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Epicatechin (EC) and main colonic phenolic acids derived from flavonoid intake have been suggested to exert healthful effects, although their mechanism of action remains unknown. Heart damage is highly prevalent in metabolic diseases, and the failure of this organ is a major cause of death worldwide. In this study, the modulation of the energy metabolism and insulin signalling by the mentioned compounds in cardiac H9c2 cells was evaluated. Incubation of cells with EC (1–20 μM) and 2,3-dihydroxybenzoic acid (DHBA, 10 μM) reduced glucose uptake, and both compounds decreased lipid accumulation at concentrations higher than 0.5 μM. EC and DHBA also increased the tyrosine phosphorylated and total insulin receptor (IR) levels, and activated the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) pathway in cardiac H9c2 cells. Interestingly, EC and DHBA did not modify glucose transporters (SGLT-1 and GLUT-1) levels, and increased GLUT-4 values. In addition, EC and DHBA decreased cluster of differentiation 36 (CD36) and fatty acid synthase (FAS) values, and enhanced carnitine palmitoyl transferase 1 (CPT1) and proliferator activated receptor α (PPARα) levels. By using specific inhibitors of AKT and 5′-AMP-activated protein kinase (AMPK), the participation of both proteins in EC- and DHBA-mediated regulation on glucose uptake and lipid accumulation was shown. Taken together, EC and DHBA modulate glucose uptake and lipid accumulation via AKT and AMPK, and reinforce the insulin signalling by activating key proteins of this pathway in H9c2 cells., This work was supported by the grant RTI2018-095059-B-I00, funded by MCIN/AEI/10.13039/501100011033/ and by “ERDF A way of making Europe”. E. G.-D. was the recipient of a contract from Comunidad de Madrid (PEJ-2020-AI/BIO-18529). Sergio Castillo-González technical assistance is acknowledged (contracted by Comunidad de Madrid, PEJ-2018-TL/SAL-10236).

Introducción: Cada año, el número de usuarios económicamente desfavorecidos que dependen de las donaciones de alimentos de forma habitual está aumentando considerablemente en países de renta alta. Dado que la disponibilidad y características de los alimentos donados afectará a su estado de salud, se plantea hacer un estudio de los tipos de alimentos solicitados por entidades de apoyo social en la Comunidad de Madrid. Metodología: Se ha desarrollado un trabajo de campo cualitativo en el que se han identificado a través de medios de comunicación y una búsqueda en internet 69 organizaciones de apoyo social de la Comunidad de Madrid que recogen alimentos, de las cuales 23 respondieron a un cuestionario sobre los alimentos requeridos, así como algunas indicaciones y recomendaciones específicas. Los datos recogidos fueron integrados en una base de datos. Resultados: Los alimentos más solicitados por las entidades en orden descendiente fueron: leche, conservas de pescado, de legumbres y de verdura, galletas, cacaos solubles, aceite de oliva, conservas de carne, azúcar, pasta y leches infantiles. Numerosas entidades indicaban que los alimentos para desayunos y meriendas debían ser leche, magdalenas, galletas, bollería, crema de cacao y zumos. La principal causa por la que pedían alimentos no perecederos era por no disponer de instalaciones apropiadas. Conclusiones: El elevado porcentaje de alimentos poco saludables que son solicitados por las diferentes asociaciones madrileñas de apoyo social no favorece la seguridad alimentaria ni satisface las necesidades nutricionales de los usuarios que dependen de estas como fuente primaria de alimentación. En el caso del desayuno y la merienda, se traslada una imagen errónea respecto a cuál debe ser la opción recomendable en la infancia. Financiación: sin financiación.

Psidium guajava L. and Psidium friedrichsthalianum Nied are part of the Psidium species native to America. Nowadays, it is essential to study the phenolic compound (PC) profile and their changes during digestion and the fractions available for absorption. This study aimed to characterize the PC profile in some Psidium species and their bioaccessibility (BA). Fifty-seven compounds were identified, and forty-six belonged to ten different phenolic classes. PC profiles showed significant differences between the species and the intestinal fraction P. friedrichsthalianum Nied. showed the highest PC content, although it mostly belonged to non-extractable polyphenols. This leads to the lowest BA (37%); P. guajava L. 'Morada' showed the highest (47%). Hydroxycinnamic acids were the most stable PC after gastrointestinal digestion. This study showed relevant differences in the PC content and profile of different Psidium species and changes between the PC in the original matrix and those released in the different stages of gastrointestinal digestion.

espanolLa evidencia cientifica acumulada en las ultimas decadas ha mostrado el importante papel de la dieta en la prevencion de diversas patologias de relevancia creciente, como son las enfermedades cardiovasculares y la diabetes tipo 2. Los polifenoles, una amplia familia de compuestos presentes en los alimentos de origen vegetal, han mostrado en estudios mecanisticos, preclinicos, clinicos y observacionales un gran potencial en la prevencion y/o modulacion de diversas alteraciones cardiometabolicas. No obstante, todavia quedan multiples aspectos en este terreno por elucidar, como la explicacion de variaciones interindividuales en la respuesta a estos compuestos. Igualmente, una fraccion de polifenoles de la dieta, los denominados no extraibles o antioxidantes macromoleculares (de alto peso molecular o asociados a macromoleculas como la fibra) ha sido hasta el momento mucho menos considerada en los estudios sobre el tema, a pesar de que han presentado resultados prometedores. Este articulo presenta diversos trabajos recientes en relacion al efecto de los polifenoles en salud, abordando tres aspectos clave: a) la determinacion de ingestas de los mismos, como paso necesario para poder establecer asociaciones con salud; b) el estudio del metabolismo de los polifenoles, ya que son los metabolitos derivados de la extensa transformacion que sufren estos compuestos los que finalmente pueden ejercer actividades biologicas sistemicas; c) el potencial de estos compuestos en el manejo de distintos parametros de riesgo cardiometabolico. Globalmente, el desarrollo de los estudios sobre los polifenoles de la dieta (a traves de una aproximacion integral que incluya las fracciones extraible y no extraible) deberia permitir establecer, tras la superacion de las limitaciones existentes, recomendaciones de salud publica sobre la ingesta recomendada de polifenoles, que puedan trasladarse al conjunto de la poblacion o a grupos poblacionales especificos. EnglishAccumulated scientific evidence has shown the important role of diet in the prevention of various pathologies of increasing relevance, such as cardiovascular disease and type 2 diabetes. Polyphenols, a large family of compounds present in plant-based foods, have shown in mechanistic, preclinical, clinical and observational studies a relevant potential in the prevention and/or modulation of several cardiometabolic alterations. However, there are still multiple aspects in this area to be elucidated, such as the explanation of interindividual variations in the response to these compounds. Similarly, a fraction of polyphenols in the diet, the so-called non-extractable or macromolecular antioxidants (of high molecular weight or associated with macromolecules such as dietary fiber) has so far been much less considered in studies on the subject, despite they have produced promising results. This article presents several recent studies on the health effects of polyphenols, addressing three key aspects: (a) estimation of dietary intakes, as a previous step in order to establish potential associations with health outcomes; b) the study of the metabolic fate of polyphenols, since metabolites derived from extensive transformation after intake are the compounds that can ultimately exert systemic biological activities; c) the potential of these compounds in the management of different cardiometabolic risk parameters. Overall, the development of studies on dietary polyphenols (through a comprehensive approach including extractable and non-extractable fractions) should allow, after overcoming existing constraints, the establishment of dietary recommendations on polyphenol intake, either for general population or for specific population groups.

Guava fruit is rich in phenolic compounds (PCs), whose metabolic fate has not been explored. Non-digestible carbohydrates and PCs in whole guava (WG) and seedless guava (SG) were submitted to an in vitro colonic fermentation, followed by evaluation of the anti-proliferative activity of the fermentation extracts in HT-29 cancer cell lines. The main PCs in both samples were (+)-gallocatechin and gallic acid, while procyanidin B was the most abundant one associated with soluble indigestible fraction and quercetin predominated in the insoluble indigestible fraction. The fermentability index at 24 h was 78.84% in WG and 84.74% for SG, near to the value for raffinose used as reference, with butyric acid as the main short chain fatty acids (SCFA) produced. The greatest antiproliferative effects were observed in the SG at 12 h of fermentation and WG at 24 h of fermentation. These results allow to suggest consumption of guava fruit, either with or without seeds, as a feasible way to maintain colonic health., FJBB thanks Consejo Nacional de Ciencia y Tecnología, México (CONACyT) for the scholarship (378371) granted.

Instant controlled pressure drop (DIC) is a technology able to modify the polyphenol profile in vegetal materials. However, information about how polyphenols are transformed, particularly regarding non-extractable polyphenol (NEPP), as well as the association with the initial content of polyphenols of the material is scarce. Thus, this work aimed to evaluate the DIC effect, modifying the pressure (0.2 and 0.4 MPa), the number of cycles (2 and 4), and grape pomace material (Malbec, Merlot, and Syrah) on extractable polyphenol (EPP) and NEPP contents. The EPP content increased during DIC application, an effect associated with the pressure, cycles, and initial polyphenol content. While for extractable and non-extractable proanthocyanidin contents, the main factors explaining the DIC effect are the pressure and number of cycles. Therefore, changes in polyphenols from grape pomace by DIC treatment are dependent upon experimental conditions, but the origin of the grape pomace also influences the extraction of EPP.

Cumulative evidence indicates the relevance of cocoa in the modulation of cardiometabolic diseases. Nevertheless, pure cocoa may be rejected by many consumers due to its bitter taste. Carob (Ceratonia siliqua L.) is a Mediterranean legume with pods rich in dietary fibre and polyphenols. In this study, carob flour was combined with cocoa, to obtain a blend which was subjected to nutritional evaluation (proximate composition, carbohydrate and fatty acid profiles, phytochemical composition, dietary fibre properties, antioxidant capacity) and sensory analysis, in order to determine whether it may be a suitable alternative to commercial sugar-rich soluble cocoa powders. The blend showed a high content of dietary fibre (56%), methylxanthines and polyphenols (55% as non-extractable proanthocyanidins). The product had good solubility and was less bitter than cocoa, as evaluated in sensory analysis, thereby suggesting that this blend may be acceptable to consumers, particularly when information about potential biological activity is provided (a significant improvement in taste evaluation was observed). The beneficial environmental impact of carob and the advantages of valorizing the commonly discarded carob pod mean that further studies of applications of this blend and its potential health effects would be of great interest., This study was performed within the project RTI2018-095059-B-I00, funded by MCIN/AEI/10.13039/501100011033/and by the European Regional Development Fund “Una manera de hacer Europa”. H.S.-A. was the recipient of a JAE-Intro fellowship from the CSIC (JAEINT_20_00536) and E.G.-D. of a contract from the European Youth Employment Initiative (Ref: CAM20_ICTAN_AI_01).

Most randomized clinical trials of polyphenols focus on individual foods. Nevertheless, due to their presence in many foods and in order to reflect a real situation, clinical trials based on polyphenol-rich diets are particularly important. This systematic review explores the characteristics of the polyphenol-rich diets used in intervention studies. The bibliography search for English-language scientific papers was performed in the Elsevier Scopus Database and PUBMED in March 2020, and focused on intervention studies with whole polyphenol-rich diets, establishing several exclusion criteria. In studies fulfilling the requirements, information on the design of the polyphenol-rich diet and associated polyphenol intake was extracted and compared. A total of 5 studies were selected. Among them, substantial differences were found in the design of the polyphenol-rich diets, regarding specific instructions and concerning the foods provided. Similarly, although a median daily polyphenol intake of 2,564 mg/day (17,945 mg/week) was obtained from the studies, which corresponds to a nutritional dose, intake values varied widely both for total polyphenols (the difference between studies reached threefold), and for individual polyphenol intake (for hydroxycinnamic acids, a tenfold difference was found between percentile 25 and percentile 75 values). These differences made the comparison of results difficult and may affected the observed health effects. Thus, despite the relevance of studying polyphenol-rich diets as a whole, this systematic review found substantial differences between the studies performed, making direct comparisons difficult., Miss Christina Gazi was the recipient of an Erasmus+grant, a programme from the European Union.

A preliminary approximation to characterizes the banana culture by-products, like banana flowers and banana pseudo-stem, including a comprehensive analysis of the phenolic compounds by HPLC-MS was performed in this study. The results suggest that both materials showed to have a potential for their use as novel food ingredients., This research was partially funded by the EU Environment and Climate Action LIFE Programme (European Union), under the LIFEBAQUA project (code: LIFE15 ENV/ES/000157).

This article belongs to the Special Issue Food Bioactive Compounds as Functional Ingredient., MicroRNAs (miRNAs) represent important tools in medicine and nutrition as new biomarkers, and can act as mediators of nutritional and pharmacological interventions. The aim of the present study was to analyse the effect of grape pomace supplementation on the expression of seven selected miRNAs and their potential relationship with the observed positive effect on glycaemic control, in order to shed light on the mechanism underlying the beneficial effect of this dietary intervention. For this purpose, plasma samples were obtained from 49 subjects with metabolic syndrome. After supplementation with grape pomace (6 weeks), these subjects were categorised as responders (n = 23) or non-responders (n = 26) according to the changes in their fasting insulin rate. MiRNA expression at baseline and at the end of the supplementation was analysed by RT-PCR, and the MiRecords Database was used to identify potential target genes for the studied miRNAs. The increase observed in miR-23a in the whole cohort was present in both subgroups of participants. The increase in miR-181a was significant among non-responders but not responders. The decrease in miR-30c and miR-222 was found in the responders, but not in the non-responders. No changes were observed in miR-10a, miR-151a, miR-181a, and miR-let-7a expressions. After analysing these results, a potential involvement of the reduced expression of miR-30c and miR-222, two microRNAs associated with insulin resistance and diabetes, in the improvement of glycaemic control produced by grape pomace administration, can be proposed. Further research is needed to confirm the involvement of glycolytic enzymes, PI3K, AMPK, and IRS-1 in the effect of grape pomace, as suggested by the changes induced in microRNAs., This research was funded by the Spanish Ministry of Economy and Competitiveness (MINECO-FEDER), grant number AGL2014-55102-JIN and AGL2017-83599-R; University of the Basque Country, grant number GIU18-173) and Carlos III Research Institute (CIBERobn).

[Scope]: Dietary polyphenols have shown promising effects in mechanistic and preclinical studies on the regulation of cardiometabolic alterations. Nevertheless, clinical trials have provided contradictory results, with high inter-individual variability. This study explores the role of gut microbiota and microRNAs (miRNAs) as factors contributing to the inter-individual variability in polyphenol response., [Methods and Results]: 49 subjects with at least two factors of metabolic syndrome are divided between responders (n = 23) or non-responders (n = 26), depending on the variation rate in fasting insulin after grape pomace supplementation (6 weeks). The populations of selected fecal bacteria are estimated from fecal deoxyribonucleic acid (DNA) by quantitative real-time polymerase chain reaction (qPCR), while the microbial-derived short-chain fatty acids (SCFAs) are measured in fecal samples by gas chromatography. MicroRNAs are analyzed on a representative sample, followed by targeted miRNA analysis. Responder subjects show significantly lower (p < 0.05) Prevotella and Firmicutes levels, and increased (p < 0.05) miR-222 levels., [Conclusion]: After evaluating the selected substrates for Prevotella and target genes of miR-222, these variations suggest that responders are those subjects exhibiting impaired glycaemic control. This study shows that fecal microbiota and miRNA expression may be related to inter-individual variability in clinical trials with polyphenols., This study was funded by the Spanish Ministry of Economy and Competitiveness (MINNECO-FEDER, grants AGL2014-55102-JIN and AGL2017-83599-R, and graduate fellowship to M.H.: BES2014-068592) University of the Basque Country, grant: GIU18-173 and Carlos III Research Institute (CIBERobn).

Instant controlled pressure drop (DIC) has been used as a pre-treatment to increase extractable polyphenols (EPP), mainly attributed to matrix structure expansion. This work aimed to evaluate the effect of DIC on non-extractable polyphenols (NEPP), EPP, and dietary fiber on grape pomace. At 0.2 MPa–60 s was observe an increase of total EPP and total anthocyanins. Despite the increment of EPP, was observe the lowest anthocyanins and non-extractable proanthocyanidins content at 0.4 MPa–120 s. This increase was due to a partial transformation of anthocyanins into phenolic acids and the depolymerization of proanthocyanidins. Also was observe partial solubilization of insoluble dietary fiber. Morphologically, the size of the pores generated by DIC was more significant at higher pressures. Thus, DIC modified the morphology and profile of the polyphenols of grape pomace, producing phenolic compounds of simpler structure and improving their antioxidant capacities.

This article belongs to the Special Issue The Health Benefits of the Bioactive Compounds in Foods., Polyphenols are dietary bioactive compounds able to induce modifications in the gut microbiota profile, although more clinical studies are needed. With this aim, a randomized cross-over clinical trial was conducted, where 49 subjects at cardiometabolic risk (exhibiting at least two metabolic syndrome factors) were supplemented with a daily dose of 8 g of grape pomace (GP) for 6 weeks, with an equivalent control (CTL) period. The levels of total bacteria and Bacteroidetes, Firmicutes, Lactobacilliales, Bacteroides and Prevotella were estimated in fecal DNA by quantitative real-time PCR (qPCR), while fecal short-chain fatty acids (SCFAs) were assessed by gas chromatography. Several cardiometabolic markers were evaluated in blood samples. GP reduced insulin levels only in half of the participants (responders). GP supplementation did not cause significant modifications in the microbiota profile of the whole group, except for a tendency (p = 0.059) towards a decrease in the proportion of Lactobacilliales, while it increased the proportion of Bacteroides in non-responder subjects. The reduction of insulin levels in subjects at cardiometabolic risk upon GP supplementation appears not to be induced by changes in the major subgroups of gut microbiota. Further studies at the species level may help to elucidate the possible role of microbiota in GP-induced insulinemic status., Funding provided by the Spanish Ministry of Science and Innovation (MINECO-FEDER grant AGL2014-55102-JIN and MINECO grant AGL2017-83599-R).

Due to the health benefits associated with proanthocyanidins (PAs), it is useful to identify dietary PA biomarkers that can be determined by simple methods. Since increased levels of circulating PA metabolites are associated with increased fecal PA content, this study explores the spectrophotometric measurement of fecal PA content and its use as a biomarker of PA intake. To this end, fecal PA content was measured using an adaptation of Porter’s spectrophotometric method in samples from a preclinical study and an observational study. In the former, excretion of 250–400 mg PA polymer equivalents/100 g feces was observed during supplementation and the day after, together with a significant association (p < 0.05) between PA intake and the excretion of both intact PAs and some PA metabolites, i.e., (+)-catechin, (−)-epicatechin and syringic acid. No relationship between intake and excretion was found in the observational study, either for the entire group (mean excretion of 240 ± 226 mg PA polymer equivalents/100 g feces) or after stratification into tertiles of consumption. In conclusion, the spectrophotometric determination of total PA content in feces proved to be a valid compliance marker in a preclinical study, but it was not associated with PA intake in free-living subjects. The potential of total PA excretion in observational studies, determined in fecal samples collected the day before dietary recall or in several fecal samples from the same subject, remains to be elucidated, as does a complete validation of the method proposed here., This study was funded...B-I00)" by this one: "This study was funded by grants PI16/01991 (Instituto de Salud Carlos III co-funded by the European Regional Development Fund/European Social Fund) and RTI2018-095059-B-I00 (Spanish Ministry of Science and Innovation/Spanish Research Agency, co-funded by the European Regional Development Fund).

[Purpose]: The aim of this study was to determine whether grape polyphenols have a “second-meal effect”, modulating glucose and lipid elevations in the postprandial period after two successive meals in subjects with obesity., [Methods]: A randomized, double-blind, placebo-controlled, acute clinical trial was conducted. Twenty-five obese subjects (BMI = ≥ 30 and, [Results]: Postprandial increases were observed as expected in, for example, glucose and triglycerides after breakfast and lunch. The grape powder supplementation did not cause any significant modification compared to placebo, in these parameters; nor did it significantly modify plasma antioxidant capacity in the 6 h postprandial period., [Discussion]: Single grape powder supplementation did not modify postprandial responses in obese subjects, probably because the polyphenol dose was insufficient to induce such an effect. The result of a combination of grape with other polyphenol-rich products or chronic supplementation with grape powder on postprandial responses remains to be elucidated., [Trial registration number]: www.clinicaltrials.gov, NCT03741218., This study was funded by the California Table Grape Commission (Health Research Grants 2018). E.G.-D. was a recipient of a JAE-Intro fellowship from CSIC. E.G.-M. was the recipient of a Development of Industrial Doctorate project from the Community of Madrid (IND2018/BIO-9554) and M.M.-S. was the recipient of a contract from the European Youth Employment Initiative (Ref: CAMPD17_ICTAN_003). Miss Anastasia Palatzidi (recipient of an Erasmus+ fellowship), Miss Andrea Almagro-Soria and Mr. Enrique Báez-García (recipient of a Beca Mixta CONACYT, ref. 701313). This study was funded by the California Table Grape Commission (Health Research Grants 2018). E.G.-M. was the recipient of a Development of Industrial Doctorate project from the Community of Madrid (IND2018/BIO-9554) and M. Martínez-Suárez was the recipient of a contract from the European Youth Employment Initiative (Ref: CAMPD17_ICTAN_003).

Solid evidence has emerged supporting the role of polyphenols and fibers as gut microbiota modulators. These studies have been limited to the data available in food composition databases, which did not include the food content of non-extractable polyphenols (NEPP). The main objective of this work is to quantify the intake of the different types of dietary polyphenols including NEPP and to evaluate their impact on the composition and activity of the intestinal microbiota.Cross-sectional descriptive study conducted on a sample of 147 adults with no declared pathologies. Dietary intake has been registered by a semi-quantitative Food Frequency Questionnaire (FFQ) and transformed into extractable (EPP) and NEPP, and dietary fibers based on available databases. Major phylogenetic types of the intestinal microbiota were determined by qPCR and fecal SCFA quantification was performed by gas chromatography.NEPP account for two-thirds of the total polyphenols intake. A combined analysis by stepwise regression model including all dietary fiber and (poly)phenols has identified hydrolysable (poly)phenol (HPP) intake, as the best predictor of Bacteroides-Prevotella-Porphyromonas group and Bifidobacterium levels in feces. Also, HPPs were positively associated with butyric acid, while insoluble fiber was identified as a predictor of propionic acid in feces.The intake of macromolecular (poly)phenols could contribute to modulate the gut microbiota by increasing the levels of certain intestinal microorganisms with proven health benefits.

The recent interest in diversification in food consumption and the current salinization and desertification processes of farmland have placed the focus on halophytic plants as new food, making necessary the characterization of their biochemical composition and the identification of possible bioactive compounds. In this work, three edible halophytic plants were characterized: common iceplant (Mesembryanthemum crystallinum), sea fennel (Crithmum maritimum), and seaside arrowgrass (Triglochin maritima). The plants studied were a good source of minerals. Sea fennel showed high contents of dietary fibre and calcium (8.5 ppm, wet weight), common iceplant had a high potassium content (6500 ppm, wet weight), while seaside arrowgrass presented high levels of iron (62 ppm, wet weight). The glucose content of the three species was below 30 mg/g per dried weight. The Sb, Pb, Cr, As, Cd, and Hg content was negligible. Polyunsaturated fatty acids, mainly α-linolenic and linoleic acid, prevailed in the three species analyzed. Hydroxycinnamic and hydroxybenzoic acids predominated in common iceplant and sea fennel. Glycosylated flavones, especially isoorientin, prevailed in seaside arrowgrass. These plants present a relevant nutritional profile for which their use as foods or ingredients should be promoted., This work was supported by the Spanish Ministry of Economy and Competitiveness project under Grant (number AGL2014-52825-R) and cofounded with European Union ERDF funds (European Regional Development Fund). Author Sánchez-Faure was also funded by the Spanish Ministry of Economy and Competitiveness (fellowship number BES-2015-074420).

Phlorotannins are phenolic characteristic compounds of brown seaweeds that are only constituted by phloroglucinol (1,3,5-trihydroxybenzene). They are chain- and net-like structures of diverse molecular weights and have been widely identified in Ecklonia, Eisenia, and Ishige species. Since the time they were discovered in the ‘70 s, phlorotannins have been suggested as a main factor responsible for the antimicrobial activities attributed to algae extracts. Currently, cumulative in vitro and in vivo research evidence the diverse bioactivities of phlorotannin extracts -such as antidiabetic, anticancer, and antibacterial- pointing out their potential pharmacological and food applications. However, metabolomic studies and clinical trials are scarce, and thus many phlorotannins health-beneficial effects in humans are not yet confirmed. This article reviews recent studies assessing the antidiabetic and anticancer activities of phlorotannins. Particularly, their potential to prevent and control the progression of these non-communicable diseases is discussed, considering in vitro and animal studies, as well as clinical interventions. In contrast to other approaches, we only included investigations with isolated phlorotannins or phlorotannin-rich extracts. Thus, phlorotannin extraction, purification and characterization procedures are briefly addressed. Overall, although considerable research showing the antidiabetic and anticancer potential of phlorotannins is now available, further clinical trials are still necessary to conclusively demonstrate the efficacy of these compounds as adjuvants for diabetes and cancer prevention or treatment., The authors appreciate the financial support from: FONDECYT Regular project number 1180571; CONICYT Doctoral scholarship (CONICYT-PFCHA/Doctorado Nacional/2017-21170535); and Programa de Ciencia y Tecnología para el Desarrollo (CYTED), Red Iberoamericana de Alimentos Autóctonos Subutilizados (ALSUB-CYTED, 118RT0543).

[Purpose]: Solid evidence has emerged supporting the role of polyphenols and fibers as gut microbiota modulators. These studies have been limited to the data available in food composition databases, which did not include the food content of non-extractable polyphenols (NEPP). The main objective of this work is to quantify the intake of the different types of dietary polyphenols including NEPP and to evaluate their impact on the composition and activity of the intestinal microbiota., [Methods]: Cross-sectional descriptive study conducted on a sample of 147 adults with no declared pathologies. Dietary intake has been registered by a semi-quantitative Food Frequency Questionnaire (FFQ) and transformed into extractable (EPP) and NEPP, and dietary fibers based on available databases. Major phylogenetic types of the intestinal microbiota were determined by qPCR and fecal SCFA quantification was performed by gas chromatography., [Results]: NEPP account for two-thirds of the total polyphenols intake. A combined analysis by stepwise regression model including all dietary fiber and (poly)phenols has identified hydrolysable (poly)phenol (HPP) intake, as the best predictor of Bacteroides–Prevotella–Porphyromonas group and Bifidobacterium levels in feces. Also, HPPs were positively associated with butyric acid, while insoluble fiber was identified as a predictor of propionic acid in feces., [Conclusion]: The intake of macromolecular (poly)phenols could contribute to modulate the gut microbiota by increasing the levels of certain intestinal microorganisms with proven health benefits., This research was funded by Plan Estatal de I + D + I through projects AGL2017-83653-R (AEI/FEDER, UE) and RTI2018-098288-B-I00 (MCIU/AEI/FEDER, UE) and by contracts with Biopolis SL (Valencia, Spain), CAUCE Foundation (Oviedo, Spain) and Alimerka Foundation (Llanera, Spain). NS. is granted by a postdoctoral contract awarded by the Fundación para la Investigación Biosanitaria de Asturias (FINBA).

[Background and objectives]: Beans (Phaseolus vulgaris L.) are widely consumed, but the bioaccessibility of their phenolic compounds (PCs) may be affected by different factors. Within this framework, an in vitro gastrointestinal digestion of two bean varieties: “Azufrado” and “Negro Jamapa,” was performed and the bioaccessibility and in vitro release kinetics of PC was evaluated. Mashed beans were prepared by two common culinary procedures in Mexico: pressure cooking followed by mashing, and pressure cooking and mashing, followed by frying., [Findings]: The bioaccessibility of PC was about 50% in the cooked samples and 30% in cooked‐fried samples. The cooking condition did not modify the PC release kinetics during the first 60 min in any of the bean preparations. Three PCs were identified by HPLC‐DAD‐MS: kaempferol‐3‐O‐glucoside, quercetin‐3‐O‐glucoside, and chlorogenic acid, which was the main PC released from all samples., [Conclusions]: Simulated gastrointestinal digestion revealed processing‐related differences in the PC bioaccessibility in these two bean varieties, which should be further considered and evaluated in nutritional studies., [Significance and novelty]: The study is in line with current approaches for assessing PC bioaccessibility during the gastrointestinal digestion, providing knowledge on the types and quantities of PC released from the food matrix of beans as eaten., Cárdenas Castro and AP acknowledge CONACYT for the financial support, Mexico, and for a grant (Registration Number: 662703).

Current research on dietary polyphenols is mostly focused on the so‐called extractable polyphenols (EPP), those released from the food matrix by several solvent combinations. However, this ignores a relevant fraction of polyphenols remaining in the residues of those extractions, the nonextractable polyphenols (NEPP) or macromolecular antioxidants. These are either polymeric structures (mostly high molecular weight proanthocyanidins) or small phenolic structures closely linked to macromolecules such as proteins or dietary fiber. This partial approach to these dietary bioactive constituents may hamper our understanding of the relevance of dietary polyphenols. This chapter provides an overview of the current knowledge of NEPP. In particular, the following aspects are explored: strategies for the release and analysis of NEPP; contribution of these compounds to total polyphenol content in foods and therefore to total polyphenol intake in different populations; evidence of their metabolic fate as well as specific features compared to those of EPP; mechanism of biological action (antioxidant effects, modulation of colonic microbiota, biological activities of NEPP‐derived metabolites, synergy with dietary fiber); evidence of biological activity (considering both local effects in the digestive tract and systemic effects through their metabolites). Finally, the chapter provides some perspectives on the main aspects that should be considered in order to advance scientific knowledge on NEPP in the future.

Despite increasing interest in the relevance of non-extractable polyphenols (NEPP) or macromolecular antioxidants as food bioactive compounds, most studies on their presence in foods focus mainly on the edible part of specific fruits, but their potential presence in fruit peels is usually ignored. The aim of this study was to evaluate NEPP content in the peels from ten common fruits. The results showed that NEPP made up more than half of the total polyphenol contents in half of the studied samples. HPLC analysis showed that NEPP were constituted by phenolic acids, flavanols and flavonols. Also, it was found that peels accounted for >40% of total NEPP in the fruit in four of the samples analysed. These results should encourage both the use of fruit peels in the fruit industry as ingredients and the consumption of whole fruits given the significant presence of NEPP in fruit peels.

Psidium guajava L. is a source of phenolic compounds (PC). The aim of this study was to evaluate the bioaccessibility and kinetics of the release of PC from guava fruit by using an in vitro digestion model. Similar percentages of bioaccessibility were observed in whole guava (WG) (64.79%) and seedless guava (SG) (67.69%), and the release rates of PC were 10.55 and 8.70 mg/min, respectively. Gallocatechin was the major compound identified in the bioaccessible fraction, and guavinoside B was the major component in the non-bioaccessible fraction. Procyanidin B and guajaverin were detected for the first time in WG and SG. These data show that PC are significantly released from the food-matrix in both samples, allowing them to be absorbed in the small intestine. Higher proportion of certain PC (guavinoside A or guavinoside B) was observed in the non-bioaccessible fraction of WG, which could be related with different biological effects., SGSA acknowledge the financial support from Tecnológico Nacional de México the project 5614.15-P. FJBB thanks the financial support from Consejo Nacional de Ciencia y Tecnología, México (CONACyT) for the scholarship 378371 granted.

Grape and pomegranate are rich sources of phenolic compounds, and their derived products could be used as ingredients for the development of functional foods and dietary supplements. However, the profile of nonextractable or macromolecular phenolic compounds in these samples has not been evaluated. Here, we show a comprehensive characterization of extractable and nonextractable phenolic compounds of a grape/pomegranate pomace dietary supplement using high-performance liquid chromatography-electrospray ionization-quadrupole time-of-flight (HPLC-ESI-QTOF) and matrix-assisted laser desorption/ionization (MALDI)-TOF techniques. The main extractable phenolic compounds were several anthocyanins (principally malvidin 3-O-glucoside) as well as gallotannins and gallagyl derivatives; some phenolic compounds were reported in grape or pomegranate for the first time. Additionally, there was a high proportion of nonextractable phenolic compounds, including vanillic acid, and dihydroxybenzoic acid. Unidentified polymeric structures were detected by MALDI-TOF MS analysis. This study shows that mixed grape and pomegranate pomaces are a source of different classes of phenolic compounds including a high proportion of nonextractable phenolic compounds., Spanish Ministry of Science and Innovation (Grant No. AGL2014−55102-JIN). The authors are grateful for the CONACyT for the international scholarship granted to I.F.P.-R.

Grape polyphenols have shown a promising role in the modulation of metabolic syndrome (MetS), mostly in animal models. However, clinical studies are scarce and they usually only consider a fraction of polyphenols, ignoring the non-extractable polyphenols (high molecular weight compounds or associated with macromolecules such as dietary fibre). This study aimed at evaluating the effect of grape pomace, rich in both extractable and non-extractable polyphenols, on markers of MetS. Fifty subjects (22 women) aged 20–65 with at least two MetS factors were randomly assigned to the product (daily dose of 8 g of dried grape pomace) or to the control group in a 6 week crossover design with a 4 week wash-out. Samples were collected at the beginning and at the end of both periods; half of the participants were subjected to an oral glucose tolerance test at the beginning and the end of the supplementation period. Grape pomace supplementation significantly improved fasting insulinaemia (p < 0.01), without affecting other cardiometabolic risk parameters. A tendency towards an improvement in postprandial insulinaemia was observed, particularly in those subjects with higher fasting insulin levels. Therefore, supplementation with grape pomace may be a strategy for improving insulin sensitivity in subjects at high cardiometabolic risk., This study was funded by the Spanish Ministry of Economy and Competitiveness (MINNECO-FEDER, grant: AGL2014-55102-JIN). A. G.-N. was funded by the Youth Employment Initiative (YEI) from the European Social Fund (ESF).

The nutritional characteristics of chocolate products may be associated with very different, and even opposite, health effects. In the present study, we collected information on chocolate products on the Polish market to assess: (i) nutritional characteristics; (ii) ingredient order; (iii) the presence of nutritional claims on the label; (iv) packaging characteristics; and (v) any association between price and cocoa contents. A total of 220 bars of solid chocolate (90 % with at least 5 ingredients) and 147 chocolate bar sweets (90 % with at least 6 ingredients) were evaluated. Mean values for calorie, total lipid, saturated fatty acid, carbohydrate, protein, sugar and salt contents were significantly different between the bars of solid chocolate and chocolate bar sweets, although the values were widely dispersed in both categories. Some aspects of food labelling may result in confusion for the consumer (such as “vegan” claims). A weak (r = 0.459), although significant (p < 0.05), association was found between cocoa content and price (€/kg) in bars of solid chocolate, although no association was found in chocolate bar sweets. Thus, depending on chocolate product selection, nutritional benefits may be rather different: an aspect not evident to most consumers based on current chocolate bar labelling., This study was funded by the Spanish Ministry of Science and Innovation/Spanish Research Agency (RTI2018-095059-B-I00), co-funded by the European Regional Development Fund. E. H. Y. was granted a Talent Fellowship from the EIT Food RIS Fellowships project, 2020.

The aim of this study was to evaluate technological and antioxidant properties, including in vitro bioaccessibility of polyphenols, conferred on raw anchovy mince by the addition of polyphenol-rich grape pomace dietary fibre at different concentrations. For this purpose, headed and gutted anchovy was heat-flayed, deboned and mixed with 0%, 2%, 3%, 4% grape pomace dietary fibre. A significant increase (P < 0.05) in the concentration of polyphenols and associated antioxidant capacity was detected when grape pomace dietary fibre was incorporated in a proportion of at least 2% of the final mixture. In vitro digestion showed that the higher the grape pomace dietary fibre content, the higher was the proportion of polyphenols reaching the large intestine. Additionally, it was observed that the ABTS (2,2′-azino-bis(3-ethylbenzo-thiazoline-6-sulfonic acid) assay seems to be more suitable for evaluating antioxidant capacity in this kind of samples than FRAP (Ferric Reducing Antioxidant Power) assay. Technological properties such as mechanical and water holding, as well as sensory scores, indicated excellent qualities and acceptability of all samples. Hence, given the good acceptance of these samples, it should be feasible to make fish products based on mince anchovy as a means of increasing dietary intake of polyphenols with antioxidant capacity, especially considering the high concentration of polyphenols bioaccessible in the large intestine., This study was funded by FINCyT, Peru (No. 160-2013). J. P.-J. acknowledges the Spanish Ministry of Science and Innovation for a Juan de la Cierva postdoctoral contract.

Studies of the bioavailability of proanthocyanidins usually consider them independently of other dietary constituents, while there is a tendency in the field of functional foods towards the combination of different bioactive compounds in a single product. This study examined the long-term effects of ω-3 polyunsaturated fatty acids of marine origin on the metabolic fate of grape proanthocyanidins. For this, female adult Wistar-Kyoto rats were fed (18 weeks) with a standard diet supplemented or not with eicosapentaenoic acid/docosahexaenoic acid (1:1, 16.6 g/kg feed), proanthocyanidin-rich grape seed extract (0.8 g/kg feed) or both. A total of 39 microbial-derived metabolites and 16 conjugated metabolites were detected by HPLC-MS/MS either in urine or in the aqueous fraction of feces. An unexpected significant increase in many proanthocyanidin metabolites in urine and feces was observed in the group supplemented with ω-3 polyunsaturated fatty acids group as compared to the animals fed a standard diet, which contains a small amount of polyphenols. However, proanthocyanidin metabolites in rats given ω-3 polyunsaturated fatty acids and grape seed extract did not significantly differ from those in the group supplemented only with grape seed extract. It was concluded that ω-3 polyunsaturated fatty acids collaborate in the metabolism of polyphenols when present at low doses in the feed matrix, while the capacity of ω-3 polyunsaturated fatty acids to induce microbiota transformations when proanthocyanidins are present at high doses is not relevant compared to that of polyphenols themselves.

Seaweeds are rich in different bioactive compounds with potential uses in drugs, cosmetics and the food industry. The objective of this study was to analyze macromolecular antioxidants or nonextractable polyphenols, in several edible seaweed species collected in Chile (Gracilaria chilensis, Callophyllis concepcionensis, Macrocystis pyrifera, Scytosyphon lomentaria, Ulva sp. and Enteromorpha compressa), including their 1st HPLC characterization. Macromolecular antioxidants are commonly ignored in studies of bioactive compounds. They are associated with insoluble dietary fiber and exhibit significant biological activity, with specific features that are different from those of both dietary fiber and extractable polyphenols. We also evaluated extractable polyphenols and dietary fiber, given their relationship with macromolecular antioxidants. Our results show that macromolecular antioxidants are a major polyphenol fraction (averaging 42% to total polyphenol content), with hydroxycinnamic acids, hydroxybenzoic acids and flavonols being the main constituents. This fraction also showed remarkable antioxidant capacity, as determined by 2 complementary assays. The dietary fiber content was over 50% of dry weight, with some samples exhibiting the target proportionality between soluble and insoluble dietary fiber for adequate nutrition. Overall, our data show that seaweed could be an important source of commonly ignored macromolecular antioxidants.

Grape byproducts are rich sources of polyphenols with powerful antioxidant and health-promoting effects. The impact of supplementing chicken diets with grape byproducts on plasma and thigh meat concentrations of phenolic metabolites was evaluated by analyzing samples by high-performance liquid chromatography quadrupole time of flight mass spectrometry. Chickens were fed three experimental diets: Control diet, Control+8% grape pomace, and Control+0.1% grape seed extract. In plasma, 32 phenolic metabolites were identified, some of which were conjugated catechin/epicatechin metabolites exclusively identified in chickens fed diets enriched in grape byproducts. Also, these chickens showed significantly higher plasmatic concentrations of 21 phenolic metabolites. In thigh meat, 14 phenolic metabolites were identified, but no differences were found between diets. Higher plasmatic tocopherol was found when supplementing diets with grape byproducts, while no changes were observed in meat. Thus, supplementing chicken diets with grape byproducts leads to a significant increase in the circulation of phenolic metabolites and tocopherol., Authors thank the CAM for financially supporting Project MEDGAN-CM S2013/ABI2913 and MINECO and CSIC for financially supporting Project Intramural 2014470E07.

The aim of the present study was to evaluate extractable (EPP), non-extractable polyphenols (NEPP) and organic acid in Roselle by-product, as well as its potential health beneficial effects in obesity control and their complication in rats fed with high caloric diet. Roselle by-product showed a higher content of dietary fiber and NEPP than Roselle calix, which was was a better source of EPP (P .05). The UPLC-QTOF MS

A controlled acute, cross-over clinical study (NCT02710461) was performed in order to evaluate the effects on glucose metabolism of a grape/pomegranate pomace dietary supplement in subjects with abdominal obesity (aged 40-60, n = 20). A standard 75 g oral glucose tolerance test (OGTT) was administered alone, together with or 10 h after the consumption of 10 g of the dietary supplement, rich in both extractable (0.4 g) and non-extractable (1.4 g) polyphenols. The dietary supplement did not ameliorate glucose or insulin at any sampling time. No improvement in antioxidant capacity was observed in plasma or urine, concordant with no increased urine polyphenol excretion. A tendency towards improved insulin sensitivity was observed when the product was consumed 10 h before glucose solution. These results suggest that a single realistic dose of grape/pomegranate pomace is not able to clearly improve glucose metabolism; chronic intake remains to be evaluated., This work was supported by the Spanish Ministry of Science and Innovation (MINECO-FEDER) under grant AGL2014-55102-JIN and by Consejo Nacional de Ciencia y Tecnologia (CONACyT) (international scholarship, I.F.P.-R.)

The aim of the present study was to evaluate extractable (EPP), non-extractable polyphenols (NEPP) and organic acid in Roselle by-product, as well as its potential health beneficial effects in obesity control and their complication in rats fed with high caloric diet. Roselle by-product showed a higher content of dietary fiber and NEPP than Roselle calix, which was was a better source of EPP (P