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Polyphenols are naturally occurring compounds found in fruits, vegetables, cereals and beverages. Nowadays, there is a high interest in these compounds because of their potential health benefits associated with the protection against the development and progression of many degenerative diseases due to their antioxidant capacity. However, their composition changes both qualitatively and quantitatively depending on the natural source. Thus, the determination of these compounds is not straightforward. Among the different techniques employed for their analysis, capillary electrophoresis is a very interesting alternative due to its high separation efficiency, high resolution power, short analysis time and low consumption of samples and reagents. This chapter presents an overview of the recent developments and applications of capillary electrophoresis for the analysis of phenolic compounds from food samples, including articles published since 2010 to date. In addition, the characteristics of the most relevant developed methodologies using different separation modes are broadly discussed.

Cocoa powder is a highly consumed product all over the world which could be substituted by cheaper raw materials resulting in food fraud. In this work, a non-targeted metabolomics approach based on the use of reversed-phase liquid chromatography coupled to high-resolution mass spectrometry was developed to carry out the characterization of cocoa powder samples adulterated, at two different levels, with carob flour, soy flour, and chicory. The sample preparation protocol and the chromatographic parameters were optimized to extract and detect the highest number of molecular features. Both non-supervised and supervised statistical methods were employed to analyze the most significant variables that gave rise to group discrimination. From the 21 and 37 significant variables analyzed in positive and negative ionization modes, respectively, a total of 20 were tentatively identified. Different families of compounds including flavonoids, fatty acids, terpenoids, lysophospholipids, and a galactolipid could be pointed out as cocoa adulteration markers.

In the last years, the fact that water is a "green" solvent capable of tunable their properties by changing temperature has tended to increase publications using pressurized hot water extraction (PHWE) as a "green" extraction technique. PHWE has been established as a special extraction technique employed in obtaining bioactive compounds such as polyphenols, diterpenes and polysaccharides, among others from natural sources. Therefore, the main goal of this review is to provide the reader with a brief description of PHWE fundamentals, an up-to-date overview on the use of PHWE to recover bioactive compounds (2015-present), following our previous work by Plaza and Turner (Trends in Analytical Chemistry 71 (2015) 39-57). The last and future trends in PHWE are presented such as its combination with ionic liquids or deep eutectic solvents as well as its coupling with drying steps in order to get higher extraction yields and dried particle formation from extracts, respectively. (C) 2019 Published by Elsevier B.V.

Olive (Olea europaea) processing results in large amounts of by-products that contain valuable molecules such as phenolic compounds and phytosterols. These molecules have demonstrated to reduce blood cholesterol levels. This work proposes the development of a method to obtain simultaneously phenolic compounds and phytosterols from the olive stone using CO2-expanded liquid extraction. Hansen solubility parameters were employed for the theoretical prediction of the most suitable bio-based solvent to extract target compounds. The Box–Behnken experimental design was employed to select the optimal conditions of pressure (8–25 MPa), the molar fraction of CO2 in ethyl acetate (0.15–0.55), and the temperature (40–80 °C). Extracts showing the highest and the lowest reductions of micellar cholesterol solubility capacity were analyzed by gas chromatography coupled to mass spectrometry to find out the compounds responsible for this activity. Different phenolic compounds, free fatty acids, and phytosterols were identified in the extracts. β-Sitosterol and, especially, tyrosol and hydroxytyrosol were the compounds that primarily contributed to the reduction of micellar cholesterol solubility capacity. Electronic supplementary material The online version of this article (10.1007/s00216-019-01970-4) contains supplementary material, which is available to authorized users.

Sweet cherry pomace is a by-product that can be a source of bioactive phenolic compounds. Usually, polyphenols have been extracted using conventional extraction methodologies. However, a significant fraction, called non-extractable polyphenols (NEPs), remains retained in the conventional extraction residues. Therefore, this work is aimed, for the first time, to investigate the release of NEPs from cherry pomace combining pressurized liquid extraction (PLE) and enzyme-assisted extraction (EAE) using Promod enzyme. A response surface methodology was employed to study the influence of temperature, time, and pH on the NEPs extraction. The response variables were the total phenolic content (TPC) measured by Folin-Ciocalteu method, total proanthocyanidin (PA) content evaluated by vanillin, DMAC, and butanol/HCl assays, and total antioxidant capacity determined by Trolox equivalent antioxidant capacity and inhibition of hydroxyl radical assays. The results indicated that PLE-EAE was more suitable and selective to obtain NEPs from sweet cherry pomace than PLE alone. In fact, the extracts obtained by PLE-EAE displayed higher TPC, PA content, and bioactivity than the extracts obtained by PLE under the same extraction conditions, and those obtained by conventional methods. Moreover, size-exclusion chromatography profiles showed that the combination of PLE and EAE enabled the recovery of NEPs with higher molecular weight than PLE without EAE treatment.

Resumen de la publicación de una participación en formato µVídeo en en el congreso Divulga NextGen (1ª edición) que se celebrará online, de manera gratuita y en las redes sociales los días 26, 27 y 28 de mayo de 2021., Agradecimientos: Los autores agradecen a la Comunidad de Madrid y los programas europeos FSE y FEDER por la concesión del proyecto S2018/BAA-4393 (AVANSECAL-II-CM) y a la Comunidad deMadrid y a la Universidad de Alcalá por el proyecto CM/JIN/2019-033 (SOSBIO). G.D.R. agradece a la Universidad de Alcalá por su contrato predoctoral

A simple and rapid direct analysis in real-time coupled to high-resolution mass spectrometry (DART-HRMS) methodology was developed to generate the extractable and non-extractable polyphenols (NEPs) fingerprint for four different passion fruits, G. mangostana, and A. squamosa peels as case-study to investigate the influence of alkaline hydrolysis and enzymatic-assisted extraction (EAE) on the recovery of NEPs. The extraction residue obtained after these treatments was also analyzed by DART-HRMS. Data compiled from DART-HRMS mass spectra were processed with principal component analysis to discriminate among the different treatments. EAE with Depol enzyme enabled to obtain NEPs with the highest signal intensity in DART-HRMS analysis from all peels except for P. edulis and A. squamosa peels. In these two cases, NEPs were better extracted by EAE with Promod enzyme and alkaline hydrolysis. Results showed that the applied treatments were efficient to extract NEPs since their signal intensities in the extraction residues were very low compared with their extracts.

Mangosteen (Garcinia mangostana L.) peel is a potential source of phenolic compounds with beneficial properties. Natural deep eutectic solvents (NaDES) have been considered an environmentally friendly and cheap alternative to conventional organic solvents. In this work, a green extraction methodology was developed using ultrasound-assisted extraction (UAE) and NaDES for the extraction of antioxidant non-extractable polyphenols (NEPs) from mangosteen peel. To select the best NaDES to extract NEPs from mangosteen peel, seven NaDES were studied. Antioxidant capacity and total phenolic and proanthocyanidin contents were determined for the extracts. The molecular weights for the NEPs present in those extracts were evaluated by size exclusion chromatography. Experimental results showed that choline chloride&-lactic acid (1:2) was the NaDES allowing the highest antioxidant proanthocyanidin content in the extracts. A Box&-Behnken experimental design was employed to optimize the main parameters in UAE with NaDES: water percentage, ultrasound amplitude, and extraction time. The optimal extraction conditions were 18.8% (v/v) water, 60% ultrasound amplitude, and 15 min as the extraction time. In addition, the cytotoxicity of the NEP extracts obtained under optimal extraction conditions was evaluated. Results indicated for the first time that the use of NaDES in combination with UAE could be a sustainable alternative for the extraction of antioxidant NEPs from mangosteen peel for important applications in the food, pharmaceutical, agrochemical, and cosmetic fields, as the extracts presented low cytotoxicity.

Sweet cherries processing produces big amounts of wastes mainly constituted by cherry pomace that can be a source of bioactive polyphenols. However, during the extraction process, an important fraction called non-extractable polyphenols (NEPs) remains retained in the extraction residue. This work describes the development of an enzyme-assisted extraction (EAE) method to obtain NEPs from sweet cherry pomace employing three different enzymes. Box-Behnken experimental designs were employed to select the optimal conditions of extraction time, temperature, enzyme concentration, and pH. The total phenolic and proanthocyanidin contents and the antioxidant and antihypertensive capacities were measured. Optimal EAE conditions extracted higher content of proanthocyanidins and with higher bioactivity from extraction residue than alkaline and acid hydrolysis. Moreover, there were higher amounts of bioactive phenolics in the extraction residue than in the sweet cherry pomace extract. The estimation of NEPs molecular weight distribution by HPLC-SEC demonstrated that EAE extracted NEPs with high molecular weight.

Olive processing generates large amounts of stones with high protein contents. Previous studies have demonstrated that Manzanilla variety olive seed proteins release peptides with lipid-lowering capacity. However, no work has demonstrated their roles in the overall hypolipidemic activity. Moreover, further studies using different olive varieties are required to propose a solid method for the exploitation of olive seeds. Twenty different olive varieties were employed in this work. Proteins were extracted using high-intensity focused ultrasound and digested with Alcalase. The released peptides were identified using proteomic techniques, and their capabilities to reduce the absorption of dietary cholesterol (by inhibiting cholesterol esterase enzyme, binding bile acids, and reducing micellar cholesterol solubility) or the biosynthesis of endogenous cholesterol were evaluated. Peptides with different lipid lowering capacities were obtained from all varieties although the genotype significantly affected the hypolipidemic characteristics. Univariate and multivariate statistical analyses showed strong correlations, positive and negative, between the presence of certain peptides in the hydrolysates and their capacity to reduce exogenous cholesterol absorption and endogenous cholesterol synthesis. Therefore, the selection of the olive seed genotype can direct its lipid-lowering properties, e.g., by promoting the reduction of dietary cholesterol absorption or the inhibition of cholesterol biosynthesis.

Sweet cherry generates large amounts of by-products within which pomace can be a source of bioactive phenolic compounds. Commonly, phenolic compounds have been obtained by conventional extraction methodologies. However, a significant fraction, called non-extractable polyphenols (NEPs), stays held in the conventional extraction residues. Therefore, in the present work, the release of NEPs from cherry pomace using pressurized liquid extraction (PLE) combined with enzyme-assisted extraction (EAE) using PromodTM enzyme is investigated for the first time. In order to study the influence of temperature, time, and pH on the NEPs extraction, a response surface methodology was carried out. PLE-EAE extracts displayed higher TPC (75 ± 8 mg GAE/100 g sample) as well as, PA content, and antioxidant capacity than the extracts obtained by PLE (with a TPC value of 14 ± 1 mg GAE/100 g sample) under the same extraction conditions, and those obtained by conventional methods (TPC of 8.30 ± 0.05 mg GAE/100 g sample). Thus, PLE-EAE treatment was more selective and sustainable to release NEPs from sweet cherry pomace compared with PLE without EAE treatment. Besides, size-exclusion chromatography profiles showed that PLE-EAE allowed obtaining NEPs with higher molecular weight (&gt, 8000 Da) than PLE alone.

Passiflora species, mangosteen, and cherimoya peels are a source of bioactive phenolic compounds. Nevertheless, a significant fraction of polyphenols, called non-extractable polyphenols (NEPs), are retained in the extraction residue after a conventional extraction. Thus, alkaline, acid, and enzymatic-assisted extractions to recover high contents of antioxidant NEPs from the extraction residue of fruit peels, were compared in this work. A high-performance thin-layer chromatography method with UV/Vis detection was developed in order to obtain the phenolic profile for the extracts. The most intense bands were further analyzed by direct analysis in real-time-high-resolution mass spectrometry to tentatively identified NEPs in fruit peel extracts. Total phenolic and proanthocyanidin contents and antioxidant capacity of the extracts were measured to carry out a multivariate statistical analysis. Alkaline hydrolysis was the most efficient treatment to recover NEPs from fruit peels as well as a promising treatment to obtain antioxidant extracts along with EAE. Cherimoya peel extracts were the richest in antioxidant NEPs. This work highlights that many NEPs remain on the extraction residue of fruit peels after conventional extraction and are not usually taken into account.

The majority of studies based on phenolic compounds from plants are focused on the extractable fraction derived from an aqueous or aqueous-organic extraction. However, an important fraction of polyphenols is ignored due to the fact that they remain retained in the residue of extraction. They are the so-called non-extractable polyphenols (NEPs) which are high molecular weight polymeric polyphenols or individual low molecular weight phenolics associated to macromolecules. The scarce information available about NEPs shows that these compounds possess interesting biological activities. That is why the interest about the study of these compounds has been increasing in the last years. Furthermore, the extraction and characterization of NEPs are considered a challenge because the developed analytical methodologies present some limitations. Thus, the present literature review summarizes current knowledge of NEPs and the different methodologies for the extraction of these compounds, with a particular focus on hydrolysis treatments. Besides, this review provides information on the most recent developments in the purification, separation, identification and quantification of NEPs from plants. (C) 2017 Elsevier B.V. All rights reserved.

Water can be considered, in many cases, the greenest solvent. In the last years, the number of publications which used water as a green extraction solvent has notably increased. One of the main reasons that makes water an interesting solvent are the physicochemical changes of water from ambient to near-critical conditions under which subcritical water extraction (SWE) (or pressurized hot water extraction (PHWE)) can be performed. This review presents a critical overview about the greenness of water as extraction solvent. The changes of its physicochemical properties from ambient to near-critical conditions will be briefly described, and some of the most relevant applications of SWE published from 2015 to 2017 will be discussed. Finally, some basic ideas about different methodologies that can be employed to evaluate the greenness of an extraction process will be provided.

Our previous work demonstrated the presence of compounds with hypocholesterolemic capacity in olive seeds. These compounds were extracted using CO2-expanded ethyl acetate and identified as tyrosol, hydroxytyrosol, and beta-sitosterol using GC&#-MS. This work describes the extraction of these compounds from different olive seeds using pressurized ethyl acetate. Their solubility in ethyl acetate at temperatures ranging from 40&-200 °C was theoretically predicted by Hansen solubility parameters. The content of these compounds was estimated by GC&#-MS, as well as, the reduction of the micellar cholesterol solubility (RMCS) capacity of extracts enabling to establish the optimum extraction temperature at 100 °C. A GC&-MS method was developed and validated in terms of its analytical characteristics for a sensitive determination and quantification of tyrosol, hydroxytyrosol, and &;946#sitosterol in different olive seeds. Within varieties, Manzanilla seeds presented the highest concentration of tyrosol, hydroxytyrosol, and the lowest concentration of beta-sitosterol, as well as the highest RMCS capacity

Pomegranate peel is a source of proteins, bioactive peptides, and phenolic compounds. The simultaneous extraction of these compounds required the use of polluting solvents and reagents that are non-suitable. This work targets the development of green methodologies based on pressurized liquids (PLE) or deep eutectic solvents (DES) for the extraction of these compounds. Extracts were digested with different proteolytic enzymes and different functionalities (antioxidant, hypocholesterolemia, and antihypertensive capacities) were evaluated. Highly antioxidant and hypocholesterolemic extracts and hydrolysates were obtained using PLE while high antihypertensive capacity was observed in the hydrolysates from proteins extracted using DES. Peptides and polyphenols were identified by HPLC-ESI-Q-TOF/MS. Higher amounts of peptides were shown in hydrolysates from DES extracts while hydrolysates from PLE extracts presented higher amounts of phenolic compounds. Some peptides were assigned to proteins from Punica granatum. Both green methods improved the extraction of bioactive compounds from pomegranate peel compared to the non-sustainable method. Industrial relevance The development of green methodologies which employ sustainable solvents such as pressurized liquids (PLE) and deep eutectic solvents (DES) allows extracting proteins and bioactive compounds from pomegranate peel. In addition, these solvents improve the extraction of health beneficial compounds compared to the non-sustainable and polluting solvents. Therefore, they could be used for the development of nutraceuticals and functional foods or even in medicinal, cosmetic, and pharmaceutical preparations.

The aim of this work was to develop a capillary electrophoresis-mass spectrometry (CE-ESI-QToF-MS) method to carry out the metabolic fingerprinting of green and roasted coffee samples (Arabica variety). To evaluate changes in the metabolic profiles of coffee occurring along the roasting process, green coffee beans were submitted to different roasting degrees. The effect of different parameters concerning the electrophoretic separation (background electrolyte, temperature, voltage, and injection time), the MS detection (temperature and flow of drying gas, sheath gas of jet stream temperature, and capillary, fragmentator, nozzle, skimmer, and octapole voltages) and the sheath liquid (composition and flow rate) was studied to achieve an adequate separation and to obtain the largest number of molecular features. The analyses were carried out in positive ESI mode allowing to detect highly polar cationic metabolites present in coffee beans. Non-supervised and supervised multivariate analyses were performed showing a good discrimination among the different coffee groups. Those features having a high variable importance in the projection values on supervised analyses were selected as significant metabolites for their identification. Thus, 13 compounds were proposed as potential markers of the coffee roasting process, being 7 of them tentatively identified and 2 of them unequivocally identified. Different families of compounds such as pyridines, pyrroles, betaines, or indoles could be pointed out as markers of the coffee roasting process. (C) 2019 Elsevier B.V. All rights reserved.

Carica papaya L. cv. Maradol is a tropical plant with high commercial value due to its consumption and high nutritional value. Recent studies have corroborated a great diversity of biological activities in extracts from different tissues of the plant that seem to be caused by the presence of phenolic compounds. In this study, the effect of drought stress on the contents of phenolic compounds and the antioxidant capacities of aqueous extracts of papaya leaves were studied. Results show drought stress in plants increased their antioxidant capacity and the content and diversity of phenolic compounds. Several phenolics were identified by high-performance liquid chromatography with photodiode array coupled to electrospray quadrupole time-of-flight mass spectrometry and some of them were exclusively detected in papaya leaves under drought stress. Since this is the first report of the drought stress influence on the accumulation of phenolic compounds in leaves from papaya plants, this research opens many perspectives for obtaining a greater quantity and diversity of phenolics from vegetal tissues under abiotic stress conditions that could be exploited in food, cosmetic and pharmaceutical industries.

Brazilian berries, such as Myrciaria jaboticaba (jaboticaba), are good sources of polyphenols with a recognized function in oxidative stress attenuation proved in non-clinical studies. In the present study, the polyphenols profile and their contribution to the antioxidant capacity of the jaboticaba peel were analyzed using high-performance liquid chromatography (HPLC) with photodiode array (DAD), electrochemical (ECD), charged aerosol (CAD), and mass spectrometry (MS) detections. Anthocyanins, ellagitannins and gallotannins, ellagic acid and derivatives, and flavonols were found in jaboticaba. Anthocyanins were the phenolics found in higher concentrations. However, ellagitannins were the main contributors to the total antioxidant capacity. Moreover, the effect of jaboticaba peel intake on antioxidant and glucose parameters in a single-blind placebo-controlled crossover study was investigated. The serum antioxidant capacity was significantly higher when the subjects had consumed the test meal containing jaboticaba. Serum insulin decreased subsequent to the second meal at 4h after jaboticaba peel consumption.

This article gives an overview on the work available on methods for berry pomace processing, on methods for polyphenol extraction and on methods for polyphenol analysis. Additionally, previous reviews on fruit pomace have been identified and categorised with respect to pomace origin, and the scientific focus of the work. Data on berry pomace proximate composition are compiled, as are methods applied for processing and stabilising pomace. The article also discusses how processing methods influence juice and pomace yield, the transfer of value compounds from the fruit to either juice or pomace and the techno-functional properties of the pomace. Methods for polyphenol extraction are summarised and interpreted, and the state-of-the-art methods for polyphenol analysis are presented in line with respective sample preparation procedures. Knowledge gaps that were identified strongly indicate that systematic work has to be done to make berry pomace available as a valuable plant-based ingredient for processed foods. (Less)

Background : The gut microbiota plays an important role in the development of obesity and obesity-associated impairments such as low-grade inflammation. Lingonberries have been shown to prevent diet-induced obesity and low-grade inflammation. However, it is not known whether the effect of lingonberry supplementation is related to modifications of the gut microbiota. The aim of the present study was to describe whether consumption of different batches of lingonberries alters the composition of the gut microbiota, which could be relevant for the protective effect against high fat (HF)-induced metabolic alterations. Methods : Three groups of C57BL/6J mice were fed HF diet with or without a supplement of 20% lingonberries from two different batches (Lingon1 and Lingon2) during 11 weeks. The composition and functionality of the cecal microbiota were assessed by 16S rRNA sequencing and PICRUSt. In addition, parameters related to obesity, insulin sensitivity, hepatic steatosis, inflammation and gut barrier function were examined. Results : HF-induced obesity was only prevented by the Lingon1 diet, whereas both batches of lingonberries reduced plasma levels of markers of inflammation and endotoxemia (SAA and LBP) as well as modified the composition and functionality of the gut microbiota, compared to the HF control group. The relative abundance of Akkermansia and Faecalibacterium , genera associated with healthy gut mucosa and anti-inflammation, was found to increase in response to lingonberry intake. Conclusions : Our results show that supplementation with lingonberries to an HF diet prevents low-grade inflammation and is associated with significant changes of the microbiota composition. Notably, the anti-inflammatory properties of lingonberries seem to be independent of effects on body weight gain. Keywords: obesity; Akkermansia; hepatic steatosis; berries; metabolic endotoxemia; LBP; high-fat diet (Published: 27 April 2016) Citation: Food & Nutrition Research 2016, 60: 29993 - http://dx.doi.org/10.3402/fnr.v60.29993

A broad vision of the pressurized hot water extraction (PHWE) process as a green technique is given in this chapter. Fundamentals of water at high temperature, equipment requirements, and selected applications from the last 3 years (2016–18) of PHWE to obtain valuable compounds from natural products, foods, and food by-products are included. In addition, the use of pressurized hot water to achieve reactions, such as hydrolysis during the extraction, as well as different aspects related with the food quality and safety using this extraction technique, is discussed. Finally, some basic ideas about different methodologies that can be employed to evaluate the greenness of an extraction process and an outline of future trends in PHWE are also provided.

Macroalgae contain significant amounts of high-quality proteins which, because of their structural diversity, contain a range of yet undiscovered peptides within their primary structures. In this work, an analytical methodology was developed for the separation and identification of peptides present in protein hydrolysates from three different edible macroalgae used for human consumption (Saccharina latissima (brown macroalga), Codium spp. (green macroalga), and Mastocarpus stellatus (red macroalga)). The extraction of aqueous and alkaline soluble proteins was carried out followed by their precipitation with HCl or acetone. The protein extracts obtained were submitted to enzymatic digestion with alcalase and subsequently analyzed by reversed-phase high-performance liquid chromatography-quadrupole-time-of flight mass spectrometry (RP-HPLC-QTOF/MS) and de novo sequencing tool to separate and identify different short chain peptides. Thirty-seven peptides were identified in the hydrolysed protein extracts from the three macroalgae, five of them being common in brown and red macroalgae. After checking against BIOPEP database, several sequenced peptides were found within longer peptides with potential antibacterial activity. Any of the identified peptides had previously been identified in macroalgae.

In this work, a non-targeted metabolomics approach based on the use of reversed-phase liquid chromatography coupled to a high-resolution mass spectrometer has been developed to provide the characterization of coffee beans roasted at three different levels (light, medium, and dark). In this way, it was possible to investigate how metabolites change during the roasting process in order to identify those than can be considered as relevant markers. Twenty-five percent methanol was selected as extracting solvent since it provided the highest number of molecular features. In addition, the effect of chromatographic and MS parameters was evaluated in order to obtain the most adequate separation and detection conditions. Data were analyzed using both non-supervised and supervised multivariate statistical methods to point out the most significant markers that allow group discrimination. A total of 24 and 33 compounds in positive and negative ionization modes, respectively, demonstrated to be relevant markers; most of them were from the hydroxycinnamic acids family. Graphical abstract ᅟ.

Pleiotropic effects of spices on health, particularly on glucose metabolism and energy regulation, deserve further clinical investigation into their efficacy. The aim of the current study was to evaluate whether consumption of a black pepper-based beverage (BPB) preload containing 20 mg gallic acid equivalent (GAE) would exert any effect on postprandial glycaemia, appetite sensations, gut hormones, thyroid function, and gastrointestinal well-being after a white wheat bread (WWB) challenge meal containing 50 g available carbohydrates (CHO) compared to a control beverage. Sixteen healthy subjects (10 men; 6 women; 26 ± 0.9 years; BMI 22.93 ± 0.53 kg m-2) completed a randomized, crossover intervention study. The BPB's bioactive compounds were characterized using ultra high-performance liquid chromatography coupled to a quadrupole time-of-flight mass spectrometer with an electrospray ionization source (UHPLC-DAD-ESI-QTOF-MS). Nine compounds tentatively identified in BPB include: dihydroxybenzoic acid hexoside-pentoside, decaffeoyl-acteoside, cynaroside A, apigenin 6,8-di-C-hexoside, luteolin 6-C-hexoside-8-C-rhamnoside, apigenin 8-C-hexoside-C-deoxyhexoside, kaempferol 3-rhamnoside-4'-xyloside, apigenin 7-neohesperidoside, and apigenin-8-C-arabinopyranoside-2''-rhamnoside. Blood glucose and serum insulin responses, insulin sensitivity and β-cell function were not affected during the acute intervention with BPB. Neither were effects on gastrointestinal well-being observed after BPB. However, BPB modulated overall acute appetite by lowering 'hunger', 'desire to eat', and 'prospective consumption', and increasing 'satiety' and 'fullness'. In contrast, there were no changes in gut (peptide tyrosine-tyrosine [PYY] and glucagon-like peptide-1 [GLP-1]) and thyroid (triiodothyronine [T3] and thyroxine [T4]) hormones after BPB compared to the control beverage. In conclusion, inclusion of BPB prior to the WWB challenge meal might be beneficial for appetite modulation, but we did not find supporting evidence in glycaemia, gut and thyroid hormones. Further studies are needed to elucidate the mechanisms of appetite-reducing pungent spices, such as black pepper.

In this study, we investigate for the first time the efficiency of an environmentally sustainable extraction technique (pressurized liquid extraction, PLE) in conjunction with a fast separation technique (ultra-high performance liquid chromatography, UHPLC) coupled to a selective mass spectrometry (MS) detector (quadrupole time-of-flight, qTOF) to extract, separate and quantify fifteen intact-glucosinolates (GLSs) in broccoli leaves. Firstly, we have developed and optimized by means of an experimental design an efficient extraction procedure based on PLE (using ethanol/water as a solvent), giving complete extraction within 15min; meanwhile, the average analyte recoveries were between 85% and 96% in all cases. Chromatography was performed on a UHPLC BEH Shield RP18 1.7μm 110Å (2.1×100mm) analytical column with a mobile phase composed by formic acid in water (0.5%, v/v) and formic acid in acetonitrile (0.5%, v/v) in gradient elution mode at 0.3mL/min, resulted in baseline-separated peaks and a run time of 13min. The method was fully validated in terms of selectivity, limits of detection (LOD) and quantification (LOQ), linearity, precision, and trueness; meanwhile a study of the matrix effect was also performed. A good selectivity, low LODs and LOQs, ranging from 2 to 26μg/g, wide linear ranges from LOQ to 2500μg/g, and satisfactory precision and trueness with relative standard deviation and relative error values lower than or equal to 9%, were obtained for the studied GLSs. Finally, the proposed method was successfully applied to the analysis of intact-GLSs in fifteen broccoli leaf samples from three different cultivars (Parthenon, Nubia, and Naxos). Nine intact-GLSs were detected in all the varieties, although in different concentrations, which ranged between 14 and 1136μg/g, depending on the broccoli cultivar. In addition, the highest total content of GLSs was found in broccoli leaf samples from Parthenon cultivar, being the Naxos cultivar the poorest in GLS content. This study demonstrates the efficiency of PLE as an environmentally sustainable alternative to extract intact-GLS from broccoli leaves, and that UHPLC-qTOF-MS allowed a rapid, selective and sensitive determination of intact-GLSs in this matrix.

The aim of this chapter is to give the reader a broad view on the developed methods for polyphenol extraction and analysis. The different workflows and steps involved in the analysis of polyphenols from plants and food (by-products) are presented. Conventional extraction techniques employed for the extraction of polyphenols from natural samples are described besides the use of advanced extraction techniques such as supercritical fluid, carbon dioxide–expanded liquid, pressurized liquid, pressurized hot water, ultrasound-assisted extraction, and microwave-assisted extraction, among others. Furthermore, the spectrophotometric methods used to determine polyphenols as well as to measure the antioxidant capacity of their extracts are critically discussed. Finally, the state-of-the-art on the advanced analytical techniques applied to the characterization of polyphenols is also addressed and discussed.

Figure S1. Chromatograms corresponding to the HPLC-DAD analysis of bilberry beverage at 280 nm, 350 nm and 520 nm. P, phenolic compounds; F, flavonols; and A, anthocyanins. Figure S2. Chromatograms corresponding to the HPLC-DAD analysis of blackcurrant beverage at 280 nm, 350 nm and 520 nm. P, phenolic compounds; F, flavonols; and A, anthocyanins. Figure S3. Chromatograms corresponding to the HPLC-DAD analysis of Rose hip beverage at 280 nm, 350 nm and 520 nm. P, phenolic compounds; and F, flavonols. Figure S4. Chromatograms corresponding to the HPLC-DAD analysis of Mango beverage at 280 nm, 350 nm and 520 nm. P, phenolic compounds; and F, flavonols. Figure S5. Chromatograms corresponding to the HPLC-DAD analysis of beetroot beverage at 280 nm, 350 nm and 520 nm. P, phenolic compounds; F, flavonols; and B, betalains. (DOCX 2460 kb)

Background Consumption of polyphenol-rich fruits and vegetables may improve postprandial glucose and insulin levels and hence promote well-being. Previously it has been observed that consumption of bilberry decreases the postprandial insulin demand. The intention with the present study was to compare the impact of different supplements with various polyphenol profiles, on the postprandial glucose and insulin responses in healthy young adults. Methods In a randomized, controlled, crossover study the postprandial glycemic and insulin responses were observed in eleven healthy adults after intake of five different beverages containing bilberry (European blueberry), blackcurrant, beetroot, mango and rose hip, respectively; all drinks were enriched with the same composition of fermented oatmeal and probiotics. The control was a glucose drink. The profile and content of the polyphenols in the different beverages were determined by HPLC-DAD analysis. The antioxidative capacity of the different beverages were measured by TEAC and DPPH assays. Results Beverages containing bilberry, blackcurrant, mango or rose hip significantly attenuated the early postprandial insulin response (0–90 min), but showed no effect on glucose response. Drinks with bilberry or rose hip reduced the insulin response from the very early phase (0–30 min), and had significantly lower insulin index compared with the control. The efficiency of the bilberry and rose hip to decrease early postprandial insulin responses correlated with higher phenolic contents. Conclusions Supplements with bilberry, blackcurrant, mango or rose hip in the tested probiotic and oatmeal enriched beverage attenuated early-phase insulin response, but had no effect on the postprandial glycemic response. The improved ability of bilberry and rose hip to lower the very early phase of insulin response seems to be due to a higher phenolic content. Trial registration The study was retrospectively registered at ClinicalTrials.gov with number NCT03159065. Electronic supplementary material The online version of this article (10.1186/s12937-018-0335-0) contains supplementary material, which is available to authorized users.

Figure S6. PCA score plot of data from phenolic analysis of the five tested drinks. PC1 and PC2 explained 60.4 and 25.2% of the variance in the data respectively. (PDF 49 kb)

Brown algae are rich in polyphenolic compounds, phlorotannins, which have been found to possess high in vitro antioxidant capacity, especially DPPH radical scavenging activity, due to the high number of hydroxyl groups. Whereas, the overall antioxidant capacity of brown algae extracts has been widely studied, the antioxidant capacity of individual phlorotannins has been rarely explored. The aim of this study was to determine the structure dependant antioxidant capacity of phlorotannins from Icelandic brown algae, Fucus vesiculosus. The antioxidant capacity of individual phlorotannins was determined by an on-line method using liquid chromatography and an electrochemical detector followed by quadrupole Time of Flight mass spectrometry (UHPLC-DAD-ECD-QTOFMS). Tentative structural elucidation of 13 phlorotannin isomers from EAF was obtained by LC-DAD-QTOFMS, ranging from 374 to 870 Da. On-line determination of antioxidant capacity of the individual phlorotannins generally showed that low molecular phlorotannins exhibited higher antioxidant capacity and that the capacity decreased with polymerisation.

Food industry generates a big amount of residues. Nowadays, there is interest in adding value to these residues with the aim of increasing the sustainability of the food chain and to reduce the environmental impact of this waste whose revalorization could also originate an economical benefit. Passion fruits are cultivated for juice and pulp production generating high amounts of vegetable residues. The scarce information about passion fruit peels confers a high interest to the study of their phenolic profiles. In this work, an efficient extraction method based on pressurized hot water extraction was employed to obtain antioxidants from four Passiflora species peels (P. ligularis, P. edulis, P. edulis flavicarpa and P. mollissima). Antioxidant properties of the extracts were tested by in vitro assays and intracellular reactive oxygen species scavenging. P. mollissima and P. edulis peel extracts presented higher antioxidant capacity and phenolic content than P. ligularis and P. edulis flavicarpa. Tentative structural elucidation of 57 phenolics was achieved by high-performance liquid chromatography-quadrupole-time of flight mass spectrometry. Flavones, chalcones and phenolic acids were the polyphenol classes that may contribute to antioxidant capacity of the Passiflora peel.

There is a great interest in searching for new environmentally sustainable techniques to enhance the use of agricultural byproducts. In this work, a response surface methodology was used to study the influence of the two independent variables, temperature (25-200 °C) and extraction time (3-17 min), in the extraction of antioxidants by pressurized hot water extraction (PHWE) from industrial apple byproducts. The optimized extraction method for determination of flavonols was at 120 °C and 3 min, giving a predicted total yield of flavonols of 1.3 μmol/g dry apple byproduct. Results obtained suggest that new antioxidant compounds were formed at the higher extraction temperatures. A desirability function response surface, considering maximum antioxidant capacity and minimal formation of brown color, was calculated and gave an optimum of 125 °C and 3 min. This latter PHWE method correlates well with the obtained results for flavonols; thus, a desirability function is a simpler alternative method for finding optimal conditions.

The purpose of this book chapter is to give the reader a thorough background to the fundamentals and applications of pressurized hot water extraction (PHWE) for the analysis of bioactive compounds. The chapter summarizes the field for 2009-2014 and includes fundamentals of water as a solvent; equipment; method optimization; a few selected applications; hyphenations and future aspects. It is highlighted that solvent properties of water are tuneable by changing the temperature, of which the most pronounced are self-ionization, dielectric constant, viscosity, diffusivity, density and surface tension. Furthermore, important aspects to consider are the risk of degradation of the analytes and other potential reactions such as hydrolysis, caramelization and Maillard reactions that may lead to erroneous results. For the extraction of bioactive compounds, PHWE methods reported are based on using water at 80-175°C and short extraction times. In conclusion, PHWE provides advantages over conventional extraction methods, such as being 'greener', faster and more efficient. (Less)

Background: Berries and associated bioactive compounds, e.g. polyphenols and dietary fibre (DF), may have beneficial implications with respect to the metabolic syndrome, including also cognitive functions. The aim of this study was to evaluate effects on cognitive functions and cardiometabolic risk markers of 5 wk intervention with a mixture of berries, in healthy humans. Methods: Forty healthy subjects between 50–70 years old were provided a berry beverage based on a mixture of berries (150g blueberries, 50g blackcurrant, 50g elderberry, 50g lingonberries, 50g strawberry, and 100g tomatoes) or a control beverage, daily during 5 weeks in a randomized crossover design. The control beverage (water based) was matched with respect to monosaccharides, pH, and volume. Cognitive tests included tests of working memory capacity, selective attention, and psychomotor reaction time. Cardiometabolic test variables investigated were blood pressure, fasting blood concentrations of glucose, insulin, blood lipids, inflammatory markers, and markers of oxidative stress. Results: The daily amounts of total polyphenols and DF from the berry beverage were 795 mg and 11g, respectively. There were no polyphenols or DF in the control beverage. The berry intervention reduced total- and LDL cholesterol compared to baseline (both P

Subcritical water extraction (SWE) is a green extraction technology that represents an alternative to conventional extraction using organic solvents for isolating bioactive compounds (mainly antioxidants) from different raw materials. In this chapter, the fundamentals of the technique, the instrumental requirements, and some relevant applications of SWE from the last 5 years are discussed. The neoformation of antioxidants by SWE is also covered, as well as an overview of future trends.