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ABSTRACT: Microcapsules of gum arabic or maltodextrin 20DE containing antioxidant molecules (AOx), for example, carotenoids and tocopherol derivatives, were prepared by the spray-drying technique. The properties of these microcapsules were evaluated by several techniques, such as dynamic light scattering, scanning electronic microscopy, and steady-state and time-resolved fluorescence spectroscopy of microencapsulated pyrene. The quenching of photochemically generated singlet molecular oxygen ((1)O(2)) by the AOx in homogeneous solvents as well as in microcapsule solutions was evaluated using time-resolved phosphorescence detection of (1)O(2). The quenching rate constant of the process, k(Q)(AOx), was strongly dependent on the type of the AOx. These results are explained by compartmentalization effects of the AOx in the core of the microcapsules and the accessibility of (1)O(2). The contribution of the biopolymer as quencher of (1)O(2) was also investigated. The present results can be applied to the design of edible antioxidant microcapsules within the food and cosmetic industries.
Journal of Agricultural and Food Chemistry 07/2010; 58(13):8004-11. · 2.82 Impact Factor
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Renata Tonhosolo,
Fabio L D'Alexandri,
Veridiana V de Rosso,
Marcos L Gazarini,
Miriam Y Matsumura,
Valnice J Peres,
Emilio F Merino,
Jane M Carlton,
Gerhard Wunderlich, Adriana Z Mercadante,
Emília A Kimura,
Alejandro M Katzin
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ABSTRACT: Carotenoids are widespread lipophilic pigments synthesized by all photosynthetic organisms and some nonphotosynthetic fungi and bacteria. All carotenoids are derived from the C40 isoprenoid precursor geranylgeranyl pyrophosphate, and their chemical and physical properties are associated with light absorption, free radical scavenging, and antioxidant activity. Carotenoids are generally synthesized in well defined subcellular organelles, the plastids, which are also present in the phylum Apicomplexa, which comprises a number of important human parasites, such as Plasmodium and Toxoplasma. Recently, it was demonstrated that Toxoplasma gondii synthesizes abscisic acid. We therefore asked if Plasmodium falciparum is also capable of synthesizing carotenoids. Herein, biochemical findings demonstrated the presence of carotenoid biosynthesis in the intraerythrocytic stages of the apicomplexan parasite P. falciparum. Using metabolic labeling with radioisotopes, in vitro inhibition tests with norflurazon, a specific inhibitor of plant carotenoid biosynthesis, the results showed that intraerythrocytic stages of P. falciparum synthesize carotenoid compounds. A plasmodial enzyme that presented phytoene synthase activity was also identified and characterized. These findings not only contribute to the current understanding of P. falciparum evolution but shed light on a pathway that could serve as a chemotherapeutic target.
Journal of Biological Chemistry 03/2009; 284(15):9974-85. · 4.77 Impact Factor
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ABSTRACT: The quenching of singlet molecular oxygen ((1)O(2)) by the flavylium cation form of six widespread anthocyanin derivatives: cyanidin 3-glucoside (CG), cyanidin 3-rutinoside (CR), cyanidin 3-galactoside (CGL), malvidin (M), malvidin 3-glucoside (MG) and malvidin 3,5-diglucoside (MDG) was studied in 1% HCl methanol solution by time-resolved phosphorescence detection (TRPD) of (1)O(2) and photostationary actinometry using perinaphthenone and methylene blue as sensitizers, respectively. The average value of the total (k(0)) and chemical (k(c)) quenching rate constants were approximately 4 x 10(8) M(-1) s(-1) and 3 x 10(6) M(-1) s(-1), respectively, indicating the good performance of the studied anthocyanins as catalytic quenchers of (1)O(2). The quenching efficiency was larger for malvidin than for cyanidin derivatives, probably by the extra electron-donating methoxy group in ring B of the malvidin derivatives; and it was also dependent on the number and type of glycosylated substitution. As observed for other phenolic-like derivatives, the quenching of (1)O(2) by anthocyanins was mediated by a charge-transfer mechanism, which was modulated by the total number of -OR substituents that increases the electron-donating ability of these compounds.
Free radical research 11/2008; 42(10):885-91. · 2.22 Impact Factor
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ABSTRACT: Anthocyanins and carotenoids are natural pigments responsible for the color of vegetables and fruits, and they are also bioactive compounds, both demonstrating important biological, therapeutic, and preventative properties. Considering the biodiversity of edible fruits, high performance liquid chromatography coupled to photodiode array and mass spectrometry detectors (HPLC-PDA-MS) was used to establish the composition of carotenoids and anthocyanins from dovyalis and tamarillo fruits. Ten anthocyanins and 26 carotenoids were found in dovyalis, whereas tamarillo showed 3 anthocyanins and 17 carotenoids. Higher contents of anthocyanins and carotenoids were found in dovyalis, 42.0 and 6.6 mg/100 g, respectively, as compared to tamarillo fruits with 8.5 and 4.4 mg/100 g, respectively. Although these fruits belong to different families, delphinidin 3-rutinoside and beta-cryptoxanthin were found to be, respectively, the major anthocyanin and carotenoid in both fruits.
Journal of Agricultural and Food Chemistry 11/2007; 55(22):9135-41. · 2.82 Impact Factor
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ABSTRACT: The major and minor carotenoids from six fruits, buriti (Mauritia vinifera), mamey (Mammea americana), marimari (Geoffrola striata), peach palm (Bactrys gasipaes), physalis (Physalis angulata), and tucuma (Astrocaryum aculeatum), all native to the Amazonia region, were determined by high-performance liquid chromatography-photodiode array detector-mass spectrometry detector (HPLC-PDA-MS/MS), fulfilling the recommended criteria for identification. A total of 60 different carotenoids were separated on a C30 column, all-trans-beta-carotene being the major carotenoid found in all fruits. The presence of apo-10'-beta-carotenol, found in mamey, was not previously reported in foods. In addition, this is the first time that the identification of beta-zeacarotene in natural sources is supported by MS data. The total carotenoid content ranged from 38 microg/g in marimari to 514 microg/g in buriti. All fruits analyzed can be considered good sources of provitamin A, especially buriti, with 7280 RE/100 g.
Journal of Agricultural and Food Chemistry 07/2007; 55(13):5062-72. · 2.82 Impact Factor
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ABSTRACT: Riboflavin (Rf)-mediated photosensitized degradation of vitamins A and D3 in skimmed milk under illumination with a white fluorescence lamp was studied by using the HPLC technique. The photosensitized degradation of both vitamins followed first-order kinetics, and the temperature effect on the observed photodegradation rate constant allowed the determination of the activation energy Ea as being 4 and 16 kcal/mol for vitamins A and D3, respectively. The addition of lycopene microencapsulated by spray-drying with a gum arabic-sucrose (8:2) mixture (MIC) produced a reduction of ca. 45% in the photosensitized degradation rate of both vitamins. Front-face fluorescence experiments showed the same photoprotection factor in the degradation of Rf itself, indicating that the photodegradation mechanism involved Rf-mediated reactive species, such as the excited triplet state of Rf, 3Rf*, and/or singlet molecular oxygen, 1O2. The interaction of both 3Rf* and 1O2 with MIC was evaluated in aqueous solutions by using laser-induced time-resolved absorption or emission spectroscopy, and the contribution of an inner-filter effect in the presence of MIC in skimmed milk was evaluated by diffuse reflectance spectroscopy. The main operating mechanism of photoprotection is due to the deactivation of 3Rf* by the proteic component of gum arabic; thus, gum arabic based microcapsules could be used to improve the photostability of milk during its storage and/or processing under light.
Journal of Agricultural and Food Chemistry 02/2007; 55(2):323-9. · 2.82 Impact Factor
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ABSTRACT: Camu-camu [Myrciaria dubia (HBK) McVaugh] is a small fruit native to the Amazonian rain forest. Its anthocyanin profile has now been investigated for the first time. Fruits from two different regions of the São Paulo state, Brazil, were analyzed. The major anthocyanins were isolated by high-speed countercurrent chromatography. HPLC-PDA, HPLC-MS/MS, and 1H NMR were used to confirm the identity of the main anthocyanins of camu-camu. Cyanidin-3-glucoside was identified as the major pigment in the fruits from both regions, representing 89.5% in the fruits produced in Iguape and 88.0% in those from Mirandópolis, followed by the delphinidin-3-glucoside, ranging between 4.2 and 5.1%, respectively. Higher total anthocyanin contents were detected in the fruits from Iguape (54.0 +/- 25.9 mg/100 g) compared to those from Mirandópolis (30.3 +/- 6.8 mg/100 g), most likely because of the lower temperatures in the Iguape region.
Journal of Agricultural and Food Chemistry 12/2005; 53(24):9531-5. · 2.82 Impact Factor
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ABSTRACT: The kinetics of the thermal degradation of the natural cis carotenoid bixin in a water/ethanol (8:2) solution was studied as a function of temperature (70-125 degrees C), using high-performance liquid chromatography. The curves for the decay of bixin and formation of products (e.g., di-cis and all-trans isomers and a C17 degradation compound) did not adjust well to a first-order rate law, but very good fits were obtained using a biexponential model. This mathematical modeling gave the rate constant values for the formation of the primary products from bixin, and the energy barrier for each step was obtained. The di-cis isomers were formed immediately (15 kcal/mol) together with the decay of bixin, followed by a slow consumption, indicating their role as reaction intermediates. In fact, the di-cis isomers could easily revert to bixin (Ea approximately 3 kcal/mol) or yield the primary C17 degradation product, with an energy barrier of 6.5 kcal/mol. In turn, 24 kcal/mol was necessary for the Bix --> all-trans step, explaining its slower formation.
Journal of Agricultural and Food Chemistry 04/2005; 53(6):2307-11. · 2.82 Impact Factor
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ABSTRACT: The photosensitized isomerization reaction of the natural cis carotenoid bixin (methyl hydrogen 9'-cis-6, 6'-diapocarotene-6, 6'-dioate) with rose bengal or methylene blue as the sensitizer in acetonitrile/methanol (1:1) solution was studied using UV-vis spectroscopy, high-performance liquid chromatography (HPLC), and time-resolved spectroscopic techniques, such as laser-flash photolysis and singlet oxygen phosphorescence detection. In both N(2)- and air-saturated solutions, the main product formed was all-trans-bixin. The observed isomerization rate constants, k(obs), decreased in the presence of air or with increase in the bixin concentration, suggesting the participation of the excited triplet state of bixin, (3)Bix, as precursor of the cis--> trans process. On the other hand, bixin solutions in the absence of sensitizer and/or light did not degrade, indicating that the ground state of bixin is stable to thermal isomerization at room temperature. Time-resolved spectroscopic experiments confirmed the formation of the excited triplet state of bixin and its deactivation by ground state bixin and molecular oxygen quenching processes. The primary isomerization products only degraded in the presence of air and under prolonged illumination conditions, probably due to the formation of oxidation products by reaction with singlet molecular oxygen. An energy-transfer mechanism was used to explain the observed results for the bixin transformations, and the consequences for food color are discussed.
Journal of Agricultural and Food Chemistry 01/2004; 52(2):367-73. · 2.82 Impact Factor
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ABSTRACT: Acerola is considered to be one of the best natural sources of ascorbic acid (AA) and, for this reason, the influence of this component on the stability of anthocyanins from acerola extracts was determined and compared to those from açai, which have no detectable AA. The addition of three different levels of AA to the solution of açai anthocyanins resulted in a 110-fold increase in the degradation rate (kobs) at the highest fortification level (276 mg/ml). The fact that the flavonoid concentration of the açai anthocyanin extract was 10 times higher than that of the acerola was probably responsible for the three times higher stability of the AA-fortified açai system compared to the acerola system, both at the same AA concentration and similar total polyphenol levels. The higher the level of AA addition to açai anthocyanin solutions, the greater was the colour fading, indicated by increase of L∗ and decrease of a∗ and C∗ values.
Food Chemistry.
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ABSTRACT: Camu–camu (Myrciaria dubia) is a small berry, native to the Amazon, known as a rich source of ascorbic acid. The carotenoid composition of this fruit was determined using high performance liquid chromatography-diode array detection on C18 and C30 columns. Fruits produced in two different regions of São Paulo State, Iguape and Mirandópolis, were analysed. All-trans-lutein was the major carotenoid in camu–camu fruits from both regions, ranging from 45% to 55% of the total carotenoid content (160.5 ± 93.1 μg/100 g for Iguape and 601.9 ± 75.6 μg/100 g for Mirandópolis fruits), followed by β-carotene, violaxanthin and luteoxanthin. The levels of lutein, β-carotene, violaxanthin, luteoxanthin and other minor carotenoids were significantly higher in the camu–camu produced in Mirandópolis region, most probably due to the higher temperature and light exposure found in this region, in comparison to those from Iguape. Maturation was also an important feature affecting batches from the same region.
Food Chemistry.
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ABSTRACT: The anthocyanins from acerola and açai, two tropical fruits known for their bioactive compounds, were studied. Two varieties of acerola in natura and one brand of frozen pulp of açai were analyzed by high-performance liquid chromatography connected to photodiode array and mass spectrometry detectors (HPLC–PDA–MS/MS). The açai pulp presented 282–303 mg/100 g of total anthocyanin, with predominance of cyanidin 3-glucoside and cyanidin 3-rutinoside, in average proportions of 13% and 87%, respectively. The composition of the two acerola varieties (Waldy Cati 30 and Olivier) were similar, being cyanidin 3-rhamnoside (76–78%) the major anthocyanin, followed by pelargonidin 3-rhamnoside (12–15%). The acerola Waldy variety showed total anthocyanin content of 6.5–7.6 mg/100 g, while 7.9–8.4 mg/100 g were found in the Olivier variety, for fruits harvested in 2003 and 2004. No statistical differences were found between varieties and harvests for the total anthocyanin content in acerola fruits.
Journal of Food Composition and Analysis.
