Encapsulating anthocyanins from Hibiscus sabdariffa L. calyces by ionic gelation: Pigment stability during storage of microparticles

Microencapsulation of Pitanga extract (Eugenia uniflora L.) by ionic gelation: Effect of wall material and fluidized bed drying

Pitanga (Eugenia uniflora L.) is a fruit native to Brazil with a large amount of bioactive compounds, antioxidant properties and attractive color. However, it is not yet well studied, despite its high availability. A technique that can improve its application and the stability of its compounds is microencapsulation. Therefore, this work aimed to develop microparticles using ionic gelation (IG), multiple emulsion and fluidized bed drying. The pitanga fruit extract presented high levels of phenolic compounds and antioxidant capacity. The encapsulation efficiency in terms of phenolic compounds ranged from 25.76 to 54.51 %. Microparticles showed D50 ranging from 455 to 676 μm. The temperature and drying time influenced the physicochemical characteristics of the microparticles as they were dried in a fluidized bed. Microparticles dried at a higher temperature, for a shorter time and with a higher final moisture content exhibited a higher concentration of phenolic compounds, lighter color, less agglomeration, but lower carotenoid content. These results demonstrate that the IG and fluidized bed drying process is a promising method to increase the commercialization of pitanga fruit. These techniques have increased the stability of the active compounds of this fruit and can enable its application in foods as a natural colorant and/or functional agent.

Alginate Microbeads for Trapping Phenolic Antioxidants in Rosemary (Rosmarinus officinalis L.): Multivariate Optimization Based on Bioactive Properties and Morphological Measurements

Medical and aromatic plant extracts are often very sensitive to environmental, gastrointestinal, and processing conditions despite their health benefits. Therefore, they can be rapidly inactivated. Microencapsulation is used to overcome such challenges. In this study, phenolic antioxidants from rosemary (Rosmarinus officinalis L.) were encapsulated in alginate beads by means of ionic gelation. A Box-Behnken design with response surface methodology (BBD-RSM) was used with three numeric factors (calcium chloride concentration, alginate concentration, and hardening time) to achieve the best formulation in terms of encapsulation efficiency, antioxidant activity, and morphological characteristics. Generally, the sodium alginate concentration of the microbeads was the most critical factor (p < 0.0001) for the quality of the products. The optimal encapsulation conditions were accessed using concentrations with almost 6% calcium chloride and 2% alginate, and a time of 10 min for bead hardening in order to obtain the highest responses (30.01% encapsulation efficiency, 7.55 mg-TEAC/g-DM of antioxidant activity value as measured by the DPPH method, a sphericity factor of 0.05, and a roundness of 0.78). At the optimum point, the microbeads were determined to be spherical in shape, and the bulk density value was measured as 0.34 ± 0.01 g/mL.

Whey Protein Isolate as a Substrate to Design Calendula officinalis Flower Extract Controlled-Release Materials

The use of natural active substances and the development of new formulations are promising directions in the cosmetic and pharmacy industries. The primary purpose of this research was the production of microparticles based on whey protein isolate (WPI) and calcium alginate (ALG) containing Calendula officinalis flower extract and their incorporation into films composed of gelatin, WPI, and glycerol. Both swollen and dry microparticles were studied by optical microscopy and their sizes were measured. Water absorption by the microparticles, their loading capacity, and the release profile of flower extract were also characterized. The films were analyzed by mechanical tests (Young's modulus, tensile strength, elongation at break), swelling capacity, contact angle, and moisture content measurements. The presented data showed that the active ingredient was successfully enclosed in spherical microparticles and completely released after 75 min of incubation at 37 °C. The incorporation of the microparticles into polymer films caused a decrease in stiffness and tensile strength, simultaneously increasing the ductility of the samples. Moreover, the films containing microparticles displayed higher swelling ability and moisture content compared to those without them. Hence, the materials prepared in this study with Calendula officinalis flower extract encapsulated into polymeric microspheres can be a starting point for the development of new products intended for skin application; advantages include protection of the extract against external factors and a controlled release profile.

Dietary Sources, Stabilization, Health Benefits, and Industrial Application of Anthocyanins-A Review

Natural phytochemicals are well known to protect against numerous metabolic disorders. Anthocyanins are vacuolar pigments belonging to the parent class of flavonoids. They are well known for their potent antioxidant and gut microbiome-modulating properties, primarily responsible for minimizing the risk of cardiovascular diseases, diabetes, obesity, neurodegenerative diseases, cancer, and several other diseases associated with metabolic syndromes. Berries are the primary source of anthocyanin in the diet. The color and stability of anthocyanins are substantially influenced by external environmental conditions, constraining their applications in foods. Furthermore, the significantly low bioavailability of anthocyanins greatly diminishes the extent of the actual health benefits linked to these bioactive compounds. Multiple strategies have been successfully developed and utilized to enhance the stability and bioavailability of anthocyanins. This review provides a comprehensive view of the recent advancements in chemistry, biosynthesis, dietary sources, stabilization, bioavailability, industrial applications, and health benefits of anthocyanins. Finally, we summarize the prospects and challenges of applications of anthocyanin in foods.

Exploring the Nutritional and Bioactive Potential of Olive Leaf Residues: A Focus on Minerals and Polyphenols in the Context of Spain's Olive Oil Production

Lyophilized plant-origin extracts are rich in highly potent antioxidant polyphenols. In order to incorporate them into food products, it is necessary to protect these phytochemicals from atmospheric factors such as heat, light, moisture, or pH, and to enhance their bioavailability due to their low solubility. To address these challenges, recent studies have focused on the development of encapsulation techniques for antioxidant compounds within polymeric structures. In this study, lyophilized olive leaf extracts were microencapsulated with the aim of overcoming the aforementioned challenges. The method used for the preparation of the studied microparticles involves external ionic gelation carried out within a water-oil (W/O) emulsion at room temperature. HPLC analysis demonstrates a high content of polyphenols, with 90% of the bioactive compounds encapsulated. Meanwhile, quantification by inductively coupled plasma optical emission spectroscopy (ICP-OES) reveals that the dried leaves, lyophilized extract, and microencapsulated form contain satisfactory levels of macro- and micro-minerals (calcium, potassium, sodium). The microencapsulation technique could be a novel strategy to harness the polyphenols and minerals of olive leaves, thus enriching food products and leveraging the antioxidant properties of the polyphenolic compounds found in the lyophilized extract.

An efficient method for improving the stability of Monascus pigments using ionic gelation

BACKGROUND

Monascus pigments (Mps) are easily impacted by heating, pH and light, resulting in degradation. In this study, Mps were encapsulated by the ionic gelation method with sodium alginate (SA) and sodium caseinate (SC), as well as CaCl2 as a crosslinker. The encapsulated Mps SA/SC in four proportions (SA/SC: 1/4, 2/3, 3/2, 4/1, w/w). Then, the encapsulation efficiency and particle size of the SA/SC-Mps system were evaluated to obtain the optimal embedding conditions. Finally, the effects of heating, pH, light and storage on the stability of non-capsulated Mps and encapsulated Mps were assessed.

RESULTS

SA/SC = 2/3 (AC2) had higher encapsulation efficiency (74.30%) of Mps and relatively small particle size (2.02 mm). The AC2 gel beads were chosen for further investigating the stability of encapsulated Mps to heating, pH, light and storage. Heat stability experiments showed that the degradation of Mps followed first-order kinetics, and the encapsulated Mps had lower degradation rates than non-capsulated Mps. Encapsulation could reduce the effect of pH on Mps. The effects of ultraviolet light on the stability of Mps were considered, and showed that the retention efficiency of encapsulated Mps was 22.01% higher than that of non-capsulated Mps on the seventh day. Finally, storage stability was also evaluated under dark refrigerated conditions for 30 days, and the results indicated that encapsulation could reduce the degradation of Mps.

CONCLUSION

This study has proved that AC2 gel beads can improve the stability of Mps. Thus, the ionic gelation method is a promising encapsulation method to improve the stability of Mps. © 2023 Society of Chemical Industry.

Encapsulation of purple basil leaf extract by electrospraying in double emulsion (W/O/W) filled alginate-carrageenan beads to improve the bioaccessibility of anthocyanins

The purple basil leaf extract (PBLE) was encapsulated in double emulsion (W1/O/W2)-loaded beads (emulgel) by electrospraying. The influence of κ-carrageenan (κ-CG) and cross-linking agents (Ca2+/K+) on the properties of alginate (SA) beads were assessed. In emulgel beads, κ-CG inclusion resulted in larger sizes and more distorted shapes, wrinkles on the surface, and lower gel strength. The encapsulation efficiency of anthocyanins (ACNs) in emulgel beads ranged from 70.73 to 87.89 %, whereas it ranged from 13.50 to 20.67 % in emulsion-free (hydrogel) beads. Fourier transforms infrared (FTIR) revealed the crosslinking of SA and κ-CG with Ca2+ and K+, thermogravimetric analysis (TGA), derivative thermogravimetric (DTG), and differential scanning calorimetry (DSC) thermograms showed emulgel beads yielded higher thermal stability. The emulgel beads elevated the in vitro bioaccessibility of ACNs under simulated digestion. At the gastric phase, 86 % of ACNs in PBLE, and 46 % of loaded ACNs in hydrogel beads were released, whereas no release was occurred in emulgel beads. At the intestinal phase, after 150 min of digestion, no ACNs were detected in PBLE and hydrogel beads, whereas all emulgel beads continued to release ACNs until 300 min. The incorporation of double emulsions in hydrogel beads can be utilized in the development of functional foods.

Pectin Hydrogels: Gel-Forming Behaviors, Mechanisms, and Food Applications

Pectin hydrogels have garnered significant attention in the food industry due to their remarkable versatility and promising properties. As a naturally occurring polysaccharide, pectin forms three-dimensional (3D) hydrophilic polymer networks, endowing these hydrogels with softness, flexibility, and biocompatibility. Their exceptional attributes surpass those of other biopolymer gels, exhibiting rapid gelation, higher melting points, and efficient carrier capabilities for flavoring and fat barriers. This review provides an overview of the current state of pectin gelling mechanisms and the classification of hydrogels, as well as their crosslinking types, as investigated through diverse research endeavors worldwide. The preparation of pectin hydrogels is categorized into specific gel types, including hydrogels, cryogels, aerogels, xerogels, and oleogels. Each preparation process is thoroughly discussed, shedding light on how it impacts the properties of pectin gels. Furthermore, the review delves into the various crosslinking methods used to form hydrogels, with a focus on physical, chemical, and interpenetrating polymer network (IPN) approaches. Understanding these crosslinking mechanisms is crucial to harnessing the full potential of pectin hydrogels for food-related applications. The review aims to provide valuable insights into the diverse applications of pectin hydrogels in the food industry, motivating further exploration to cater to consumer demands and advance food technology. By exploiting the unique properties of pectin hydrogels, food formulations can be enhanced with encapsulated bioactive substances, improved stability, and controlled release. Additionally, the exploration of different crosslinking methods expands the horizons of potential applications.

Bioactive Compounds from BRS Violet Grape Pomace: An Approach of Extraction and Microencapsulation, Stability Protection and Food Application

Microencapsulating phenolic compounds and anthocyanins from grape pomace, a by-product of the food industry, is attractive because of the many beneficial health effects associated with these compounds. At first, we evaluated the cultivar BRS Violeta using microencapsulation, indicating the degree of innovation in the present research. This study aims to microencapsulate grape pomace extract in a combination of maltodextrin and xanthan gum via lyophilization, and determine the protective effect of this microcapsule on the phenolic compounds and anthocyanins. Thus, the microcapsule stability was determined over 120 days, under different temperature conditions (4 and 25 °C) and in the presence or absence of light. Additionally, a gelatin application test was performed to investigate the effect of the microcapsule on color stability. When comparing the extract versus microcapsules, the microcapsule results were better both for total anthocyanins (1.69 to 1.54-fold) and total phenolic compounds (3.06 to 1.74-fold), indicating a longer half-life after encapsulation. The microcapsule application in gelatin demonstrated that the encapsulating matrix retained the color for 30 days. Thus, the encapsulation method can be recommended to preserve the bioactive compounds and the coloration in food products such as gelatin.

The potential of anthocyanin-loaded alginate hydrogel beads for intelligent packaging applications: Stability and sensitivity to volatile amines

pH indicators have emerged as promising tools for real-time monitoring of product freshness and quality in intelligent food packaging applications. However, ensuring the stability of these indicators is critical for practical use. This study aims to evaluate the stability of anthocyanins-loaded alginate hydrogel beads of varying sizes at different temperatures under accelerated light conditions and relative humidity (RH) levels of 53% and 97% during 21 days of storage. Moreover, their sensitivity to the principal spoilage volatiles of muscle food products such as ammonia (NH3), dimethylamine (DMA) and trimethylamine (TMA) was investigated. The half-life of cyanidin-3-glucoside in small hydrogel beads was roughly twice as long as that of the larger beads under accelerated light exposure at 4 °C and they were less likely to undergo noticeable color changes over time. Both sizes of hydrogel beads stored at 97% RH and 4 °C showed color stability over the 21-day period with minimal color variation (|ΔE| ≤ 3). The UV-vis spectra of the purple corn extract exhibited changes across pH 2 to 12, as evidenced by the visible color variations, ranging from pink to green. The limit of detection (LOD) for NH3 was 25 ppm for small beads and 15 ppm for large ones. Both types of beads exhibited similar LOD for DMA and TMA, around 48 ppm. This research showed that alginate hydrogel beads containing anthocyanins from purple corn are a viable option for developing intelligent packaging of muscle foods. Furthermore, the use of hydrogel beads of different sizes can be customized to specific muscle foods based on the primary spoilage compound generated during spoilage.

Stability of yerba mate extract, evaluation of its microencapsulation by ionic gelation and fluidized bed drying

Studies show that yerba mate (Ilex paraguariensis) has high antioxidant capacity occasioned by its high contents of total phenolic compounds. Microencapsulation, specifically ionic gelation, since it does not use heating during process, is considered as an alternative for preserving and applying the extract. The purpose of this study was to evaluate general characteristics and stability of hydroalcoholic extract of yerba mate, conduct the extract microencapsulation by ionic gelation followed by microparticle fluidized bed drying. The extract was evaluated for color stability, total phenolic compounds, and antioxidant activity for nine weeks and at three temperatures (5, 15, and 25 °C). From the extract, a double emulsion (W/O/W), generation of microparticles (ionic gelation by dripping), and fluidized bed drying were conducted. The extract had 32912.55 mg GAE/100 g of phenolic compounds and 2379.49 μmol TE/g of antioxidant activity. The main compound observed was chlorogenic acid (5-CQA) with 0.35 ± 0.01 g/100 mL. In the stability study, the temperature was observed to influence in phenolic compounds reduction, as well as in total color difference of the extract. Double emulsion has shown to be stable and appropriate for use. The values of microparticles total phenolic compounds and antioxidant activity were 423.18 ± 8.60 mg GAE/100 g and 21.17 ± 0.24 μmol TE/g, respectively. After drying, the moisture of microparticles was reduced from 79.2% to 19%. The extract had high total phenolic compound content and high antioxidant activity. Storage at the lowest temperature (5 °C) assured better preservation of extract total phenolic compounds. The dried microparticles showed content of total phenolic compounds and antioxidant activity with potential for commercialization and future application in food matrices.

Fabrication of anthocyanin–rich W1/O/W2 emulsion gels based on pectin–GDL complexes: 3D printing performance

The stability of anthocyanin-rich W₁/O/W₂ double emulsions prepared with Nicandra physalodes (Linn.) Gaertn. Seeds pectin was investigated, including droplet sizes, ζ-potential, viscosity, color, microstructures and encapsulation efficiency. Furthermore, the gelation behavior, rheological behavior, texture behavior and three-dimensional (3D) printing effects of the W₁/O/W₂ emulsion gels induced with Glucono-delta-lactone (GDL) were studied. The L*, b*, ΔE, droplet sizes and ζ-potential of the emulsions were gradually increased, while other indicators were gradually decreased during 28 days of storage under 4 ℃. The storage stability of sample under storage at 4 ℃ was higher than 25 ℃. The G' of W₁/O/W₂ emulsion gels gradually boosted with increased GDL addition, and reached the highest after the addition of 1.6 % GDL. In creep-recovery sweep, the minimum strain of 1.68 % and the highest recovery rate of 86 % were also found for the emulsion gels with 1.6 % GDL. Accordingly, the models "KUST", hearts, flowers printed by emulsion gels after 60 min addition of 1.6 % GDL had the best printing effects. The W₁/O/W₂ emulsion gels based on pectin-GDL complexes exhibited good performance in protecting anthocyanins and suggested as a potential ink for food 3D printing.

Antioxidant and Antiradical Activities of Hibiscus sabdariffa L. Extracts Encapsulated in Calcium Alginate Spheres

The interest in natural sources with high antioxidant powder has recently increased in several sectors. Ionic gelation methods could be used to protect bioactive substances to control the kinetics and release of these ingredients to the food matrix. This study dealt with the evaluation of the antioxidant capacity and scavenging activity of extracts of Hibiscus Sabdariffa L. (HSL) (with 50% ethanol) encapsulated in calcium alginate spheres as a new source for preserving food against oxidative damage. Their antioxidant activity was measured in different o/w emulsions in which HSL spheres reduced the formation of hydroperoxides (~80%) and thiobarbituric-acid-reactive substance products (~20%). The scavenging activity of HSL extracts was measured in different food simulants (water, water acidified with 3% acetic acid, ethanol at 50%, and pure ethanol), and corresponded to 0.20–0.43, 0.31–0.62, and 11.13–23.82 mmol Trolox/mL extract for Trolox equivalent antioxidant capacity (TEAC), 2,2-diphenylpicrylhydrazyl (DPPH), and oxygen radical absorbance capacity (ORAC) assays, respectively. In general, the best antiradical activity was observed in the ethanolic and acidified mediums, in which the highest concentration of released polyphenols ranged from 0.068 to 0.079 mg GAE/mL. This work indicates the potential of alginate spheres for encapsulating antioxidant compounds as an innovative strategy for several industrial applications.

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.

Improved Stabilization and In Vitro Digestibility of Mulberry Anthocyanins by Double Emulsion with Pea Protein Isolate and Xanthan Gum

There is significant evidence that double emulsion has great potential for successfully encapsulating anthocyanins. However, few research studies are currently using a protein-polysaccharide mixture as a stable emulsifier for double emulsion. This study aimed to improve the stability and in vitro digestibility of mulberry anthocyanins (MAs) by employing a double emulsion composed of pea protein isolate (PPI) and xanthan gum (XG). The influence of various XG concentrations (0%, 0.2%, 0.4%, 0.6%, 0.8%, 1.0%) and different temperatures (5 °C, 25 °C, 45 °C, 65 °C) on the physical stability and the thermal degradation of MAs from double emulsions were investigated. In addition, the physicochemical properties of double emulsions and the release performance of MAs during in vitro simulated digestion were evaluated. It was determined that the double emulsion possessed the most stable physical characteristics with the 1% XG addition. The PPI-1% XG double emulsion, when compared to the PPI-only double emulsion, expressed higher thermal stability with a retention rate of 83.19 ± 0.67% and a half-life of 78.07 ± 4.72 days. Furthermore, the results of in vitro simulated digestion demonstrated that the MAs in the PPI-1% XG double emulsion were well-protected at oral and gastric with ample release found in the intestine, which was dissimilar to findings for the PPI-only double emulsion. Ultimately, it was concluded that the double emulsion constructed by the protein-polysaccharide system is a quality alternative for improving stability and absorption with applicability to a variety of food and beverage systems.

Resveratrol: Its Path from Isolation to Therapeutic Action in Eye Diseases

Due to the confirmed therapeutic potential of resveratrol (Rv) for eye diseases, namely its powerful anti-angiogenic and antioxidant effects, this molecule must be studied more deeply. Nowadays, the pharmaceutic and pharmacokinetic available studies offer a troubling picture because of its low stability and bioavailability. To overcome this problem, researchers started to design and create different delivery systems that could improve the delivery amount of Rv. Therefore, this review aims to shed light on the proper and efficient techniques to isolate, purify and quantify the Rv molecule, and how this therapeutic molecule can be a part of a delivery system. The Rv great impact on aspects regarding its stability, bioavailability and absorption are also debated here, based on the existent literature on in vitro and in vivo human and animal studies. Moreover, after its absorption the Rv influence at the molecular level in ocular pathologies is described. In addition, the present review summarizes the available literature about Rv, hoping that Rv will gain more attention to investigate its unexplored side.

Pectin-based color indicator films incorporated with spray-dried Hibiscus extract microparticles

Colorimetric films incorporated with anthocyanins as an indicator for freshness monitoring have aroused growing interest recently. The pH-sensing colorimetric film were developed based on pectin (HM), containing aqueous hibiscus extract microparticles (HAE). HAE microparticles were obtained by spray drying with different wall materials (Inulin -IN, maltodextrin- MD and their combination). The films were obtained on large scale by continuous casting. These films were characterized for physicochemical analysis, morphological structure, thermal and barrier properties, antioxidant activity, and color change at different pH. The addition of HAE microparticles caused relevant changes to HM-based films, such as in mechanical behavior and improved barrier property (11-22% WVTR reduction) depending on the type of wall material used and the concentration added. It was verified with the thermal stability of films, with a slight increase being observed. The color variation of smart films was entirely pH-dependent. Overall, the proposed color indicator films showed unique features and functionalities and could be used as an alternative natural pH indicator in smart packaging systems.

Active and pH-Sensitive Nanopackaging Based on Polymeric Anthocyanin/Natural or Organo-Modified Montmorillonite Blends: Characterization and Assessment of Cytotoxicity

Polymeric anthocyanins are biologically active, pH-sensitive natural compounds and pigments with beneficial functional, pharmacological and therapeutic properties for consumer health. More recently, they have been used for the manufacture of active and pH-sensitive ("intelligent") food nanopackaging, due to their bathochromic effect. Nevertheless, in order for polymeric anthocyanins to be included either as a functional food or as a pharmacological additive (medicinal food), they inevitably need to be stabilized, as they are highly susceptible to environmental conditions. In this regard, nanopackaging has become a tool to overcome the limitations of polymeric anthocyanins. The objective of this study was to evaluate their structural, thermal, morphological, physicochemical, antioxidant and antimicrobial properties, as well as their responses to pH changes, and the cytotoxicity of blends made from polymeric anthocyanins extracted from Jamaica flowers (Hibiscus sabdariffa) and natural or organo-modified montmorillonite (Mt), as active and pH-sensitive nanopackaging. This study allowed us to conclude that organo-modified Mts are efficient pH-sensitive and antioxidant nanopackaging systems that contain and stabilize polymeric anthocyanins compared to natural Mt nanopackaging and stabilizing polymeric anthocyanins. However, the use of these polymeric anthocyanin-stabilizing organo-modified Mt-based nanopackaging systems are limited for food applications by their toxicity.

Alginate Particles for Encapsulation of Phenolic Extract from Spirulina sp. LEB-18: Physicochemical Characterization and Assessment of In Vitro Gastrointestinal Behavior

Encapsulation can be used as a strategy to protect and control the release of bioactive extracts. In this work, an extract from Spirulina sp. LEB-18, rich in phenolic compounds, was encapsulated in biopolymeric particles (i.e., composed of alginate) and characterized concerning their thermal behavior using differential scanning calorimetry (DSC), size, morphology, swelling index (S), and encapsulation efficiency (EE%); the release profile of the phenolic compounds at different pHs and the particle behavior under in vitro gastrointestinal digestion were also evaluated. It was shown that it is possible to encapsulate the phenolic extract from Spirulina sp. LEB-18 in alginate particles with high encapsulation efficiency (88.97%). It was also observed that the particles are amorphous and that the encapsulated phenolic compounds were released at a pH 7.2 but not at pH 1.5, which means that the alginate particles are able to protect the phenolic compounds from the harsh stomach conditions but lose their integrity under intestinal pH conditions. Regarding bioaccessibility, it was observed that the encapsulated phenolic compounds showed higher bioaccessibility compared to phenolic compounds in free form. This work increases the knowledge about the behavior of alginate particles encapsulating phenolic compounds during in vitro gastrointestinal digestion. It also provides essential information for designing biopolymeric particle formulations encapsulating phenolic compounds for application in pharmaceutical and food products.

Formulation of Chitosan Microparticles for Enhanced Intranasal Macromolecular Compound Delivery: Factors That Influence Particle Size during Ionic Gelation

Therapeutic macromolecules (e.g., protein and peptide drugs) present bioavailability challenges via extravascular administration. The nasal route presents an alternative non-invasive route for these drugs, although low bioavailability remains challenging. Co-administration of permeation enhancers is a promising formulation approach to improve the delivery of poorly bioavailable drugs. The aim of this study was to prepare and characterize chitosan microparticulate formulations containing a macromolecular model compound (fluorescein isothiocyanate dextran 4400, FD-4) and a bioenhancer (piperine). Ionic gelation was used to produce chitosan microparticle delivery systems with two distinct microparticle sizes, differing one order of magnitude in size (±20 µm and ±200 µm). These two microparticle delivery systems were formulated into thermosensitive gels and their drug delivery performance was evaluated across ovine nasal epithelial tissues. Dissolution studies revealed a biphasic release pattern. Rheometry results demonstrated a sol-to-gel transition of the thermosensitive gel formulation at a temperature of 34 °C. The microparticles incorporating piperine showed a 1.2-fold increase in FD-4 delivery across the excised ovine nasal epithelial tissues as compared to microparticles without piperine. This study therefore contributed to advancements in ionic gelation methods for the formulation of particulate systems to enhance macromolecular nasal drug delivery.

Development of alginate/pectin microcapsules by a dual process combining emulsification and ultrasonic gelation for encapsulation and controlled release of anthocyanins from grapes (Vitis labrusca L.)

The aim of this study was to investigate the physicochemical, morphological, and gastrointestinal release properties of an anthocyanin-rich extract of grapes in alginate and pectin beads as carriers; the effects of ultrasonic gelation combined with emulsification were also investigated. In general, the alginate beads showed smaller size and more regular shape compared to pectin. The effect of emulsification combined with ionic gelation was more pronounced in the alginate beads and resulted in higher retention of anthocyanins, higher antioxidant capacity, and also allowed the best release profile during intestinal digestion. Thus, the simultaneous strategy could be an interesting delivery system and enhance the release of anthocyanins, providing an opportunity for the development of ingredients with different bioactive properties.

Entrapment of Black Carrot Anthocyanins by Ionic Gelation: Preparation, Characterization, and Application as a Natural Colorant in Yoghurt

Black carrot (BC) with its potential health benefits due to the greater amount of anthocyanins and the potent antioxidant activity could be utilized as a natural colorant. The objective of this study was the entrapment of BC anthocyanins by external ionic gelation technique within the biopolymer matrix including pectin, alginate, and the mixture of both. Beads were characterized in terms of entrapment efficiency (EE), morphology, total anthocyanin content, and antioxidant capacity measured by the 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid assay. Furthermore, the color of the beads as well as yoghurt samples fortified with BC-containing beads were evaluated during storage at 4 °C for 4 weeks. While the EE for anthocyanins ranged between 47.3 and 96.6%, the antioxidant capacity changed from 50.4 to 97.7%. The maximum anthocyanin retention was found as 91.7% for 1% BC containing 1% pectin (P) + 1% alginate (A)-based beads after 4 weeks of storage. In addition, anthocyanin protection reached up to 62% and antioxidant capacity up to 55.6% in the fortified yoghurt samples containing A-based beads during storage. It is concluded that external ionic gelation could be a feasible method for BC anthocyanins due to its protective effect against acidic environment.

Fabrication and Characterization of Alginate Hydrogels for Control Release System of Catechin-Derived Tea Leave Extract

Polyphenolic chemicals found in tea leaves are frequently used in pharmaceutics and the food industry. Catechin is a polyphenol that has antimicrobial, antioxidant, and antibacterial effects, as well as other health advantages. The goal of this study was to create a catechin-encapsulated alginate hydrogel (Cate-ALG) that would protect catechin from degradation and bioactivity loss in stressful environments while also delivering catechin. The antioxidant ability of catechin was found to be greater than that of vitamin C using the 2,2-diphenyl-1-pierylhyrazyl assay. The FT-IR spectra revealed the distinct peaks of catechin and alginate. Additionally, due to the hydrogen bond interaction between alginate and catechin molecules, frequency downshifting was observed in the carbonyl and hydroxyl regions. Furthermore, release profile revealed a burst release of 5% catechin-ALG in the first 25 min. On the other hand, the 3% Cate-ALG approached the controlled release profile of catechin and increased the release time by more than 40 minutes. The catechin in alginate hydrogel has the potential for controlled release via transdermal and wound dressing applications.

Microparticulate and nanotechnology mediated drug delivery system for the delivery of herbal extracts

There has been a growing interest in the scientific community to explore the complete potential of phytoconstituents, herbal or plant-based ingredients owing to a range of benefits they bring along. The herbal plants accommodate many phytoconstituents that are responsible for various activities such as anti-oxidant, antimicrobial, anticancer, anti-inflammatory, anti-allergic, hepatoprotective, etc. However, these phytoconstituents are highly sensitive to several environmental and physiological factors such as pH, oxygen, heat, temperature, humidity, stomach acid, enzymes, and light. Hence, there is need for the development of a drug delivery system that can protect the phytoconstituents from both internal and external conditions. In this regard, a microparticulate drug delivery system is considered amongst the ideal choice owing to its small size, ability to protect the environment-sensitive active constituents, in achieving sustained drug delivery, targeted drug delivery, protection of the drug from physiological conditions, minimizing drug-related side effects, etc.

Research progress of anthocyanin prebiotic activity: A review

BACKGROUND

Anthocyanins are a kind of flavonoids and natural water-soluble pigments, which endow fruits, vegetables, and plants with multiple colors. They are important source of new products with prebiotic activity. However, there is no systematic review documenting prebiotic activity of anthocyanins and their structural analogues. This study aims to fill this gap in literature.

PURPOSE

The objective of this review is to summarize and evaluate the prebiotic activity of anthocyanin's, and discuss the physical and molecular modification methods to improve their biological activities.

STUDY DESIGN AND METHODS

In this review, the databases (PubMed, Google Scholar, Web of Science, Researchgate and Elsevier) were searched profoundly with keywords (anthocyanin's, prebiotics, probiotics, physical embedding and molecular modification).

RESULTS

A total of 34 articles were considered for reviewing. These studies approved that anthocyanins play an important role in promoting the proliferation of probiotics, inhibiting the growth of harmful bacteria and improving the intestinal environment. In addition, physical embedding and molecular modification have also been proved to be effective methods to improve the prebiotic activity of anthocyanins. Anthocyanins could promote the production of short chain fatty acids, accelerate self degradation and improve microbial related enzyme activities to promote the proliferation of probiotics. They inhibited the growth of harmful bacteria by inhibiting the expression of harmful bacteria genes, interfering with the role of metabolism related enzymes and affecting respiratory metabolism. They promoted the formation of a complete intestinal barrier and regulated the intestinal environment to keep the body healthy. Physical embedding, including microencapsulation and colloidal embedding, greatly improved the stability of anthocyanins. On the other hand, molecular modification, especially enzymatic modification, significantly improved the biological activities (antioxidant, prebiotic activity and so on) of anthocyanins.

CONCLUSION

All these research results displayed by this review indicate that anthocyanins are a useful tool for developing prebiotic products. The better activities of the new anthocyanins formed by embedding and modification may make them become more effective raw materials. Our review provides a scientific basis for the future research and application of anthocyanins.

Water-in-Oil-in-Water Double Emulsions as Protective Carriers for Sambucus nigra L. Coloring Systems

The use of natural colorants is needed to overcome consumer concerns regarding synthetic food colorants' safety. However, natural pigments have, in general, poor stability against environmental stresses such as temperature, ionic strength, moisture, light, and pH, among others. In this work, water-in-oil-in-water (W1/O/W2) emulsions were used as protective carriers to improve color stability of a hydrophilic Sambucus nigra L. extract against pH changes. The chemical system comprised water and corn oil as the aqueous and oil phases, respectively, and polyglycerol polyricinoleate (PGPR), Tween 80, and gum Arabic as stabilizers. The primary emulsion was prepared using a W1/O ratio of 40/60 (v/v). For the secondary emulsion, W1/O/W2, different (W1/O)/W2 ratios were tested with the 50/50 (v/v) formulation presenting the best stability, being selected as the coloring system to test in food matrices of different pH: natural yogurt (pH 4.65), rice drink (pH 6.01), cow milk (pH 6.47), and soy drink (pH 7.92). Compared to the direct use of the extract, the double emulsion solution gave rise to higher color stability with pH change and storage time, as corroborated by visual and statistical analysis.

Pharmaceutical nanotechnology: from the bench to the market

Background

Nanotechnology is considered a new and rapidly emerging area in the pharmaceutical and medicinal field. Nanoparticles, as drug delivery systems, impart several advantages concerning improved efficacy as well as reduced adverse drug reactions.

Main body

Different types of nanosystems have been fabricated including carbon nanotubes, paramagnetic nanoparticles, dendrimers, nanoemulsions, etc. Physicochemical properties of the starting materials and the selected method of preparation play a significant aspect in determining the shape and characteristics of the developed nanoparticles. Dispersion of preformed polymers, coacervation, polymerization, nano-spray drying and supercritical fluid technology are among the most extensively used techniques for the preparation of nanocarriers. Particle size, surface charge, surface hydrophobicity and drug release are the main factors affecting nanoparticles physical stability and biological performance of the incorporated drug. In clinical practice, many nanodrugs have been used for both diagnostic and therapeutic applications and are being investigated for various indications in clinical trials. Nanoparticles are used for the cure of kidney diseases, tuberculosis, skin conditions, Alzheimer’s disease, different types of cancer as well as preparation of COVID-19 vaccines.

Conclusion

In this review, we will confer the advantages, types, methods of preparation, characterization methods and some of the applications of nano-systems.

Microparticles coated with proteins in their natural state and in vitro gastrointestinal simulation

Abstract This study aimed to produce pectin and alginate microparticles by ionic gelation coated with different concentrations of bovine blood and egg white protein in their natural state. The coated microparticles were characterized, and their physical resistance and morphology were evaluated, as well as the released protein during in vitro gastrointestinal simulation. The highest protein adsorption (65.47%) was shown by pectin microparticles coated with bovine blood (10%), regardless of the protein type and concentration used. Likewise, higher amounts of adsorbed protein resulted as protein concentration increased, regardless of the type of microparticle. Nevertheless, the physical resistance of coated microparticles was affected more by the type of polysaccharide, being alginate microparticles more resistant. Adsorbed proteins on microparticles surface showed higher solubility values in vitro gastrointestinal simulation regardless of protein type. Bovine blood and egg white proteins in their natural state can be used as alternative coating materials for microparticles.

Physicochemical and release behaviour of phytochemical compounds based on black jamun pulp extracts-filled alginate hydrogel beads through vibration dripping extrusion

The phytochemical-rich extract obtained from black jamun pulp were encapsulated using vibrating dripping extrusion technique. The utilisation of alginate (AL) with four variations of core-shell material comprising gum Arabic (AL-GA), guar gum (AL-GG), pectin (AL-P) and xanthan gum (AL-X) was engaged to form calcium-alginate based lyophilised jamun extract encapsulated beads. It resulted that among four variations, lyophilised alginate with AL-GG based encapsulated jamun extract filled beads have better physicochemical characteristics and 95% encapsulation efficiency. The results revealed the morphological comparison of each variation. The release behaviour of AL-GG based beads has a higher release of total phenolics (TPC) and total anthocyanin content (TAC). The release kinetics model involving Ritger-Peppas and Higuchi model were applied for release TPC and TAC of all variations of beads. The Ritger-Peppas model was found best suitable in terms of average R² (0.965) and lowest χ² (0.0039). The release kinetics study showed that AL-GA based beads followed by AL-GG could also be the best suitable in release behaviour using simulated gastrointestinal fluids at 140-160 min. Overall, results shown the encapsulated Jamun beads have the best agro-industrial efficacy in form of phytochemical compounds based microparticles, holding decent antioxidant potential.

Encapsulation of bioactive compounds extracted from plants of genus Hibiscus: A review of selected techniques and applications

The genus Hibiscus includes more than 250 species, and many studies showed that these plants contain bioactive compounds with technological potential to be used in the development of functional foods. However, the instability of these compounds during typical food processing conditions, such as exposure to high temperatures, pH changes and presence of light and oxygen have stimulated the use of encapsulation techniques to increase their stability and applicability. Among the existing Hibiscus species, only H. sabdariffa, H. cannabinus, and H. acetosella have been investigated in encapsulation studies, being spray drying the most common method approached. Considering the high technological potential offered by the incorporation of encapsulated bioactive compounds from plants of the genus Hibiscus in food formulations, this review discusses key information of selected encapsulation techniques, which represents promising alternatives to increase food systems' stability and stimulate the design of new functional foods. Relevant gaps in the literature were also noticed, mainly the lack of systematic studies regarding the composition of bioactive compounds after encapsulation, instead of total determinations, and biological activities in different analytical systems, such as antioxidant, antimicrobial and anti-inflammatory properties as well as bioaccessibility and bioavailability.

Nanoencapsulation in low-molecular-weight chitosan improves in vivo antioxidant potential of black carrot anthocyanin

BACKGROUND

Anthocyanins are flavonoids that are potential antioxidant, anti-inflammatory, anti-obesity, and anti-carcinogenic nutraceutical ingredients. However, low chemical stability and low bioavailability limit the use of anthocyanins in food. Nanoencapsulation using biopolymers is a recent successful strategy for stabilization of anthocyanins. This study reports the development, characterization, and antioxidant activity of black carrot anthocyanin-loaded chitosan nanoparticles (ACNPs).

RESULTS

The ionic gelation technique yielded the ACNPs. The mean hydrodynamic diameter d and polydispersity index PDI of chitosan nanoparticles and ACNPs were found to be d = 455 nm and PDI = 0.542 respectively for chitosan nanoparticles and d = 274 nm and PDI = 0.376 respectively for ACNPs. The size distribution was bimodal. The surface topography revealed that the ACNPs are spherical and display a coacervate structure. Fourier transform infrared analysis revealed physicochemical interactions of anthocyanins with chitosan. The loading process could achieve an encapsulation efficiency of 70%. The flow behavior index η of encapsulated ACNPs samples revealed Newtonian and shear thickening characteristics. There was a marginal reduction in the in vitro antioxidant potential of anthocyanins after nanoencapsulation, as evidenced from 2,2-diphenyl-1-picrylhydrazyl, ferric reducing antioxidant power, and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) assays. Interestingly, the in vivo antioxidant potential of anthocyanins improved following nanoencapsulation, as observed in the serum antioxidant assays.

CONCLUSION

The optimized nanoencapsulation process resulted in spherical nanoparticles with appreciable encapsulation efficiency. The nanoencapsulation process improved the in vivo antioxidant activity of anthocyanins, indicating enhanced stability and bioavailability. The promising antioxidant activity of the ACNPs suggests a potential for utilization as a nutraceutical supplement. © 2021 Society of Chemical Industry.

A comprehensive review on innovative and advanced stabilization approaches of anthocyanin by modifying structure and controlling environmental factors

Anthocyanins are pigments abundant in fruits and vegetables, and commonly applied in foods due to attractive colour and health-promoting benefits. However, instability of anthocyanins leads to their easy degradation, reduced bioactivity, and colour fading in food processing, limiting their application and causing economic losses. Stability of anthocyanins depends on their own structures and environmental factors. For structural factors, modification including copigmentation, acylation and biosynthesis is a potential solution to increase anthocyanin stability due to forming stable structures. With regard to environmental factors, encapsulation such as microencapsulation, liposome and nanoparticles has been shown effectively to enhance the stability. We proposed the potential challenges and perspectives for the diversification of anthocyanin-rich products for food application, particularly, introduction of hazards, technical limitations, interaction with other ingredients in food system and exploration of pyranoanthocyanins. The integrated strategies are warranted for improving anthocyanin stabilization for promoting their further application in food industry.

Effect of temperature and relative humidity on the stability of betalains encapsulated in cryogels from protein and polysaccharide

The stability of betalains (Bet) encapsulated in cryogels made with a mixture of albumin (ALB) and albumin-pectin (ALB-PEC) as wall materials were evaluated during storage at 32% and 83% relative humidity (RH) at several different temperature conditions (4 °C, 30 °C and 40 °C). The retention of betalains (betanin + isobetanin) and phenolic compounds and the antioxidant activity were determined by high-performance liquid chromatography, the Folin-Ciocalteu method and radical ABTS*+ capture methodology. The color parameters and images of the encapsulated betalains were obtained. Cryogels prepared with ALB at 32% RH and at 4 °C provided betanin and isobetanin retention of 72% and 82%, with half-life times of 108 and 165 days, respectively. The antioxidant activity and phenolic compounds showed retention greater than 70% during storage at 32% RH at all temperatures. Cryogels prepared with ALB-PEC also conferred high retention percentages of phenolic compounds at 83% RH, but this high RH caused a significant decrease in the retention of betalains. Both ALB and ALB-PEC improved betalain stability during storage compared with the extracts without encapsulating. Therefore, cryogels could be used as protection matrices for betalains.

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.