxidant activity (AA) measurements of wines lees solid-liquid extracts have been undertaken on a dry extract (DE) basis. Solvents with different polarities (water, methanol, ethanol, two hydroalcoholic mixtures and acetone) were used. Total phenolic (TPC) and total flavonoid contents (TFC) were determined. The mixture of 75:25(v/v) EtOH:H2O showed the highest values with 254mgGAE/gDE and 146mgCATE/gDE respectively. HORAC, HOSC and FRAP were used to determine the AA of the extracts being also highest for the mixture of 75:25(v/v) EtOH:H2O (4,690 µmolCAE/gDE, 4,527 µmolTE/gDE and 2,197 µmolTE/gDE, respectively). For ORAC method, methanol extract showed the best value with 2,771µmolTE /gDE. Correlations between TPC, TFC, phenolic compounds and AA were determined. Most relevant compounds contributing to AA were identified using data from mass spectrometry, being mainly anthocyanins.2019-04-0

Microwave and ultrasound pre-treatments to enhance anthocynins extraction from different wine lees.

Wine lees are rich in anthocyanins (AC), natural colorants with health promoting properties. The extraction kinetics of AC from different wine lees in conventional solid-liquid extraction were studied for the first time. The influence of parameters such as temperature, solid-liquid ratio (RS-L) and type of solvent (hydro-alcoholic mixtures) was also studied. Furthermore, microwaves (MW) and ultrasounds (US) were used as pre-treatments (a prior step to the conventional extraction) in order to increase AC yield. Maximum extraction yield (2.78 mgMALVIDIN-EQUIVALENTS/gDRY-LEES) was achieved after 15 minutes at 25ºC, with a RS-L of 1/10 (g/mL) and with a 50%vol. ethanol mixture. When MW were used AC extraction yield was doubled (6.20 mgMALVIDIN-EQUIVALENTS/gDRY-LEES) and the required time to achieve a constant yield was reduced (from 15 min to 90s). Meanwhile, US only shortened extraction time in less proportion (from 15 to 5 min). Putative identification of main extract compounds was performed by LC/MS-MS.2019-09-012019-09-0

Pressurized liquid extraction optimization from supercritical defatted olive pomace: a green and selective phenolic extraction process

Producción CientíficaOlive pomace (OP) is the main by-product of the olive oil industry produced in large quantities. Its valorization as a source of phenolic bioactive compounds is paramount for the sustainable growth of related industries. This work proposes an intensified process to maximize the recovery of phenolic compounds in dry extracts using hydroalcoholic mixtures. Supercritical carbon dioxide defatting pre-treatment was performed. Following this, pressurized liquid extraction was optimized through a circumscribed central composite design. The factors consisted of temperature (65.0–185.0 °C), ethanol percentage (8.0–92.0%), and solid/liquid ratio (0.2–0.8 gOP/mLSOLVENT). Besides the total phenolic content (TPC) and the total flavonoid content (TFC), the major phenolic compounds of OP [hydroxytyrosol (HT), tyrosol (TY), and oleuropein (OL)] were evaluated. Further, decarboxymethyl OL aglycone dialdehyde (3,4-DHPEA-DEDA) was identified by HPLC-DAD-MS/MS as the most abundant polyphenol and was studied for the first time for OP. Different conditions were found to optimize each key compound. In 67% shorter extraction time and 38% less solvent consumption compared to conventional extraction, an increase of 475% for OL, 428% for HT, 194% for TY, 373% for 3,4-DHPEA-DEDA, 89% for TPC, and 158% for TFC was observed. The antioxidant activity by oxygen radical absorbance capacity (ORAC) assay increased 89% (optimal conditions) and correlated with TPC, 3,4-DHPEA-DEDA, and TFC. Thus, an efficient, selective, scalable, and green extraction process was established.European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie Initial Training Network (ITN) “IT-DED3” (H2020-MSCA-ITN-2017) grant agreement No. 765608Fundação para a Ciência e Tecnologia (FCT) and Portugal 2020 to the Portuguese Mass Spectrometry Network (Rede Nacional de Espectrometria de Massa RNEM; LISBOA 01 0145 FEDER 402 022125

Polyphenol-Rich Extracts Obtained from Winemaking Waste Streams as Natural Ingredients with Cosmeceutical Potential

Producción CientíficaPhenolics present in grapes have been explored as cosmeceutical principles, due to their antioxidant activity and ability to inhibit enzymes relevant for skin ageing. The winemaking process generates large amounts of waste, and the recovery of bioactive compounds from residues and their further incorporation in cosmetics represents a promising market opportunity for wine producers and may contribute to a sustainable development of the sector. The extracts obtained from grape marc and wine lees, using solid–liquid (SL) extraction with and without microwave (MW) pretreatment of the raw material, were characterized in terms of antioxidant activity through chemical (ORAC/HOSC/HORAC) and cell-based (keratinocytes—HaCaT; fibroblasts—HFF) assays. Furthermore, their inhibitory capacity towards specific enzymes involved in skin ageing (elastase; MMP-1; tyrosinase) was evaluated. The total phenolic and anthocyanin contents were determined by colorimetric assays, and HPLC–DAD–MS/MS was performed to identify the main compounds. The MW pretreatment prior to conventional SL extraction led to overall better outcomes. The red wine lees extracts presented the highest phenolic content (3 to 6-fold higher than grape marc extracts) and exhibited the highest antioxidant capacity, being also the most effective inhibitors of elastase, MMP-1 and tyrosinase. The results support that winemaking waste streams are valuable sources of natural ingredients with the potential for cosmeceutical applications.European project WineSense (project FP7-386 MC-IAPP)Junta de Castilla y León (project VA040U16)Ministerio de Educación y Formación Profesional (fellowship FPU13/04678)Portuguese Fundação para a Ciência e Tecnologia (FCT) (grants PEst-OE/EQB/LA0004/2011 and UID/Multi/04462/2013)iNOVA4Health (grant UID/Multi/04462/2013

Interlaboratory Coverage Test on Plant Food Bioactive Compounds and their Metabolites by Mass Spectrometry-Based Untargeted Metabolomics.

Bioactive compounds present in plant-based foods, and their metabolites derived from gut microbiota and endogenous metabolism, represent thousands of chemical structures of potential interest for human nutrition and health. State-of-the-art analytical methodologies, including untargeted metabolomics based on high-resolution mass spectrometry, are required for the profiling of these compounds in complex matrices, including plant food materials and biofluids. The aim of this project was to compare the analytical coverage of untargeted metabolomics methods independently developed and employed in various European platforms. In total, 56 chemical standards representing the most common classes of bioactive compounds spread over a wide chemical space were selected and analyzed by the participating platforms (n = 13) using their preferred untargeted method. The results were used to define analytical criteria for a successful analysis of plant food bioactives. Furthermore, they will serve as a basis for an optimized consensus method

The flavonoid-rich fraction of Coreopsis tinctoria promotes glucose tolerance regain through pancreatic function recovery in streptozotocin-induced glucose-intolerant rats

Aim of the study: Infusions of Coreopsis tinctoria Nutt. flowering tops have been used traditionally in Portugal to control hyperglycaemia and a previous study revealed that daily administration of the infusion during a 3-week period promoted the recovery of glucose tolerance by a mechanism different from inhibition of glucose absorption and direct promotion of insulin secretion. We know report the study of the ethyl acetate fraction of Coreopsis tinctoria flowers infusion aiming to confirm flavonoids as bioactive metabolites. To give one step forward into the antihyperglycaemic mechanism of action of this traditionally used plant we also studied the activity of Coreopsis tinctoria flavonoids on the pancreatic function of glucose-intolerant rats. A standard antioxidant, Trolox, was also studied for comparative purposes as the antioxidant mechanism has been frequently purposed as one of the mechanisms mediating antihyperglycaemic effects of flavonoid-rich extracts. Material and methods: Thirteen compounds, mainly of flavanone and chalcone flavonoidal type, have been identified in this fraction by HPLC-DAD-ESI-MS/MS, and the major one (marein) quantified by HPLC-UV. The fraction (125 mg containing 20 mg of marein/kg b.w.) and Trolox (50 mg/kg b.w.) were administered daily by oral gavage to normal and STZ (40 mg/kg b.w.)-induced glucose-intolerant Wistar rats for 3 weeks. Blood glucose levels were measured weekly by Oral Glucose Tolerance Test. Pancreatic function was evaluated by plasma lipase of treated and non-treated glucose-tolerant and- intolerant rats after the 3-week treatment period. Results: After 2 weeks oral treatment with Coreopsis tinctoria AcOEt fraction the animals were no longer glucose-intolerant, an effect maintained over the remaining experimental period. Additionally, plasma lipase values of glucose-intolerant animals treated with the AcOEt fraction (13.5 +/- 0.84 U/L) showed a clear reduction when compared with the glucose-intolerant group (34.60 +/- 1.76 U/L: