Encapsulation of β-carotene in alginate-based hydrogel beads: Impact on physicochemical stability and bioaccessibility

Carotenoids: Considerations for Their Use in Functional Foods, Nutraceuticals, Nutricosmetics, Supplements, Botanicals, and Novel Foods in the Context of Sustainability, Circular Economy, and Climate Change

Carotenoids are versatile isoprenoids that are important in food quality and health promotion. There is a need to establish recommended dietary intakes/nutritional reference values for carotenoids. Research on carotenoids in agro-food and health is being propelled by the two multidisciplinary international networks, the Ibero-American Network for the Study of Carotenoids as Functional Foods Ingredients (IBERCAROT; http://www.cyted.org) and the European Network to Advance Carotenoid Research and Applications in Agro-Food and Health (EUROCAROTEN; http://www.eurocaroten.eu). In this review, considerations for their safe and sustainable use in products mostly intended for health promotion are provided. Specifically, information about sources, intakes, and factors affecting bioavailability is summarized. Furthermore, their health-promoting actions and importance in public health in relation to the contribution of reducing the risk of diverse ailments are synthesized. Definitions and regulatory and safety information for carotenoid-containing products are provided. Lastly, recent trends in research in the context of sustainable healthy diets are summarized.

The colorful world of carotenoids: a profound insight on therapeutics and recent trends in nano delivery systems

The therapeutic effects of carotenoids as dietary supplements to control or even treat some specific diseases including diabetic retinopathy, cardiovascular diseases, bacterial infections, as well as breast, prostate, and skin cancer are discussed in this review and also thoughts on future research for their widespread use are emphasized. From the stability standpoint, carotenoids have low bioavailability and bioaccessibility owing to their poor water solubility, deterioration in the presence of environmental stresses such as oxygen, light, and high heat as well as rapid degradation during digestion. Nanoencapsulation technologies as wall or encapsulation materials have been increasingly used for improving food product functionality. Nanoencapsulation is a versatile process employed for the protection, entrapment, and the delivery of food bioactive products including carotenoids from diverse environmental conditions for extended shelf lives and for providing controlled release. Therefore, we present here, recent (mostly during the last five years) nanoencapsulation methods of carotenoids with various nanocarriers. To us, this review can be considered as the first highlighting not only the potential therapeutic effects of carotenoids on various diseases but also their most effective nanodelivery systems.HighlightsBioactive compounds are of deep interest to improve food properties.Carotenoids (such as β-carotene and xanthophylls) play indispensable roles in maintaining human health and well-being.A substantial research effort has been carried out on developing beneficial nanodelivery systems for various carotenoids.Nanoencapsulation of carotenoids can enhance their functional properties.Stable nanoencapsulated carotenoids could be utilized in food products.

Potential of Nanonutraceuticals in Increasing Immunity

Nutraceuticals are defined as foods or their extracts that have a demonstrably positive effect on human health. According to the decision of the European Food Safety Authority, this positive effect, the so-called health claim, must be clearly demonstrated best by performed tests. Nutraceuticals include dietary supplements and functional foods. These special foods thus affect human health and can positively affect the immune system and strengthen it even in these turbulent times, when the human population is exposed to the COVID-19 pandemic. Many of these special foods are supplemented with nanoparticles of active substances or processed into nanoformulations. The benefits of nanoparticles in this case include enhanced bioavailability, controlled release, and increased stability. Lipid-based delivery systems and the encapsulation of nutraceuticals are mainly used for the enrichment of food products with these health-promoting compounds. This contribution summarizes the current state of the research and development of effective nanonutraceuticals influencing the body's immune responses, such as vitamins (C, D, E, B12, folic acid), minerals (Zn, Fe, Se), antioxidants (carotenoids, coenzyme Q10, polyphenols, curcumin), omega-3 fatty acids, and probiotics.

Microencapsulation of vitamin D3 by complex coacervation using carboxymethyl tara gum (Caesalpinia spinosa) and gelatin A

Vitamin D₃ plays a fundamental role in human health; however, it is highly susceptible to environmental conditions and the gastrointestinal tract. In this study, complex coacervates obtained from gelatin A and carboxymethyl tara gum (CMTG) were used as wall materials for the encapsulation of vitamin D₃ (VD₃). Zeta potential and turbidity measurements were employed to optimize the pH and ratio (gelatin A:CMTG), and the results showed that the ideal conditions for the complex coacervation were pH 4.0 and a 6:1 ratio. The encapsulation efficiency (EE) was determined as a function of the total concentration of biopolymers (TC%) and the core-to-wall ratio, and the greatest EE (80%) was achieved at a TC of 1% and a ratio of 1:2; spherical particles with an average size of 0.25 µm were obtained. The microencapsulation increased the thermal stability of VD₃, and FTIR confirmed the presence of the biopolymers and VD₃ in the capsules. An in vitro simulation showed a more pronounced release in the small intestine with a vitamin bioaccessibility of 56%. The encapsulation of bioactive lipophilic compounds by complex coacervates of gelatin A and CMTG resulted in improved stability and prolonged release during digestion.

Emulsifying properties of a ferulic acid-grafted curdlan conjugate and its contribution to the chemical stability of β-carotene

A biopolymer-polyphenol conjugate-stabilized oil-in-water emulsion system was established to improve the chemical stability and bioaccessibility of β-carotene (BC). In this study, the emulsifying properties and contribution of a ferulic acid-grafted curdlan conjugate (Cur-D-g-FA) to the chemical stability of BC were investigated. Results showed that the emulsification ability of emulsions stabilized by Cur-D-g-FA remarkably increased with an increasing concentration from 0.05% to 0.8% (w/v) along with decreasing average droplet sizes, negatively charged zeta potentials, and uniform size distributions. The emulsions stabilized by 0.8% Cur-D-g-FA exhibited pronounced shear thinning and solid-like elastic properties as well as satisfactory oxidation stability. The emulsions stabilized by 0.8% Cur-D-g-FA had excellent ability to improve the chemical stability of BC when exposed to different environmental stresses and resulted in the favorable bioaccessibility of BC in vitro. The results prove that Cur-D-g-FA as a promising stabilizer has great potential to protect liposoluble nutrients in food-grade emulsion-delivery systems.

Factors affecting the fate of β-carotene in the human gastrointestinal tract: A narrative review

Carotenoids and their metabolites play crucial roles in human health such as in immunity, cell differentiation, embryonic development, maintenance of plasma membrane integrity, and gastrointestinal functions, in addition to counteracting night blindness and other eye-related diseases. However, carotenoid bioavailability is highly variable and often low. The bioavailability of β-carotene, among the most frequently consumed carotenoid from the diet, is determined by food matrix related factors such as carotenoid dose, its location in food the matrix, the physical state in food, the presence of other food compounds in the matrix such as dietary fiber, dietary lipids, other micronutrients present such as minerals, and food processing, influencing also the size of food particles, and the presence of absorption inhibitors (fat replacers and anti-obesity drugs) or enhancers (nano-/micro-formulations). However, also host-related factors such as physiochemical interactions by gastrointestinal secretions (enzyme and salts) and other host-related factors such as surgery, age, disease, obesity, and genetic variations have shown to play a role. This review contributes to the knowledge regarding factors affecting the bioavailability of β-carotene (food and host-relegated), as well as highlights in vitro models employed to evaluate β-carotene bioavailability aspects.

Versatile preparation of spherically and mechanically controllable liquid-core-shell alginate-based bead through interfacial gelation

Developing alginate-based beads with liquid-core-shell structure is highly appealing for industrial applications as a promising delivery matrix material. Herein, based on the reaction-diffusion mechanism, a facile method that includes dissolving natural polymer in calcium ion core solution followed by dripping it to alginate shell bath is proposed through interfacial gelation. By facilely tuning the viscosity and surface tension, the boundary condition for forming spherical beads with applicable mechanical properties was obtained. The universal viscosity-boundary relationship was independent of the type or charge condition of polymers in liquid-core. However, chitosan in the core solution significantly affected mechanical properties due to polyelectrolyte interaction with alginate, based on FTIR and SEM analyses. Moreover, a larger spherical zone was obtained by adding a surfactant into the shell bath. By varying calcium ion concentration and reaction time, beads of superior mechanical properties were obtained with an increase in shell membrane compactness.

Enhancing Efficacy, Performance, and Reliability of Cannabis Edibles: Insights from Lipid Bioavailability Studies

The legal sale of cannabis-enriched foods and beverages for medical or recreational purposes is increasing in many states and countries, especially in North America and Europe. These food-based cannabis delivery systems vary considerably in their compositions and structures, ranging from low-viscosity watery beverages to solid fatty chocolates. The rate and extent of release of the bioactive components in cannabis within the human gastrointestinal tract (GIT) affect their health and psychoactive effects. Studies with other types of hydrophobic bioactives, such as nutraceuticals and vitamins, have shown that food composition and structure have a major impact on their bioaccessibility, transformation, and absorption within the GIT, thereby influencing their bioavailability and bioactivity. This review outlines how insights on the bioavailability of other lipophilic bioactives can be used to facilitate the design of more efficacious and consistent cannabis-enriched products intended for oral consumption. In particular, the importance of food-matrix composition (such as fat type and level) and structural organization (such as fat domain dimensions) are discussed.

Modulation of physicochemical stability and bioaccessibility of β-carotene using alginate beads and emulsion stabilized by scallop (Patinopecten yessoensis) gonad protein isolates

The colloidal delivery systems fabricated by emulsion containing natural proteins and lipids have been utilized to protect carotenoids as well as to release the carotenoids in the simulated in vitro gastrointestinal tract (GIT). In this study, β-carotene (BC) was embedded into emulsions that were stabilized by scallop gonad protein isolates (SGPIs), and the emulsion droplets containing BC were then entrapped into calcium-alginate beads. The results showed that the oil-in-water emulsions coated by SGPIs only showed good stability at pH 7-8, while the emulsion-alginate beads remained relatively intact at pH 3-8. BC encapsulated in emulsions was extremely unstable and prone to degradation when stored at the comparatively higher temperature (37 °C), whereas the stability of BC was greatly enhanced through incorporation into emulsion-alginate beads. The digestion rate and extent of lipid droplets constructed within SGPIs-stabilized emulsion-alginate beads were slower than that in emulsions during GIT. The confocal laser scanning microscopy revealed that the lipid droplets in emulsions were aggregated after exposure to the mouth and gastric phases, while the emulsion-alginate beads maintained their spherical shape after exposure to the oral and gastric phases. Moreover, the free lipid droplets in the emulsions showed a higher bioaccessibility of BC (66%) than that in the emulsion-alginate beads (38%), whereas the BC transformation was on the contrary. The findings in this study indicated that SGPIs-stabilized emulsion in alginate beads can potentially be utilized for the encapsulation and controlled release of lipophilic bioactive compounds.

Carotenoid-loaded nanocarriers: A comprehensive review

Carotenoids retain plenty of health benefits and attracting much attention recently, but they have less resistance to processing stresses, easily oxidized and chemically unstable. Additionally, their application in food and pharmaceuticals are restricted due to some limitations such as poor bioavailability, less solubility and quick release. Nanoencapsulation techniques can be used to protect the carotenoids and to uphold their original characteristics during processing, storage and digestion, improve their physiochemical properties and enhance their health promoting effects. The importance of nanocarriers in foods and pharmaceuticals cannot be denied. This review comprehensively covers recent advances in nanoencapsulation of carotenoids with biopolymeric nanocarriers (polysaccharides and proteins), and lipid-based nanocarriers, their functionalities, aptness and innovative developments in preparation strategies. Furthermore, the present state of the art encapsulation of different carotenoids via biopolymeric and lipid-based nanocarriers have been enclosed and tabulated well. Nanoencapsulation has a vast range of applications for protection of carotenoids. Polysaccharides in combination with different proteins can offer a great avenue to achieve the desired formulation for encapsulation of carotenoids by using different nanoencapsulation strategies. In terms of lipid based nanocarriers, solid lipid nanoparticles and nanostructure lipid carriers are proving as the encouraging candidates for entrapment of carotenoids. Additionally, nanoliposomes and nanoemulsion are also promising and novel-vehicles for the protection of carotenoids against challenging aspects as well as offering an effectual controlled release on the targeted sites. In the future, further studies could be conducted for exploring the application of nanoencapsulated systems in food and gastrointestinal tract (GIT) for industrial applications.

Impact of calcium levels on lipid digestion and nutraceutical bioaccessibility in nanoemulsion delivery systems studied using standardized INFOGEST digestion protocol

The bioaccessibility of hydrophobic bioactives may be greatly reduced in the presence of calcium.

Factors impacting lipid digestion and β-carotene bioaccessibility assessed by standardized gastrointestinal model (INFOGEST): oil droplet concentration

The impact of oil droplet concentration on lipid digestion and vitamin bioaccessibility was measured using the INFOGEST method.

The Influence of the Agglomeration Process on Stability of Microencapsulated β-Carotene

Effects of agglomeration of β-carotene microencapsulated by spray drying on its stability were analysed. Mixtures of Arabic gum (GA), maltodextrin (MD), modified starch (OSA), and whey protein (WP) were used as carriers. GA + MD and OSA + MD microcapsules were subjected to agglomeration. All the samples were stored for 60 days with access to daylight. Stability of the emulsions had a significant effect on efficiency of microencapsulation but had no effect on β-carotene retention during sample storage. Among the tested samples, the highest retention of colorant characterized the samples containing GA + MD. The agglomeration process reduced the content of β-carotene in the microcapsules almost by half. However, retention of the colorant during storage of the microcapsules was increased most of all and half-life of β-carotene was significantly prolonged. Changes in L* and a* colour parameters during storage were more limited in the case of agglomerated samples.

Citric-acid modified banana starch nanoparticles as a novel vehicle for β-carotene delivery

BACKGROUND

Starch nanoparticles have become among the most interesting nanovehicles for drug delivery because of their relatively easy synthesis, biocompatibility, and numerous botanical sources. Starch nanoparticles obtained from green bananas were cross-linked with citric acid and loaded with β-carotene.

RESULTS

Mean particle size, encapsulation efficiency, and β-carotene release in simulated gastric and intestinal fluids and food simulants were studied. Cross-linked nanoparticles showed higher loading efficiency and encapsulation capacity, indicating that they can accommodate more molecules than their unmodified counterparts, while mathematical models showed a diffusion of released β-carotene into food simulant media.

CONCLUSIONS

Cross-linked nanoparticles showed more controlled release under gastric conditions, mainly in the simulated intestinal fluid, indicating that they are suitable as vehicles for intestine-specific targeting. This controlled released was also observed in food simulants, with lower release values in the more aqueous simulants. © 2019 Society of Chemical Industry.

Preparation and characterisation of novel water-soluble β-carotene-chitooligosaccharides complexes

β-carotene and chitooligosaccharides are bioactive compounds that find their application in the food industry as well in biomedical fields. However, the application of β-carotene is limited due to its very low water solubility, as well as its air, light and temperature sensitivity. The preparation of β-carotene-chitooligosaccharides complexes by mechanochemical methods was presented. Their physical and chemical properties including solubility, size, zeta potential and radical scavenging activity were investigated. The interaction of the two components was shown by NMR, FT-IR, and Raman spectroscopy. The complexes were analysed by scanning and transmission electron microscopy. Chitooligosaccharides could serve as a carrier for β-carotene delivery. The complexation did not cause the loss of the radical scavenging activity of β-carotene and guaranteed its water solubility.

Enhanced stability of C-phycocyanin colorant by extrusion encapsulation

C-phycocyanin (C-PC) a blue color phycobiliproteins used as a food colorant, therapeutics, medicines, health food and biomarkers. In the present study, morphological property of encapsulated C-PC and its stability under various conditions like temperature, pH conditions are discussed. Microencapsulated droplets formed by extrusion found to be spherical with average size 1.2 ± 0.1 mm. SEM micrographs of freeze dried encapsulate confirmed the spherical shape. The effect of droplet formation with varying alginate percentage (1.5%, 2.0% and 2.5% w/v) was studied. In the stability test at 70 °C and 80 °C relative concentration (C_R  %) was found to be 86.89 and 88.19%, respectively. The encapsulated C-PC showed a slow degradation at higher temperature compared to without encapsulated C-PC which was confirmed by UV-visible absorbance. At 45 °C and 55 °C temperatures the stability was studied at various pH conditions (pH 4.5, 5.5, 6.5, and 7.0) and reported. Aggregation of C-PC protein will not change during encapsulation was confirmed by SDS-PAGE. FTIR analysis of encapsulate and the alginate depicted similar characteristics of the compound compared to that of native C-phycocyanin colorant. Microencapsulation improves the stability and increases the shelf life of colorant.

Hierarchically structured phase separated biopolymer hydrogels create tailorable delayed burst release during gastrointestinal digestion

The on demand delivery of novel peptide actives, traditional pharmaceuticals, nutrients and/or vitamins is a ever present challenge due to the digestive and metabolic degradation of the active and the delivery vehicle. Biodegradable biopolymer hydrogels have long held promise as candidates for creating tailored release profiles due to the ability to control gel porosity. The present study describes the creation of novel hierarchical biopolymer hydrogels for the controlled release of lipids/lipophilic actives pharmaceutical ingredients (APIs), and mathematically describes the mechanisms that affect the timing of release. The creation of phase separated protein/polysaccharide core (6.6 wt% gelatin, 40 wt% Oil in water emulsion) shell structures (7 g/L xanthan with 70-140 g/L β-lactoglobulin) altered enzyme mass transport processes. This core shell structure enabled the creation of a tailorable burst release of API during gastrointestinal digestion where there is a delay in the onset of release, without affecting the kinetics of release. The timing of the delay could be readily programmed (with release of between 60 and 240 min) by controlling either the thickness or protein concentration (between 70 g/L and 140 g/L β-lactoglobulin) of the outer mixed biopolymer hydrogel shell (7 g/L xanthan with 70-140 g/L β-lactoglobulin). Enzyme diffusion measurements demonstrated that surface erosion was the main degradation mechanism. A kinetic model was created to describe the delayed burst release behaviour of APIs encapsulated within the core, and successfully predicted the influence of shell thickness and shell protein density on the timing of gastro-intestinal release (in vitro). Our work highlights the creation of a novel family of core-shell hydrogel oral dosage forms capable of programmable delivery of lipids/lipophilic APIs. These findings could have considerable implications for the delivery of peptides, poorly soluble drugs, or the programmed delivery of lipids within the gastrointestinal tract.

Raman Sensing and Its Multimodal Combination with Optoacoustics and OCT for Applications in the Life Sciences

Currently, many optical modalities are being investigated, applied, and further developed for non-invasive analysis and sensing in the life sciences. To befit the complexity of the study objects and questions in this field, the combination of two or more modalities is attempted. We review our work on multimodal sensing concepts for applications ranging from non-invasive quantification of biomolecules in the living organism to supporting medical diagnosis showing the combined capabilities of Raman spectroscopy, optical coherence tomography, and optoacoustics.

An update on polymer-lipid hybrid systems for improving oral drug delivery

INTRODUCTION

A promising approach that has recently emerged to overcome the complex biobarriers and interrelated challenges associated with oral drug absorption is to combine the benefits of polymeric and lipid-based nanocarriers within one hybrid system. This multifaceted formulation strategy has given rise to a plethora of polymer-lipid hybrid (PLH) systems with varying nanostructures and biological activities, all of which have demonstrated the ability to improve the biopharmaceutical performance of a wide range of challenging therapeutics.

AREAS COVERED

The multitude of polymers that can be combined with lipids to exert a synergistic effect for oral drug delivery have been identified, reviewed and critically evaluated. Specific focus is attributed to preclinical studies performed within the past 5 years that have elucidated the role and mechanism of the polymer phase in altering the oral absorption of encapsulated therapeutics.

EXPERT OPINION

The potential of PLH systems has been clearly identified; however, improved understanding of the structure-activity relationship between PLH systems and oral absorption is fundamental for translating this promising delivery approach into a clinically relevant formulation. Advancing research within this field to identify optimal polymer, lipid combinations and engineering conditions for specific therapeutics are therefore encouraged.

Bioavailability of nanotechnology-based bioactives and nutraceuticals

Bioaccessibility and bioavailability of some hydrophobic bioactives (e.g., carotenoids, polyphenols, fat-soluble vitamins, phytosterols and fatty acids) are limited due to their low water solubility, and in some instances low chemical stability. Nanotechnology involving nanometric (r<500nm) delivery systems, can be used to improve the solubility and thus enhance the bioaccessibility and bioavailability of hydrophobic compounds. Nanometric delivery systems, derived from food grade phospholipids and biopolymers adopt many forms, including liposomes, micelles, micro/nanoemulsions, particles, polyelectrolyte complexes, and hydrogels. The small particle sizes and customized materials used to create delivery systems confer their unique properties such as higher stability and/or resistance to enzymatic activity in the gastrointestinal tract. This chapter provides an overview of bioaccessibility and bioavailability of different classes of hydrophobic bioactive compounds, focusing on nanometric delivery systems and methods of evaluation.

Bioaccessibility and cellular uptake of β-carotene in emulsion-based delivery systems using scallop (Patinopecten yessoensis) gonad protein isolates: effects of carrier oil

Emulsion-based delivery systems were structured using scallop gonad protein isolates as novel food-grade emulsifiers.

Preparation and characterization of nanoemulsion based β-carotene hydrogels

The aim of this study was to develop β-carotene hydrogels using nanoemulsions, with increased β-carotene aqueous solubility, bioavailability and improved physical and chemical stabilities. The nanoemulsion of β-carotene was prepared using a solvent-displacement technique and converted into hydrogels using sodium alginate as stabilizer and calcium chloride as cross-linker. The effects of formulation parameters, mainly, the effects sodium alginate and calcium chloride concentrations on the physicochemical properties of hydrogels were evaluated using a surface response methodology. The second order polynomial equations, subsequently, were suggested to predict the changes of studied physicochemical characteristics of hydrogels, with relatively high regression of coefficients values. Based on numerical multiple optimization, it was concluded that using 4.1 g/l sodium alginate and 5.7 g/l calcium chloride, resulted in a hydrogel with the most desired physicochemical characteristics. No significant differences between the measured and predicted data, reconfirmed the accuracy of the models.

Enhanced delivery of lipophilic bioactives using emulsions: a review of major factors affecting vitamin, nutraceutical, and lipid bioaccessibility

Many researchers are currently developing emulsion-based delivery systems to increase the bioavailability of lipophilic bioactive agents, such as oil-soluble vitamins, nutraceuticals, and lipids. Oil-in-water emulsions can be specifically designed to improve the bioavailability of these bioactives by altering their composition and structural organization. This article reviews recent progress in understanding the impact of emulsion properties on the bioaccessibility of lipophilic bioactive agents, including oil phase composition, aqueous phase composition, droplet size, emulsifier type, lipid physical state, and droplet aggregation state. This knowledge can be used to design emulsions that can enhance the bioavailability and efficacy of encapsulated hydrophobic bioactives.