[Show abstract][Hide abstract] ABSTRACT: Lignin constitutes up to one-third of the material found in plant cell walls and is considered the second most abundant natural polymer in the world. Despite unique characteristics of lignin, it is mostly used for low-value commercial applications. In this study, lignin obtained after alkaline treatment of steam-exploded sugarcane bagasse was submitted to an acidification process. The soluble fractions produced at different pH values were comprehensively characterized and in vitro antioxidant capacity against reactive oxygen (ROO and H2O2) and nitrogen (ONOO-) species was evaluated. The soluble fraction obtained at pH 2 exhibited the highest scavenging capacities against all species tested (10.2±0.7mmol Trolox equivalent g-1 for ROO, IC30=14.9μgmL-1 for H2O2 and IC50=2.3μgmL-1 for ONOO-) and the lowest polydispersity value (1.2) compared to others fractions. According to the SAXS data, the soluble fractions obtained at pH 4 and pH 2 consisted of small nanometer-sized discs and low molecular weight polyphenolic clusters, while soluble fractions obtained at high pH predominated wide lignin nanoparticles and larger aggregates. Mass spectroscopy analysis revealed the presence of phenolic and non-phenolic compounds, well-known as efficient antioxidants, which were identified in all soluble fractions. Collectively, our results provided further demonstration that acidification treatment is a promising strategy to upgrade heterogeneous lignin-enriched stream from sugarcane bagasse, such as preparations with homogeneous compositions and high antioxidant activity.
Full-text · Article · May 2016 · Industrial Crops and Products
[Show abstract][Hide abstract] ABSTRACT: Carotenoid biosynthesis in papaya fruits from the cultivars (cv.) ‘Golden’ and ‘Sunrise Solo’ was studied throughout three different ripening stages. The content of these secondary metabolites was assessed using HPLC–PDA–MSn. Carotenoid levels increased during ripening, with all-trans-lycopene varying from 0.73 to 1.58 μg/g in the cv. ‘Golden’ and from 0.68 to 1.67 μg/g in the cv. ‘Sunrise Solo’. The all-trans-β-cryptoxanthin content varied from 1.29 to 3.0 μg/g in the cv. ‘Golden’ and from 0.28 to 5.13 μg/g in the cv. ‘Sunrise Solo’. The Zds gene showed a different pattern of expression during the ripening and between cultivars, while the Lcyβ gene expression was up-regulated in the two cultivars. The capacity to scavenge peroxyl radicals did not show a significant difference among the ripening stages and between the different cultivars. This study describes, for the first time, a tentative correlation between carotenoid biosynthesis in papaya pulp and the gene expression of the enzymes related to this pathway.
[Show abstract][Hide abstract] ABSTRACT: The production of superoxide anion radical (O2•-) is essential for the life of aerobic organisms. This free radical acts as a signaling molecule, regulating numerous biological processes including apoptosis, aging, and senescence. Nevertheless, when overproduction of O2•- occurs and/or antioxidant defences are deficient, oxidative stress may develop, damaging important biomolecules and altering their physiological function. These effects have been associated to the development of several diseases. Scavenging of O2•- has been used as a hallmark to test the antioxidant capacity of several types of compounds in cellular and non-cellular systems. However, despite the pathophysiological importance of O2•-, the information about its endogenous and/or chemical generation and detection is dispersed and there are no reports that concisely cover the information in an integrated form. This gap can explain the limitations attributed to the currently used systems, namely in what concerns the selectivity, specificity and validation. This review attempts to provide a critical assessment of the available O2•- generating and detection, both in endogenous and chemical systems, scrutinizing its advantages and limitations in order to facilitate the choice and implementation of the O2•- generator and/or detection method that better fits the researchers' objectives.
No preview · Article · Oct 2015 · Current Medicinal Chemistry
[Show abstract][Hide abstract] ABSTRACT: The aim of this study is to investigate the effects of different home cooking techniques (boiling, steaming, and stir-frying) in kale and red cabbage, on the levels of bioactive compounds (carotenoids, anthocyanins and phenolic compounds) determined by high-performance liquid chromatography coupled with photodiode array and mass spectrometry detectors (HPLC-DAD-MSn), and on the antioxidant activity evaluated by ABTS, ORAC and cellular antioxidant activity (CAA) assays. The steaming technique resulted in a significant increase in phenolic content in kale (86.1%; p < 0.001) whereas in red cabbage it was significantly reduced (34.6%; p < 0.001). In the kale, steaming resulted in significant increases in antioxidant activity levels in all of the evaluation methods. In the red cabbage, boiling resulted in a significant increase in antioxidant activity using the ABTS assay but resulted in a significant decrease using the ORAC assay. According to the CAA assay, the stir-fried sample displayed the highest levels of antioxidant activity.
[Show abstract][Hide abstract] ABSTRACT: Among the large number of scientifically oblivious fruits from Amazonia biome, Couepia bracteosa figures as an interesting source of bioactive compounds, such as phenolic compounds and carotenoids, which may be used for protecting human health against oxidative damage. For the first time, the phenolic compounds and carotenoids of extracts obtained from the pulp, shell and seeds of C. bracteosa fruits are reported, as well as its in vitro scavenging capacities against some reactive oxygen species (ROS) and reactive nitrogen species (RNS). The shell extract presented the highest phenolic compound and carotenoid contents (5540 and 328 µg/g extract, dry basis, respectively), followed by the pulp and seed extracts. The major phenolic compound was acacetin sulphate (one methoxy and two OH groups) (62%) in the shells; however, only seeds presented apigenin sulphate (three OH groups), in which it was the major compound (44%). The high content of apigenin sulphate may explain the highest scavenging efficiency of the seed extract against all tested ROS/RNS among the studied extracts. Regarding carotenoids, all-trans-neochrome (17%) and all-trans-β-carotene (16%) were the major carotenoids in the pulp extracts, while all-trans-lutein (44%) was the major in shell and all-trans-α-carotene (32%) and all-trans-β-carotene (29%) were the major ones in seed extracts.
[Show abstract][Hide abstract] ABSTRACT: The profile of the three classes of pigments (carotenoids, chlorophylls and phycobiliproteins) and the peroxyl radical scavenger capacity of extracts from microalgae Phormidium autumnale was determined. Twenty-four carotenoids, three phycobiliproteins and two chlorophylls were identified. The major carotenoids of biomass were all-trans-β-carotene (225.44 μg.g- 1), all-trans-lutein (117.56 μg.g- 1) and all-trans-zeaxanthin (88.46 μg.g- 1). Furthermore, characteristic carotenoids in cyanobacteria such as echinenone (79.07 μg.g- 1), myxoxanthophyll (18.83 μg.g- 1) and canthaxanthin (1.89 μg.g- 1) were found. The chlorophyll a (2.700 μg.g- 1) and C-phycocyanin (2.05 × 105 μg.g- 1) were predominant pigments in the other fractions of color compounds from biomass. The carotenoid and chlorophyll extracts were shown to be potent scavengers of peroxyl radical, being almost 28 and 85 times more potent α-tocopherol respectively, and for phycobiliproteins, the antioxidant capacity was 274 μmol trolox.g- 1 (dry wt).
Full-text · Article · Apr 2015 · Food Research International
[Show abstract][Hide abstract] ABSTRACT: Different storage conditions can induce changes in the colour and carotenoid profiles and levels in some fruits. The goal of this work was to evaluate the influence of low temperature storage on the colour and carotenoid synthesis in two banana cultivars: Prata and Nanicão. For this purpose, the carotenoids from the banana pulp were determined by HPLC–DAD–MS/MS, and the colour of the banana skin was determined by a colorimeter method. Ten carotenoids were identified, of which the major carotenoids were all-trans-lutein, all-trans-α-carotene and all-trans-β-carotene in both cultivars. The effect of the low temperatures was subjected to linear regression analysis. In cv. Prata, all-trans-α-carotene and all-trans-β-carotene were significantly affected by low temperature (p < 0.01), with negative estimated values (β coefficients) indicating that during cold storage conditions, the concentrations of these carotenoids tended to decrease. In cv. Nanicão, no carotenoid was significantly affected by cold storage (p > 0.05). The accumulation of carotenoids in this group may be because the metabolic pathways using these carotenoids were affected by storage at low temperatures. The colour of the fruits was not negatively affected by the low temperatures (p > 0.05).
[Show abstract][Hide abstract] ABSTRACT: There is no consensus in the literature regarding the decrease of kahweol and cafestol contents during coffee roasting, but it has been reported that these compounds can undergo dehydration under heat. Kahweol and cafestol were quantified in Arabica and Robusta coffees with different roasting degrees (2, 4, 6, 8 and 10 min at 230 A degrees C). The structures of the diterpenes and the presence of derivative compounds were determined by liquid chromatography with UV-Vis and mass spectrometry detection. In the dark roast samples, dehydro derivatives were found. The roasting process influenced the level of diterpenes in both species of coffee, but the effect was dependent on the intensity of the process. Cafestol and kahweol were degraded (general losses from 60 to 75 % on a lipid basis) to dehydrocafestol and dehydrokahweol, respectively, after 8 min of process, which corresponds to the commercial roasting degree. On the other hand, the amounts of cafestol and kahweol (mg/100 g of coffee) remained stable during the roasting process due to relative increase in lipid concentration.
No preview · Article · Dec 2014 · European Food Research and Technology
[Show abstract][Hide abstract] ABSTRACT: Addition of lutein to dairy products is an alternative that widens the range of foods which could be lutein sources. However, bioaccessibility is an essential aspect to be considered during the development of products with added bioactive substances. We evaluated the in vitro bioaccessibility of lutein esters added to milk and yogurt with different fat contents, and determined the efficiency of enzymatic hydrolysis of the esters during digestion. Bioaccessibility of lutein and efficiency of hydrolysis were significantly lower in skimmed products than semi-skimmed and whole products, indicating that a minimal amount of fat is required to allow micellization and hydrolysis. The efficiency of ester hydrolysis ranged between 12 and 35%, which was attributed to pancreatic lipase. Whole and semi-skimmed samples were shown to be good vehicles for the addition of lutein, since presented bioaccessibility indices (38.3–47.5%) are similar to those found in natural food sources of xanthophylls.
Full-text · Article · Nov 2014 · Food Research International
[Show abstract][Hide abstract] ABSTRACT: The aim of this work was to evaluate the production of carotenoids from microalgae Phormidium autumnale cultivated using agroindustrial wastes. The carotenoid profile from microalgae biomass was assessed by high performance liquid chromatography coupled with a photodiode array and mass spectrometry detectors. A total of twenty carotenoids were separated from the biomass. The all-trans-β-carotene (70.22 μg/g), all-trans-zeaxanthin (26.25 μg/g), all-trans-lutein (21.92 μg/g), all-trans-echinenone (19.87 μg/g) and cis-echinenone (15.70 μg/g) were the major ones. For the production of single-cell carotenoids it is possible to estimate a total carotenoid production of up to 107,902.5 kg/year in an industrial scale. Based on these results, we observed the potential of P. autumnale to the production of microalgal carotenoid in agroindustrial wastewater.
Full-text · Article · Nov 2014 · Food Research International
[Show abstract][Hide abstract] ABSTRACT: Genipap fruits, native to the Amazonic region, were classified in relation to their stage of ripeness according to the firmness and peel color. The influence of the part of the genipap fruits and ripeness stage on the iridoid and phenolic compound profiles was evaluated by HPLC-DAD-MSn and a total of 17 compounds were identified. Geniposide was the major compound in both parts of the unripe genipap fruits, representing more than 70% of the total iridoids, whilst 5-caffeoylquinic acid was the major phenolic compound. In ripe fruits, genipin- gentiobioside was the major compound in the endocarp (38%) and no phenolic compounds were detected. During ripening, the total iridoid content decreased by more than 90%, which could explain the absence of blue pigment formation in the ripe fruits after their injury. This is the first time that the phenolic compound composition and iridoid contents of genipap fruits have been reported in the literature.
No preview · Article · Oct 2014 · Journal of Agricultural and Food Chemistry
[Show abstract][Hide abstract] ABSTRACT: A hydrophilic extract of murici (Byrsonima crassifolia), a fruit native to the North and Northeast regions of Brazil, was evaluated in relation to its phenolic composition and in vitro antioxidant potential against some physiologically relevant reactive oxygen and nitrogen species. Additionally, the protective effect of murici extract against peroxyl radical (ROOradical dot)-induced toxicity to human erythrocytes was also determined. The major phenolic compound, determined by HPLC–DAD–MSn, was quercetin (2.72 ± 0.35 μg/mL). The extract was able to scavenge ROOradical dot (0.30 ± 0.04 μmol trolox equivalent/mg), hypochlorous acid (IC50 = 10.0 ± 0.1 μg/mL), hydroxyl radical (IC50 = 7 ± 1 μg/mL) and peroxynitrite anion (IC50 = 21.0 ± 0.6 μg/mL and 17.0 ± 1.6 μg/mL, respectively, in absence and presence of NaHCO3). Human erythrocytes were subjected to oxidative damage, but murici extract was not able to inhibit hemolysis, even at the highest tested concentration. On the other hand, the extract inhibited hemoglobin oxidation (IC50 = 271 ± 44 μg/mL), lipid peroxidation (1000 μg/mL) by 48 ± 5%, depletion of glutathione (100 μg/mL) by 49 ± 2% and formation of its oxidized form (100 μg/mL) by 96 ± 4%.
No preview · Article · Oct 2014 · Food Research International
[Show abstract][Hide abstract] ABSTRACT: Solanum sessiliflorum Dunal is a native shrub often found in the Amazon Forest. Its fruits, known as maná-cubiu, possess an unusual flavor and are consumed in salads and juices, mainly by the local community of Northern Brazil. Because these fruits are used in traditional medicine as hypoglycemic and hypocholesterolemic agents, it is important to establish whether the consumption of maná-cubiu is safe using in vivo genotoxicity tests. Here, we investigated the genotoxic and antigenotoxic potential of maná-cubiu for doxorucibin(DXR)-induced DNA damage using the micronucleus test and the comet assay in Wistar rats. Moreover, oxidative stress parameters were determined in the heart and liver of the animals by measuring the thiobarbituric acid reactive species (TBARS), a biomarker of lipid peroxidation, and reduced glutathione (GSH) content. The relative expression of Pgts2 mRNA in the livers of the animals was also determined. The tests were performed with maná-cubiu pulp (125, 250, 375 or 500 mg/kg body weight - b.w.) by gavage for 14 days, followed by intraperitoneal injection of saline or DXR (16 mg/kg b.w.) immediately after the last gavage, which occurred 24 hours before euthanasia. The results showed that maná-cubiu at all tested doses had no cytotoxic effects on bone marrow cells and was not genotoxic to heart or liver cells. In addition, maná-cubiu treatments decreased DXR-induced DNA damage according to the comet assay in heart and liver cells. Reductions in micronuclei frequency in peripheral blood cells occurred at 125, 250 and 375 mg/kg b.w doses of maná-cubiu, and the TBARS content induced by DXR was also reduced by maná-cubiu. Furthermore, maná-cubiu did not modulate the transcription of the Ptgs2 gene. In conclusion, maná-cubiu pulp fruit was not cytotoxic or genotoxic in Wistar rats, suggesting its safety for human consumption, at least considering genotoxic effects. The antioxidant capacity of maná-cubiu pulp fruit may contribute to the antigenotoxic effects of this fruit at the doses used in this study.
Full-text · Article · Aug 2014 · Food Research International
[Show abstract][Hide abstract] ABSTRACT: β-Carotene, zeaxanthin, lutein, β-cryptoxanthin, and lycopene are liposoluble pigments widely distributed in vegetables and fruits and, after ingestion, these compounds are usually detected in human blood plasma. In this study, we evaluated their potential to inhibit hemolysis of human erythrocytes, as mediated by the toxicity of peroxyl radicals (ROO•). Thus, 2,2′-azobis (2-methylpropionamidine) dihydrochloride (AAPH) was used as ROO• generator and the hemolysis assay was carried out in experimental conditions optimized by response surface methodology, and successfully adapted to microplate assay. The optimized conditions were verified at 30 × 106 cells/mL, 17 mM of AAPH for 3 h, at which 48 ± 5% of hemolysis was achieved in freshly isolated erythrocytes. Among the tested carotenoids, lycopene (IC50 = 0.24 ± 0.05 μM) was the most efficient to prevent the hemolysis, followed by β-carotene (0.32 ± 0.02 μM), lutein (0.38 ± 0.02 μM), and zeaxanthin (0.43 ± 0.02 μM). These carotenoids were at least 5 times more effective than quercetin, trolox, and ascorbic acid (positive controls). β-Cryptoxanthin did not present any erythroprotective effect, but rather induced a hemolytic effect at the highest tested concentration (3 μM). These results suggest that selected carotenoids may have potential to act as important erythroprotective agents by preventing ROO•-induced toxicity in human erythrocytes.Practical ApplicationSelected carotenoids may have potential to be used in the development of phytopharmaceutical products as important erythroprotective agents by preventing ROO•-induced toxicity in human erythrocytes.
No preview · Article · Aug 2014 · Journal of Food Science
[Show abstract][Hide abstract] ABSTRACT: Lutein (LT) is a carotenoid obtained by diet and despite its antioxidant activity had been biochemically reported, few studies are available concerning its influence on the expression of antioxidant genes. The expression of 84 genes implicated in antioxidant defense was quantified using quantitative reverse transcription polymerase chain reaction array. DNA damage was measured by comet assay and glutathione (GSH) and thiobarbituric acid reactive substances (TBARS) were quantified as biochemical parameters of oxidative stress in mouse kidney and liver. cDDP treatment reduced concentration of GSH and increased TBARS, parameters that were ameliorated in treatment associated with LT. cDDP altered the expression of 32 genes, increasing the expression of GPx2, APC, Nqo1 and CCs. LT changed the expression of 37 genes with an induction of 13 mainly oxygen transporters. In treatments associating cDDP and LT, 30 genes had their expression changed with a increase of the same genes of the cDDP treatment alone. These results suggest that LT might act scavenging reactive species and also inducing the expression of genes related to a better antioxidant response, highlighting the improvement of oxygen transport. This improved redox state of the cell through LT treatment could be related to the antigenotoxic and antioxidant effects observed.
No preview · Article · May 2014 · Food and Chemical Toxicology
[Show abstract][Hide abstract] ABSTRACT: Fruits from the Atlantic Forest have received increasing interest because they contain high levels of bioactive compounds with notable functional properties. The composition of carotenoids and phenolic compounds from fruits found in the Atlantic Forest (jussara, uvaia, araça and grumixama) was determined by high-performance liquid chromatography coupled to diode array and mass spectrometry detectors. Uvaia showed the highest levels of carotenoids (1306.6 μg/100 g fresh matter (f.m.)). Gallic acid was major phenolic compound in araça (12.2 mg GAE/100 g f.m.) and uvaia (27.5 mg GAE/100 g f.m.). In grumixama, eight quercetin derivatives were found; the main carotenoids included all-trans-β-cryptoxanthin (286.7 μg/100 g f.m.) and all-trans-lutein (55.5 μg/100 g f.m.). Uvaia and grumixama contain high amounts of carotenoids, while jussara showed greater levels of phenolic compounds (415 mg GAE/100 g f.m.), particularly anthocyanins (cyanidin 3-rutinoside: 179.60 mg/100 g f.m. and cyanidin 3-glucoside: 47.93 mg/100 g f.m.).
Full-text · Article · Apr 2014 · Journal of Agricultural and Food Chemistry
[Show abstract][Hide abstract] ABSTRACT: In this study HPLC-DAD-MS/MS was applied for the identification of compounds derived from (all-E)-β-carotene following epoxidation and oxidative cleavage. The consequences on the CIELAB colour parameters and antioxidant capacity (AC) were also evaluated. Five apocarotenoids, three secocarotenoids, seven Z isomers and two epoxides were detected as a result of the oxidative cleavage. Four epoxides and three Z isomers were detected as a consequence of the epoxidation reaction. Some compounds were detected for the first time as a result of oxidation reactions. Both treatments led to a marked decrease in b(∗) and Cab(∗) values, indicating that these colour parameters can be used for the rapid assessment of β-carotene oxidation. The oxidative cleavage of β-carotene resulted in increased capacity to both scavenge ABTS(+) and quench singlet oxygen. These results suggest that the study of the AC of these oxidative derivatives and their possible usefulness as food ingredients deserves further attention.