Encapsulation of anthocyanins from bilberries – Effects on bioavailability and intestinal accessibility in humans

The mechanism of pectin in improving anthocyanin stability and the application progress of their complexes: A review

Improving anthocyanin stability is a major challenge for the food industry. Studies have revealed that the interaction with pectin through non-covalent bonds can improve the anthocyanin stability, thus showing the potential to alleviate the above challenges. However, the interactions are highly complex and diverse. Thus, analyzing the effect of this interaction on anthocyanin stability is essential to promote anthocyanin-pectin complexes application in functional foods. Pectin can interact with anthocyanins through covalent and non-covalent interactions, and these interactions are affected by their structure, the external environment, and the processing methods. Through their interaction with pectin, the thermal, color, and storage stability of anthocyanins are improved, enhancing their bioavailability in the gastrointestinal and facilitating their application range in food processing. This review provides a theoretical reference for improving anthocyanin stability and increasing the application range of anthocyanin-pectin complexes.

Nano techniques: an updated review focused on anthocyanin stability

Anthocyanins (ACNs) are one of the subgroups of flavonoids and getting intensive attraction due to the nutritional values. However, their application of ACNs is limited due to their poor stability and bioavailability. Accordingly, nanoencapsulation has been developed to enhance its stability and bio-efficacy. This review focuses on the nano-technique applications of delivery systems that be used for ACNs stabilization, with an emphasis on physicochemical stability and health benefits. ACNs incorporated with delivery systems in forms of nano-particles and fibrils can achieve advanced functions, such as improved stability, enhanced bioavailability, and controlled release. Also, the toxicological evaluation of nano delivery systems is summarized. Additionally, this review summarizes the challenges and suggests the further perspectives for the further application of ACNs delivery systems in food and medical fields.

Exploring the Potential of Anthocyanins for Repairing Photoaged Skin: A Comprehensive Review

Long-term exposure to ultraviolet (UV) rays can result in skin photoaging, which is primarily characterized by dryness, roughness, pigmentation, and a loss of elasticity. However, the clinical drugs commonly employed to treat photoaged skin often induce adverse effects on the skin. Anthocyanins (ACNs) are water-soluble pigments occurring abundantly in various flowers, fruits, vegetables, and grains and exhibiting a range of biological activities. Studies have demonstrated that ACNs contribute to the repair of photoaged skin due to their diverse biological characteristics and minimal side effects. Evidence suggests that the stability of ACNs can be enhanced through encapsulation or combination with other substances to improve their bioavailability and permeability, ultimately augmenting their efficacy in repairing photoaged skin. A growing body of research utilizing cell lines, animal models, and clinical studies has produced compelling data demonstrating that ACNs mitigate skin photoaging by reducing oxidative stress, alleviating the inflammatory response, improving collagen synthesis, alleviating DNA damage, and inhibiting pigmentation. This review introduces sources of ACNs while systematically summarizing their application forms as well as mechanisms for repairing photoaged skin. Additionally, it explores the potential role of ACNs in developing functional foods. These findings may provide valuable insight into using ACNs as promising candidates for developing functional products aimed at repairing photoaged skin.

Does Encapsulation Improve the Bioavailability of Polyphenols in Humans? A Concise Review Based on In Vivo Human Studies

BACKGROUND/OBJECTIVES

Polyphenols offer an array of health benefits that can contribute to well-being. Nevertheless, their bioactivity can be compromised due to their low bioavailability. Encapsulation has been explored as a strategy to enhance the stability and bioavailability of polyphenols. During encapsulation, polyphenols are protected from degradation by a wall material that acts as a protective coating. This coating shields the polyphenols from the harsh physiological conditions of digestion, ensuring their delivery to the intestine. However, the majority of evidence, particularly regarding bioavailability after digestion, is derived from in vitro studies. While these studies provide valuable preliminary insights, they cannot definitively confirm the effects in vivo due to their inability to accurately replicate physiological conditions and the complex gut microbial ecosystem. Consequently, this review seeks to evaluate the current evidence from in vivo human studies to elucidate the efficacy of encapsulation in improving polyphenols' bioavailability.

RESULTS AND CONCLUSIONS

Current clinical evidence on the impact of encapsulation on polyphenol bioavailability is primarily focused on polyphenols derived from grape pomace, cocoa, and bilberries, as well as individual polyphenols such as fisetin, hesperidin, and curcumin. Encapsulation has been an effective technique in improving the bioavailability of individual polyphenols like hesperidin, fisetin, and curcumin. However, this approach has not yielded consistent results when applied to groups of polyphenols, such as bilberry anthocyanins or cocoa phenolic acids. Encapsulation by micellization has shown promising results in improving the bioavailability of curcumin in a nutraceutical context. Further studies are needed to explore the bioavailability of encapsulated polyphenols, especially in the functional food context.

Development of microencapsulated grape juice powders using black 'Isabel' grape peel pectin and application in jelly formulation with enhanced in vitro bioaccessibility of anthocyanins

In this study, pigmented pectin (grape pectin, GP) was extracted from the peels of black Isabel grapes. This highly methoxylated GP was composed mainly of galacturonic acid, arabinose, and other neutral monosaccharides. Its red color was ascribed to the anthocyanin content, and the main contribution was from malvidin-3-O-glucoside. To improve the yield and color properties of spray-dried Isabel grape juice powders, maltodextrin (MD) was substituted with this colored GP. When 25% of MD was substituted with GP, the powder yield increased from 46.0% to 60.4%, but it decreased to 21% when the substitution was 40%. GP inclusion increased the encapsulation efficiency of total anthocyanin in powders from 55.70% to 88.66%. When this spray-dried grape juice powder containing GP was utilized in a jelly recipe (4%-10%), a higher level of inclusion yielded stronger and more brittle jellies. When the jellies containing varying amounts of GP were subjected to in vitro digestion, the formulation with a higher amount of GP yielded a higher recovery of anthocyanins. In addition to being utilized as a carrier agent for spray-drying applications, this pigmented GP can also be tailored for a variety of applications, such as the development of pH-sensitive edible films and functional beverage formulations.

Anthocyanin-Loaded Polymers as Promising Nature-Based, Responsive, and Bioactive Materials

Anthocyanins are a specific group of molecules found in nature that have recently received increasing attention due to their interesting biological and colorimetric properties that have been successfully applied in several fields such as food preservation and biomedicine. Consequently, reviews devoted to a general overview of these flavonoids have proliferated in recent years. Meanwhile, the incorporation of anthocyanins into polymeric systems has become an interesting strategy to widen the applicability of these molecules and develop new smart and functional polymers in the above cited areas. However, anthocyanin-based polymers have been scarcely reviewed in the literature. Accordingly, this review aims to be a systematic summary of the most recent approaches for the incorporation of anthocyanins into macro-, micro-, or nanostructured polymers. Moreover, this work describes the fundamentals of the applicability of smart anthocyanin-based polymers and offers an updated review of their most interesting applications as sensors, biological regulators, and active materials.

Anthocyanins as Immunomodulatory Dietary Supplements: A Nutraceutical Perspective and Micro-/Nano-Strategies for Enhanced Bioavailability

Anthocyanins (ACNs) have attracted considerable attention for their potential to modulate the immune system. Research has revealed their antioxidant and anti-inflammatory properties, which play a crucial role in immune regulation by influencing key immune cells, such as lymphocytes, macrophages, and dendritic cells. Moreover, ACNs contribute towards maintaining a balance between proinflammatory and anti-inflammatory cytokines, thus promoting immune health. Beyond their direct effects on immune cells, ACNs significantly impact gut health and the microbiota, essential factors in immune regulation. Emerging evidence suggests that they positively influence the composition of the gut microbiome, enhancing their immunomodulatory effects. Furthermore, these compounds synergize with other bioactive substances, such as vitamins and minerals, further enhancing their potential as immune-supporting dietary supplements. However, detailed clinical studies must fully validate these findings and determine safe dosages across varied populations. Incorporating these natural compounds into functional foods or supplements could revolutionize the management of immune-related conditions. Personalized nutrition and healthcare strategies may be developed to enhance overall well-being and immune resilience by fully understanding the mechanisms underlying the actions of their components. Recent advancements in delivery methods have focused on improving the bioavailability and effectiveness of ACNs, providing promising avenues for future applications.

Effects of α-casein on the excretion of blueberry anthocyanins via urine and feces: Analysis of their bioavailability

Anthocyanins are bioactive compounds found in blueberries. However, their poor bioavailability restricts their functional activities in vivo, which is a challenging issue in the application of blueberry anthocyanins. Our current study utilized α-casein as a carrier and analyzed its influence on the excretion of blueberry anthocyanins in urine and feces in a rat model to reflect the enhanced bioavailability of blueberry anthocyanins by α-casein in vivo. The results showed that α-casein suppressed the excretive content of blueberry anthocyanins (malvidin-3-O-galacoside (M3G), cyanidin-3-O-glucoside (C3G), and delphinidin-3-O-glucoside (D3G)), increased the content of metabolites in urine (syringic acid, ferulic acid, 4-hydroxybenzoic acid, and vanillic acid), and reduced metabolite content in feces (syringic acid, ferulic acid, and gallic acid), indicating that α-casein was effective in controlling the excretion of blueberry anthocyanins and their metabolites. In summary, these results provided sufficient evidence for the positive effects of α-casein on the bioavailability of blueberry anthocyanins.

Nanoformulations for the Delivery of Dietary Anthocyanins for the Prevention and Treatment of Diabetes Mellitus and Its Complications

Diabetes mellitus (DM) is a metabolic disease characterized by abnormal blood glucose levels-hyperglycemia, caused by a lack of insulin secretion, impaired insulin action, or a combination of both. The incidence of DM is increasing, resulting in billions of dollars in annual healthcare costs worldwide. Current therapeutics aim to control hyperglycemia and reduce blood glucose levels to normal. However, most modern drugs have numerous side effects, some of which cause severe kidney and liver problems. On the other hand, natural compounds rich in anthocyanidins (cyanidin, delphinidin, malvidin, pelargonidin, peonidin, and petunidin) have also been used for the prevention and treatment of DM. However, lack of standardization, poor stability, unpleasant taste, and decreased absorption leading to low bioavailability have hindered the application of anthocyanins as therapeutics. Therefore, nanotechnology has been used for more successful delivery of these bioactive compounds. This review summarizes the potential of anthocyanins for the prevention and treatment of DM and its complications, as well as the strategies and advances in the delivery of anthocyanins using nanoformulations.

Anthocyanins: Modified New Technologies and Challenges

Anthocyanins are bioactive compounds belonging to the flavonoid class which are commonly applied in foods due to their attractive color and health-promoting benefits. However, the instability of anthocyanins leads to their easy degradation, reduction in bioactivity, and color fading in food processing, which limits their application and causes economic losses. Therefore, the objective of this review is to provide a systematic evaluation of the published research on modified methods of anthocyanin use. Modification technology of anthocyanins mainly includes chemical modification (chemical acylation, enzymatic acylation, and formation of pyran anthocyanidin), co-pigmentation, and physical modification (microencapsulation and preparation of pickering emulsion). Modification technology of anthocyanins can not only increase bioavailability and stability of anthocyanin but also can improve effects of anthocyanin on disease prevention and treatment. We also propose potential challenges and perspectives for diversification of anthocyanin-rich products for food application. Overall, integrated strategies are warranted for improving anthocyanin stabilization and promoting their further application in the food industry, medicine, and other fields.

Protein-binding approaches for improving bioaccessibility and bioavailability of anthocyanins

Color is an important characteristic of food. Over the last 15 years, more attention has been paid to natural colorants because of the rising demand for clean-label food products. Anthocyanins, which are a group of phytochemicals responsible for the purple, blue or red hues of many plants, offer a market advantage. In addition, anthocyanin-rich foods are associated with protection against cardiovascular disease, thrombosis, diabetes, cancer, microbial-based disorders, neurological disorders, and vision ailments. However, the real health value of anthocyanins, whether as a natural colorant or a functional ingredient, is dependent on the ultimate bioaccessibility and bioavailability in the human body. Many animal and human clinical studies revealed that, after intake of anthocyanin-rich foods or anthocyanin extracts, only trace amounts (< 1% of ingested content) of anthocyanins or their predicted metabolites were detected in plasma after a standard blood draw, which was indicative of low bioavailability of anthocyanins. Protein binding to anthocyanins is a strategy that has recently been reported to enhance the ultimate bioactivity, bioaccessibility, and bioavailability of anthocyanins as compared to anthocyanins delivered without a protein carrier. Therefore, in this review, we address anthocyanin properties in food processing and digestion, anthocyanin-protein complexes used in food matrices, and changes in the bioaccessibility and bioavailability of anthocyanins when bound into anthocyanin-protein complexes in foods. Finally, we summarize the challenges and prospects of this delivery system for anthocyanin pigments.

Research Progress on Absorption, Metabolism, and Biological Activities of Anthocyanins in Berries: A Review

Berries, as the best dietary sources for human health, are rich in anthocyanins, vitamins, fiber, polyphenols, essential amino acids, and other ingredients. Anthocyanins are one of the most important bioactive components in berries. The attractive color of berries is attributed to the fact that berries contain different kinds of anthocyanins. Increasing research activity has indicated that anthocyanins in berries show various biological activities, including protecting vision; antioxidant, anti-inflammatory and anti-tumor qualities; inhibition of lipid peroxidation; anti-cardiovascular disease properties; control of hypoglycemic conditions; and other activities. Hence, berries have high nutritional and medicinal values. The recognized absorption, metabolism, and biological activities of anthocyanins have promoted their research in different directions. Hence, it is necessary to systematically review the research progress and future prospects of anthocyanins to promote a better understanding of anthocyanins. The absorption, metabolism, and biological activities of anthocyanins from berries were reviewed in this paper. The findings of this study provide an important reference for basic research, product development and utilization of berries' anthocyanins in food, cosmetics, and drugs.

Anti-Inflammatory Activity of Bilberry (Vaccinium myrtillus L.)

Inflammation is important in the pathogenesis of several chronic diseases. The anti-inflammatory properties of berries have been investigated but the anti-inflammatory activity of bilberry has received little attention and a detailed review is yet to be published. Therefore, we compiled information on the phytochemicals of bilberry and preclinical and clinical studies of its anti-inflammatory properties. The review was based on studies from 2007 to date. Phytoconstituents of bilberries were phenolic acids, organic acids, anthocyanins, coumarins, flavonols, flavanols, tannins, terpenoids, and volatile chemicals. Data from cell and animal model studies show that bilberry has an anti-inflammatory effect by lowering tumor necrosis factor-α, interleukin (IL)-6, and IL-1β expression, inducing nitric oxide synthases and cyclooxygenases, and altering the nuclear factor kappa B and Janus kinase-signal transducer and activator of transcription signaling pathways. Bilberry supplementation as fruits (frozen, processed, and whole), juices, and anthocyanins reduced levels of inflammatory markers in most clinical studies of metabolic disorders. Therefore, bilberry may be useful for the prevention and treatment of chronic inflammatory disorders.

An Oral Polyphenol Formulation to Modulate the Ocular Surface Inflammatory Process and to Improve the Symptomatology Associated with Dry Eye Disease

Due to their antioxidant, anti-inflammatory, neuroprotective, and anti-angiogenic effects, polyphenols are first-rate candidates to prevent or treat chronic diseases in which oxidative stress-induced inflammation plays a role in disease pathogenesis. Dry eye disease (DED) is a common pathology, on which novel phenolic compound formulations have been tested as an adjuvant therapeutic approach. However, polyphenols are characterized by limited stability and solubility, insolubility in water, very rapid metabolism, and a very short half-life. Thus, they show poor bioavailability. To overcome these limitations and improve their stability and bioavailability, we evaluated the safety and efficacy of an oral formulation containing among other compounds, polyphenols and omega-3 fatty acids, with the addition of a surfactant in patients with DED. Subjects were randomly assigned to one of four study groups including the study formulation (A), placebo (P), the study formulation + eye lubricant (A + L), and placebo + eye lubricant (P + L). Patients from the A and P groups were instructed to take two capsules every 24 h, while patients in the L groups also added one drop of lubricant twice a day for 12 weeks as well. Regarding safety, non-ocular abnormalities were observed during study formulation therapy. Liver function tests did not show any statistically significant difference (baseline vs. week 4). Concerning efficacy, there was a statistically significant difference between baseline, month 1, and month 3 in the OSDI (Ocular Surface Disease Index) test results in both treatment groups (group A and group A + L). Furthermore, both groups showed statistically significant differences between baseline and month 3 regarding the non-invasive film tear breakup time (NIF-BUT) score and a positive trend related to Shirmer's test at month 3. The non-invasive average breakup time (NIAvg-BUT) score showed a statistically significant difference at month 3 when compared with baseline in the A + L group. The P + L group showed a statistically significant difference in terms of the OSDI questionary between baseline and month 3. Regarding the lissamine green staining, the A + L group showed a statistical difference between baseline and month 3 (p = 0.0367). The placebo + lubricant group did not show statistically significant differences. Finally, the placebo group did not show any data with statistically significant differences. Consequently, this polyphenol formulation as a primary treatment outperformed the placebo alone, and the polyphenol oral formulation used as an adjuvant to artificial tears was superior to the combination of the placebo and the artificial tears. Thus, our data strongly suggest that this polyphenol oral formulation improves visual strain symptoms and tear film status in patients with mild to moderate DED.

Effects of casein on the stability, antioxidant activity, and bioavailability of lotus anthocyanins

Effects of casein on the stability, antioxidant activity, and bioavailability of lotus anthocyanins were investigated. Casein could inhibit the unsatisfactory pH-induced color change of lotus anthocyanins, and improved their photo, oxidation, and thermal stabilities. During the simulated digestion, the anthocyanin retention increased from 65.39 to 76.14 mg C3G/L with the protection of casein, while the DPPH and ABTS scavenging activities of lotus anthocyanins with casein increased to 62.33% and 46.58%, respectively. However, casein with lower concentration showed a better protective effect on lotus anthocyanins due to its self-aggregation tendency at high dose. The zebrafish model further verified that casein could enhance the bioavailability of lotus anthocyanins. Furthermore, molecular docking revealed that casein could interact with anthocyanin by hydrogen bond and hydrophobic interaction, which led to the stronger stability and bioavailability of lotus anthocyanins. The results conveyed that casein could be used as a wall material to protect anthocyanins. PRACTICAL APPLICATIONS: Anthocyanins are natural colorants with multiple biological activities, but the poor stability during processing and digestion limits their application in food industry. In the present research, casein exhibited conspicuous ability to enhance the stability of lotus anthocyanins toward detrimental conditions. Additionally, casein could preserve anthocyanins from degradation during digestion and thus improve the bioavailability. These findings indicated that casein could serve as a potential carrier for encapsulating and delivering anthocyanins. The better stability and bioavailability would promote the application of anthocyanins in food products and human health.

Technological and Biotechnological Processes To Enhance the Bioavailability of Dietary (Poly)phenols in Humans

The health effects of (poly)phenols (PPs) depend upon their bioavailability that, in general, is very low and shows a high interindividual variability. The low bioavailability of PPs is mainly attributed to their low absorption in the upper gastrointestinal tract as a result of their low water solubility, their presence in foods as polymers or in glycosylated forms, and their tight bond to food matrices. Although many studies have investigated how technological and biotechnological processes affect the phenolic composition of fruits and vegetables, limited information exists regarding their effects on PP bioavailability in humans. In the present review, the effect of food processing (mechanical, thermal, and non-thermal treatments), oral-delivery nanoformulations, enzymatic hydrolysis, fermentation, co-administration with probiotics, and generation of postbiotics in PP bioavailability have been overviewed, focusing in the evidence provided in humans.

Advanced approaches for improving bioavailability and controlled release of anthocyanins

Anthocyanins are a group of phytochemicals responsible for the purple or red color of plants. Additionally, they are recognized to have health promoting functions including anti-cardiovascular, anti-thrombotic, anti-diabetic, antimicrobial, neuroprotective, and visual protective effect as well as anti-cancer activities. Thus, consumption of anthocyanin supplement or anthocyanin-rich foods has been recommended to prevent the risk of development of chronic diseases. However, the low stability and bioavailability of anthocyanins limit the efficacy and distribution of anthocyanins in human body. Thus, strategies to achieve target site-local delivery with good bioavailability and controlled release rate are necessary. This review introduced and discussed the latest advanced techniques of designing lipid-based, polysaccharide-based and protein-based complexes, nano-encapsulation and exosome to overcome the limitation of anthocyanins. The improved bioavailability and controlled release of anthocyanins have great significance for gastrointestinal tract absorption, transepithelial transportation and cellular uptake. The techniques of applying different biocompatible materials and modifying the solubility of anthocyanins complex could achieve target site-local delivery with negligible degradation and good bioavailability in human body.

Pharmacokinetic and excretion study of Aronia melanocarpa anthocyanins bound to amylopectin nanoparticles and their main metabolites using high-performance liquid chromatography-tandem mass spectrometry

Anthocyanins of Aronia melanocarpa are known for their therapeutic properties; however, they are unstable and easily degrade in the environment and in vivo. Herein, we investigated the stability and bioavailability of four anthocyanins bound to amylopectin nanoparticles (APNPs) through a pharmacokinetic and excretion study using high-performance liquid chromatography-tandem mass spectrometry. An EC-C18 column with methanol and 0.1% formic acid as the mobile phase was used during the analysis. After APNP treatment, anthocyanins and metabolites exhibited a marked increase, whereas their maximum oral bioavailability reached 440% and 593%, respectively. The delayed elimination half time demonstrated that APNPs had a sustained-release effect on anthocyanins. Pharmacokinetic results revealed that APNPs effectively protect anthocyanins in vivo. Excretion studies in urine and feces had shown a decrease in excretion of anthocyanins and most of the metabolites after APNP treatment. The results of excretion study further proved the protective effect of APNPs on anthocyanins in vivo.

Potential micro-/nano-encapsulation systems for improving stability and bioavailability of anthocyanins: An updated review

Anthocyanins (ACNs) are notable hydrophilic compounds that belong to the flavonoid family, which are available in plants. They have excellent antioxidants, anti-obesity, anti-diabetic, anti-inflammatory, anticancer activity, and so on. Furthermore, ACNs can be used as a natural dye in the food industry (food colorant). On the other hand, the stability of ACNs can be affected by processing and storage conditions, for example, pH, temperature, light, oxygen, enzymes, and so on. These factors further reduce the bioavailability (BA) and biological efficacy of ACNs, as well as limit ACNs application in both food and pharmaceutics field. The stability and BA of ACNs can be improved via loading them in encapsulation systems including nanoemulsions, liposomes, niosomes, biopolymer-based nanoparticles, nanogel, complex coacervates, and tocosomes. Among all systems, biopolymer-based nanoparticles, nanohydrogels, and complex coacervates are comparatively suitable for improving the stability and BA of ACNs. These three systems have excellent functional properties such as high encapsulation efficiency and well-stable against unfavorable conditions. Furthermore, these carrier systems can be used for coating of other encapsulation systems (such as liposome). Additionally, tocosomes are a new system that can be used for encapsulating ACNs. ACNs-loaded encapsulation systems can improve the stability and BA of ACNs. However, further studies regarding stability, BA, and in vivo work of ACNs-loaded micro/nano-encapsulation systems could shed a light to evaluate the therapeutic efficacy including physicochemical stability, target mechanisms, cellular internalization, and release kinetics.

The interactions between anthocyanin and whey protein: A review

Anthocyanins (ACN) are natural pigments that produce bright red, blue, and purple colors in plants and can be used to color food products. However, ACN sensitivity to different factors limits their applications in the food industry. Whey protein (WP), a functional nutritional additive, has been shown to interact with ACN and improve the color, stability, antioxidant capacity, bioavailability, and other functional properties of the ACN-WP complex. The WP's secondary structure is expected to unfold due to heat treatment, which may increase its binding affinity with ACN. Different ACN structures will also have different binding affinity with WP and their interaction mechanism may also be different. Circular dichroism (CD) spectroscopy and Fourier transform infrared (FTIR) spectroscopy show that the WP secondary structure changes after binding with ACN. Fluorescence spectroscopy shows that the WP maximum fluorescence emission wavelength shifts, and the fluorescence intensity decreases after interaction with ACN. Moreover, thermodynamic analysis suggests that the ACN-WP binding forces are mainly hydrophobic interactions, although there is also evidence of electrostatic interactions and hydrogen bonding between ACN and WP. In this review, we summarize the information available on ACN-WP interactions under different conditions and discuss the impact of different ACN chemical structures and of WP conformation changes on the affinity between ACN and WP. This summary helps improve our understanding of WP protection of ACN against color degradation, thus providing new tools to improve ACN color stability and expanding the applications of ACN and WP in the food and pharmacy industries.

A Review of the Properties of Anthocyanins and Their Influence on Factors Affecting Cardiometabolic and Cognitive Health

The incidence of cardiovascular and metabolic diseases has increased over the last decades and is an important cause of death worldwide. An upcoming ingredient on the nutraceutical market are anthocyanins, a flavonoid subgroup, abundant mostly in berries and fruits. Epidemiological studies have suggested an association between anthocyanin intake and improved cardiovascular risk, type 2 diabetes and myocardial infarct. Clinical studies using anthocyanins have shown a significant decrease in inflammation markers and oxidative stress, a beneficial effect on vascular function and hyperlipidemia by decreasing low-density lipoprotein and increasing high-density lipoprotein. They have also shown a potential effect on glucose homeostasis and cognitive decline. This review summarizes the effects of anthocyanins in in-vitro, animal and human studies to give an overview of their application in medical prevention or as a dietary supplement.

Dietary Effects of Anthocyanins in Human Health: A Comprehensive Review

In recent years, the consumption of natural-based foods, including beans, fruits, legumes, nuts, oils, vegetables, spices, and whole grains, has been encouraged. This fact is essentially due to their content in bioactive phytochemicals, with the phenolic compounds standing out. Among them, anthocyanins have been a target of many studies due to the presence of catechol, pyrogallol, and methoxy groups in their chemical structure, which confer notable scavenging, anti-apoptotic, and anti-inflammatory activities, being already recommended as supplementation to mitigate or even attenuate certain disorders, such as diabetes, cancer, and cardiovascular and neurological pathologies. The most well-known anthocyanins are cyanidin 3-O-glucoside and cyanidin 3-O-rutinoside. They are widespread in nature, being present in considerable amounts in red fruits and red vegetables. Overall, the present review intends to discuss the most recent findings on the potential health benefits from the daily intake of anthocyanin-rich foods, as well as their possible pharmacological mechanisms of action. However, before that, some emphasis regarding their chemical structure, dietary sources, and bioavailability was done.

Combination of copigmentation and encapsulation strategies for the synergistic stabilization of anthocyanins

Copigmentation and encapsulation are the two most commonly used techniques for anthocyanin stabilization. However, each of these techniques by itself suffers from many challenges associated with the simultaneous achievement of color intensification and high stability of anthocyanins. Integrating copigmentation and encapsulation may overcome the limitation of usage of a single technique. This review summarizes the most recent studies and their challenges aiming at combining copigmentation and encapsulation techniques. The effective approaches for encapsulating copigmented anthocyanins are described, including spray/freeze-drying, emulsification, gelation, polyelectrolyte complexation, and their combinations. Other emerging approaches, such as layer-by-layer deposition and ultrasonication, are also reviewed. The physicochemical principles underlying the combined strategies for the fabrication of various delivery systems are discussed. Particular emphasis is directed toward the synergistic effects of copigmentation and encapsulation, for example, modulating roles of copigments in the processes of gelation and complexation. Finally, some of the major challenges and opportunities for future studies are highlighted. The trend of integrating copigmentation and encapsulation has been just started to develop. The information in this review should facilitate the exploration of the combination of multistrategy and the fabrication of robust delivery systems for copigmented anthocyanins.

Effects of α-Casein on the Absorption of Blueberry Anthocyanins and Metabolites in Rat Plasma Based on Pharmacokinetic Analysis

Blueberry anthocyanins are well known for their beneficial biological activities. However, the poor bioavailability of anthocyanins limits their functional capacity in vivo. Our current study aimed to detect the effects of α-casein on the absorption of blueberry anthocyanins and their metabolites in rats. Blueberry anthocyanins with and without α-casein were intragastrically administered to two groups of rats and their blood samples were collected within 24 h. Results illustrated that rapid absorption of anthocyanins was observed in the rat plasma, but their concentration was relatively low. With the complexation of α-casein, the maximum concentration (C_max) of bioavailable anthocyanins and metabolites could increase by 1.5-10.1 times (P < 0.05 or P < 0.01). The promotional effect on the plasma absorption of malvidin-3-O-galactoside and vanillic acid was outstanding with the C_max increasing from 0.032 to 0.323 and from 0.360 to 1.902 μg/mL, respectively (P < 0.01). Besides, the molecular docking models presented that anthocyanins could enter the structural cavity and interact with amino acid residues of α-casein, which was in accordance with the improved bioavailability of anthocyanins. Therefore, α-casein could assist more blueberry anthocyanins and their metabolites to enter blood circulation.

Pectin-Based Formulations for Controlled Release of an Ellagic Acid Salt with High Solubility Profile in Physiological Media

Among bioactive phytochemicals, ellagic acid (EA) is one of the most controversial because its high antioxidant and cancer-preventing effects are strongly inhibited by low gastrointestinal absorption and rapid excretion. Strategies toward an increase of solubility in water and bioavailability, while preserving its structural integrity and warranting its controlled release at the physiological targets, are therefore largely pursued. In this work, EA lysine salt at 1:4 molar ratio (EALYS), exhibiting a more than 400 times increase of water solubility with respect to literature reports, was incorporated at 10% in low methoxylated (LM) and high methoxylated (HM) pectin films. The release of EA in PBS at pH 7.4 from both film preparations was comparable and reached 15% of the loaded compound over 2 h. Under simulated gastric conditions, release of EA from HM and LM pectin films was minimal at gastric pH, whereas higher concentrations—up to 300 μM, corresponding to ca. 50% of the overall content—were obtained in the case of the HM pectin film after 2 h incubation at the slightly alkaline pH of small intestine environment, with the enzyme and bile salt components enhancing the release. EALYS pectin films showed a good prebiotic activity as evaluated by determination of short chain fatty acids (SCFAs) levels following microbial fermentation, with a low but significant increase of the effects produced by the pectins themselves. Overall, these results highlight pectin films loaded with EALYS salt as a promising formulation to improve administration and controlled release of the compound.

The influence of nanodelivery systems on the antioxidant activity of natural bioactive compounds

Bioactive compounds may lose their antioxidant activity (e.g., phenolic compounds) at elevated temperatures, enhanced oxidative conditions and severe light exposures so they should be protected by various strategies such as nano/microencapsulation methods. Encapsulation technology has been employed as a proper method for using antioxidant ingredients and to provide easy dispersibility of antioxidants in all matrices including food and pharmaceutical products. It can improve the food fortification processes, release of antioxidant ingredients, and extending the shelf-life and bioavailability of them when ingested in the intestine. In this study, our main goal is to have an overview of the influence of nanoencapsulation on the bioactivity and bioavailability, and cellular activities of antioxidant ingredients in different delivery systems. Also, the effect of encapsulation process conditions, storage conditions, carrier wall materials, and release profile on the antioxidant activity of different natural bioactives are explained. Finally, analytical techniques for measuring antioxidant activity of nanoencapsulated ingredients will be covered.

Effects of Lipid-Based Encapsulation on the Bioaccessibility and Bioavailability of Phenolic Compounds

Phenolic compounds (quercetin, rutin, cyanidin, tangeretin, hesperetin, curcumin, resveratrol, etc.) are known to have health-promoting effects and they are accepted as one of the main proposed nutraceutical group. However, their application is limited owing to the problems related with their stability and water solubility as well as their low bioaccessibility and bioavailability. These limitations can be overcome by encapsulating phenolic compounds by physical, physicochemical and chemical encapsulation techniques. This review focuses on the effects of encapsulation, especially lipid-based techniques (emulsion/nanoemulsion, solid lipid nanoparticles, liposomes/nanoliposomes, etc.), on the digestibility characteristics of phenolic compounds in terms of bioaccessibility and bioavailability.

A molecular docking and molecular dynamics simulation study on the interaction between cyanidin-3-O-glucoside and major proteins in cow's milk

The objective of this study was to investigate the molecular interaction and complex stability of four major cow's milk (CM) proteins (α-LA, β-LG, α_s1 -CA, and β-CA) with cyanidin-3-O-glucoside (C3G) using computational methods. The results of molecular docking analysis revealed that hydrogen bond and hydrophobic interaction were the main binding forces to maintain the stability of the C3G-CM protein complexes. Molecular dynamics simulation results showed that all complexes except for C3G-α_s1 -CA were found to reach equilibrium within 50 ns of simulation. α_s1 -CA and β-CA switched to a more compact conformation after binding with C3G. Additionally, the radius of gyration, number of hydrogen bond, radial distribution function, and interaction energy showed that β-CA is the best C3G carrier protein among the four CM proteins. This study can provide valuable information for CM proteins to serve as C3G delivery carriers. PRACTICAL APPLICATIONS: Anthocyanins (ACNs) are flavonoid-based pigments that play an important functional role in regulating human's health. Cow's milk (CM) proteins are the most representative protein-based carriers that can improve the short-term bioavailability and stability of ACNs. Thus, it is important to study the interactions between ACNs and CM proteins at the molecular level for the development of effective ACNs delivery carriers. Our study showed that caseins (α_s1 -CA and β-CA) had more hydrophobic and hydrogen-bonding sites with cyanidin-3-O-glucoside (C3G) than whey proteins using computational methods. Among the four CM proteins, β-CA was the best C3G carrier protein showing the best interaction stability with C3G. Thus, it is helpful for us to screen effective ACNs carriers from multiple protein sources by computational methods.

The Anti-Neuroinflammatory Role of Anthocyanins and Their Metabolites for the Prevention and Treatment of Brain Disorders

Anthocyanins are naturally occurring polyphenols commonly found in fruits and vegetables. Numerous studies have described that anthocyanin-rich foods may play a crucial role in the prevention and treatment of different pathological conditions, which have encouraged their consumption around the world. Anthocyanins exhibit a significant neuroprotective role, mainly due to their well-recognized antioxidant and anti-inflammatory properties. Neuroinflammation is an intricate process relevant in both homeostatic and pathological circumstances. Since the progression of several neurological disorders relies on neuroinflammatory process, targeting brain inflammation has been considered a promising strategy in those conditions. Recent data have shown the anti-neuroinflammatory abilities of many anthocyanins and of their metabolites in the onset and development of several neurological disorders. In this review, it will be discussed the importance and the applicability of these polyphenolic compounds as neuroprotective agents and it will be also scrutinized the molecular mechanisms underlying the modulation of neuroinflammation by these natural compounds in the context of several brain diseases.

Changes in Bioactive Compounds, Antioxidant Activity, and Nutritional Quality of Blood Orange Cultivars at Different Storage Temperatures

Information about the postharvest physiological behavior of blood orange cultivars can provide comprehensive insight into the best period of storage to maintain the highest fruit quality during prolonged cold storage. In this paper, changes in nutritional quality, bioactive compounds, and antioxidant enzymes in the juice of four blood orange cultivars ("Moro", "Tarocco", "Sanguinello", and "Sanguine") stored at 2 and 5 °C were studied. Parameters were measured after 0, 30, 60, 90, 120, 150, and 180 days, plus 2 days at 20 °C for shelf life. Sucrose was the sugar found in higher concentrations and decreased during storage in all cultivars, as did glucose and fructose. Organic acids decreased at both temperatures, with the highest content found in "Sanguinello", especially major (citric acid) and ascorbic acid. Total phenolics content (TPC), total anthocyanins (TAC), and individual cyanidin 3-glucoside and cyanidin 3-(6″-malonylglucoside) increased for all cultivars, with "Sanguinello" having higher concentrations. The antioxidant enzymes catalase (CAT), ascorbate peroxidase (APX), and superoxide dismutase (SOD) were also higher in "Sanguinello" and increased during storage. Overall, these results together with the sensory analysis suggested that "Sanguinello" would be the best cultivar for prolonged storage. The results of this study could be useful to select the best storage duration and temperature for each cultivar and provide the presence of such a high-value commodity for fresh consumption or juice processing long after the harvest season.

A review of the interaction between anthocyanins and proteins

Anthocyanins have good physiological functions, but they are unstable. The interaction between anthocyanins and proteins can improve the stability, nutritional and functional properties of the complex. This paper reviews the structural changes of complex of anthocyanins interacting with proteins from different sources. By circular dichroism (CD) spectroscopy, it was found that the contents of α-helix (from 15.90%-42.40% to 17.60%-52.80%) or β-sheet (from 29.00%-50.00% to 29.40%-57.00%) of the anthocyanins-proteins complex increased. Fourier transform infrared spectroscopy showed that the regions of amide I (from 1627.87-1641.41 cm^-1 to 1643.34-1651.02 cm^-1) and amide II (from 1537.00-1540.25 cm^-1 to 1539.00-1543.75 cm^-1) of anthocyanins-proteins complex were shifted. Fluorescence spectroscopy showed that the fluorescence intensity of the complex decreased from 150-5100 to 40-3900 a.u. The thermodynamic analysis showed that there were hydrophobic interactions, electrostatic and hydrogen bonding interactions between anthocyanins and proteins. The kinetic analysis showed that the half-life and activation energy of the complex increased. The stability, antioxidant, digestion, absorption, and emulsification of the complex were improved. This provides a reference for the study and application of anthocyanins and proteins interactions.

Role of the Encapsulation in Bioavailability of Phenolic Compounds

Plant-derived phenolic compounds have multiple positive health effects for humans attributed to their antioxidative, anti-inflammatory, and antitumor properties, etc. These effects strongly depend on their bioavailability in the organism. Bioaccessibility, and consequently bioavailability of phenolic compounds significantly depend on the structure and form in which they are introduced into the organism, e.g., through a complex food matrix or as purified isolates. Furthermore, phenolic compounds interact with other macromolecules (proteins, lipids, dietary fibers, polysaccharides) in food or during digestion, which significantly influences their bioaccessibility in the organism, but due to the complexity of the mechanisms through which phenolic compounds act in the organism this area has still not been examined sufficiently. Simulated gastrointestinal digestion is one of the commonly used in vitro test for the assessment of phenolic compounds bioaccessibility. Encapsulation is a method that can positively affect bioaccessibility and bioavailability as it ensures the coating of the active component and its targeted delivery to a specific part of the digestive tract and controlled release. This comprehensive review aims to present the role of encapsulation in bioavailability of phenolic compounds as well as recent advances in coating materials used in encapsulation processes. The review is based on 258 recent literature references.

Anthocyanins: A Comprehensive Review of Their Chemical Properties and Health Effects on Cardiovascular and Neurodegenerative Diseases

Anthocyanins are a class of water-soluble flavonoids widely present in fruits and vegetables. Dietary sources of anthocyanins include red and purple berries, grapes, apples, plums, cabbage, or foods containing high levels of natural colorants. Cyanidin, delphinidin, malvidin, peonidin, petunidin, and pelargonidin are the six common anthocyanidins. Following consumption, anthocyanin, absorption occurs along the gastrointestinal tract, the distal lower bowel being the place where most of the absorption and metabolism occurs. In the intestine, anthocyanins first undergo extensive microbial catabolism followed by absorption and human phase II metabolism. This produces hybrid microbial-human metabolites which are absorbed and subsequently increase the bioavailability of anthocyanins. Health benefits of anthocyanins have been widely described, especially in the prevention of diseases associated with oxidative stress, such as cardiovascular and neurodegenerative diseases. Furthermore, recent evidence suggests that health-promoting effects attributed to anthocyanins may also be related to modulation of gut microbiota. In this paper we attempt to provide a comprehensive view of the state-of-the-art literature on anthocyanins, summarizing recent findings on their chemistry, biosynthesis, nutritional value and on their effects on human health.

Fruit and vegetable waste management: Conventional and emerging approaches

Valorization of Fruit and Vegetable Wastes (FVW) is challenging owing to logistic-related problems, as well as to their perishable nature and heterogeneity, among other factors. In this work, the main existing routes for food waste valorization are critically reviewed. The study focuses on FVW because they constitute an important potential source for valuable natural products and chemicals. It can be concluded that FVW management can be carried out following different processing routes, though nowadays the best solution is to find an adequate balance between conventional waste management methods and some emerging valorization technologies. Presently, both conventional and emerging technologies must be considered in a coordinated manner to enable an integral management of FVW. By doing so, impacts on food safety and on the environment can be minimized whilst wasting of natural resources is avoided. Depending on the characteristics of FVW and on the existing market demand, the most relevant valorization options are extraction of bioactive compounds, production of enzymes and exopolysaccharides, synthesis of bioplastics and biopolymers and production of biofuels. The most efficient emergent processing technologies must be promoted in the long term, in detriment of the conventional ones used nowadays. In consequence, future integral valorization of FVW will probably comprise two stages: direct processing of FVW into value-added products, followed by processing of the residual streams, byproducts and leftover matter by means of conventional waste management technologies.

Comparative Phytochemical Characterization, Genetic Profile, and Antiproliferative Activity of Polyphenol-Rich Extracts from Pigmented Tubers of Different Solanum tuberosum Varieties

Plants produce a vast array of biomolecules with beneficial effects for human health. In this study, polyphenol and anthocyanin-rich extracts (PAE) from pigmented tubers of Solanum tuberosum L. varieties “Blue Star”, “Magenta Love”, and “Double Fun” in comparison with the more extensively studied “Vitelotte” were evaluated and compared for antiproliferative effects in human leukemia cells, and their phytochemical and genetic profiles were determined. In U937 cells, upon treatment with PAE, it was possible to reveal the expression of specific apoptotic players, such as caspase 8, 9, 3, and poly (ADP-ribose) polymerase (PARP), as well as the induction of monocyte and granulocyte differentiation. A liquid chromatography/electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) investigation revealed the presence of polyphenolic compounds in all the varieties of potatoes analyzed, among which caffeoyl and feruloyl quinic acid derivatives were the most abundant, as well as several acylated anthocyanins. Each pigmented variety was genotyped by DNA-based molecular markers, and flavonoid-related transcription factors were profiled in tubers in order to better characterize these outstanding resources and contribute to their exploitation in breeding. Interesting biological activities were observed for “Blue Star” and “Vitelotte” varieties with respect to the minor or no effect of the “Double Fun” variety.

Anthocyanins: From plant pigments to health benefits at mitochondrial level

Anthocyanins are water-soluble pigments providing certain color for various plant parts, especially in edible berries. Earlier these compounds were only known as natural food colorants, the stability of which depended on pH, light, storage temperature and chemical structure. However, due to the increase of the in vitro, in vivo experimental data, as well as of the epidemiological studies, today anthocyanins and their metabolites are also regarded as potential pharmaceutical compounds providing various beneficial health effects on either human or animal cardiovascular system, brain, liver, pancreas and kidney. Many of these effects are shown to be related to the free-radical scavenging and antioxidant properties of anthocyanins, or to their ability to modulate the intracellular antioxidant systems. However, it is generally overlooked that instead of acting exclusively as antioxidants certain anthocyanins affect the activity of mitochondria that are the main source of energy in cells. Therefore, the aim of the present review is to summarize the major knowledge about the chemistry and regulation of biosynthesis of anthocyanins in plants, to overview the facts on bioavailability, and to discuss the most recent experimental findings related to the beneficial health effects emphasizing mitochondria.

Blueberry pectin and increased anthocyanins stability under in vitro digestion

Pectin was extracted from blueberry powder as water soluble fraction (WSF), rich in branched regions, and chelator soluble fraction (CSF), linear, with strong negative charge. Binding of pectins with three anthocyanin standards (malvidin-3-glucoside; M3G, cyanidin-3-glucoside; C3G, and delphinidin-3-glucoside; D3G) and blueberry extract (BBE) were used. Without blueberry pectin, M3G was the most stable followed by C3G, whereas D3G completely disappeared after gastrointestinal digestion. CSF prevented M3G and C3G degradation more than WSF, the in vitro stability was highest with CSF and C3G. Increased stability of anthocyanins after simulated gastrointestinal digestion suggests that anthocyanins can be transported to colon where gut microbiota actively produce anthocyanin metabolites. The amount of bound anthocyanins that interacted with blueberry pectin increased as the number of hydroxyl groups increased on anthocyanins. Hydrogen bonding in addition to electrostatic interaction contribute to stability of pectin-anthocyanins interaction at pH 4.0 and contribute to stability under gastrointestinal simulation.

Dietary Anthocyanins and Stroke: A Review of Pharmacokinetic and Pharmacodynamic Studies

Cerebrovascular accidents are currently the second major cause of death and the third leading cause of disability in the world, according to the World Health Organization (WHO), which has provided protocols for stroke prevention. Although there is a multitude of studies on the health benefits associated with anthocyanin (ACN) consumption, there is no a rigorous systematization of the data linking dietary ACN with stroke prevention. This review is intended to present data from epidemiological, in vitro, in vivo, and clinical studies dealing with the stroke related to ACN-rich diets or ACN supplements, along with possible mechanisms of action revealed by pharmacokinetic studies, including ACN passage through the blood-brain barrier (BBB).

Delivery of phytochemicals by liposome cargos: recent progress, challenges and opportunities

Bio-availability is a major concern in delivery of dietary phytochemicals for better bio-efficacy. The reduced bio-availability of food bioactive compounds is evident due to degradation during human digestion process which involves liberation, absorption, distribution, metabolism and elimination. The bio-efficacy of any nutrient can be increased by increasing bio-availability. Different technologies are available for engineered efficient delivery systems; still many challenges remain with advancement of delivery systems. The ease of preparedness and adaptability of liposomes has resulted in wide-range of applicability and acceptability in scientific field, especially as delivery vehicles. In view, of properties like biocompatibility and biodegradability, liposomes have been modified with different usable methodologies for delivery of phytochemicals. The aim of this review is to abridge liposomes, methods of preparation, their application as delivery cargo in dietary phytochemicals, result of using different preparation techniques on properties.

Absorption of Anthocyanin Rutinosides after Consumption of a Blackcurrant ( Ribes nigrum L.) Extract

The dominant anthocyanins in blackcurrant are delphinidin-3-O-rutinoside and cyanidin-3-O-rutinoside. Data on their absorption and distribution in the human body are limited. Therefore, we performed a human pilot study on five healthy male volunteers consuming a blackcurrant ( Ribes nigrum L.) extract. The rutinosides and their degradation products gallic acid and protocatechuic acid were determined in plasma and urine. The rutinosides' concentrations peaked in both plasma and urine samples within 2 h of extract ingestion. The recoveries of delphinidin-3-O-rutinoside and cyanidin-3-O-rutinoside from urine samples were 0.040 ± 0.011% and 0.048 ± 0.016%, respectively, over a 48 h period. Protocatechuic acid concentration increased significantly after ingestion of the blackcurrant extract. Our results show that after ingestion of a blackcurrant extract containing delphinidin-3-O-rutinoside and cyanidin-3-O-rutinoside, significant quantities of biologically active compounds circulated in the plasma and were excreted via urine. Furthermore, these results contribute to the understanding of anthocyanin metabolism in humans.

Nanoemulsion and Nanoliposome Based Strategies for Improving Anthocyanin Stability and Bioavailability

BACKGROUND

Anthocyanins, a flavonoid class of water-soluble pigments, are reported to possess several biological activities, including antioxidant, anti-inflammatory, and anti-cancer. However, anthocyanins are highly susceptible to degradation in high pH, light, heat, and oxygen during processing and storage. Conventional microencapsulation techniques fail to provide stability to anthocyanins under physiological environments mainly because of their large particle size as well as low zeta potential and encapsulation efficiency.

METHODS

Nanotechnology provides novel strategies for preparing nanoformulations to enhance the physicochemical stability of anthocyanins. Nanoemulsion and nanoliposome are the two most commonly used nanosystems in pharmaceutical and food-related fields. In this review, an overview of various nanoemulsion and nanoliposome systems reported recently for enhancing stability, bioavailability, and bioactivity of anthocyanins is presented.

RESULTS

Anthocyanin nanoemulsions with different oil, water, surfactant, and cosurfactant ratios were prepared from extracts of mangosteen peel, purple sweet potato, cranberry, red cabbage, blueberry, jaboticaba peel, and acai berry and evaluated for their antioxidant activity, enhancement of physicochemical stability, topical skin application, and urinary tract infection. Likewise, unilamellar and multilamellar nanoliposomes were prepared using different types and levels of lecithin without or with cholesterol from anthocyanin standards and extracts of Hibiscus sabdariffa, mulberry, elderberry, black carrot, and pistachio green hull for the evaluation of physicochemical and oxidative stability, in vitro bioaccessibility, and melanogenic activity, as well as protective effects against diabetes mellitus and cataract.

CONCLUSION

This review provides an insight into the current nanotechnology updates on enhancement of anthocyanin stability and biological activity.