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Wee Sim Choo - One of the best experts on this subject based on the ideXlab platform.

  • Betacyanin inhibited biofilm formation of co-culture of Staphylococcus aureus and Pseudomonas aeruginosa on different polymer surfaces.
    FEMS microbiology letters, 2020
    Co-Authors: Yi Yi Yong, Gary A. Dykes, Michelle Wei Kim Ong, Wee Sim Choo
    Abstract:

    Staphylococcus aureus and Pseudomonas aeruginosa are bacteria that cause biofilm-associated infections. The aim of this study was to determine the activity of combined betacyanin fractions from Amaranthus dubius (red spinach) and Hylocereus polyrhizus (red pitahaya) against biofilms formed by co-culture of S. aureus and P. aeruginosa on different polymer surfaces. Various formulations containing different concentrations of the betacyanin fractions were investigated for biofilm inhibiting activity on polystyrene surfaces using the crystal violet assay and scanning electron microscopy. A combination of each betacyanin fraction (0.625 mg mL-1) reduced biofilm formation of five S. aureus strains and four P. aeruginosa strains from OD values of 1.24-3.84 and 1.25-3.52 to 0.81-2.63 and 0.80-1.71, respectively. These combined fractions also significantly inhibited dual-species biofilms by 2.30 and reduced 1.0-1.3 log CFU cm-2 bacterial attachment on polymer surfaces such as polyvinyl chloride, polyethylene, polypropylene and silicone rubber. This study demonstrated an increase in biofilm inhibiting activity against biofilms formed by two species using combined fractions than that of using single fractions. Betacyanins found in different plants could collectively be used to potentially decrease the risk of biofilm-associated infections caused by these bacteria on hydrophobic polymers.

  • Betacyanins from Hylocereus polyrhizus: pectinase-assisted extraction and application as a natural food colourant in ice cream
    Journal of Food Science and Technology, 2020
    Co-Authors: Ashwini Gengatharan, Gary Dykes, Wee Sim Choo
    Abstract:

    The effect of solvent, substrate-to-solvent ratio and concentration of pectinase on the extraction of Betacyanins from the pulp of red pitahaya (Hylocereus polyrhizus) was evaluated with respect to yield, betacyanin content (BC) and total sugar content. The application of Betacyanins from red pitahaya in ice cream was then evaluated by comparison to a commercial colourant, E-162. Without the use of pectinase, the highest yields (9.11 ± 0.35%) of Betacyanins were obtained using 95% ethanol at a substrate-to-solvent ratio of 1:1. With the use of pectinase at a concentration of 1.5%, the highest yield (17.11–17.45%) of Betacyanins were obtained using water as a solvent at a substrate-to-solvent ratio of 1:1 and 1:2. Pectinase treatment (1.5–2.5%) using water as a solvent yielded Betacyanins with the highest BC (126.47–130.83 g kg^−1) and lowest total sugar content (57.85–59.74 g kg^−1). The BC and total colour changes were similar in ice cream containing Betacyanins from red pitahaya and E-162 throughout the 21-days of frozen storage at −18 °C. Betacyanins from red pitahaya or E-162 enhanced the antioxidant properties of ice cream. The sensory evaluation of ice cream containing Betacyanins from red pitahaya showed a better colour acceptability than E-162.

  • Antiviral activity of Betacyanins from red pitahaya (Hylocereus polyrhizus) and red spinach (Amaranthus dubius) against dengue virus type 2 (GenBank accession no. MH488959).
    Access microbiology, 2019
    Co-Authors: Ying Jun Chang, Lian Yih Pong, Sharifah Syed Hassan, Wee Sim Choo
    Abstract:

    This study investigated the antiviral activity of Betacyanins from red pitahaya (Hylocereus polyrhizus) and red spinach (Amaranthus dubius) against dengue virus type 2 (DENV-2). The pulp of red pitahaya and the leaves of red spinach were extracted using methanol followed by sub-fractionation and Amberlite XAD16N column chromatography to obtain betacyanin fractions. The half maximum cytotoxicity concentration for betacyanin fractions from red pitahaya and red spinach on Vero cells were 4.346 and 2.287 mg ml−1, respectively. The half-maximal inhibitory concentration (IC50) of betacyanin fraction from red pitahaya was 125.8 μg ml−1 with selectivity index (SI) of 5.8. For betacyanin fraction from red spinach, the IC50 value was 14.62 µg ml−1 with SI of 28.51. Using the maximum non-toxic betacyanin concentration, direct virucidal effect against DENV-2 was obtained from betacyanin fraction from red pitahaya (IC50 of 126.70 μg ml−1; 95.0 % virus inhibition) and red spinach (IC50 value of 106.80 μg ml−1; 65.9 % of virus inhibition). Betacyanin fractions from red pitahaya and red spinach inhibited DENV-2 in vitro.

  • Biofilm inhibiting activity of Betacyanins from red pitahaya (Hylocereus polyrhizus) and red spinach (Amaranthus dubius) against Staphylococcus aureus and Pseudomonas aeruginosa biofilms
    Journal of applied microbiology, 2018
    Co-Authors: Yi Yi Yong, Gary A. Dykes, Sui Mae Lee, Wee Sim Choo
    Abstract:

    AIMS To investigate the biofilm inhibitory activity of Betacyanins from red pitahaya (Hylocereus polyrhizus) and red spinach (Amaranthus dubius) against Staphylococcus aureus and Pseudomonas aeruginosa biofilms. METHODS AND RESULTS The pulp of red pitahaya and the leaves of red spinach were extracted using methanol followed by subfractionation to obtain betacyanin fraction. The anti-biofilm activity was examined using broth microdilution assay on polystyrene surfaces and expressed as minimum biofilm inhibitory concentration (MBIC). The betacyanin fraction from red spinach showed better anti-biofilm activity (MBIC: 0·313-1·25 mg ml-1 ) against five Staph. aureus strains while the betacyanin fraction from red pitahaya showed better anti-biofilm activity (MBIC: 0·313-0·625 mg ml-1 ) against four P. aeruginosa strains. Both betacyanin fraction significantly reduced hydrophobicity of Staph. aureus and P. aeruginosa strains. Numbers of Staph. aureus and P. aeruginosa attached to polystyrene were also reduced without affecting their cell viability. CONCLUSION Betacyanins can act as anti-biofilm agents against the initial step of biofilm formation, particularly on a hydrophobic surface like polystyrene. SIGNIFICANCE AND IMPACT OF THE STUDY This study is the first to investigate the use of betacyanin as a biofilm inhibitory agent. Betacyanin could potentially be used to reduce the risk of biofilm-associated infections.

  • Effect of refrigerated storage on betacyanin composition, antibacterial activity of red pitahaya (Hylocereus polyrhizus) and cytotoxicity evaluation of betacyanin rich extract on normal human cell lines
    LWT, 2018
    Co-Authors: Yi Yi Yong, Gary A. Dykes, Sui Mae Lee, Wee Sim Choo
    Abstract:

    Abstract Red pitahaya fruit is rich in purplish-red color water-soluble Betacyanins. The effect of refrigerated storage at 4 °C on the betacyanin composition of red pitahaya was monitored each day, for one week, using HPLC. The betacyanin content of red pitahaya had increased by 57.2% after storage for six days at 4 °C. From day 2 to day 7, the phyllocactin content decreased from 45.4 ± 1.5% to 38.3 ± 3.1%, whereas the betanin content increased from 37.9 ± 1.6% to 42.7 ± 1.5%. Antimicrobial activity was determined using the broth microdilution assay and expressed as minimum inhibitory concentration (MIC). As compared to the freshly harvested fruits (MIC values: 50,000–>50,000 μg mL−1), fruits that were stored for six days at 4 °C demonstrated better antimicrobial activity (MIC values: 3130–6250 μg mL−1) against 10 pathogenic Gram-positive and 6 Gram-negative bacteria. Betacyanin rich extract was also examined against normal human cell lines (HEK-293 and THP-1) and found to be not cytotoxic at the levels of 0.39–3.13 mg mL−1. In summary, refrigerated storage for 6 days increased the betacyanin content, changed the betacyanin composition in red pitahaya and contributed to higher antimicrobial activity.

Yi Yi Yong - One of the best experts on this subject based on the ideXlab platform.

  • Betacyanin inhibited biofilm formation of co-culture of Staphylococcus aureus and Pseudomonas aeruginosa on different polymer surfaces.
    FEMS microbiology letters, 2020
    Co-Authors: Yi Yi Yong, Gary A. Dykes, Michelle Wei Kim Ong, Wee Sim Choo
    Abstract:

    Staphylococcus aureus and Pseudomonas aeruginosa are bacteria that cause biofilm-associated infections. The aim of this study was to determine the activity of combined betacyanin fractions from Amaranthus dubius (red spinach) and Hylocereus polyrhizus (red pitahaya) against biofilms formed by co-culture of S. aureus and P. aeruginosa on different polymer surfaces. Various formulations containing different concentrations of the betacyanin fractions were investigated for biofilm inhibiting activity on polystyrene surfaces using the crystal violet assay and scanning electron microscopy. A combination of each betacyanin fraction (0.625 mg mL-1) reduced biofilm formation of five S. aureus strains and four P. aeruginosa strains from OD values of 1.24-3.84 and 1.25-3.52 to 0.81-2.63 and 0.80-1.71, respectively. These combined fractions also significantly inhibited dual-species biofilms by 2.30 and reduced 1.0-1.3 log CFU cm-2 bacterial attachment on polymer surfaces such as polyvinyl chloride, polyethylene, polypropylene and silicone rubber. This study demonstrated an increase in biofilm inhibiting activity against biofilms formed by two species using combined fractions than that of using single fractions. Betacyanins found in different plants could collectively be used to potentially decrease the risk of biofilm-associated infections caused by these bacteria on hydrophobic polymers.

  • Biofilm inhibiting activity of Betacyanins from red pitahaya (Hylocereus polyrhizus) and red spinach (Amaranthus dubius) against Staphylococcus aureus and Pseudomonas aeruginosa biofilms
    Journal of applied microbiology, 2018
    Co-Authors: Yi Yi Yong, Gary A. Dykes, Sui Mae Lee, Wee Sim Choo
    Abstract:

    AIMS To investigate the biofilm inhibitory activity of Betacyanins from red pitahaya (Hylocereus polyrhizus) and red spinach (Amaranthus dubius) against Staphylococcus aureus and Pseudomonas aeruginosa biofilms. METHODS AND RESULTS The pulp of red pitahaya and the leaves of red spinach were extracted using methanol followed by subfractionation to obtain betacyanin fraction. The anti-biofilm activity was examined using broth microdilution assay on polystyrene surfaces and expressed as minimum biofilm inhibitory concentration (MBIC). The betacyanin fraction from red spinach showed better anti-biofilm activity (MBIC: 0·313-1·25 mg ml-1 ) against five Staph. aureus strains while the betacyanin fraction from red pitahaya showed better anti-biofilm activity (MBIC: 0·313-0·625 mg ml-1 ) against four P. aeruginosa strains. Both betacyanin fraction significantly reduced hydrophobicity of Staph. aureus and P. aeruginosa strains. Numbers of Staph. aureus and P. aeruginosa attached to polystyrene were also reduced without affecting their cell viability. CONCLUSION Betacyanins can act as anti-biofilm agents against the initial step of biofilm formation, particularly on a hydrophobic surface like polystyrene. SIGNIFICANCE AND IMPACT OF THE STUDY This study is the first to investigate the use of betacyanin as a biofilm inhibitory agent. Betacyanin could potentially be used to reduce the risk of biofilm-associated infections.

  • Effect of refrigerated storage on betacyanin composition, antibacterial activity of red pitahaya (Hylocereus polyrhizus) and cytotoxicity evaluation of betacyanin rich extract on normal human cell lines
    LWT, 2018
    Co-Authors: Yi Yi Yong, Gary A. Dykes, Sui Mae Lee, Wee Sim Choo
    Abstract:

    Abstract Red pitahaya fruit is rich in purplish-red color water-soluble Betacyanins. The effect of refrigerated storage at 4 °C on the betacyanin composition of red pitahaya was monitored each day, for one week, using HPLC. The betacyanin content of red pitahaya had increased by 57.2% after storage for six days at 4 °C. From day 2 to day 7, the phyllocactin content decreased from 45.4 ± 1.5% to 38.3 ± 3.1%, whereas the betanin content increased from 37.9 ± 1.6% to 42.7 ± 1.5%. Antimicrobial activity was determined using the broth microdilution assay and expressed as minimum inhibitory concentration (MIC). As compared to the freshly harvested fruits (MIC values: 50,000–>50,000 μg mL−1), fruits that were stored for six days at 4 °C demonstrated better antimicrobial activity (MIC values: 3130–6250 μg mL−1) against 10 pathogenic Gram-positive and 6 Gram-negative bacteria. Betacyanin rich extract was also examined against normal human cell lines (HEK-293 and THP-1) and found to be not cytotoxic at the levels of 0.39–3.13 mg mL−1. In summary, refrigerated storage for 6 days increased the betacyanin content, changed the betacyanin composition in red pitahaya and contributed to higher antimicrobial activity.

  • Comparative Study of Betacyanin Profile and Antimicrobial Activity of Red Pitahaya (Hylocereus polyrhizus) and Red Spinach (Amaranthus dubius)
    Plant Foods for Human Nutrition, 2017
    Co-Authors: Yi Yi Yong, Gary Dykes, Wee Sim Choo
    Abstract:

    Betacyanins are reddish to violet pigments that can be found in red pitahaya ( Hylocereus polyrhizus ) and red spinach ( Amaranthus dubius ). This study investigated the impact of sub-fractionation (solvent partitioning) on betacyanin content in both plants. Characterization of Betacyanins and evaluation of their antimicrobial activities were also carried out. Betanin was found in both plants. In addition, isobetanin, phyllocactin and hylocerenin were found in red pitahaya whereas amaranthine and decarboxy-amaranthine were found in red spinach. Sub-fractionated red pitahaya and red spinach had 23.5 and 121.5 % more betacyanin content, respectively, than those without sub-fractionation. Sub-fractionation increased the betanin and decarboxy-amaranthine content in red pitahaya and red spinach, respectively. The betacyanin fraction from red spinach (minimum inhibitory concentration [MIC] values: 0.78–3.13 mg/mL) demonstrated a better antimicrobial activity profile than that of red pitahaya (MIC values: 3.13–6.25 mg/mL) against nine Gram-positive bacterial strains. Similarly, the red spinach fraction (MIC values: 1.56–3.13 mg/mL) was more active than the red pitahaya fraction (MIC values: 3.13–6.25 mg/mL) against five Gram-negative bacterial strains. This could be because of a higher amount of betacyanin, particularly amaranthine in the red spinach.

Reinhold Carle - One of the best experts on this subject based on the ideXlab platform.

  • structural and chromatic stability of purple pitaya hylocereus polyrhizus weber britton rose Betacyanins as affected by the juice matrix and selected additives
    Food Research International, 2006
    Co-Authors: Kirsten M Herbach, Florian C Stintzing, Michael Rohe, Reinhold Carle
    Abstract:

    Ascorbic, isoascorbic, and citric acids were applied for stabilisation of Betacyanins during thermal treatment of purple pitaya juice at pH 4 and 6, respectively. In addition, to exclude matrix effects of juice constituents, selected food ingredients were added to a pigment preparation comprising the entire betacyanin pattern of purple pitaya, but being devoid of sugars, acids and pectic substances. After thermal treatment at pH 4, pigment retention, overall colour changes, betanin isomerisation, and phyllocactin deacylation were determined. As supported by statistical analyses, pigment stability and colour depended on type and concentration of the respective additive as well as on the pH conditions. Unexpectedly, the stabilising effects of the additives under investigation were more pronounced in purple pitaya juice than in the pigment preparation. After heating at 85 °C for 1 h, optimal pigment retention amounting to 91% was obtained in the juice supplemented with 1% ascorbic acid and adjusted to pH 4. For the first time, formation of indicaxanthin and isoindicaxanthin upon thermal treatment of purple pitaya juice is reported.

  • betalain stability and degradation structural and chromatic aspects
    Journal of Food Science, 2006
    Co-Authors: Kirsten M Herbach, Florian C Stintzing, Reinhold Carle
    Abstract:

    In recent years, food coloring with artificial colorants has been increasingly disapproved by consumers. In return, application of coloring foodstuffs, among them betalain-containing fruits and vegetables, has gained importance for the food industry. As commonly true for natural pigments, betalains are afflicted with inferior stability compared to synthetic dyes. Especially temperature, oxygen, and light are known to exhibit detrimental effects on betalain integrity, while certain antioxidants and chelating agents may act as stabilizers. Only recently, several studies expanded the knowledge on betalain degradation pathways, especially focusing on betacyanin decomposition. Additionally, new findings on stability and stabilization of betalains in cactus fruit juices extended the application range of betalainic foodstuffs. Focusing on Betacyanins, the present review discusses betalain degradation mechanisms and provides a survey of compounds and conditions governing betalain stability in a beneficial or an unfavorable way. Finally, strategies for maintaining the chromatic properties and tinctorial strength of betalain-based juices and pigment preparations as well as tools for color modulation by targeted betacyanin degradation are discussed.

  • Betalain Stability and Degradation—Structural and Chromatic Aspects
    Journal of Food Science, 2006
    Co-Authors: Kirsten M Herbach, Florian C Stintzing, Reinhold Carle
    Abstract:

    In recent years, food coloring with artificial colorants has been increasingly disapproved by consumers. In return, application of coloring foodstuffs, among them betalain-containing fruits and vegetables, has gained importance for the food industry. As commonly true for natural pigments, betalains are afflicted with inferior stability compared to synthetic dyes. Especially temperature, oxygen, and light are known to exhibit detrimental effects on betalain integrity, while certain antioxidants and chelating agents may act as stabilizers. Only recently, several studies expanded the knowledge on betalain degradation pathways, especially focusing on betacyanin decomposition. Additionally, new findings on stability and stabilization of betalains in cactus fruit juices extended the application range of betalainic foodstuffs. Focusing on Betacyanins, the present review discusses betalain degradation mechanisms and provides a survey of compounds and conditions governing betalain stability in a beneficial or an unfavorable way. Finally, strategies for maintaining the chromatic properties and tinctorial strength of betalain-based juices and pigment preparations as well as tools for color modulation by targeted betacyanin degradation are discussed.

  • Betacyanins in fruits from red purple pitaya hylocereus polyrhizus weber britton rose
    Food Chemistry, 2002
    Co-Authors: Florian C Stintzing, Reinhold Carle
    Abstract:

    Abstract The betalain pattern of Hylocereus polyrhizus (Weber) Britton & Rose is reported for the first time and a highly practicable technique is described for the simultaneous isolation of pigment and mucilage from the mesocarp by extraction with water. Whereas betaxanthins were totally absent, 10 Betacyanins could be separated by HPLC-PDA. For eight Betacyanins the respective molecular masses could be obtained by positive ion electrospray mass spectrometry. Five of them were unequivocally assigned to bougainvillein-r-I, betanin, isobetanin, phyllocactin, and iso-phyllocactin. The remaining Betacyanins were tentatively identified as (6′-O-3-hydroxy-3-methyl-glutaryl)-betanin, its C15-stereoisomer, and (6′-O-3-hydroxy-3–butyryl)-betanin, respectively. Using the β-glucosidase assay, acylated structures could be distinguished from non-acylated Betacyanins. Contrary to white-fleshed Hylocereus undatus (Haworth) Britton & Rose with a slightly pink mesocarp, H. polyrhizus most likely possesses the same set of betalain forming enzymes in both pulp and mesocarp as the betacyanin pattern was found to be similar.

Slawomir Wybraniec - One of the best experts on this subject based on the ideXlab platform.

  • separation of Betacyanins from flowers of amaranthus cruentus l in a polar solvent system by high speed counter current chromatography
    IEEE Journal of Solid-state Circuits, 2019
    Co-Authors: Aneta Spornakucab, Edward Szneler, Agnieszka Kumorkiewicz, Natalia Szmyr, Slawomir Wybraniec
    Abstract:

    Betacyanin extract of Amaranthus cruentus L. flowers was fractionated by semi-preparative high-speed counter-current chromatography in a highly polar solvent system: propan-1-ol/acetonitrile/(NH4 )2 SO4satd. soln /H2 O (1.0:0.5:1.2:1.0, v/v/v/v) in tail-to-head mode with 76% retention of the stationary phase. The crude extract as well as the fractions containing Betacyanins were analyzed by liquid chromatography with tandem mass spectrometry as well as by high-resolution ion-trap time-of-flight mass spectrometry detection technique for the molecular formulae and multi-step fragmentation pattern elucidation. Four Betacyanins; namely, amaranthin, betanin, 6'-O-formyl-amaranthin, and 6'-O-malonyl-amaranthin as well as their diastereomeric forms differing in the configuration of the C-15 carbon atom were identified in the fractions. Amaranthin was the dominant pigment in the extract and was additionally analyzed by nuclear magnetic resonance correlation techniques after the counter-current chromatographic and high-performance liquid chromatographic isolation. Betacyanins were highly enriched during a single high-speed counter-current chromatographic step; therefore, the tentative identification of new compounds for the whole Amaranthaceae family, 6'-O-formyl-amaranthin and 6'-O-malonyl-amaranthin was possible. Different elution profiles of the pigments observed in the counter-current chromatographic system in comparison to high-performance liquid chromatography system confirm a complementarity of both the techniques especially in the separation of diastereomeric pairs of Betacyanins.

  • study on betalains in celosia cristata linn callus culture and identification of new malonylated amaranthins
    Journal of Agricultural and Food Chemistry, 2018
    Co-Authors: Kateryna Lystvan, Agnieszka Kumorkiewicz, Edward Szneler, Slawomir Wybraniec
    Abstract:

    Betacyanins and betaxanthins were characterized and determined in an intensely pigmented red-colored callus culture of Celosia cristata L. (Amaranthaceae). A new malonyl derivative, 6′-O-malonyl-amaranthin (celoscristatin) was isolated and identified by spectroscopic and mass spectrometric techniques. Its stereoisomer, 4′-O-malonyl-amaranthin (celoscristatin acyl-migrated), as well as its 15R diastereomer were also detected in the callus as a result of the malonyl group migration in celoscristatin/isoceloscristatin, respectively. Amaranthin occurs in the callus as the major betacyanin, followed by celoscristatin, betanin, phyllocactin, and other minor Betacyanins. The effect of different carbon sources on the growth rates of the Celosia callus as well as on betalains profiles in the callus cultures was studied. High dopamine content in the callus culture was determined and compared with the content in C. cristata inflorescences. The dopamine-based betalain (miraxanthin V) was detected as the main betaxant...

  • separation of amaranthine type Betacyanins by ion pair high speed countercurrent chromatography
    Journal of Chromatography A, 2014
    Co-Authors: Gerold Jerz, Nadine Gebers, Peter Winterhalter, D Szot, Maciej Szaleniec, Slawomir Wybraniec
    Abstract:

    Betacyanins, red-violet plant pigments, were fractionated by ion-pair high-speed countercurrent chromatography (IP-HSCCC) from leaves extract of Iresine lindenii Van Houtte, an ornamental plant of the family Amaranthaceae. An HSCCC solvent system consisting of TBME–1-BuOH–ACN–H2O (1:3:1:5, v/v/v/v) was applied using ion-pair forming heptafluorobutyric acid (HFBA). Significantly different elution profiles of betacyanin diastereomeric pairs (derivatives based on betanidin and isobetanidin) observed in the HSCCC in comparison to HPLC systems indicate a complementarity of both techniques’ fractionation capabilities. The numerous diastereomeric pairs can be selectively separated from each other using the HSCCC system simplifying the pigment purification process. Apart from the three well known highly abundant pigments (amaranthine, betanin and iresinin I) together with their isoforms, three new acylated (feruloylated and sinapoylated) Betacyanins as well as known pigment hylocerenin (previously isolated from cacti fruits) were characterized in the plant for the first time and they are new for the whole Amaranthaceae family.

  • ion pair high speed countercurrent chromatography in fractionation of a high molecular weight variation of acyl oligosaccharide linked Betacyanins from purple bracts of bougainvillea glabra
    Journal of Chromatography B, 2010
    Co-Authors: Slawomir Wybraniec, Gerold Jerz, Nadine Gebers, Peter Winterhalter
    Abstract:

    Abstract The natural pigment composition of purple bracts of Bougainvillea glabra (Nyctaginaceae) consists of a highly complex mixture of Betacyanins solely differing by the substitution with a variety of acyl-oligoglycoside units. This study was focused on a two-dimensional chromatography approach, a combination of preparative high-speed countercurrent chromatography (HSCCC) and analytical C18-HPLC with ESI–DAD–MS/MS detection which finally enabled a more detailed view into the pigment profile and elucidated the existence of an overwhelming amount of varying betacyanin structures occurring in Bougainvillea bracts. The detected molecular weights of the pigments reached so far unknown high values and ranged up to maximum values of 1653 and 1683 Da for the largest molecules due to oligosaccharide linkage and multiple acyl substitutions. The preparative IP–HSCCC separation yielded 15 complex fractions containing Betacyanins of enhanced polarity as well as structures with highly increased lipophilicity. Betacyanin structures extended by large oligosaccharide chains with bigger number of glycoside units and also carrying a reduced number of hydroxycinnamic acid substitutions were characteristic for polar pigments occurring mainly in the early eluting CCC fractions. IP–HSCCC was proven to be extremely effective for fractionating this complex crude betalain pigment extract into more defined ‘ polarity-windows ’. Structural analysis by analytical LC–ESI–MS/MS in the positive ionization mode detected a total sum of 146 different betacyanin pigments in the CCC fractions of reduced complexity.

  • generation of decarboxylated and dehydrogenated Betacyanins in thermally treated purified fruit extract from purple pitaya hylocereus polyrhizus monitored by lc ms ms
    Journal of Agricultural and Food Chemistry, 2005
    Co-Authors: Slawomir Wybraniec, Yosef Mizrahi
    Abstract:

    Pigments of purple pitaya [Hylocereus polyrhizus (F.A.C. Weber) Britton and Rose] fruits were submitted to extraction and were decarboxylated during heating experiments in acidified ethanolic and aqueous solutions. Groups of Betacyanins with different decarboxylation levels were identified in the heating products by LC-DAD and LC-MS/MS. The main decarboxylation products were 2-decarboxy-Betacyanins, 17-decarboxy-Betacyanins, and 2,17-bidecarboxy-Betacyanins. The structures of other compounds were assigned to 2,15,17-tridecarboxy-Betacyanins and 14,15-dehydrogenated derivatives (neo-derivatives) of all decarboxylated Betacyanins found.

Gary A. Dykes - One of the best experts on this subject based on the ideXlab platform.

  • Betacyanin inhibited biofilm formation of co-culture of Staphylococcus aureus and Pseudomonas aeruginosa on different polymer surfaces.
    FEMS microbiology letters, 2020
    Co-Authors: Yi Yi Yong, Gary A. Dykes, Michelle Wei Kim Ong, Wee Sim Choo
    Abstract:

    Staphylococcus aureus and Pseudomonas aeruginosa are bacteria that cause biofilm-associated infections. The aim of this study was to determine the activity of combined betacyanin fractions from Amaranthus dubius (red spinach) and Hylocereus polyrhizus (red pitahaya) against biofilms formed by co-culture of S. aureus and P. aeruginosa on different polymer surfaces. Various formulations containing different concentrations of the betacyanin fractions were investigated for biofilm inhibiting activity on polystyrene surfaces using the crystal violet assay and scanning electron microscopy. A combination of each betacyanin fraction (0.625 mg mL-1) reduced biofilm formation of five S. aureus strains and four P. aeruginosa strains from OD values of 1.24-3.84 and 1.25-3.52 to 0.81-2.63 and 0.80-1.71, respectively. These combined fractions also significantly inhibited dual-species biofilms by 2.30 and reduced 1.0-1.3 log CFU cm-2 bacterial attachment on polymer surfaces such as polyvinyl chloride, polyethylene, polypropylene and silicone rubber. This study demonstrated an increase in biofilm inhibiting activity against biofilms formed by two species using combined fractions than that of using single fractions. Betacyanins found in different plants could collectively be used to potentially decrease the risk of biofilm-associated infections caused by these bacteria on hydrophobic polymers.

  • Biofilm inhibiting activity of Betacyanins from red pitahaya (Hylocereus polyrhizus) and red spinach (Amaranthus dubius) against Staphylococcus aureus and Pseudomonas aeruginosa biofilms
    Journal of applied microbiology, 2018
    Co-Authors: Yi Yi Yong, Gary A. Dykes, Sui Mae Lee, Wee Sim Choo
    Abstract:

    AIMS To investigate the biofilm inhibitory activity of Betacyanins from red pitahaya (Hylocereus polyrhizus) and red spinach (Amaranthus dubius) against Staphylococcus aureus and Pseudomonas aeruginosa biofilms. METHODS AND RESULTS The pulp of red pitahaya and the leaves of red spinach were extracted using methanol followed by subfractionation to obtain betacyanin fraction. The anti-biofilm activity was examined using broth microdilution assay on polystyrene surfaces and expressed as minimum biofilm inhibitory concentration (MBIC). The betacyanin fraction from red spinach showed better anti-biofilm activity (MBIC: 0·313-1·25 mg ml-1 ) against five Staph. aureus strains while the betacyanin fraction from red pitahaya showed better anti-biofilm activity (MBIC: 0·313-0·625 mg ml-1 ) against four P. aeruginosa strains. Both betacyanin fraction significantly reduced hydrophobicity of Staph. aureus and P. aeruginosa strains. Numbers of Staph. aureus and P. aeruginosa attached to polystyrene were also reduced without affecting their cell viability. CONCLUSION Betacyanins can act as anti-biofilm agents against the initial step of biofilm formation, particularly on a hydrophobic surface like polystyrene. SIGNIFICANCE AND IMPACT OF THE STUDY This study is the first to investigate the use of betacyanin as a biofilm inhibitory agent. Betacyanin could potentially be used to reduce the risk of biofilm-associated infections.

  • Effect of refrigerated storage on betacyanin composition, antibacterial activity of red pitahaya (Hylocereus polyrhizus) and cytotoxicity evaluation of betacyanin rich extract on normal human cell lines
    LWT, 2018
    Co-Authors: Yi Yi Yong, Gary A. Dykes, Sui Mae Lee, Wee Sim Choo
    Abstract:

    Abstract Red pitahaya fruit is rich in purplish-red color water-soluble Betacyanins. The effect of refrigerated storage at 4 °C on the betacyanin composition of red pitahaya was monitored each day, for one week, using HPLC. The betacyanin content of red pitahaya had increased by 57.2% after storage for six days at 4 °C. From day 2 to day 7, the phyllocactin content decreased from 45.4 ± 1.5% to 38.3 ± 3.1%, whereas the betanin content increased from 37.9 ± 1.6% to 42.7 ± 1.5%. Antimicrobial activity was determined using the broth microdilution assay and expressed as minimum inhibitory concentration (MIC). As compared to the freshly harvested fruits (MIC values: 50,000–>50,000 μg mL−1), fruits that were stored for six days at 4 °C demonstrated better antimicrobial activity (MIC values: 3130–6250 μg mL−1) against 10 pathogenic Gram-positive and 6 Gram-negative bacteria. Betacyanin rich extract was also examined against normal human cell lines (HEK-293 and THP-1) and found to be not cytotoxic at the levels of 0.39–3.13 mg mL−1. In summary, refrigerated storage for 6 days increased the betacyanin content, changed the betacyanin composition in red pitahaya and contributed to higher antimicrobial activity.

  • The effect of pH treatment and refrigerated storage on natural colourant preparations (Betacyanins) from red pitahaya and their potential application in yoghurt
    LWT - Food Science and Technology, 2017
    Co-Authors: Ashwini Gengatharan, Gary A. Dykes, Wee Sim Choo
    Abstract:

    The present study investigated the effects of pH (pH 3, 4, 5 and 6) treatment and refrigerated storage at 4 °C on the stability of colourant preparations from red pitahaya and compared to a commercial colourant preparations from red beet, E-162. The potential of using colourant preparations from red pitahaya in yoghurt and compared to E-162 was also investigated. Immediately after pH treatment, the highest percentage of reduction of betacyanin was observed at pH 3. The loss of betacyanin content in yoghurts containing colourant preparations from red pitahaya and E-162 over 14-days of refrigerated storage was 1.0± 0% and 1.6± 0.1%, respectively. Syneresis in yoghurt containing colourant preparations from red pitahaya and E-162 were lower than that of plain yoghurt. The addition of Betacyanins from red pitahaya or E-162 increased the free radical scavenging activity in yoghurts. The total microbial counts of Streptococcus thermophilus and Lactobacillus delbrueckii ssp. bulgaricus in yoghurts containing colourant preparations from red pitahaya and E-162 were in the 108–109 CFU/mL range. The colour acceptability of yoghurt containing colourant preparation from red pitahaya was similar with E-162 and a commercial strawberry flavoured yoghurt suggesting its potential application as a natural functional colourant.

  • Stability of betacyanin from red pitahaya (Hylocereus polyrhizus) and its potential application as a natural colourant in milk
    International Journal of Food Science and Technology, 2016
    Co-Authors: Ashwini Gengatharan, Gary A. Dykes, Wee Sim Choo
    Abstract:

    The effects of temperature (30, 50, 85 and 100 °C) treatment and 10 weeks of refrigerated storage (4 °C) on the betacyanin content and colour stability of Betacyanins from red pitahaya (Hylocereus polyrhizus) were investigated and compared to red beet (Beta vulgaris; E-162) which was used as a control. Tempera- ture treatment at 50 and 85 °C caused a greater reduction in betacyanin content (BC) in E-162 compared to red pitahaya by inducing changes in betacyanin profile. The 10 weeks of refrigerated storage at 4 °C induced colour changes in Betacyanins from red pitahaya and E-162. In milk, Betacyanins from red pita- haya presented a lower loss of BC and total colour changes (DE*) compared to E-162. The microbial onset in milk containing Betacyanins from red pitahaya and E-162 was delayed up to day 5 of refrigerated storage at 4 °C compared to day 3 in plain milk. Milk containing Betacyanins from red pitahaya showed better colour acceptability (3.89 ? 1.89) compared to E-162 (6.10 ? 1.71). Hence, Betacyanins from red pitahaya may be a potential natural functional colourant to simulate strawberry colour in milk.