Anthocyanins: New techniques and challenges in microencapsulation

Valorization of natural colors as health-promoting bioactive compounds: Phytochemical profile, extraction techniques, and pharmacological perspectives

Color is the prime attribute with a large impact on consumers' perception, selection, and acceptance of foods. However, the belief in bio-safety protocols, health benefits, and the nutritional importance of food colors had focused the attention of the scientific community across the globe towards natural colorants that serve to replace their synthetic toxic counterparts. Moreover, multi-disciplinary applications of greener extraction techniques and their hyphenated counterparts for selective extraction of bioactive compounds is a hot topic focusing on process intensification, waste valorization, and retention of highly stable bioactive pigments from natural sources. In this article, we have reviewed available literature to provide all possible information on various aspects of natural colorants, including their sources, photochemistry and associated biological activities explored under in-vitro and in-vivo animal and human studies. However a particular focus is given on innovative technological approaches for the effective extraction of natural colors for nutraceutical and pharmaceutical applications.

Anthocyanins Recovered from Agri-Food By-Products Using Innovative Processes: Trends, Challenges, and Perspectives for Their Application in Food Systems

Anthocyanins are naturally occurring phytochemicals that have attracted growing interest from consumers and the food industry due to their multiple biological properties and technological applications. Nevertheless, conventional extraction techniques based on thermal technologies can compromise both the recovery and stability of anthocyanins, reducing their global yield and/or limiting their application in food systems. The current review provides an overview of the main innovative processes (e.g., pulsed electric field, microwave, and ultrasound) used to recover anthocyanins from agri-food waste/by-products and the mechanisms involved in anthocyanin extraction and their impacts on the stability of these compounds. Moreover, trends and perspectives of anthocyanins' applications in food systems, such as antioxidants, natural colorants, preservatives, and active and smart packaging components, are addressed. Challenges behind anthocyanin implementation in food systems are displayed and potential solutions to overcome these drawbacks are proposed.

Microencapsulation of Anthocyanins—Critical Review of Techniques and Wall Materials

Anthocyanins are value-added food ingredients that have health-promoting impacts and biological functionalities. Nevertheless, there are technological barriers to their application in the food industry, mainly because of their poor stability and susceptibility to harsh environmental conditions, such as oxygen, temperature, pH, and light, which could profoundly influence the final food product′s physicochemical properties. Microencapsulation technology is extensively investigated to enhance stability, bioaccessibility, and impart controlled release properties. There are many varieties of microencapsulation methods and diverse types of wall materials. However, choosing a proper approach involves considering the processing parameters, equipment availability, and application purposes. The present review thoroughly scrutinizes anthocyanins′ chemical structure, principles, benefits, and drawbacks of different microencapsulation methods, including spray drying, freeze drying, electrospinning/electrospraying, inclusion complexes, emulsification, liposomal systems, ionic gelation, and coacervation. Furthermore, wall materials applied in different techniques plus parameters that affect the powders′ encapsulation efficiency and physicochemical properties are discussed. Future studies should focus on various processing parameters and the combination of different techniques and applications regarding microencapsulated anthocyanins in functional foods to assess their stability, efficiency, and commercialization potentials.

Kinetics Drying of Blackberry Bagasse and Degradation of Anthocyanins and Bioactive Properties

The process of drying food is necessary to preserve it; however, some bioactive compounds can be degraded during drying process. In this work, the convective drying process of Peruvian blackberry bagasse and the degradation of anthocyanins, total phenolic content (TPC), and antioxidant capacity (AC) were studied. The logarithmic model fitted well to the data and could predict the process, showing that 6 h of drying at 90 °C is enough to reach equilibrium moisture. Anthocyanin degradation followed a first-order kinetic model with reaction rate constant between 5.45 × 10^-2 ± 4.68 × 10^-3 and 1.21 × 10^-1 ± 2.31 × 10^-2 h^-1, and activation energy of 25.11 kJ/mol. The highest retention (84.38%) of anthocyanins was obtained in 1 h at 50 °C and the highest degradation (68.54%) in 6 h at 90 °C. The TPC and AC increased with the drying time and temperature due to the increased water evaporation.

Novel Processes for the Extraction of Phenolic Compounds from Olive Pomace and Their Protection by Encapsulation

Olive pomace, the solid by-product derived from olive oil production consists of a high concentration of bioactive compounds with antioxidant activity, such as phenolic compounds, and their recovery by applying innovative techniques is a great opportunity and challenge for the olive oil industry. This study aimed to point out a new approach for the integrated valorization of olive pomace by extracting the phenolic compounds and protecting them by encapsulation or incorporation in nanoemulsions. Innovative assisted extraction methods were evaluated such as microwave (MAE), homogenization (HAE), ultrasound (UAE), and high hydrostatic pressure (HHPAE) using various solvent systems including ethanol, methanol, and natural deep eutectic solvents (NADESs). The best extraction efficiency of phenolic compounds was achieved by using NADES as extraction solvent and in particular the mixture choline chloride-caffeic acid (CCA) and choline chloride-lactic acid (CLA); by HAE at 60 °C/12,000 rpm and UAE at 60 °C, the total phenolic content (TPC) of extracts was 34.08 mg gallic acid (GA)/g dw and 20.14 mg GA/g dw for CCA, and by MAE at 60 °C and HHPAE at 600 MPa/10 min, the TPC was 29.57 mg GA/g dw and 25.96 mg GA/g dw for CLA. HAE proved to be the best method for the extraction of phenolic compounds from olive pomace. Microencapsulation and nanoemulsion formulations were also reviewed for the protection of the phenolic compounds extracted from olive pomace. Both encapsulation techniques exhibited satisfactory results in terms of encapsulation stability. Thus, they can be proposed as an excellent technique to incorporate phenolic compounds into food products in order to enhance both their antioxidative stability and nutritional value.

Polyphenols from food by-products: An alternative or complementary therapy to IBD conventional treatments

Inflammatory bowel diseases (IBD) are illnesses characterized by chronic intestinal inflammation and microbial dysbiosis that have emerged as a public health challenge worldwide. It comprises two main conditions: Crohn's disease and ulcerative colitis. Currently, conventional therapy to treat IBD are not free from side effects, such as liver and kidney toxicity, drug resistance, and allergic reactions. In view of this, there is growing research for alternative and complementary therapies that, in addition to acting in the prevention or the control of the disease, do not compromise the quality of life and health of individuals. In this sense, a growing body of evidence has confirmed the benefits of natural phenolic compounds in intestinal health. Phenolic compounds or polyphenols are molecules widely distributed throughout the plant kingdom (flowers, vegetables, leaves, and fruits), including plant materials remaining of the handling and food industrial processing, referred to in the scientific literature as by-products, food waste, or bagasse. Since by-products are low-cost, abundant, easily accessible, safe, and rich in bioactive compounds, it becomes an exciting option to extract, concentrate or isolate phenolic compounds to be posteriorly applied in the therapeutic approach of IBD. In this article, we have reviewed the main phenolic compounds present in various plants and by-products that have shown beneficial and/or promising effects in experimental pre-clinical, clinical, and in vitro research with IBD. In addition, we have mentioned and suggested several plants and by-products originated and produced in Latin America that could be part of future research as good sources of specific phenolic compounds to be applied in the prevention and development of alternative treatments for IBD. This review may offer a valuable reference for studies related to IBD administering phenolic compounds from natural, cheap, and easily accessible raw and undervalued materials.

Blueberry Supplementation in Neuronal Health and Protective Technologies for Efficient Delivery of Blueberry Anthocyanins

Blueberries are consumed as healthy fruits that provide a variety of benefits to the nervous system. Scientists have found that blueberries can be used as a daily edible source for supplementation to prevent and minimize complexities of age-related diseases as well as to improve learning and memory in children. Anthocyanins are the most mentioned compounds among the components in blueberries, as they play a major role in providing the health benefits of this fruit. However, while they are highly active in impeding biological impairment in neuronal functions, they have poor bioavailability. This review focuses on neurological investigations of blueberries from in vitro cell studies to in vivo studies, including animal and human studies, with respect to their positive outcomes of neuroprotection and intervention in neurodegenerative conditions. Readers will also find information on the bioavailability of anthocyanins and the considerable factors affecting them so that they can make informed decisions regarding the daily consumption of blueberries. In this context, the ways in which blueberries or blueberry supplementation forms are consumed and which of these forms is best for maximizing the health benefits of blueberries should be considered important decision-making factors in the consumption of blueberries; all of these aspects are covered in this review. Finally, we discuss recent technologies that have been employed to improve the bioavailability of blueberry anthocyanins in the development of effective delivery vehicles supporting brain health.

Comparative Study of the Structural Properties, Color, Bioactive Compounds Content and Antioxidant Capacity of Aerated Gelatin Gels Enriched with Cryoconcentrated Blueberry Juice during Storage

Cryoconcentrated blueberry juice (CBJ) was incorporated into aerated gelatin gel and the effects on the mechanical properties, phenolic compounds and antioxidant activity (AA) were evaluated at day 1 and day 28 under refrigerated storage. At day 1, 8 g of gelatin gel and 40 g of CBJ (called M5) exhibited a soft texture and heterogeneous and non-spherical small bubbles, with values close to 10.5, 8.0 and 7.1 N, for hardness, gumminess and chewiness, respectively. M5 presented an increase of approximately 1.7, 1.9 and 1.9, and 1.2, 1.8, 2.1 and 1.3 times in comparison to the other samples, for total polyphenol, anthocyanin and flavonoid contents, and individual phenolic compounds, 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP) and oxygen radical absorbance capacity (ORAC) assays, respectively. At day 28, the samples showed a weakening of the 3D network, with high degradation of phenolic compounds and AA due to the oxidation, polymerization and syneresis. Therefore, CBJ might be an interesting functional ingredient to add to (aerated and non-aerated) gelatin gel without affecting its properties, and thus different food products with high nutritional values and without added artificial sweeteners could be developed. Additionally, the gelatin gel/CBJ combinations might be suitable for additive manufacturing as a coating of food matrices.

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.

Stable vesicle self-assembled from phospholipid and mannosylerythritol lipid and its application in encapsulating anthocyanins

Stable vesicles were formulated based on the self-assembling of L-α-phosphatidylcholine (PC) and mannosylerythritol lipid-A (MEL-A) in a manner of weak or non-cooperative interactions. Their structural characterization, stability and encapsulation properties were evaluated. The results showed that the predominant average diameters varied ranging from 200 nm to 700 nm with MEL-A/PC ratio changed. In case of the ratio at 5:5, 6:4 or 7:3, the vesicles performed the smaller size or turbidity and larger entrapment efficiency for hydrophilic molecules. Anthocyanins were successfully encapsulated using these vesicles, which was confirmed by the formation of egg-shaped structures with the core size less than 500 nm and an encapsulation efficiency of 54.9 ± 1.6%. Compared with free anthocyanins, the encapsulated anthocyanins displayed higher retention rates when exposed to storage and simulated gastrointestinal fluid conditions, and their antioxidant capacity after simulated intestinal digestion was enhanced by 3-3.5 times because of protection of vesicle encapsulation and possible synergic effects.

Recent advances in food products fortification with anthocyanins

Anthocyanins are polyphenolic compounds belonging to the group of flavonoids in charge of providing red, purple, and blue colourations to different parts of trees and plants, such as leaves, flowers, fruits, roots, and stems. These substances have potential health benefits due to characteristics such as antioxidant and anti-inflammatory properties, which could be leveraged in the food industry. However, the use and handling of anthocyanins are conditioned due to the low stability of these molecules. For this reason, the application of adequate extraction, purification and stabilization techniques is required for its subsequent management. In this regards, green extraction methods and novel stabilization techniques are of particular interest in the utilization of these biocompounds. This review provides in-depth information about the extraction, purification, and stabilization of anthocyanins from different plant sources. Additionally, this work highlights the potential use of anthocyanins in the food industry for the formulation of different fortified foods and beverages, which could have beneficial health effects. Green technologies, are a promising tool to recover extracts rich in anthocyanins from different vegetable matrices, including by-products. The extracts obtained can be easily used in the fortification of baked foods, dairy products, and different beverages.

Oxidative stress mitigation by antioxidants - An overview on their chemistry and influences on health status

The present review paper focuses on the chemistry of oxidative stress mitigation by antioxidants. Oxidative stress is understood as a lack of balance between the pro-oxidant and the antioxidant species. Reactive oxygen species in limited amounts are necessary for cell homeostasis and redox signaling. Excessive reactive oxygenated/nitrogenated species production, which counteracts the organism's defense systems, is known as oxidative stress. Sustained attack of endogenous and exogenous ROS results in conformational and oxidative alterations in key biomolecules. Chronic oxidative stress is associated with oxidative modifications occurring in key biomolecules: lipid peroxidation, protein carbonylation, carbonyl (aldehyde/ketone) adduct formation, nitration, sulfoxidation, DNA impairment such strand breaks or nucleobase oxidation. Oxidative stress is tightly linked to the development of cancer, diabetes, neurodegeneration, cardiovascular diseases, rheumatoid arthritis, kidney disease, eye disease. The deleterious action of reactive oxygenated species and their role in the onset and progression of pathologies are discussed. The results of oxidative attack become themselves sources of oxidative stress, becoming part of a vicious cycle that amplifies oxidative impairment. The term antioxidant refers to a compound that is able to impede or retard oxidation, acting at a lower concentration compared to that of the protected substrate. Antioxidant intervention against the radicalic lipid peroxidation can involve different mechanisms. Chain breaking antioxidants are called primary antioxidants, acting by scavenging radical species, converting them into more stable radicals or non-radical species. Secondary antioxidants quench singlet oxygen, decompose peroxides, chelate prooxidative metal ions, inhibit oxidative enzymes. Moreover, four reactivity-based lines of defense have been identified: preventative antioxidants, radical scavengers, repair antioxidants, and those relying on adaptation mechanisms. The specific mechanism of a series of endogenous and exogenous antioxidants in particular aspects of oxidative stress, is detailed. The final section resumes critical conclusions regarding antioxidant supplementation.

The Therapeutic Potential of Anthocyanins: Current Approaches Based on Their Molecular Mechanism of Action

Anthocyanins are natural phenolic pigments with biological activity. They are well-known to have potent antioxidant and antiinflammatory activity, which explains the various biological effects reported for these substances suggesting their antidiabetic and anticancer activities, and their role in cardiovascular and neuroprotective prevention. This review aims to comprehensively analyze different studies performed on this class of compounds, their bioavailability and their therapeutic potential. An in-depth look in preclinical, in vitro and in vivo, and clinical studies indicates the preventive effects of anthocyanins on cardioprotection, neuroprotection, antiobesity as well as their antidiabetes and anticancer effects.