Anthocyanins: New techniques and challenges in microencapsulation

Effects of sweet potato vine silage supplementation on meat quality, antioxidant capacity and immune function in finishing pigs

Sweet potato vine, the byproduct of sweet potato, has a high nutritional value. Silage is an effective solution for nutrient preservation. This article explored the effects of sweet potato vine silage (SPVS) supplementation on meat quality, antioxidant capacity and immune function in finishing pigs. One hundred and eighty finishing pigs (Berkshire × Licha Black) with a body weight of 74.54 ± 3.32 kg were randomly divided into three groups. The three groups were separately fed basal diet (Ctrl), Ctrl supplemented with 2.5% SPVS (LSPVS) or 5% SPVS (HSPVS) on a dry matter basis. Results showed that the eye muscle area in the LSPVS group was significantly increased. The carcass weight in the HSPVS was significantly reduced compared with Ctrl. For the meat quality, only cooking loss in both HSPVS and LSPVS was reduced while other indexes had no significant differences. For the antioxidant capacity, the hepatic level of glutathione (GSH) peroxidase (GSH-PX) was significantly upregulated in LSPVS but downregulated in HSPVS. In the serum, HSPVS decreased GSH level and increased GSH-PX level. HSPVS significantly reduced hepatic interleukin-1β (IL-1β) levels and LSPVS significantly reduced IL-12 levels and increased IL-8 and IL-6 levels. Moreover, HSPVS and LSPVS promoted the secretion of immunoglobulin M (IgM) and IgG in the serum. Our data showed that low-dose SPVS supplementation improved carcass traits and high-dose SPVS supplementation increased immune function in finishing pigs, which provides a new alternative to improve animal health.

A comprehensive review of intelligent packaging for fruits and vegetables: Target responders, classification, applications, and future challenges

Post-harvest fruits and vegetables are extremely susceptible to dramatic and accelerated quality deterioration deriving from their metabolism and adverse environmental influences. Given their vigorous physiological metabolism, monitoring means are lacking due to the extent that unnecessary waste and damage are caused. Numerous intelligent packaging studies have been hitherto carried out to investigate their potential for fruit and vegetable quality monitoring. This state-of-the-art overview begins with recent advances in target metabolites for intelligent packaging of fruits and vegetables. Subsequently, the mechanisms of action between metabolites and packaging materials are presented. In particular, the exact categorization and function of intelligent packaging of fruits and vegetables, are all extensively and comprehensively described. In addition, for the sake of further research in this field, the obstacles that impede the scaling up and commercialization of intelligent packaging for fruits and vegetables are also explored, to present valuable references.

Colorimetric porous microspheres of natural sodium alginate for chilled pork visual monitoring

Chilled meat is subject to deterioration by various factors during storage and distribution. Therefore, it is very important to monitor the quality of meat in real time. This study aims at preparing a natural, low-cost indicating microsphere to visualize the freshness of meat by the combination of sodium alginate (SA) and chitosan with 0-10 wt% anthocyanins derived from chokeberry as a colorant using ionic gelation method. Size-controlled porous SA microspheres with were further constructed by freeze-drying and their physicochemical properties were characterized by SEM, FTIR, DSC, and XRD. Results showed that microspheres with 1 wt% anthocyanin showed good responsiveness to different concentrations of ammonia and were able to effectively identify the freshness of chilled meat by color change. Principal component analysis showed that the color difference of the porous microspheres was highly significantly correlated with pH, TVB-N, total plate count and thiobarbituric acid active substance (p < 0.01), suggesting a visible satisfactory capability of the microspheres to identify the spoilage in pork. Principal component analysis showed that the color difference of the porous microspheres was highly significantly correlated with pH, TVB-N, total plate count and thiobarbituric acid active substance (P < 0.01), suggesting a visible satisfactory capability of the microspheres to identify the spoilage in pork.

Extraction, microencapsulation, and application of anthocyanins from juçara palm fruit (Euterpe edulis Mart.): enhancement of natural pigment

The Juçara fruit (Euterpe edulis Martius) has been progressively standing out for presenting significant biological and nutritional activity. Its functional characteristics are related to its high content of anthocyanins, which, when isolated, are highly unstable, limiting their applications. The present research proposed to obtain an anthocyanin-rich extract from the juçara pulp, microencapsulate it with the maltodextrin and beta-cyclodextrin (beta-CD) matrices and evaluate the stability of the microencapsulated anthocyanins against light, pH, and milk development fermented. The use of encapsulating agents brought the anthocyanins significant thermal and light stability, in addition to intensifying their colors in a broader pH range. The FTIR-ATR techniques and the thermal analyzes of DSC and TGA showed that there was no molecular inclusion between the anthocyanins in the extract and beta-CD, but there was a physical interaction with the maltodextrin. In the development of fermented milk, the use of maltodextrin showed better product color stability. Therefore, anthocyanin microencapsulation processes can contribute to the development of innovative, more stable, and effective commercial food products.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-022-05623-w.

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.

Physical Properties, α-Glucosidase Inhibitory Activity, and Digestive Stability of Four Purple Corn Cob Anthocyanin Complexes

In this study, pectin (PC), whey protein isolate (WPI), and chitosan (CS) were combined with purple corn cob anthocyanins (PCCA). Four complexes, PC-PCCA, WPI-PCCA, WPI-PC-PCCA, and CS-PC-PCCA were prepared to evaluate the improvement in the α-glucosidase inhibitory activity and digestive stability of PCCA. The encapsulation efficiency (EE), particle size, physical properties, and mode of action of the synthesized PCCA complexes were evaluated. Among them, CS-PC-PCCA had the highest EE (48.13 ± 2.73%) except for WPI-PC-PCCA; furthermore, it had a medium size (200-300 nm), the lowest hygroscopicity (10.23 ± 0.28%), lowest solubility (10.57 ± 1.26%), and highest zeta potential (28.20 ± 1.14). CS-PC-PCCA was multigranular and irregular in shape; x-ray diffraction showed that it was amorphous; and Fourier transform infrared spectroscopy confirmed that it was joined with PCCA through hydrogen bonds and electrostatic interactions. Compared with PCCA, the four complexes showed a higher α-glucosidase inhibition activity and digestive stability, except for WPI-PC-PCCA. Furthermore, CS-PC-PCCA exhibited the best α-glucosidase inhibition and simulated digestion stability.

Enzymatic acylation of cyanidin-3-O-glucoside in raspberry anthocyanins for intelligent packaging: Improvement of stability, lipophilicity and functional properties

Anthocyanins (ACNs) as one category of water-soluble flavonoid pigments are increasingly employed in pH sensing indicator applications for monitoring food freshness. Nevertheless, considering that anthocyanins are sensitive to environmental factors, their practical applications in food industries are still rather limited. In order to improve the stability of anthocyanins and capitalize upon their application in pH-color responsive intelligent packaging, this study aims to graft octanoic aid onto raspberry anthocyanins catalyzed by immobilized Candida antarctica lipase B (Novozymes 435). Structural analyses based on Fourier transform infrared spectroscopy (FTIR), UV-Vis, liquid chromatography-mass spectrometry (LC-MS), and nuclear magnetic resonance (NMR) revealed that octanoic acid was regioselective grafted onto the 6-OH position of its glucoside. The acylation efficiency of C3G by octanoic acid up to 47.1%. The octanoic acid moiety was found to improve lipophilicity, antioxidant activity and stability of C3G. In addition, acylated derivative also maintained the pH-color response characteristics of nature ACNs and exhibited excellent NH3 response properties. These results indicated that acylated anthocyanins exhibit potential application as intelligent packaging indicator for monitoring food freshness.

Recent Developments in the Microencapsulation of Fish Oil and Natural Extracts: Procedure, Quality Evaluation and Food Enrichment

Due to the beneficial health effects of omega-3 fatty acids and antioxidants and their limited stability in response to environmental and processing factors, there is an increasing interest in microencapsulating them to improve their stability. However, despite recent developments in the field, no specific review focusing on these topics has been published in the last few years. This work aimed to review the most recent developments in the microencapsulation of fish oil and natural antioxidant compounds. The impact of the wall material and the procedures on the quality of the microencapsulates were preferably evaluated, while their addition to foods has only been studied in a few works. The homogenization technique, the wall-material ratio and the microencapsulation technique were also extensively studied. Microcapsules were mainly analyzed for size, microencapsulation efficiency, morphology and moisture, while in vitro digestion, flowing properties, yield percentage and Fourier transform infrared spectroscopy (FTIR) were used more sparingly. Findings highlighted the importance of optimizing the most influential variables of the microencapsulation procedure. Further studies should focus on extending the range of analytical techniques upon which the optimization of microcapsules is based and on addressing the consequences of the addition of microcapsules to food products.

Colorimetric Indicators Based on Anthocyanin Polymer Composites: A Review

This review explores the colorimetric indicators based on anthocyanin polymer composites fabricated in the last decade, in order to provide a comprehensive overview of their morphological and compositional characteristics and their efficacy in their various application fields. Notably, the structural properties of the developed materials and the effect on their performance will be thoroughly and critically discussed in order to highlight their important role. Finally, yet importantly, the current challenges and the future perspectives of the use of anthocyanins as components of colorimetric indicator platforms will be highlighted, in order to stimulate the exploration of new anthocyanin sources and the in-depth investigation of all the possibilities that they can offer. This can pave the way for the development of high-end materials and the expansion of their use to new application fields.

In Vitro Release of Anthocyanins from Microencapsulated Natal Plum (Carissa macrocarpa) Phenolic Extract in Alginate/Psyllium Mucilage Beads

Natal plum (Carissa macrocarpa) contains anthocyanins, cyanidin 3-O-β-sambubioside (Cy-3-Sa), and cyanidin 3-O-glucoside (Cy-3-G) that possess great bioactive properties. During in vitro gastrointestinal digestion, Cy-3-Sa and Cy-3-G are highly sensitive to pH changes and have low bioaccessibility rates of 7.9% and 22%, respectively. This study aimed to therefore use microencapsulation techniques to improve the bioaccessibility of Cy-3-Sa and Cy-3-G. The crude anthocyanin-rich extract was extracted from freeze-dried Natal plum fruit using ultrasonic-assisted ethanol extraction. The anthocyanin-rich extract was encapsulated using the ionic gelation method. Four distinct carrier agents, namely sodium alginate, pectin, xanthan gum and psyllium mucilage were used to form the wall materials. Encapsulation efficiency was highest for alginate/psyllium mucilage beads (93.67%), while alginate showed the least efficiency (86.80%). Scanning Electron Microscopy revealed a cracked and porous structure for the Natal plum extract and a continuous smooth structure for all the beads. Fourier transform infrared spectroscopy showed peaks at 3300 and 1610 cm⁻¹, confirming the presence of polyphenols and polysaccharides in all beads. Thermal stability was higher for the alginate/psyllium mucilage beads and the observed thermal transitions were due to the bonds formed between the polymers and the polyphenols. Alginate beads combined with xanthan gum, pectin, and psyllium mucilage showed a prolonged release of anthocyanins compared to alginate in vitro alone. The highest anthocyanin bioaccessibility was obtained from alginate/psyllium mucilage beads (85.42 ± 1.03%). The results showed the effectiveness of alginate/psyllium mucilage beads in improving stability and in vitro anthocyanin release.

Updated design strategies for oral delivery systems: maximized bioefficacy of dietary bioactive compounds achieved by inducing proper digestive fate and sensory attributes

Interest in the application of dietary bioactive compounds (DBC) in healthcare and pharmaceutical industries has motivated researchers to develop functional delivery systems (FDS) aiming to maximize their bioefficacy. As the direct and indirect health benefiting effects of DBC are acknowledged, traditional design principle of FDS aiming at improving the bioavailability of intact DBC is challenged by the updated one, where the maximized bioefficacy of DBC delivered by FDS will be achieved via rationally absorbed at target sites with proper metabolism pathways. This article briefly summarized the absorption and metabolic fates of orally digested DBC along with their direct and indirect mechanisms to perform health benefiting effects. Current strategies in designing the next generation FDS with an emphasis on their modulation effects on the distribution portion between the upper and lower digestive tract, portal vein and lymphatic absorption, human digestive and gut microbiota enzymatic mediated metabolism were highlighted. Updated research progresses of FDS in adjusting sensory attributes of food end products and inducing synergistic effects rooting from matrix materials and co-delivered cargos were also discussed. Challenges as well as future perspectives concerning the precise nutrition and the critical role of delivery systems in dietary intervention were proposed.

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.

Nanoencapsulated anthocyanin as a functional ingredient: Technological application and future perspectives

Anthocyanins are an important group of phenolic compounds responsible for pigmentation in several plants, and regular consumption is associated with a reduced risk of several diseases. However, the application of anthocyanins in foods represents a challenge due to molecular instability. The encapsulation of anthocyanins in nanostructures is a viable way to protect from the factors responsible for degradation and enable the industrial application of these compounds. Nanoencapsulation is a set of techniques in which the bioactive molecules are covered by resistant biomaterials that protect them from chemical and biological factors during processing and storage. This review comprehensively summarizes the existing knowledge about the structure of anthocyanins and molecular stability, with a critical analysis of anthocyanins' nanoencapsulation, the main encapsulating materials (polysaccharides, proteins, and lipids), and techniques used in the formation of nanocarriers to protect anthocyanins. Some studies point to the effectiveness of nanostructures in maintaining anthocyanin stability and antioxidant activity. The main advantages of the application of nanoencapsulated anthocyanins in foods are the increase in the nutritional value of the food, the addition of color, the increase in food storage, and the possible increase in bioavailability after oral ingestion. Nanoencapsulation improves stability for anthocyanin, thus demonstrating the potential to be included in foods or used as dietary supplements, and current limitations, challenges, and future directions of anthocyanins' have also been discussed.

Morphological and chemical characterizations of jujube (Ziziphus jujuba Mill.) to select superior accessions

The fruits of jujube (Ziziphus jujuba Mill.) are consumed worldwide as food and herbal medicine because of their impact on human health and benefits. Here, phenotypic and chemical variation of this species was investigated to select superior accessions. The selected accessions showed significant differences based on the measured characteristics. Fresh fruit weight varied from 2.72 to 6.42 g with an average of 4.54, while dry fruit weight ranged from 0.89 to 2.57 g with an average of 1.55. Total phenolic content ranged from 1.69 to 14.05 mg gallic acid equivalent (GAE) g-1 fresh weight (FW) and total flavonoid content varied from 0.25 to 2.01 mg quercetin equivalents (QE) g-1 FW. Total anthocyanin content varied from 5.98 to 76.32 µg CyE g-1 FW. Radical scavenging activity (2,2-diphenyl-1-picryl-hydrazyl-hydrate [DPPH]) ranged from 1.32 to 5.82 mg ascorbic acid equivalents (AsAE) g-1 FW, while ferric reducing antioxidant power (FRAP) varied from 35.37 to 93.35 µM FeSO4. The present study showed high diversity in morphological and chemical properties of jujube accessions. Based on the traits related to fruit quality such as fruit weight, fruit skin color, and fruit flavor, as well as in terms of chemical characteristics related to medicinal properties such as total anthocyanin content and antioxidant activity, 13 accessions were superior and are recommended to use in breeding programs. The commercial orchard of those best accessions should be extensively constructed to take advantage of the high yield of this tree as a crop and its medicinal properties.

Advancement of Protein- and Polysaccharide-Based Biopolymers for Anthocyanin Encapsulation

Although evidence shows that anthocyanins present promising health benefits, their poor stability still limits their applications in the food industry. Increasing the stability of anthocyanins is necessary to promote their absorption and metabolism and improve their health benefits. Numerous encapsulation approaches have been developed for the targeted release of anthocyanins to retain their bioactivities and ameliorate their unsatisfactory stability. Generally, choosing suitable edible encapsulation materials based on biopolymers is important in achieving the expected goals. This paper presented an ambitious task of summarizing the current understanding and challenges of biopolymer-based anthocyanin encapsulation in detail. The food-grade edible microencapsulation materials, especially for proteins and polysaccharides, should be employed to improve the stability of anthocyanins for effective application in the food industry. The influence factors involved in anthocyanin stability were systematically reviewed and highlighted. Food-grade proteins, especially whey protein, caseinate, gelatin, and soy protein, are attractive in the food industry for encapsulation owing to the improvement of stability and their health benefits. Polysaccharides, such as starch, pectin, chitosan, cellulose, mucilages, and their derivatives, are used as encapsulation materials because of their satisfactory biocompatibility and biodegradability. Moreover, the challenges and perspectives for the application of anthocyanins in food products were presented based on current knowledge. The proposed perspective can provide new insights into the amelioration of anthocyanin bioavailability by edible biopolymer encapsulation.

Preparation, characterization and antioxidant activity of sinapic acid grafted chitosan and its application with casein as a nanoscale delivery system for black rice anthocyanins

Anthocyanins (ACNs) have attracted considerable research attention because of their excellent health benefits, but their low stability and bioavailability limit their applications. In this study, sinapic acid-grafted-chitosan (SA-g-CS) conjugate was synthesized by grafting SA onto CS via a free radical mediated method. Nanoparticles were prepared using casein (CA) together with SA-g-CS to improve the performance and sustained release of black rice anthocyanins (BRA). The results of UV-Vis, FTIR and ¹H NMR spectra for SA-g-CS conjugates demonstrated the successful grafting of SA onto CS. The results of DPPH, ABTS and ferric ion reducing antioxidant power assays showed that the SA-g-CS conjugates had strong antioxidant capacities, and the higher the pH of the grafting reaction system, the stronger the antioxidant capacity of the conjugates. X-ray diffraction and scanning electron microscopy analyses showed that the crystallographic property and microstructure of CS were improved by the grafting of SA. Compared with BRA loaded nanoparticles prepared with CA alone or the combination of CS and CA, the BRA loaded nanoparticles constructed by SA-g-CS and CA have smaller particle size, better dispersion, encapsulation efficiency and sustained-release property. These results provided great potential for the application of phenolic acid grafted CS in stabilizing ACNs.

Anthocyanins and Carotenoids Characterization in Flowers and Leaves of Cyclamen Genotypes Linked with Bioactivities Using Multivariate Analysis Techniques

The present study was carried out to evaluate and compare in vitro antioxidant (2,2-diphenyl-1-picrylhydrazyl (DPPH), Trolox equivalent antioxidant capacity (TEAC), and ferric reducing antioxidant power (FRAP)), antimicrobial, anticancer activities, and the individual carotenoids and anthocyanins content of methanol extracts of the Cyclamen genotypes: Persian cyclamen accessions (Cyclamen persicum Mill.), sowbread (C. mirabile Hildebr.), and ivy-leaved cyclamen (C. hederifolium Mill.) aerial parts. The HPLC-PDA analysis revealed the presence of five individual carotenoids (i.e., neoxanthin, violaxanthin, lutein, β-carotene, and cis-β-carotene) as the main compounds in Cyclamen leaves, and the presence of seven individual anthocycanins (i.e., cyanidin 3,5-di-O-glucoside, peonidin-rutinoside, peonidin 3,5-di-O-glucoside, peonidin 3-O-glucoside, malvidin 3-O-glucoside, malvidin 3,5-di-O-glucoside, and malvidin-rutinoside) in Cyclamen flowers reported, hereby, for the first time. The highest phenolic content was found in the leaves of LC6, C. mirabile (46.32 ± 0.14 mg/g gallic acid equivalents [GAE]), and in the flowers of C. persicum Merengue Magenta (FC15) (58.63 ± 0.17 mg/g GAE), whereas the highest flavonoid content was reported in C. persicum Halios Falbala leaves, namely LC9 (54.90 ± 0.27 mg/g quercetin equivalents [QE]) and in flowers of C. persicum Victora (FC2) (77.87 ± 0.25 mg/g QE). The highest antioxidant activity in DPPH and FRAP assays was reported in C. persicum Dark Violet (LC1) and Victoria (LC2), whereas C. mirabile (LC6) had the highest activity in the TEAC assay. In flowers, high antioxidant activities in DPPH and TEAC were noticed in C. persicum Superserie Red (FC7) and Dark Violet (FC1), respectively, and Halios Falbala (FC9) exhibited the highest activity in the TEAC assay. Additionally, FC9 exhibited the highest antibacterial activity in almost all tested bacteria compared with the leaves extracts. Furthermore, the highest in vitro citotoxicity in MDA-MB-231 cells was noticed in C. hederifolium LC18 (56.71-69.35%) and FC18 (40.07-41.43%), with a lower effect against BJ cells demonstrating selective toxicity. The above findings, highlight the potential use of the Cyclamen flower and leaf extracts as significant anticancer agents along with their antioxidant and antimicrobial properties.

Effects of Cryoconcentrated Blueberry Juice as Functional Ingredient for Preparation of Commercial Confectionary Hydrogels

Hydrogels can absorb and/or retain components in the interstitial spaces due to the 3D cross-linked polymer network, and thus, these matrices can be used in different engineering applications. This study focuses on the physicochemical and textural properties, as well as bioactive compounds and their antioxidant activity stability of commercial hydrogels fortified with cryoconcentrated blueberry juice (CBJ) stored for 35 days. CBJ was added to commercial hydrogels (gelatin gel (GG), aerated gelatin gel (AGG), gummy (GM), and aerated gummy (AGM)). The samples showed a total polyphenol, anthocyanin, and flavonoid content ranging from 230 to 250 mg GAE/100 g, 3.5 to 3.9 mg C3G/100 g, and 120 to 136 mg CEQ/100 g, respectively, and GG and GM showed the lowest bioactive component degradation rate, while AGM presented the highest degradation. GG and GM samples could be stored for up to 21 days without significant changes, while the results indicated ≈15 days for the AGG and AGM samples. Thereby, CBJ offers enormous possibilities to be used as a functional ingredient due to the high nutritional values, and it allows enriching different hydrogel samples, and in turn, the structures of hydrogels protected components during in vitro digestion, enhancing the bioaccessibility after the digestion process.

Stability and bioavailability of protein matrix-encapsulated astaxanthin ester microcapsules

BACKGROUND

Astaxanthin ester derived from Haematococcus pluvialis is often used as a functional and nutritional ingredient in foods. However, its utilization is currently limited as a result of its chemical instability and low bioavailability. Food matrix microcapsules are becoming increasingly popular because of their safety and high encapsulation efficiency. In the present study, the effect of protein matrixes on the properties of microcapsules was evaluated.

RESULTS

We investigated the effects of storage on astaxanthin ester microcapsules and the corresponding rehydration solution at 40 °C under a nitrogen atmosphere, as well as in darkness. The results showed that the stability of products prepared based on whey protein (WP) and corn-gluten was superior to that of products prepared based on lactoferrin, soy protein and sodium caseinate. The bioavailability of astaxanthin ester microcapsules encapsulated with different proteins and examined by means of astaxanthin concentrations in the serum and liver after oral administration was compared. All five protein wall materials could significantly improve the bioavailability of astaxanthin ester. The microcapsules prepared based on WP had the highest bioavailability, with a value of 10.69 ± 0.75 μg·h mL^-1 , which was 3.15 times higher compared to that of the control group.

CONCLUSION

The results of the present study showed that protein encapsulation, especially WP encapsulation, could effectively improve the stability, water solubility and bioavailability of astaxanthin esters. Thus, WP can be used as the main wall material in delivery systems. © 2021 Society of Chemical Industry.

Effect of high-pressure processing and thermal treatments on color and in vitro bioaccessibility of anthocyanin and antioxidants in cloudy pomegranate juice

In this study, the effect of high-pressure processing (HPP) and thermal treatments, including pasteurization (PT) and high-temperature short-time sterilization (HTST) on pomegranate juice (PJ) color attributes, anthocyanin (ACNs), vitamin C, and in vitro bioaccessibility of ACNs and antioxidants were investigated. Compared to HPP, thermal treatments significantly changed the CIE color, decreased the total monomeric ACNs and total vitamin C contents, and increased the percent polymeric color (PPC) and browning index (BI). Correlation analysis showed that the generation of polymeric ACNs played a significant role in color change during thermal treatments. The recovery of 7 ACNs in the control sample after in vitro gastrointestinal digestion was ranged from 0.43% to 5.0% and total individual ACNs after digestion showed no significant changes among different treatments. These results contributed to promoting the color quality and health benefits of pomegranate juice rich in ACNs by optimizing the processing conditions in the food industry.

Nanotechnology as a Tool to Mitigate the Effects of Intestinal Microbiota on Metabolization of Anthocyanins

Anthocyanins are an important group of phenolic compounds responsible for pigmentation in several plants. For humans, a regular intake is associated with a reduced risk of several diseases. However, molecular instability reduces the absorption and bioavailability of these compounds. Anthocyanins are degraded by external factors such as the presence of light, oxygen, temperature, and changes in pH ranges. In addition, the digestion process contributes to chemical degradation, mainly through the action of intestinal microbiota. The intestinal microbiota has a fundamental role in the biotransformation and metabolization of several dietary compounds, thus modifying the chemical structure, including anthocyanins. This biotransformation leads to low absorption of intact anthocyanins, and consequently, low bioavailability of these antioxidant compounds. Several studies have been conducted to seek alternatives to improve stability and protect against intestinal microbiota degradation. This comprehensive review aims to discuss the existing knowledge about the structure of anthocyanins while discussing human absorption, distribution, metabolism, and bioavailability after the oral consumption of anthocyanins. This review will highlight the use of nanotechnology systems to overcome anthocyanin biotransformation by the intestinal microbiota, pointing out the safety and effectiveness of nanostructures to maintain molecular stability.

A review on enzymatic acylation as a promising opportunity to stabilizing anthocyanins

Anthocyanins are naturally occurring bioactive compounds found mainly in fruits, vegetables, and grains. They are usually extracted due to their biological properties and great potential for technological applications. These compounds have characteristic pH-dependent colorations that are natural dyes since they come in different colors. However, they are susceptible to processing conditions, remarkably light, temperature, and oxygen. The acylated anthocyanins showed better stability characteristics, and therefore, an acylation process of these compounds could improve their applications. The enzymatic acylation was effective and showed promising results. The current review provides an overview of the works that performed enzymatic acylation of anthocyanins and studies on the stability, antioxidant activity, and lipophilicity. In general, enzymatically acylated anthocyanins showed better stability to light and temperature than non-acylated compounds. In addition, they were liposoluble, a characteristic that allows their addition to products with lipid matrices. The results showed that these compounds formed by enzymatic acylation have perspectives of application mainly as natural colorants in food products. Therefore, the enzymatic acylation of anthocyanins appears viable to increase the industrial applicability of anthocyanins. There are still some gaps to be filled in process optimization, the reuse of enzymes, and toxicity analysis of the acylated compounds formed.

Acetylated pelargonidin-3-O-glucoside exhibits promising thermostability, lipophilicity, and protectivity against oxidative damage by activating Nrf2/ARE pathway

Anthocyanins are natural products displayed diverse bioactivities, but low stability and bioavailability limit their applications. Acylated anthocyanins were found to possess higher stability, while their bioactivities are still obscure. In...

Anthocyanins: Factors Affecting Their Stability and Degradation

Anthocyanins are secondary metabolites and water-soluble pigments belonging to the phenolic group, with important functions in nature such as seed dispersal, pollination and development of plant organs. In addition to these important roles in plant life, anthocyanins are also used as natural pigments in various industries, due to the color palette they can produce from red to blue and purple. In addition, recent research has reported that anthocyanins have important antioxidant, anticancer, anti-inflammatory and antimicrobial properties, which can be used in the chemoprevention of various diseases such as diabetes, obesity and even cancer. However, anthocyanins have a major disadvantage, namely their low stability. Thus, their stability is influenced by a number of factors such as pH, light, temperature, co-pigmentation, sulfites, ascorbic acid, oxygen and enzymes. As such, this review aims at summarizing the effects of these factors on the stability of anthocyanins and their degradation. From this point of view, it is very important to be precisely aware of the impact that each parameter has on the stability of anthocyanins, in order to minimize their negative action and subsequently potentiate their beneficial health effects.

Anti-inflammatory activity of cyanidin-3-O-glucoside and cyanidin-3-O-glucoside liposomes in THP-1 macrophages

Cyanidin-3-O-glucoside (C3G) is a kind of water-soluble pigment widely existing in many plants. It has strong antioxidant and anti-inflammatory activities. However, C3G cannot exist stably for a long time because of the phenolic hydroxyl groups in its structure. Liposome technology could improve the stability and bioavailability of compounds. Based on our previous studies, C3G liposomes prepared by ethanol injection method have a certain stability in two weeks of storage. In this study, THP-1 macrophages treated with C3G and C3G liposomes can reduce the levels of inflammatory-related factors, such as tumor necrosis factor-a (TNF-a), interleukin (IL)-1β, IL-6, and IL-8, stimulated by lipopolysaccharide (LPS). Further studies showed that the LPS induction could increase the level of phosphorylated nuclear transcription factor NF-κB and phosphorylated IkBa, while C3G and C3G liposomes could inhibit the expression of phosphorylated proteins. Moreover, C3G and C3G liposomes could protect macrophages from apoptosis. In conclusion, C3G prepared by liposome technology exhibits anti-inflammatory activity, which provides a theoretical basis for the food industry to study functional food.

Advanced approaches for improving bioavailability and controlled release of anthocyanins

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

Anthocyanin content and storage stability of spray/freeze drying microencapsulated anthocyanins from berries: a review

A comprehensive literature search for articles published on spray and freeze-dried anthocyanins from a large variety of berries was performed. Out of a total of two-hundred and eight collected values, anthocyanin content in encapsulates had a 120-fold variation depending on the raw material and type of encapsulating agents. Highest observed anthocyanin concentration amounted to about 3500 mg/100 g powder. In most cases increasing the amount of encapsulant agents led to a noticeable reduction in the concentration of anthocyanins, this being attributable to a predominance of the dilution effect. Retention of encapsulated anthocyanins after storage at 25 °C (in darkness) for periods between 90 and 180 days were in the range of 80–67%, as long as the water activity (aw) was 0.33 or less. Some predicted values of half-time (t1/2) from literature must be taken with precaution since in many cases they were derived from experimental measurements taken at storage times smaller than predicted half times. Anthocyanin degradation during storage occurred even below the glass transition temperature (Tg) of the amorphous matrices.

The nutritional profile and human health benefit of pigmented rice and the impact of post-harvest processes and product development on the nutritional components: A review

Pigmented rice has attracted considerable attention due to its nutritional value, which is in large conferred by its abundant content of phenolic compounds, considerable micronutrient concentrations, as well as its higher resistant starch and thereby slower digestibility properties. A wide range of phenolic compounds identified in pigmented rice exhibit biological activities such as antioxidant activity, anti-inflammatory, anticancer, and antidiabetic properties. Post-harvest processes significantly reduce the levels of these phytochemicals, but recent developments in processing methods have allowed greater retention of their contents. Pigmented rice has also been converted to different products for food preservation and to derive functional foods. Profiling a large set of pigmented rice cultivars will thus not only provide new insights into the phytochemical diversity of rice and the genes underlying the vast array of secondary metabolites present in this species but also provide information concerning their nutritional benefits, which will be instrumental in breeding healthier rice. The present review mainly focuses on the nutritional composition of pigmented rice and how it can impact human health alongside the effects of post-harvest processes and product development methods to retain the ambient level of phytochemicals in the final processed form in which it is consumed.

An Insight into Anti-Inflammatory Activities and Inflammation Related Diseases of Anthocyanins: A Review of Both In Vivo and In Vitro Investigations

Anthocyanin is a type of flavonoid pigment widely present in fruits and vegetables. It can not only be used as natural pigment, but also has a variety of health functions, for instance, anti-oxidant, anti-inflammatory, anti-tumor, and neuroprotective activities. Persistent proinflammatory status is a major factor in the development, progression, and complications of chronic diseases. Not surprisingly, there are thus many food ingredients that can potentially affect inflammation related diseases and many studies have shown that anthocyanins play an important role in inflammatory pathways. In this paper, the inflammation related diseases (such as, obesity, diabetes, cardiovascular disease, and cancer) of anthocyanins are introduced, and the anti-inflammatory effect of anthocyanins is emphatically introduced. Moreover, the anti-inflammatory mechanism of anthocyanins is elaborated from the aspects of NF-κB, toll like receptor, MAPKs, NO, and ROS and the main efficacy of anthocyanins in inflammation and related diseases is determined. In conclusion, this review aims to get a clear insight into the role of anthocyanins in inflammation related diseases.

Preparation and Sustained-Release Performance of PLGA Microcapsule Carrier System

Microcapsules have been widely studied owing to their biocompatibility and potential for application in various areas, particularly drug delivery. However, the size of microcapsules is difficult to control, and the size distribution is very broad via various encapsulation techniques. Therefore, it is necessary to obtain microcapsules with uniform and tailored size for the construction of controlled-release drug carriers. In this study, emulsification and solvent evaporation methods were used to prepare a variety of ovalbumin-loaded poly (lactic-co-glycolic acid) (PLGA) microcapsules to determine the optimal preparation conditions. The particle size of the PLGA microcapsules prepared using the optimum conditions was approximately 200 nm, which showed good dispersibility with an ovalbumin encapsulation rate of more than 60%. In addition, porous microcapsules with different pore sizes were prepared by adding a varying amount of porogen bovine serum albumin (BSA) to the internal water phase. The release curve showed that the rate of protein release from the microcapsules could be controlled by adjusting the pore size. These findings demonstrated that we could tailor the morphology and structure of microcapsules by regulating the preparation conditions, thus controlling the encapsulation efficiency and the release performance of the microcapsule carrier system. We envision that this controlled-release novel microcapsule carrier system shows great potential for biomedical applications.

Impact of Wall Materials on Physico-Chemical Properties and Stability of Eggplant Peels Anthocyanin Hydrogels

In this study, eggplant peel extract was used to obtain hydrogels. Two experimental variants were realized by varying the wall materials. Whey proteins isolate (WPI), citrus pectin (P), and sodium carboxymethylcellulose (CMCNa) were used as wall materials. The microcapsules were obtained by the gelation technique, followed by freeze-drying in order to obtain powders. Both experimental variants were analyzed in terms of phytochemical content, antioxidant activity, storage stability, and in vitro digestibility. Additionally, confocal microscopy was used to observe the encapsulation of the bioactive compounds from the eggplant peel extract into the selected matrices. The encapsulation efficiency of the powders varied from 64.67 ± 0.68% for variant 1 (V1) to 96.44 ± 3.43% for variant 2 (V2). Both powders presented high bioactive compound content with high antioxidant activity. V2 showed the highest stability within 28 days of storage, but also in the simulated digestive system.

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

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

Encapsulation of Anthocyanins from Cornelian Cherry Fruits Using Heated or Non-Heated Soy Proteins

In the current study, the effect of temperature on the potential of soy proteins to ensure the encapsulation and gastric stability of bioactives, such as anthocyanins from cornelian cherry fruits, was investigated. The powders obtained after freeze-drying were analyzed in relation to flow properties, encapsulation retention and efficiency, stability in simulated gastrointestinal medium, color, and morphology. Preheating the soy proteins generated a powder with low density. Powders obtained with native soy proteins allowed the highest encapsulation efficiency and the lowest was obtained when using preheated soy proteins. The heat treatment of the mixture of soy proteins and cornelian cherry fruits prior to encapsulation generated powders with the highest lightness and the lowest intensity of red shades among all samples. The in vitro experiments revealed that the highest protection in simulated gastric environment was provided when protein was heat treated either alone or in combination with bioactives to be encapsulated. The morphological analysis highlighted that powders consisted of large and rigid structures.