44,465 research outputs found

    Anthocyanin Stability in Food Products made with Freeze-Dried Blueberry Powder

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    This study evaluated the stability of anthocyanins in six blueberry products (gummy, graham bar, oatmeal bar, rice krispy bar, ice pop and juice) prepared with freeze-dried wild blueberry powder during processing and over eight weeks storage. Total anthocyanins were determined by HPLC before processing and at day 0 and 2, 4, 6, and 8 weeks of storage. Thermal processing of gummy and graham bar products resulted in significant losses of anthocyanins (50% and 31%, respectively). An eight-week storage time also resulted in a significant decrease in anthocyanins (7% to 51%) in products stored at ambient temperature. The ice pop, which was stored at -20oC, was the best product for shelf-stability as it experienced no significant decline in total anthocyanins during processing or over the entire shelf-life study. Future research should be conducted to determine the differences in total anthocyanins in the products over time when they are stored under refrigeration. Additionally, polymeric color should be analyzed as this indicator has the potential to further explain the nature of the decreases in anthocyanins observed during storage

    Anthocyanins do not influence long-chain n-3 fatty acid status:Studies in cells, rodents and humans

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    Increased tissue status of the long-chain n-3 polyunsaturated fatty acids (LC n-3 PUFA), eicosapentaenoic (EPA) and docosahexaenoic acid (DHA) is associated with cardiovascular and cognitive benefits. Limited epidemiological and animal data suggest that flavonoids, and specifically anthocyanins, may increase EPA and DHA levels, potentially by increasing their synthesis from the shorter-chain n-3 PUFA, α-linolenic acid. Using complimentary cell, rodent and human studies we investigated the impact of anthocyanins and anthocyanin-rich foods/extracts on plasma and tissue EPA and DHA levels and on the expression of fatty acid desaturase 2 (FADS2), which represents the rate limiting enzymes in EPA and DHA synthesis. In experiment 1, rats were fed a standard diet containing either palm oil or rapeseed oil supplemented with pure anthocyanins for 8 weeks. Retrospective fatty acid analysis was conducted on plasma samples collected from a human randomized controlled trial where participants consumed an elderberry extract for 12 weeks (experiment 2). HepG2 cells were cultured with α-linolenic acid with or without select anthocyanins and their in vivo metabolites for 24 h and 48 h (experiment 3). The fatty acid composition of the cell membranes, plasma and liver tissues were analyzed by gas chromatography. Anthocyanins and anthocyanin-rich food intake had no significant impact on EPA or DHA status or FADS2 gene expression in any model system. These data indicate little impact of dietary anthocyanins on n-3 PUFA distribution and suggest that the increasingly recognized benefits of anthocyanins are unlikely to be the result of a beneficial impact on tissue fatty acid status

    Anthocyanin absorption and metabolism by human intestinal Caco-2 cells: a review

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    Anthocyanins from different plant sources have been shown to possess health beneficial effects against a number of chronic diseases. To obtain any influence in a specific tissue or organ, these bioactive compounds must be bioavailable, i.e., effectively absorbed from the gut into the circulation and transferred to the appropriate location within the body while still maintaining their bioactivity. One of the key factors affecting the bioavailability of anthocyanins is their transport through the gut epithelium. The Caco-2 cell line, a human intestinal epithelial cell model derived from a colon carcinoma, has been proven to be a good alternative to animal studies for predicting intestinal absorption of anthocyanins. Studies investigating anthocyanin absorption by Caco-2 cells report very low absorption of these compounds. However, the bioavailability of anthocyanins may be underestimated since the metabolites formed in the course of digestion could be responsible for the health benefits associated with anthocyanins. In this review, we critically discuss recent findings reported on the anthocyanin absorption and metabolism by human intestinal Caco-2 cells

    Concentration of Hot Water Extracts of Anthocyanins obtained from Muscadine Grape Pomace using Membrane-Osmotic Distillation

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    Anthocyanins are well known for their health-promoting benefits. The goal of this study was to evaluate a distillation-based membrane technology to concentrate aqueous anthocyanins extracted from muscadine grape pomace using polypropylene (PP) or ethylene chlorotrifluoroethylene (ECTFE) membranes. A hot water extraction method was utilized to extract the anthocyanins from the pomace. A pre-experimental run using DI water as feed was conducted to optimize the NaCl brine concentration for osmotic distillation and it was determined that 4M was the optimal concentration. The aqueous anthocyanins extraction was filtrated through a series of filter of different pore sizes before the distillation process. Membrane distillation (MD), osmotic distillation (OD), and membrane osmotic distillation (OMD) were all carried out over a 6-hour period to determine the optimal distillation process. Among the three processes, OMD demonstrated the highest permeate flux value, therefore, it was utilized to conduct the concentration using either PP or ECTFE membranes. The anthocyanins contents before and after the concentration process were measured by High Performance Liquid Chromatography machine. The result shows that OMD paired with ECTFE membrane concentrated the aqueous anthocyanins up to 196% but OMD with PP membrane exhibited a better performance. Concentrating the aqueous anthocyanin extract 280% over a 12-hour period. In addition, the quality of the concentrate was also investigated in terms of NaCl transferring across the membrane to the feed solution. only 0.02% - 0.03% of NaCl was transferred across the membrane to the feed side, indicating it is feasible to obtain concentrated anthocyanin extracts with low salt concentratio

    Storage effects of gel encapsulation on stability of chokeberry monomeric anthocyanins, procyanidins, color density, and percent polymeric color

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    Chokeberries (Aronia melanocarpa) are an antioxidant-rich plant product due to their high content of polyphenols, especially anthocyanins and procyanidins. These polyphenols have been shown to provide protection against coronary heart disease, stroke, and lung cancer, as well as against oxidative stress, the main cause behind chronic diseases promoted by free radicals. The objective of this study was to determine the storage effects of gelatin encapsulation on monomeric anthocyanins, procyanidins, color density, and percent polymeric color of three gummy candies of different strengths formulated with a base of 25.4% chokeberry concentrate, 47.6% sucrose, 1.3% Splenda, and 0.025% potassium sorbate. The gum strengths varied by percentages of gelatin and water in the formulations, with 19.1:6.6, 17.8:7.9, and 16.5:9.2 ratios used to produce soft, medium, and hard strength gummies, respectively. Total monomeric anthocyanins, total procyanidins, color density, and percent polymeric color of the gummies were determined 1 day post-processing and after 2, 4, and 6 months of storage at refrigerated and room temperatures. Storage for 6 months at room temperature resulted in dramatic losses of monomeric anthocyanins (80-82%), total procyanidins (48-54%), and color density (76-80%). Anthocyanin losses during storage coincided with marked increases in percent polymeric color values indicating that anthocyanins and procyanidins underwent condensation reactions to form polymers. Refrigerated storage ameliorated losses of monomeric anthocyanins (61-65%), total procyanidins (17-22%), and color density (60-67%) over 6 months of storage compared to samples stored at ambient temperature. Refrigerated storage also ameliorated the increase in polymeric color values observed in samples stored at room temperature indicating condensation reactions responsible for polymer formation were retarded. Gum strength did not have a significant effect on retention of anthocyanins and procyanidins

    Extraction of anthocyanins and total phenolic compounds from açai (euterpe oleracea mart.) using an experimental design methodology. part 1: Pressurized liquid extraction

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    Currently, açai is one of the most important fruits present in the world. Several studies have demonstrated its high content in phenolic compounds and anthocyanins. Both of them are responsible of interesting properties of the fruit such as anti-inflammatory, antioxidant or anticancer. In the present study, two optimized pressurized liquid extraction (PLE) methods have been developed for the extraction of anthocyanins and total phenolic compounds from açai. A full factorial design (Box-Behnken design) with six variables (solvent composition (25%-75% methanol-in-water), temperature (50-100°C), pressure (100-200 atm), purge time (30-90 s), pH (2-7) and flushing (50%-150%)) were employed. The percentage of methanol in the extraction solvent was proven to be the most significant variable for the extraction of anthocyanins. In the case of total phenolic compounds, the extraction temperature was the most influential variable. The developed methods showed high precision, with relative standard deviations (RSD) of less than 5%. The applicability of the methods was successfully evaluated in real samples. In conclusion, two rapid and reliable PLE extraction methods to be used for laboratories and industries to determine anthocyanins and total phenolic compounds in açai and its derived products were developed in this work

    Extraction of Anthocyanins and Total Phenolic Compounds from Açai (Euterpe oleracea Mart.) Using an Experimental Design Methodology. Part 3: Microwave-Assisted Extraction

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    In this work, two methods based on microwave-assisted extraction techniques for the extraction of both anthocyanins and total phenolic compounds from acai have been developed. For that, a full factorial design (Box-Behnken design) has been used to optimize the following four variables: solvent composition (25-75% methanol in water), temperature (50-100 degrees C), pH (2-7), and sample/solvent ratio (0.5 g: 10 mL-0.5 g: 20 mL). The anthocyanins and total phenolic compounds content have been determined by ultra high-pressure liquid chromatography and Folin-Ciocalteu method, respectively. The optimum conditions for the extraction of anthocyanins were 38% MeOH in water, 99.63 degrees C, pH 3.00, at 0.5 g: 10 mL of ratio, while for the extraction of total phenolic compounds they were 74.16% MeOH in water, 99.14 degrees C, pH 5.46, at 0.5 g: 20 mL of ratio. Both methods have shown a high repeatability and intermediate precision with a relative standard deviation lower than 5%. Furthermore, an extraction kinetics study was carried out using extraction periods ranging from 2 min until 25 min. The optimized methods have been applied to acai-containing real samples. The results with such real samples have confirmed that both methods are suitable for a rapid and reliable extraction of anthocyanins and total phenolic compounds

    <i>Clitoria ternatea</i> L. flower extract inhibits α-amylase during <i>in vitro </i>starch digestion

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    This study aimed to investigate the inhibitory effect of Clitoria ternatea flower against α-amylase during simulated in vitro wheat starch digestion. The dark-blue tropical flower is used as a food colorant but its ability to modulate starch digestion has not been tested before. The aqueous extract of the flower containing anthocyanins was a competitive inhibitor against α-amylase with an IC50 value (concentration of inhibitor required to reduce the enzyme activity by half) and inhibition constant, Ki, of 0.91 mg/mL and 0.75 mg/mL,respectively. Subjecting the extract to pasteurisation (72oC for 15 s) and boiling (for 30 min) it significantly (P&lt;0.05) decreased the anthocyanin content as determined by a pH-shift method, although the light absorbance profile of the extract remained virtually unchanged, suggesting that the equilibrium mixture of anthocyanin species was unaffected. The thermal degradation of the anthocyanins explained the partial loss of inhibition activity of the extract, as indicated by the decrease in Michaelis-Menten constant, Km, from 14.8 mg/mL in thesystems with unheated extract to 11.3 and 6.1 mg/mL in pasteurised and boiled extracts, respectively. The thermal treatments, however, did not change the type (competitive) of inhibition. The results from this work demonstrated the potential of C. ternatea flower extract in inhibiting α-amylase during starch digestion, which might lead to development of functional food/drink for controlling postprandial blood glucose level

    The Change of Total Anthocyanins in Blueberries and Their Antioxidant Effect After Drying and Freezing

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    This study examined the effects of freezing, storage, and cabinet drying on the anthocyanin content and antioxidant activity of blueberries (Vaccinium corymbosum L). Fresh samples were stored for two weeks at 5(°)C while frozen samples were kept for up to three months at −20(°)C. There were two drying treatments, one including osmotic pretreatment followed by cabinet drying and the other involving only cabinet drying. Total anthocyanins found in fresh blueberries were 7.2 ± 0.5 mg/g dry matter, expressed as cyanidin 3-rutinoside equivalents. In comparison with fresh samples, total anthocyanins in untreated and pretreated dried blueberries were significantly reduced to 4.3 ± 0.1 mg/g solid content, 41% loss, and 3.7 ± 0.2 mg/g solid content, 49% loss, respectively. Osmotic treatment followed by a thermal treatment had a greater effect on anthocyanin loss than the thermal treatment alone. In contrast, the frozen samples did not show any significant decrease in anthocyanin level during three months of storage. Measurement of the antioxidant activity of anthocyanin extracts from blueberries showed there was no significant difference between fresh, dried, and frozen blueberries
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