Release Of Anthocyanins Research Articles

Development and evaluation of a novel alginate-based in situ gelling system to modulate the release of anthocyanins

Several health benefits have been associated with the consumption of anthocyanins (ACNs). These compounds are absorbed in the upper digestive tract (stomach and initial sections of the small intestine). However, an insufficient residence time of ACNs in these organs could result in limited absorption and contribute to degradation. In this paper, a novel alginate-based in situ gastroretentive gelling system is described as a platform to modulate the release and increase the retention time of ACNs from haskap berries in sites where their absorption and stability are favored. Thirteen formulations were assessed, where their composition differed by the concentrations of alginate, sodium bicarbonate, and calcium carbonate. Freeze-dried ACN-rich extract from haskap berries was incorporated into selected formulations. The ACN release profile indicated that the Peppas (power law) equation had the best fit to the experimental data and diffusion was most likely the dominant release mechanism.

In vitro digestion of dairy and egg products enriched with grape extracts: Effect of the food matrix on polyphenol bioaccessibility and antioxidant activity

The aim of this study was to evaluate the effect of the food matrix on polyphenol bioaccessibility and antioxidant activity during the in-vitro digestion of dairy and egg products enriched with grape extracts (GE). Four GE-enriched matrices produced under industrial conditions (custard dessert, milkshake, pancake and omelet) and the GE dissolved in water (control solution) were submitted to in vitro digestion and the bioaccessibility of the major classes of polyphenols as well as the evolution of the antioxidant activity of the matrices were monitored at oral, gastric and intestinal level. Apart from the digestion effect itself, the release, stability and solubility of polyphenols was governed by mainly two factors: 1 — the composition and structure of the food matrices and 2 — the class of polyphenol. Results showed that the inclusion of the GE extracts into the different egg and dairy food matrices greatly impacted the release and solubility of anthocyanins and proanthocyanidins during digestion, especially in the solid food matrices and during the oral and gastric phases of digestion. Also, the presence of the food matrices protected anthocyanins from degradation during the intestinal phase. However, if the total phenolic content is considered at the end of the whole digestion process, the proportion of soluble (bioaccessible) and insoluble phenolics delivered by the enriched-matrices was quite similar to that of the control solution. On the contrary, the food matrix effect did not affect the antioxidant activity of the matrices, which remained constant during the oral and gastric phases but greatly increased during the intestinal phase of digestion. Among the GE-enriched matrices, omelet presented higher recoveries of total phenolics and antioxidant activity at the end of digestion.

Effect of Combining Pulsed Electric Fields with Maceration Time on Merlot Grapes in Protecting Caco-2 Cells from Oxidative Stress

The objective of this study was to investigate the effect of different maceration times (0, 2, 4, 8 and 14 days) after pulsed electric field (PEF) processing (1.5 kV/cm, either at 15 or 70 kJ/kg) on the release of anthocyanins from Merlot grapes (Vitis vinifera) and the bioprotective potentials of grape juice against H2O2-induced oxidative stress using human intestinal Caco-2 cell culture model. Cell viability, lactate dehydrogenase membrane leakage and nitric oxide production in Caco-2 cells were used as biomarkers to indicate general cellular health and integrity that ultimately represent the bioprotective potentials of grape juice. The results showed that PEF at 70 kJ/kg was the most effective in accelerating the release of anthocyanins from grape skin. Furthermore, the amount and the type of anthocyanins being released varied as a result of combined effect of PEF processing intensity and maceration time. Linear correlations between anthocyanins and the bioprotective capacity markers (R 2 = 0.4–0.8) were found. Compared to the untreated Merlot, PEF treatment either at 15 or 70 kJ/kg reduced the maceration time from 14 to 8 and 2 days, respectively, to achieve similar degree of bioprotective effect. This implies the possibility of using combined PEF and maceration time to tailor the profile of bioactive compounds with the same bioprotective potentials.

Biotransformation of anthocyanins from two purple-fleshed sweet potato accessions in a dynamic gastrointestinal system

Cooked, milled purple-fleshed sweet potato (PFSP) accessions, PM09.812 and PM09.960, underwent digestion in a dynamic human gastrointestinal (GI) model that simulates gut digestive conditions to study the bioaccessibility and biotransformation of anthocyanins. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry showed accession-dependent variations in anthocyanin release and degradation. After 24h, more anthocyanin species were detected in the small intestinal vessel relative to other vessels for accession PM09.960 whereas more species appeared in the ascending colonic vessel for accession PM09.812. The ferric reducing antioxidant power was increased in the small intestinal vessel for PM09.960 and in the ascending colonic vessel for accession PM09.812, corresponding to the appearance of a majority of anthocyanins for each accession. These results show that intestinal and colonic microbial digestion of PFSP leads to an accession-dependent pattern for anthocyanin bioaccessibility and degradation.

Controlled release of anthocyanins from oxidized konjac glucomannan microspheres stabilized by chitosan oligosaccharides

A novel oxidized konjac glucomannan (OKGM) microsphere system was developed to protect and targeted deliver the sensitive antioxidant–anthocyanins into intestine. The microspheres were made of oxidized konjac glucomannan, which was cross-linked by Fe3+ via emulsification method. The absorption of anthocyanins was driven by the electrostatic interaction between the negatively charged OKGM microspheres and positively charged anthocyanins. CLSM images showed that anthocyanins distributed homogenously through the OKGM microspheres. The absorption and release behavior of anthocyanins on OKGM microspheres were determined as a function of pH and salt concentration. A maximum absorption capacity was obtained at pH 3 and low salt concentration. However, anthocyanins were released significantly at simulated stomach conditions due to fast degradation of OKGM microspheres. An extra positively charged chitosan oligosaccharides (COS) layer was applied on OKGM microspheres to prevent H+ ions permeating into microspheres under stomach condition. COS oligomers were cross-linked with glutaraldehyde to further strengthen the OKGM microspheres' structure. Finally, glutaraldehyde cross-linked COS stabilized OKGM microspheres became stable against H+ ions in simulated stomach condition, therefore OKGM microspheres can prevent an early release of the anthocyanins in stomach condition and achieve a sustained released in the intestinal condition. The in vitro release experiments revealed that the OKGM microspheres had a potential as a carrier of targeted delivery of bioactive compounds in the intestine.

In vitro fermentation of anthocyanins encapsulated with cyclodextrins: Release, metabolism and influence on gut microbiota growth

Anthocyanins are thought to exert protective influences on chronic gut disorders such as colon cancer and inflammatory bowel disease. They may also positively modulate intestinal bacterial populations. However, their bioavailability in the gastrointestinal tract is an important determinant factor for their in vivo activity. In this study, we attempted to increase their stability by encapsulation with cyclodextrins. From anaerobic batch-culture fermentation experiments with gut bacteria, release of anthocyanins and the formation of phenolic microbial metabolites were quantified. Despite a rapid release of anthocyanins observed within the first 30 min, encapsulation allowed anthocyanin degradation to be slowed down. As a consequence of anthocyanin degradation phenolic acids were formed. Quantitative analysis of bacterial populations revealed that there was a significant growth of members of the domain Bacteria in vessels with malvidin-3-glucoside, compared to the negative control, and there was inhibition of the Clostridium histolyticum group in those vessels where delphinidin-3-glucoside or cyanidin-3-glucoside was added. These results illustrate the ability of encapsulation to increase bioavailability of anthocyanins, allowing them to be released in the colon and to exert their potential health benefits.

The encapsulation of anthocyanins from berry-type fruits. Trends in foods.

During the last decade, many berry-type fruits have been recognised as good sources of anthocyanins. Nevertheless, the use of anthocyanins in the development of food colourants and healthy and/or functional ingredients has been limited because of their low stability under given environmental conditions and interaction with other compounds in the food matrix. This review compiles information about the encapsulation of anthocyanins from twelve different berry-type fruit species as a technology for improving the stability and/or bioavailability of anthocyanins. Encapsulation by spray drying has been the primary method used to encapsulate anthocyanins, and some studies attempt to keep anthocyanin microparticles stable during storage. Nevertheless, more studies are needed to determine the stability of anthocyanin microparticles in food matrices over the product shelf life in the development of food colourants. Studies about encapsulated anthocyanins in simulated gastrointestinal models have primarily been conducted on the release of anthocyanins from microparticles to evaluate their bioavailability. However, adding anthocyanin microparticles to a food vehicle must guarantee the health properties attributed to the specific anthocyanins present in berry-type fruits.

Sulčių spaudimas iš sušaldytų/atšildytų mėlynių taikant impulsinio elektrinio lauko metodą

Pulsed electric field is an efficient method for cell membrane permeabilization of food tissues with most research being done on fresh plant cells. Freeze/thawing is also known to be capable of cell membrane permeabilization. In this work, frozen/thawed European blueberry (Vaccinium myrtillus L.) fruits were treated with pulsed electric field in order to further enhance the cell membrane permeabilization and, hence, the quality of blueberry juice during the subsequent pressing process. Blueberries tissues were exposed to 20 μs monopolar square wave pulses of different electric field strength (E = 1–3–5 kV cm-1) and total specific energy input (WT = 1–5–10 kJ kg -1), with their permeabilization being characterized by electrical impedance measurements and cell disintegration index (Zp). The juice, obtained after pressing (1.32 bar), was characterized for total polyphenols, anthocyanins content and antioxidant activity. The cell disintegration index (Zp) significantly (p < 0.05) increased from 0.2 up to 0.6 with increasing pulsed electric field treatment intensity (E and WT). As a results, in comparison with control, pulsed electric field treatment induced a slightly higher release of polyphenols (up to +8.0%) and anthocyanins (up to +8.3%), thus improving the antioxidant activity of the juice (up to +16.7%). In conclusion, frozen/thawed blueberries could be pulsed electric field treated in order to further increase juice quality.

Impact of maceration enzymes on skin softening and relationship with anthocyanin extraction in wine grapes with different anthocyanin profiles

The impact of an enzyme preparation on the extraction of grape skin anthocyanins into a wine-like solution was evaluated during maceration (25°C, 8days). The study was performed on Vitis vinifera L. cv. Cabernet Sauvignon and Nebbiolo because of their different anthocyanin profiles, which are mainly composed of tri- and disubstituted forms, respectively. Maceration enzymes enhanced the skin releasing capacity for anthocyanins between 8% and 15% more, depending on the enzyme dose and variety, and shortened the time required to reach the maximum extraction yield by about 40h, when compared to the control samples. The effect of enzymes on the profile and total content of anthocyanins during maceration was significant only for Cabernet Sauvignon. Therefore, a variety effect was found. In particular, the relative amount of malvidin glucosides increased up to 9% more whereas that of delphinidin, cyanidin and peonidin glucosides decreased up to 5%, 2% and 3% more, respectively, with the addition of the enzyme preparation. The results also showed lower anthocyanin degradation at maceration times longer than 72h with the use of enzymes. Furthermore, the relationship between this enzyme effect and the instrumental skin hardness was assessed for the first time, as no previous study deals with the variation in the mechanical properties of the berry skin after using maceration enzymes. Significant positive relationships were found between the skin softening and the anthocyanin extraction yield (R>0.69, p<0.01), which confirmed that the skin degradation by enzymes facilitates the anthocyanin release.

In vitro release properties of encapsulated blueberry (Vaccinium ashei) extracts

We aimed to determine the effect of encapsulation on the release properties of blueberry extracts during simulated gastrointestinal digestion. An ethanolic pomace extract was microencapsulated with whey protein isolate via spray drying. The in vitro release of monomeric anthocyanins, phenolics and ferric reducing antioxidant activity of the microcapsules (W) were evaluated for the microcapsules and two non-encapsulated systems: ethanolic pomace extract (P) and freeze-dried juice (F). Concentrations of anthocyanin and phenolics were normalised prior to digestion. Results showed that antioxidant activity was in the order of: F>W>P. Regardless of encapsulation, more phenolics were released from W and P than F. Anthocyanin concentration decreased after intestinal digestion for W, but remained constant for P and F. MALDI-MS showed similar spectra for P and F but not for W. The spray-dried product has comparable release characteristics to freeze-dried juice, and may be investigated for food applications.

Phytochemicals in Japanese plums: impact of maturity and bioaccessibility

In recent years there has been increasing consumer interest in the potential health benefits of dietary derived phytochemicals such as polyphenols (including anthocyanins and flavonols) and carotenoids. A new variety of Japanese plum (Prunus salicina Lindl.), named Queen Garnet (QG), was developed as a high anthocyanin plum in a Queensland (Australia) Government breeding program and may be attractive to consumers, but knowledge of other phytochemical content, and bioaccessibility, is currently limited. As a result, the present study examined (1) the impact of harvest date on anthocyanins, quercetin glycosides and carotenoids in Queen Garnet and another red fleshed commercial Japanese plum variety, Black Diamond (BD), (2) the content of bound phenolics in plum fruit and (3) the in vitro bioaccessibility and release of these phytochemicals as an initial measure to predict their potential bioavailability. For both QG and BD, the last harvest resulted in the highest anthocyanin content in peel, flesh and whole fruit, whereas no significant effects could be observed for quercetin glycosides, and total carotenoids decreased over time. The highest content of bound phenolics (30% of total amount) could be found in BD flesh. Between 53% and 59% of quercetin glycosides and anthocyanins were released from QG after the gastric and small intestinal digestion procedure, whereas the release of carotenoids ranged between 4–6%. A relative high release of anthocyanins and quercetin glycosides could be observed from QG which may result in a higher gastro-intestinal absorption rate of these compounds. However, follow-up studies (clinical trials) are warranted to investigate the in vivo bioavailability and subsequently biological activity of QG.

TRIGGERED GASTROINTESTINAL RELEASE OF ANTHOCYANINS FROM BILBERRIES (VACCINIUM MYRTILLUS L.)

Bilberries (Vaccinium myrtillus L.) are reported to show preventive activities against inflammatory bowel diseases (IBD), colon cancer or degenerative disease such as Alzheimer’s dementia. These findings are attributed to the antioxidative and anti-inflammatory activities of one of the main ingredients, the anthocyanins. However, anthocyanins are sensitive to environmental conditions, thus their bioavailability in the gastrointestinal tract is an important determinant of their in vivo activity. In the study reported here, the potential benefits of encapsulating an anthocyanin rich bilberry extract (BE) on anthocyanin stability were investigated. Non-encapsulated BE and three different BE loaded microcapsule systems were incubated anaerobically in intestinal fluid, namely ileostomy effluents from volunteers. After exposure to these media released anthocyanins were identified and quantified by HPLC with UV/VIS detection. A constant degradation of anthocyanins from BE was observed to 29.7% of the applied amount within 24 h. In contrast to this, encapsulation of anthocyanins lead to a constant liberation for at least 6 h of about 14.5 to 20.5% of the initial concentration of anthocyanins from the matrix. These results illustrate the ability of encapsulation to provide a constant (triggered) release of anthocyanins into the intestinal system, but in contrast to the non-encapsulated BE lower low amounts being liberated.

Microencapsulation of Andes Berry (Rubus glaucus Benth.) Aqueous Extract by Spray Drying

The Andes berry (Rubus glaucus Benth.), a tropical fruit with a high anthocyanin content and pleasant aroma, was selected for spray drying to produce solids that preserve the sensory characteristics (colour, odour and taste) of the fresh fruit. A factorial design (9 × 2) was implemented to evaluate the influence of the encapsulating agent (maltodextrin DE 20, arabic gum, corn starch, yucca starch, Capsul® TA and Hi-CapTM 100, as well as three mixtures of them) and the nozzle diameter (1.0 and 2.0 mm) on the characteristics of solids, anthocyanin content, moisture and water activity. All solids showed water activity values (a w) between 0.199 and 0.422, and particle size ranging from 3 to 15 μm according to microscopy results. The samples exhibiting the highest anthocyanin content were subjected to a discriminative sensory analysis. The Andes berry microencapsulates obtained with Hi-CapTM 100 and maltodextrin DE 20 as wall materials were chosen because of their sensory properties. The release of anthocyanins as well as volatile aroma compounds by water dissolution was confirmed by both liquid and gas chromatography coupled to mass spectrometry (HPLC-MS and GCMS, respectively). The chroma (C*ab) and a* values of the solutions were higher than those of the powders, which indicated a more intense red colour. Thermal analyses (thermogravimetric analyses and differential scanning calorimetry) showed that these two solids were stable up to 100 °C under a nitrogen atmosphere. Remarkably, the anthocyanin content did not change during 180 days at 18 °C and a relative humidity of less than 60 %. However, the shelf life of these products is highly dependent on the humidity during storage because a relative humidity increase causes significant damage to the microcapsule structures and the loss of the encapsulated materials.

Release and Degradation of Anthocyanins and Phenolics from Blueberry Pomace during Thermal Acid Hydrolysis and Dry Heating

In this study, blueberry pomace was soaked in pH 1, 4, or 7 solution for 10 min followed by boiling hydrolysis. Nine anthocyanins and 11 other phenolic compounds were released after acid hydrolysis. The highest anthocyanin release (4.70 mg/g) was achieved by boiling at pH 1 for 15 min followed by 3.94 mg/g at pH 4 and 3.46 mg/g at pH 7. Phenolics were released more quickly than anthocyanins during boiling. The change of antioxidant activity of the pomace during boiling was correlated with the total phenolic content but not anthocyanin content. The degradation rate of anthocyanins during boiling eventually surpassed the release rate from the pomace. Protocatechuic acid and catechin continuously increased during heating. Dry heat resulted in continuous degradation of anthocyanins and other phenolics in the pomace. The reduction in antioxidant activity of the pomace during dry heating was correlated with both the phenolic and anthocyanin contents.

A Study of Controlled Uptake and Release of Anthocyanins by Oxidized Starch Microgels

Anthocyanins are well-known antioxidants, but they are sensitive to environmental conditions. Herein we used oxidized starch microgel to prevent their early degradation and deliver them to the target place. The aim of this study was to investigate the uptake and the release ability of anthocyanins by the oxidized starch microgels and measure their in vitro gastrointestinal release. The gels were made of oxidized potato starch polymers, which were chemically cross-linked by sodium trimetaphosphate (STMP). In this study, the uptake and release behaviors of anthocyanins by starch microgel were investigated under various pH and salt concentrations. The microgel of high degree of oxidation and high cross-link density had a high uptake capacity for anthocyanins at low pH and salt concentration; 62 mg anthocyanins had been absorbed per gram of dry DO100% (degree of oxidation 100%) microgel at pH 3 with ionic strength 0.05M. The in vitro study of the release was investigated under stimulated gastrointestinal fluid. The anthocyanins were identified and quantified by UV/vis detection. The results indicated that the oxidized starch microgels had a potential for being a carrier system for protecting anthocyanins from degradation in the upper gastric tract and for delivering them to the intestine. This paper provides a good reference for an intestinal-targeted delivery system of vulnerable functional ingredients by oxidized starch microgel.

Effect of Microformulation on the Bioactivity of an Anthocyanin-rich Bilberry Pomace Extract (Vaccinium myrtillus L.) in Vitro

In cell culture were compared the different release rates of anthocyanins from a bilberry pomace extract encapsulated either in food grade whey protein-based matrix capsules (WPC) or in pectin amid-based hollow spherical capsules (PHS). The impact of the formulations on typical anthocyanin-associated biological end points such as inhibition of the epidermal growth factor receptor (EGFR) and suppression of cell growth in HT29 colon carcinoma cells was assessed. The purpose was to find whether the release rates are sufficient to maintain biological activity and whether encapsulation affected EGFR inhibitory and growth suppressive properties of the extract. Even though anthocyanin release from extract-loaded capsules was proven under cell culture conditions, the inhibitory potential toward the EGFR was diminished. However, nonencapsulated extract as well as both extract-loaded encapsulation systems diminished the growth of HT29 cells to a comparable extent. The loss of EGFR inhibitory properties by encapsulation despite anthocyanin release indicates substantial contribution of other further constituents not monitored so far. Taken together, both applied encapsulation strategies allowed anthocyanin release and maintained biological activity with respect to growth inhibitory properties. However, the loss of EGFR inhibitory effects emphasizes the need for biological profiling to estimate process-induced changes of plant constituent's beneficial potencies.

Lack of release of bound anthocyanins and phenolic acids from carrot plant cell walls and model composites during simulated gastric and small intestinal digestion

Separately, polyphenols and plant cell walls (PCW) are important contributors to the health benefits associated with fruits and vegetables. However, interactions with PCW which occur either during food preparation or mastication may affect bioaccessibility and hence bioavailability of polyphenols. Binding interactions between anthocyanins, phenolic acids (PAs) and PCW components, were evaluated using both a bacterial cellulose-pectin model system and a black carrot puree system. The majority of available polyphenols bound to PCW material with 60-70% of available anthocyanins and PAs respectively binding to black carrot puree PCW matter. Once bound, release of polyphenols using acidified methanol is low with only ∼20% of total anthocyanins to ∼30% of PAs being released. Less than 2% of bound polyphenol was released after in vitro gastric and small intestinal (S.I.) digestion for both the model system and the black carrot puree PCW matter. Confocal laser scanning microscopy shows localised binding of anthocyanins to PCW. Very similar patterns of binding for anthocyanins and PAs suggest that PAs form complexes with anthocyanins and polysaccharides. Time dependent changes in extractability with acidified methanol but not the total bound fraction suggests that initial non-specific deposition on cellulose surfaces is followed by rearrangement of the bound molecules. Minimal release of anthocyanins and PAs after simulated gastric and S.I. digestion indicates that polyphenols in fruits and vegetables which bind to the PCW will be transported to the colon where they would be expected to be released by the action of cell wall degrading bacteria.

Drug stabilization and controlled release from AB3 type tetra block copolymer based polymersome

In order to increase the bioavailability of hydrophilic unstable drugs, polymersomes from AB3 type tetra block copolymers composing of poly(ethylene glycol)-b-(3) poly(lactic acid) (EO-3LA) as a water-soluble drug delivery carrier have been investigated due to its unique properties such as high stability and high water soluble drug loading efficiency. The sizes of EO-3LA polymersomes determined by dynamic light scattering were ranged in 190–220 nm with monodispersion. Its polymeric layer with 10–20 nm at the outershell was observed by field emission scanning electron microscopy. The polymersomes showed low critical aggregation concentrations (9.2–14.9 ug/ml). Anthocyanin was employed as a model drug for unstable drug in this study. The anthocyanin loading contents of EO-3LA polymersomes are depending on PLLA content in the polymers. The high loading contents (6.6–7.0 wt%) of the polymersomes are due to their tight and rigid polymeric membranes. The polymeric membrane in EO-3LA polymersomes contributed to improve drug stability on various pHs. Moreover, this property induced sustained anthocyanin release pattern from the polymersome. Therefore, the polymersome has potential as a drug carrier for water-soluble and unstable drugs.

Preparation and Comparative Release Characteristics of Three Anthocyanin Encapsulation Systems

Bilberries (Vaccinium myrtillus L.) and their major polyphenolic constituents, anthocyanins, have preventive activities inter alia against colon cancer and inflammatory bowel diseases. However, anthocyanins are sensitive to environmental conditions; thus their bioavailability in the gastrointestinal tract is an important determinant of their in vivo activity. In the study reported here, the potential benefits of encapsulating an anthocyanin rich bilberry extract (BE) on anthocyanin stability were investigated. Nonencapsulated BE and three different BE loaded microcapsule systems were incubated in simulated gastric fluid (SGF) and fed state simulated intestinal fluid (FeSSIF). After exposure to these media, released anthocyanins were identified and quantified by HPLC with UV/Vis detection. Although a rapid release of anthocyanins was observed within the first 20 min, encapsulation of anthocyanins doubled the amount of available anthocyanins after 150 min of incubation. These results illustrate the ability of encapsulation to inhibit early degradation of anthocyanins in the intestinal system.

Influence of different pectins on powder characteristics of microencapsulated anthocyanins and their impact on drug retention of shellac coated granulate

Blueberry extract was spray dried using different pectins and caffeine as copigment for anthocyanins in order to influence the release of anthocyanins from the shellac coated maltodextrin granulates in simulated gastric fluid. The addition of pectin did not have any influence on the structure of spray dried microcapsules as well as on the coating layer of the granulates. The initial retention of anthocyanins depended significantly on the waterbinding ability of spray dried microcapsules. The higher the waterbinding capacity of spray dried powders the lower was the anthocyanin release. Highest waterbinding capacity and lowest anthocyanin release was gained by citrus pectin with a high degree of esterification (DE) and sugar beet pectin. In general high DE pectins inhibited the release stronger than low DE pectins.