Fortification of blackcurrant juice with crowberry: Impact on polyphenol composition, urinary phenolic metabolites, and postprandial glycemic response in healthy subjects

Incorporation of microencapsulated polyphenols from jabuticaba peel (Plinia spp.) into a dairy drink: stability, in vitro bioaccessibility, and glycemic response

This work incorporated bioactives extracted from jabuticaba peel in the form of concentrated extract (JBE) and microencapsulated powders with maltodextrin (MDP) and gum arabic (GAP) in a dairy drink, evaluating its stability, in vitro bioaccessibility, and glycemic response. We evaluated the pH, acidity, colorimetry, total phenolics and anthocyanins, antioxidant capacity, degradation kinetics and half-life of anthocyanins, bioaccessibility, and postprandial glycemic physicochemical characteristics response in healthy individuals. The drinks incorporated with polyphenols (JBE, GAP, and MDP) and the control dairy drink (CDD) maintained stable pH and acidity over 28 days. In color, the parameter a*, the most relevant to the study, was reduced for all formulations due to degradation of anthocyanins. Phenolic and antioxidant content remained constant. In bioaccessibility, we found that after the gastrointestinal simulation, there was a decrease in phenolics and anthocyanins in all formulations. In the glycemic response, we observed that the smallest incremental areas of glucose were obtained for GAP and JBE compared to CDD, demonstrating that polyphenols reduced glucose absorption. Then, the bioactives from jabuticaba peel, incorporated into a dairy drink, showed good storage stability and improved the product's functional aspects.

On the Valorization of Arbutus unedo L. Pomace: Polyphenol Extraction and Development of Novel Functional Cookies

The fruits of Arbutus unedo L. have a crimson colour and are enriched with remarkable concentrations of bioactive compounds such as anthocyanins and polyphenols. These fruits are commonly used in the production of a Portuguese Protected Geographical Indication distillate called "Aguardente de Medronho". During this process, a solid pomace is generated and presently discarded without valuable applications. In this work, two strategies have been developed for the valorisation of A. unedo pomace. The first approach considers the extraction of polyphenols from this by-product through the optimization of an ultrasound-assisted method using a Box-Behnken design coupled with response surface methodology. The results indicate that the temperature and the percentage of methanol, along with their interaction, significantly influence the total concentration of polyphenols and the antioxidant activity of the extracts obtained. The optimal conditions identified consider the extraction of 0.5 g of sample with 20 mL of a solvent containing 74% MeOH (aq), at a pH of 4.8, maintained at 70 °C for 15 min. On the other hand, the second valorisation strategy considered the use of A. unedo pomace in the development of functional cookies. The incorporation of 15-20% pomace in the cookie formulation was well-received by consumers. This incorporation results in an intake of ca. 6.55 mg of polyphenols per gram of cookie consumed, accompanied by an antioxidant activity of 4.54 mg Trolox equivalents per gram of cookie consumed. Overall, these results encourage the employment of A. unedo pomace either as a reliable source of extracts enriched in polyphenols or as a nutraceutical active ingredient in functional cookies, thereby positively impacting human health.

Biomarkers of Berry Intake: Systematic Review Update

Berries are rich in (poly)phenols, and these compounds may be beneficial to human health. Estimating berry consumption through self-reported questionnaires has been challenging due to compliance issues and a lack of precision. Estimation via food-derived biomarkers in biofluids was proposed as a complementary alternative. We aimed to review and update the existing evidence on biomarkers of intake for six different types of berries. A systematic literature search was performed to update a previous systematic review on PubMed, Web of Science, and Scopus from January 2020 until December 2022. Out of 42 papers, only 18 studies were eligible. A multimetabolite panel is suggested for blueberry and cranberry intake. Proposed biomarkers for blueberries include hippuric acid and malvidin glycosides. For cranberries, suggested biomarkers are glycosides of peonidin and cyanidin together with sulfate and glucuronide conjugates of phenyl-γ-valerolactone derivatives. No new metabolite candidates have been found for raspberries, strawberries, blackcurrants, and blackberries. Further studies are encouraged to validate these multimetabolite panels for improving the estimation of berry consumption.

Effect of Blackcurrant Consumption on the Genitourinary System: A Literature Review

Both in vivo and in vitro studies have shown that functional plant-based food such as fruits, vegetables, and berries can enhance health, have preventive effects, and reduce the risk of several chronic diseases. This review discusses blackcurrant fruit usage in humans and experimental animals and its effect on the genitourinary system (GUS). This comprehensive review demonstrates that blackcurrants and their bioactive compounds possess medicinal and therapeutic properties related to the GUS. Emphasis in the literature has been placed on the bioavailability of the active blackcurrant components. Nonetheless, future clinical trials are needed to investigate and improve the bioavailability of blackcurrant phenolic compounds, such as anthocyanins, and to expand the evidence that active blackcurrant compounds can treat various genitourinary diseases.

Innovative Processing Technologies to Develop a New Segment of Functional Citrus-Based Beverages: Current and Future Trends

The food industries are interested in developing functional products due to their popularity within nutritional and healthy circles. Functional fruit-based beverages represent one of the fast-growing markets due to the high concentrations of bioactive compounds (BCs), which can be health promoters. Hence, functional beverages based on citrus fruits are a potential way to take advantage of their nutritional and bioactive properties that could attract the interest of consumers. In order to ensure microbial and quality stability, the beverages are subjected to preservation treatment; however, the application of high temperatures leads to the loss of thermolabile BCs. Nowadays, innovative processing technologies (IPT) such as pulsed electric field (PEF), high-pressure processing (HPP), ultrasound processing (US), ohmic heating (OH), and microwave (MW) are a promising alternative due to their efficiency and low impact on juice BCs. The available literature concerning the effects of these technologies in functional fruit-based beverages is scarce; thus, this review gathers the most relevant information about the main positive and negative aspects of the IPT in functional properties, safety, and consumer acceptance of functional citrus-based beverages, as well as the use of citrus by-products to promote the circular economy in citrus processing.

Riceberry rice beverage decreases postprandial glycemic response, inflammatory markers and antioxidant status induced by a high-carbohydrate and moderate-fat meal in overweight and obese men

Recent clinical studies support the beneficial role of riceberry rice and its food products in controlling the glycemic response in healthy subjects. The aim of the current work was to determine the effects of riceberry rice beverage (RRB) on postprandial glycemic, insulin and triglyceride responses, inflammatory biomarkers, and antioxidant status as well as appetite sensation following a high-carbohydrate and moderate-fat (HCMF) meal in overweight/obese subjects. Thirteen participants, overweight and obese men (age = 24.46 ± 0.90 years and BMI = 25.92 ± 0.69 kg m^-2), completed a randomized, crossover intervention study. They consumed an HCMF meal with or without RRB (2 g of riceberry rice extract powder/400 ml). Blood samples and appetite sensation were measured at the fasting state and up to 6 h after meal consumption. The ingestion of the HCMF meal accompanied by RRB had a lower incremental area under the curve (iAUC) for postprandial plasma glucose, insulin, malondialdehyde (MDA) and serum triglyceride concentrations when compared to the control. A significant increase in the ferric reducing ability of plasma (FRAP), Trolox equivalent antioxidant capacity (TEAC), and thiol level, all measures of antioxidant capacity, was also observed in the participants who consumed the HCMF meal accompanied by RRB. The postprandial level of pro-inflammatory cytokines (IL-1β, IL-6 and TNF-α) significantly increased at 3 h and 6 h after the HCMF meal intake when compared to the fasting state. Interestingly, these values were significantly decreased upon consumption of RRB. However, there were no statistically significant differences in the rating scores of hunger, fullness, desire to eat, and satiety among the tested meals. In conclusion, RRB intake prevented HCMF meal-induced postprandial glycemic, lipemic, and pro-inflammatory responses and improved plasma antioxidant capacity in overweight and obese participants.

Potential of Beetroot and Blackcurrant Compounds to Improve Metabolic Syndrome Risk Factors

Metabolic syndrome (MetS) is a group of metabolic abnormalities, which together lead to increased risk of coronary heart disease (CHD) and type 2 diabetes mellitus (T2DM), as well as reduced quality of life. Dietary nitrate, betalains and anthocyanins may improve risk factors for MetS and reduce the risk of development of CHD and T2DM. Beetroot is a rich source of dietary nitrate, and anthocyanins are present in high concentrations in blackcurrants. This narrative review considers the efficacy of beetroot and blackcurrant compounds as potential agents to improve MetS risk factors, which could lead to decreased risk of CHD and T2DM. Further research is needed to establish the mechanisms through which these outcomes may occur, and chronic supplementation studies in humans may corroborate promising findings from animal models and acute human trials.

Beverages Based on Second Quality Citrus Fruits and Maqui Berry, a Source of Bioactive (Poly)phenols: Sorting Out Urine Metabolites upon a Longitudinal Study

The intake of sugar-sweetened beverages has been associated with an augmented prevalence of metabolic diseases, namely, obesity, type II diabetes, and metabolic syndrome. On the other hand, nowadays, it is broadly accepted that foods and beverages rich in (poly)phenols could contribute to reducing the incidence of these pathologies. In this sense, the objective of the work was to revalue second quality citrus fruits for the development of new beverages, rich in anthocyanins and flavanones (maqui berry and second qualities citrus-based), and evaluate the influence of alternative sweeteners (sucralose, sucrose, or stevia), regarding the bioaccessibility and bioavailability of these bioactive compounds in the frame of a chronic (longitudinal) intervention. To fulfill this objective, a longitudinal study of the urinary excretion of anthocyanins and flavanones, after 2-months of ingestion of the developed maqui-citrus beverage, by 138 volunteers (n = 46 per beverage) and the analysis of the resulting phenolic metabolites by ultra-high performance liquid chromatography coupled to mass spectrometry (UHPLC-ESI-QqQ-MS/MS) was carried out. As major results, the bioavailable metabolites of caffeic acid (CA), catechol (CAT), 3,4-di-hydroxyphenylacetic acid (DHPAA), eriodictyol (E), homoeriodictyol (HE), hippuric acid (HA), naringenin (N), trans-ferulic acid (TFA), 2,4,6-tri-hydroxybenzaldehyde (THBA), trans-isoferulic acid (TIFA), and vanillic acid (VA) were detected. Accordingly, significantly different bioavailability was dependent on the sweetener used, allowing proposing stevia and, to a lower extent, sucralose, as valuable alternatives to sucrose.

Inhibitory Effect of Antidesma bunius Fruit Extract on Carbohydrate Digestive Enzymes Activity and Protein Glycation In Vitro

Antidesma bunius (L.) spreng (Mamao) is widely distributed in Northeastern Thailand. Antidesma bunius has been reported to contain anthocyanins, which possess antioxidant and antihypertensive actions. However, the antidiabetic and antiglycation activity of Antidesma bunius fruit extract has not yet been reported. In this study, we investigated the inhibitory activity of anthocyanin-enriched fraction of Antidesma bunius fruit extract (ABE) against pancreatic α-amylase, intestinal α-glucosidase (maltase and sucrase), protein glycation, as well as antioxidant activity. A liquid chromatography-tandem mass spectrometry (LC-MS/MS) chromatogram revealed that ABE contained phytochemical compounds such as cyanidin-3-glucoside, delphinidin-3-glucoside, ellagic acid, and myricetin-3-galactoside. ABE inhibited intestinal maltase and sucrase activity with the IC₅₀ values of 0.76 ± 0.02 mg/mL and 1.33 ± 0.03 mg/mL, respectively. Furthermore, ABE (0.25 mg/mL) reduced the formation of fluorescent AGEs and the level of N^ε-carboxymethyllysine (N^ε-CML) in fructose and glucose-induced protein glycation during four weeks of incubation. During the glycation process, the protein carbonyl and β-amyloid cross structure were decreased by ABE (0.25 mg/mL). In addition, ABE exhibited antioxidant activity through DPPH radical scavenging activity and Trolox equivalent antioxidant capacity (TEAC) with the IC₅₀ values 15.84 ± 0.06 µg/mL and 166.1 ± 2.40 µg/mL, respectively. Meanwhile, ferric reducing antioxidant power (FRAP) showed an EC₅₀ value of 182.22 ± 0.64 µg/mL. The findings suggest that ABE may be a promising agent for inhibiting carbohydrate digestive enzyme activity, reducing monosaccharide-induced protein glycation, and antioxidant activity.

Postprandial Effect of Yogurt Enriched with Anthocyanins from Riceberry Rice on Glycemic Response and Antioxidant Capacity in Healthy Adults

The pigment of riceberry rice has been reported to contain anthocyanins which act as a free radical scavenger and inhibitor of carbohydrate digestive enzymes. Since the probiotic yogurt incorporated with the pigment of riceberry rice extract was previously developed, the present study was aimed to investigate the acute effect of riceberry rice yogurt consumption on postprandial glycemic response, antioxidant capacity, and subjective ratings in healthy adults. In a cross-over design, 19 healthy participants were randomized to consume 350 g of yogurt supplemented with 0.25% (w/w) riceberry rice extract or the control yogurt. Postprandial plasma glucose, antioxidant status, and subjective ratings were measured at fasting and intervals (0–3 h) after ingestion of yogurt. The primary outcome was glycemic response; the secondary outcomes were plasma antioxidant capacity. In comparison to the yogurt control, riceberry rice yogurt reduced plasma glucose concentration after 30 min of consumption. The incremental area under the curve (iAUC) was significantly lower after riceberry rice yogurt load than after the control yogurt load. The consumption of riceberry yogurt caused an acute increase in plasma ferric reducing ability of plasma (FRAP), Trolox equivalent antioxidant capacity (TEAC), and oxygen radical absorbance capacity (ORAC) from the baseline values after 60 min of 0.25 ± 0.06 mM FeSO₄, 253.7 ± 35.5 mM Trolox equivalents, and 166.8 ± 28.9 mM Trolox equivalents, respectively. Furthermore, the iAUCs for FRAP, TEAC, ORAC, and protein thiol were higher in riceberry yogurt consumption compared with the control yogurt (1.6-, 1.6-, 2.9-, and 1.9-fold, respectively). A decrease in iAUC for plasma malondialdehyde (MDA) concentration was also observed in the riceberry yogurt group. However, consumption of riceberry rice yogurt and control yogurt showed similar subjective rating scores of hunger, desire to eat, fullness, and satiety. In conclusion, acute consumption of riceberry rice yogurt suppressed postprandial glucose level and improved plasma antioxidant capacity in healthy volunteers.

Food intake biomarkers for berries and grapes

Grapes and berries are two types of widely consumed fruits characterized by a high content in different phytochemicals. However, their accurate dietary assessment is particularly arduous, because of the already wide recognized bias associated with self-reporting methods, combined with the large range of species and cultivars and the fact that these fruits are popularly consumed not only in fresh and frozen forms but also as processed and derived products, including dried and canned fruits, beverages, jams, and jellies. Reporting precise type and/or quantity of grape and berries in FFQ or diaries can obviously be affected by errors. Recently, biomarkers of food intake (BFIs) rose as a promising tool to provide accurate information indicating consumption of certain food items. Protocols for performing systematic reviews in this field, as well as for assessing the validity of candidate BFIs have been developed within the Food Biomarker Alliance (FoodBAll) Project. This paper aims to evaluate the putative BIFs for blueberries, strawberries, raspberries, blackberries, cranberries, blackcurrant, and grapes. Candidate BFIs for grapes were resveratrol metabolites and tartaric acid. The metabolites considered as putative BFI for berries consumption were mostly anthocyanins derivatives together with several metabolites of ellagitannins and some aroma compounds. However, identification of BFIs for single berry types encountered more difficulties. In the absence of highly specific metabolites reported to date, we suggested some multi-metabolite panels that may be further investigated as putative biomarkers for some berry fruits.

Stevia vs. Sucrose: Influence on the Phytochemical Content of a Citrus-Maqui Beverage-A Shelf Life Study

The consumption of sugar-sweetened beverages has been related with the risk of cardiovascular diseases and other pathophysiological situations, such as obesity or diabetes mellitus. Given the increasing awareness on this fact, food industries are developing new products to reduce the amount of added sugar in development of food products development. Accordingly, in the present work, new functional beverages, constituting a dietary source of bioactive phenolics and supplemented with stevia or sucrose, were designed in order to study the influence of the sweetener during processing and shelf-life. This study is of critical for the informed selection of the sweetener based on its effect on the final phytochemical profile of beverages, especially taking into consideration that there are no previous studies on Stevia rebaudiana. Physicochemical features and phytochemical composition, as well as stability of the different beverages concerning these parameters, were evaluated for 90 days during storage under different conditions (refrigeration (4 °C) and room temperature (25 °C) under light or darkness conditions). Physicochemical parameters (pH, titratable acidity, total soluble solids, and color) did not display statistically significant differences between beverages. Storage temperature was the greatest determinant affecting the stability of all the analyzed bioactive compounds (vitamin C, anthocyanins, and flavanones). The main difference between sweeteners was observed in flavanones, which exhibited a higher loss during storage under day light conditions when stevia was added instead of sucrose. In addition, the juices’ colors were rather stable, keeping a reddish coloration and natural appearance throughout the shelf life. Hence, stevia could be considered as an alternative sweetener by the beverage industry.

Quantitative trait loci mapping of polyphenol metabolites in blackcurrant (Ribes nigrum L.)

INTRODUCTION

Commercially, blackcurrants (Ribes nigrum L.) are grown mainly for processing, especially for juice production. They are valued for their high levels of polyphenols, especially anthocyanins, which contribute to their characteristic deep colour, but also as a good source of vitamin C. Recently, evidence has accrued that polyphenols, such as anthocyanins, may have specific human health benefits.

OBJECTIVE

The aims of this study were to investigate the genetic control of polyphenols and other key juice processing traits in blackcurrants.

METHODS

The levels, over 2 years, of vitamin C, citrate, malate, succinate, total organic acids, total anthocyanins and total phenolics together with 46 mainly polyphenol metabolites were measured in a blackcurrant biparental mapping population. Quantitative trait loci (QTLs) for these traits were mapped onto a high-density SNP linkage map.

RESULTS

At least one QTL was detected for each trait, with good consistency between the 2 years. Clusters of QTLs were found on each of the eight linkage groups (LG). For example, QTLs for the major anthocyanidin glucosides, delphinidin-3-O-glucoside and cyanidin-3-O-glucoside, co-localised with a QTL for total anthocyanin content on LG3 whereas the major anthocyanidin rutinosides, delphinidin-3-O-rutinoside and cyanidin-3-O-rutinoside, had QTLs on LG1 and LG2. Many of the QTLs explained a high proportion of the trait variation, with the most significant region, on LG3 at ~ 35 cM, explaining more than 60% of the variation in the coumaroylated metabolites, Cyanidin-coumaroyl-glucose, Delphinidin-coumaroyl-glucose, Kaempferol-coumaroyl-glucose and Myricetin-coumaroyl-glucose.

CONCLUSION

The identification of robust QTLs for key polyphenol classes and individual polyphenols in blackcurrant provides great potential for marker-assisted breeding for improved levels of key components.

Anthocyanin Metabolites in Human Urine after the Intake of New Functional Beverages

Sugar intake abuse is directly related with the increase of metabolic diseases such as type 2 diabetes, obesity, and insulin resistance. Along this line, the development of new beverages using alternative sweeteners could help with combatting the pathophysiological disorders associated to the consumption of sugar. To provide evidence on this issue, in the present work, the bioavailability of anthocyanins was evaluated after the acute ingestion of a new maqui-citrus-based functional beverage rich in polyphenols, and supplemented with a range of sweeteners including sucrose (natural high caloric), stevia (natural non-caloric), and sucralose (artificial non-caloric), as an approach that would allow reducing the intake of sugars while providing bioactive phenolic compounds (anthocyanins). This approach allowed the evaluation of the maximum absorption and the diversity of metabolites excreted through urine. The beverages created were ingested by volunteers (n = 20) and the resulting anthocyanin metabolites in their urine were analyzed by UHPLC-ESI-MS/MS. A total of 29 degradation metabolites were detected: Caffeic acid, catechol, 3,4-dihidroxifenilacetic acid, hippuric acid, trans-ferulic acid, 2,4,6-trihydroxybenzaldehyde, trans-isoferulic acid, and vanillic acid derivatives, where peak concentrations were attained at 3.5 h after beverage intake. Sucralose was the sweetener that provided a higher bioavailability for most compounds, followed by stevia. Sucrose did not provide a remarkably higher bioavailability of any compounds in comparison with sucralose or stevia. The results propose two sweetener alternatives (sucralose and stevia) to sucrose, an overused high calorie sweetener that promotes some metabolic diseases.

Alternative Sweeteners Modify the Urinary Excretion of Flavanones Metabolites Ingested through a New Maqui-Berry Beverage

Dietary sugar has been largely related to the onset of metabolic diseases such as type 2 diabetes and obesity, among others. The growing awareness on the close relationship between the dietary habits and this health disturbance has encouraged the development of new beverages using alternative sweeteners that could contribute to combat the above referred pathophysiological disorders. To gain further insight into this issue, the present work, upon an acute dietary intervention, evaluated the urinary excretion of flavanones ingested through polyphenols-rich beverages composed of maqui berry and citrus, with the aim of establishing the highest urinary excretion rate and metabolite profiles. The functional beverages evaluated were supplemented with a range of sweeteners including sucrose (natural and high caloric), stevia (natural and non-caloric), and sucralose (artificial and non-caloric) as an approach that would allow reducing the intake of sugars and provide bioactive phenolics (flavanones). The juices developed were ingested by volunteers (n = 20) and the resulting flavanones and their phase II metabolites in urine were analyzed by Ultra-High Performance Liquid Chromatography ElectroSpray Ionization Mass Spectrometry (UHPLC-ESI-MS/MS). A total of 16 metabolites were detected: eriodyctiol, naringenin, and homoeriodyctiol derivatives, where peak concentrations were attained 3.5 h after beverage intake. Sucralose and stevia were the sweeteners that provided the highest urinary excretion for most compounds. Sucrose did not provide a remarkable higher elimination through urine of any compounds in comparison with sucralose or stevia. These results propose two alternative sweeteners to sucrose (sucralose and stevia), an overused, high caloric sweetener that promotes some metabolic diseases.

Dietary polyphenols modulate starch digestion and glycaemic level: a review

Polyphenols, as one group of secondary metabolite, are widely distributed in plants and have been reported to show various bioactivities in recent year. Starch digestion not only is related with food industrial applications such as brewing but also plays an important role in postprandial blood glucose level, and therefore insulin resistance. Many studies have shown that dietary phenolic extracts and pure polyphenols can retard starch digestion in vitro, and the retarding effect depends on the phenolic composition and molecular structure. Besides, dietary polyphenols have also been reported to alleviate elevation of blood glucose level after meal, indicating the inhibition of starch digestion in vivo. This review aims to analyze how dietary polyphenols affect starch digestion both in vitro and in vivo. We can conclude that the retarded starch digestion in vitro by polyphenols results from inhibition of key digestive enzymes, including α-amylase and α-glucosidase, as well as from interactions between polyphenols and starch. The alleviation of postprandial hyperglycemia by polyphenols might be caused by both the inhibited starch digestion in vivo and the influenced glucose transport. Therefore, phenolic extracts or pure polyphenols may be alternatives for preventing and treating type II diabetes disease.

The Role of Polyphenols in Human Health and Food Systems: A Mini-Review

This narrative mini- review summarizes current knowledge of the role of polyphenols in health outcomes-and non-communicable diseases specifically-and discusses the implications of this evidence for public health, and for future directions for public health practice, policy, and research. The publications cited originate mainly from animal models and feeding experiments, as well as human cohort and case-control studies. Hypothesized protective effects of polyphenols in acute and chronic diseases, including obesity, neurodegenerative diseases, type 2 diabetes, and cardiovascular diseases, are evaluated. Potential harmful effects of some polyphenols are also considered, counterbalanced with the limited evidence of harm in the research literature. Recent international governmental regulations are discussed, as the safety and health claims of only a few specific polyphenolic compounds have been officially sanctioned. The implications of food processing on the bioavailability of polyphenols are also assessed, in addition to the health claims and marketing of polyphenols as a functional food. Finally, this mini-review asserts the need for increased regulation and guidelines for polyphenol consumption and supplementation in order to ensure consumers remain safe and informed about polyphenols.

Dietary Flavonoids in the Prevention of T2D: An Overview

Type 2 diabetes (T2D) is a progressive metabolic disease that is increasing in prevalence globally. It is well established that insulin resistance (IR) and a progressive decline in functional β-cell mass are hallmarks of developing T2D. Obesity is a leading pathogenic factor for developing IR. Constant IR will progress to T2D when β-cells are unable to secret adequate amounts of insulin to compensate for decreased insulin sensitivity. Recently, a considerable amount of research has been devoted to identifying naturally occurring anti-diabetic compounds that are abundant in certain types of foods. Flavonoids are a group of polyphenols that have drawn great interest for their various health benefits. Results from many clinical and animal studies demonstrate that dietary intake of flavonoids might be helpful in preventing T2D, although cellular and molecular mechanisms underlying these effects are still not completely understood. This review discusses our current understanding of the pathophysiology of T2D and highlights the potential anti-diabetic effects of flavonoids and mechanisms of their actions.

Obesity and neurological disorders: Dietary perspective of a global menace

Obesity is considered a major public health concern throughout the world among children, adolescents, as well as adults and several therapeutic, preventive and dietary interventions are available. In addition to life style changes and medical interventions, significant milestones have been achieved in the past decades in the development of several functional foods and dietary regimens to reduce this menace. Being a multifactorial phenomenon and related to increased fat mass that adversely affects health, obesity has been associated with the development of several other co-morbidities. A great body of research and strong scientific evidence identifies obesity as an important risk factor for onset and progression of several neurological disorders. Obesity induced dyslipidaemia, metabolic dysfunction, and inflammation are attributable to the development of a variety of effects on central nervous system (CNS). Evidence suggests that neurological diseases such as Parkinson's disease and Alzheimer's disease could be initiated by various metabolic changes, related to CNS damage, caused by obesity. These metabolic changes could alter the synaptic plasticity of the neurons and lead to neural death, affecting the normal physiology of CNS. Dietary intervention in combination with exercise can affect the molecular events involved in energy metabolism and synaptic plasticity and are considered effective non-invasive strategy to counteract cognitive and neurological disorders. The present review gives an overview of the obesity and related neurological disorders and the possible dietary interventions.

Phenolic Compounds and Its Bioavailability: In Vitro Bioactive Compounds or Health Promoters?

Botanical preparations present a widespread and secular history of use. In fact, natural matrices possess a rich pool of phytochemicals, with promising biological effects. Among them, phenolic compounds have revealed to confer very important attributes to improve the well-being and longevity of worldwide population. Numerous in vitro studies have been carried out evaluating the wide spectrum of bioactivities of phenolic compounds, including its health effects, but through in vivo experiments some of these previous results cannot be properly confirmed, and considerable variations are observed. Pharmacokinetic parameters, including the assessment of bioavailability and bioefficacy of phenolic compounds, still continue to be largely investigated and considered a great hot topic among the food science and technology researchers. Thus, based on these crucial aspects, this chapter aims to provide an extensive approach about the question of the bioavailability of phenolic compounds, describing its biosynthetic routes and related mechanisms of action; to focus on the current facts and existing controversies, highlighting the importance of in vivo studies and the impact of phenolic compounds on the quality of life and longevity.

Black Crowberry (Empetrum nigrum L.) Flavonoids and Their Health Promoting Activity

Nowadays, much research attention is focused on underutilized berry crops due to the high antioxidant activity of fruits. Black crowberry (Empetrum nigrum L.) represents an important source of flavonols (quercetin, rutin, myricetin, naringenin, naringin, morin, and kaempferol) and anthocyanins. The fruit components could be utilised as natural colourants or as a part of functional foods and, because of the high antioxidant activity, the berries of black crowberry can be used in the treatment of diseases accompanied with inflammation, or as an effective antibacterial and antifungal remedy. Moreover, the reduction of lipid accumulation and total cholesterol as well as an improvement of postprandial hyperglycaemia have been proven. This review summarizes for the first time the main antioxidants (flavonoids) of black crowberry fruits, with a focus on their health promoting activity.

Delphinidin-Rich Maqui Berry Extract (Delphinol®) Lowers Fasting and Postprandial Glycemia and Insulinemia in Prediabetic Individuals during Oral Glucose Tolerance Tests

Delphinidin anthocyanins have previously been associated with the inhibition of glucose absorption. Blood glucose lowering effects have been ascribed to maqui berry (Aristotelia chilensis) extracts in humans after boiled rice consumption. In this study, we aimed to explore whether a standardized delphinidin-rich extract from maqui berry (Delphinol) affects glucose metabolism in prediabetic humans based on glycemia and insulinemia curves obtained from an oral glucose tolerance test (OGTT) after a challenge with pure glucose. Volunteers underwent four consecutive OGTTs with at least one week washout period, in which different doses of Delphinol were administered one hour before glucose intake. Delphinol significantly and dose-dependently lowered basal glycemia and insulinemia. Lower doses delayed postprandial glycemic and insulinemic peaks, while higher doses reversed this tendency. Glycemia peaks were dose-dependently lowered, while insulinemia peaks were higher for the lowest dose and lower for other doses. The total glucose available in blood was unaffected by treatments, while the total insulin availability was increased by low doses and decreased by the highest dose. Taken together, these open exploratory results suggest that Delphinol could be acting through three possible mechanisms: by inhibition of intestinal glucose transporters, by an incretin-mediated effect, or by improving insulin sensitivity.

Drinks containing anthocyanin-rich blackcurrant extract decrease postprandial blood glucose, insulin and incretin concentrations

Blackcurrants are rich in polyphenolic glycosides called anthocyanins, which may inhibit postprandial glycemia. The aim was to determine the dose-dependent effects of blackcurrant extract on postprandial glycemia. Men and postmenopausal women (14M, 9W, mean age 46 years, S.D.=14) were enrolled into a randomized, double-blind, crossover trial. Low sugar fruit drinks containing blackcurrant extract providing 150-mg (L-BE), 300-mg (M-BE) and 600-mg (H-BE) total anthocyanins or no blackcurrant extract (CON) were administered immediately before a high-carbohydrate meal. Plasma glucose, insulin and incretins (GIP and GLP-1) were measured 0-120min, and plasma 8-isoprostane F_2α, together with arterial stiffness by digital volume pulse (DVP) was measured at 0 and 120min. Early plasma glucose response was significantly reduced following H-BE (n=22), relative to CON, with a mean difference (95% CI) in area over baseline (AOB) 0-30min of -0.34mmol/l.h (-0.56, -0.11, P<.005); there were no differences between the intermediate doses and placebo. Plasma insulin concentrations (AOB 0-30min) were similarly reduced. Plasma GIP concentrations (AOB 0-120min) were significantly reduced following H-BE, with a mean difference of -46.6ng/l.h (-66.7, -26.5, P<.0001) compared to CON. Plasma GLP-1 concentrations were reduced following H-BE at 90min. There were no effects on 8-isoprostane F_2α or vascular function. Consumption of blackcurrant extract in amounts roughly equivalent to 100-g blackcurrants reduced postprandial glycemia, insulinemia and incretin secretion, which suggests that inclusion of blackcurrant polyphenols in foods may provide cardio-metabolic health benefits. This trial was registered at clinicaltrials.gov as NCT01706653.

Gastroretentive systems - a proposed strategy to modulate anthocyanin release and absorption for the management of diabetes

Several reports have indicated a positive correlation between the consumption of anthocyanins (ACN) and biomarkers relating to the improvement of type 2 diabetes (T2D). However, the results from in vitro studies often do not translate into clinical evidence. Potential causes of these discrepancies are experimental conditions that lack physiological relevancy; extensive degradation of these compounds in vivo due to changes in pH and metabolism; and a short residence time in the absorption window in relation to the absorption rate. Here, gastroretentive systems (GRS) are proposed as a strategy to overcome the limitations in ACN delivery and to reduce the existing bench-to-subject gap. This review summarizes recent literature on the use of ACN for the management and control of T2D, followed by GRS platforms to promote a sustained release of ACN for increased health benefits.

Profiling the metabolome changes caused by cranberry procyanidins in plasma of female rats using (1) H NMR and UHPLC-Q-Orbitrap-HRMS global metabolomics approaches

SCOPE

The objective was to investigate the metabolome changes in female rats gavaged with partially purified cranberry procyanidins (PPCP) using (1) H NMR and UHPLC-Q-Orbitrap-HRMS metabolomics approaches, and to identify the contributing metabolites.

METHODS AND RESULTS

Twenty-four female Sprague-Dawley rats were randomly separated into two groups and administered PPCP or partially purified apple procyanidins (PPAP) for three times using a 250 mg extracts/kg body weight dose. Plasma was collected 6 h after the last gavage and analyzed using (1) H NMR and UHPLC-Q-Orbitrap-HRMS. No metabolome difference was observed using (1) H NMR metabolomics approach. However, LC-HRMS metabolomics data show that metabolome in the plasma of female rats administered PPCP differed from those gavaged with PPAP. Eleven metabolites were tentatively identified from a total of 36 discriminant metabolic features based on accurate masses and/or product ion spectra. PPCP caused a greater increase of exogenous metabolites including p-hydroxybenzoic acid, phenol, phenol-sulphate, catechol sulphate, 3, 4-dihydroxyphenylvaleric acid, and 4'-O-methyl-(-)-epicatechin-3'-O-beta-glucuronide in rat plasma. Furthermore, the plasma level of O-methyl-(-)-epicatechin-O-glucuronide, 4-hydroxy-5-(hydroxyphenyl)-valeric acid-O-sulphate, 5-(hydroxyphenyl)-ϒ-valerolactone-O-sulphate, 4-hydroxydiphenylamine, and peonidin-3-O-hexose were higher in female rats administered with PPAP.

CONCLUSION

The metabolome changes caused by cranberry procyanidins were revealed using an UHPLC-Q-Orbitrap-HRMS global metabolomics approach. Exogenous and microbial metabolites were the major identified discriminate biomarkers.

Effects of a beetroot juice with high neobetanin content on the early-phase insulin response in healthy volunteers

Produce rich in phytochemicals may alter postprandial glucose and insulin responses by interacting with the pathways that regulate glucose uptake and insulin secretion in humans. The aims of the present study were to assess the phytochemical constituents of red beetroot juice and to measure the postprandial glucose and insulin responses elicited by either 225 ml beetroot juice (BEET), a control beverage matched for macronutrient content (MCON) or a glucose beverage in healthy adults. Beetroot juice was a particularly rich source of betalain degradation compounds. The orange/yellow pigment neobetanin was measured in particularly high quantities (providing 1·3 g in the 225 ml). A total of sixteen healthy individuals were recruited, and consumed the test meals in a controlled single-blind cross-over design. Results revealed a significant lowering of the postprandial insulin response in the early phase (0-60 min) (P < 0·05) and a significantly lower glucose response in the 0-30 min phase (P < 0·05) in the BEET treatment compared with MCON. Betalains, polyphenols and dietary nitrate found in the beetroot juice may each contribute to the observed differences in the postprandial insulin concentration.

The polyphenol-rich baobab fruit (Adansonia digitata L.) reduces starch digestion and glycemic response in humans

The baobab fruit (Adansonia digitata L.) is found throughout regions of Africa and is becoming increasingly recognized for its high nutrient and polyphenol content. Polyphenols have been beneficial for their effects on reducing the glycemic response (GR) and for improving various other metabolic parameters. Based on previous research, it was hypothesized that the baobab fruit extract would reduce starch digestion in vitro and would show potential for reducing the GR and for increasing satiety and diet-induced thermogenesis in humans. Six extracts of baobab from 6 different locations in Africa were measured for their antioxidant and polyphenol content using the ferric ion-reducing antioxidant power and the Folin-Ciocalteu methods, respectively. Baobab extract was baked into white bread at different doses to determine the optimal dose for reducing starch breakdown and sugar release from white bread after an in vitro digestion procedure. In vivo, baobab extract was consumed in solution at both a low-dose (18.5 g) and a high-dose (37 g) aqueous drink in 250 mL of water along with white bread, and resulting GR, satiety, and postprandial energy expenditure were measured. All extracts in this study were shown to be good sources of polyphenols. Baobab fruit extract added to white bread at 1.88 % significantly (P < .05) reduced rapidly digestible starch from white bread samples. In vivo, the baobab fruit extract at both low and high doses significantly (P < .05) reduced GR, although there was no significant effect on satiety or on energy expenditure.

Food-based ingredients to modulate blood glucose

Maintenance of normal blood glucose levels is important for avoiding chronic diseases such as type 2 diabetes, cardiovascular problems, and obesity. Type 2 diabetes is one of the major health problems affecting the world population and this condition can be exacerbated by poor diet, low physical activity, and genetic abnormalities. Food plays an important role in the management of blood glucose and associated complications in diabetes. This is attributed to the ability of food-based ingredients to modulate blood glucose without causing any adverse health consequences. This chapter focuses on four important food groups such as cereals, legumes, fruits, and spices that have active ingredients such as soluble dietary fiber, polyphenols, and antinutrients with the ability to reduce glycemic and insulin response in humans. Other food ingredients such as simple sugars, sugar alcohols, and some proteins are also discussed in moderation.