High Levels Of Carotenoids Research Articles

No evidence that carotenoid pigments boost either immune or antioxidant defenses in a songbird

Dietary carotenoids have been proposed to boost immune system and antioxidant functions in vertebrate animals, but studies aimed at testing these physiological functions of carotenoids have often failed to find support. Here we subject yellow canaries (Serinus canaria), which possess high levels of carotenoids in their tissue, and white recessive canaries, which possess a knockdown mutation that results in very low levels of tissue carotenoids, to oxidative and pathogen challenges. Across diverse measures of physiological performance, we detect no differences between carotenoid-rich yellow and carotenoid-deficient white canaries. These results add further challenge to the assumption that carotenoids are directly involved in supporting physiological function in vertebrate animals. While some dietary carotenoids provide indirect benefits as retinoid precursors, our observations suggest that carotenoids themselves may play little to no direct role in key physiological processes in birds.

Fruit Juice Supplementation Alters Human Skin Antioxidant Levels In Vivo: Case Study of Korean Adults by Resonance Raman Spectroscopy

Carotenoids, found in many fruits and vegetables, are antioxidants that protect human skin from UV radiation. In humans, fruit and vegetable intake increases carotenoid contents in skin, which are conventionally assessed by invasive blood tests. In this study, 47 healthy Korean subjects (volunteers) consumed fruit juice containing tomato, apple, strawberry, or grape three times per week for 6 weeks. Skin antioxidant levels were measured by non-invasive resonance Raman spectroscopy. The correlation between skin carotenoid (SC) score with demographic data (age, height, weight) and juice supplementation and changes in SC scores among groups were analyzed. Variations in skin antioxidant levels increased with juice supplementation (p < 0.05). Fruit juice intake was significantly correlated with SC score, indicating increased skin antioxidant levels. Grape and tomato increased skin antioxidant levels and showed higher antioxidant activity than other fruits. Fruit juices containing high levels of carotenoids and antioxidants may provide modest benefits to human health.

Quality characteristics and thermal behavior of buriti (&lt;em&gt;Mauritia flexuosa&lt;/em&gt; L.) oil

This work reports a complete characterization of buriti oil. Physicochemical properties were determined according to AOCS methodologies and thermophysical properties were measured using a controlled stress rheometer and a digital electronic density meter. β-carotene and tocopherol contents were obtained using HPLC systems. Fatty acids and acylglycerol classes were determined using GC and HPSEC systems, respectively, while triacylglycerol composition was estimated using the software PrOleos. Thermal behavior (crystallization and melting) was analyzed using a DSC. The results attested high levels of total carotenoids with β-carotene as the major one; total tocopherols contained α- and β-tocopherols which accounted for 91% of the total; and monounsaturated fatty acids were mainly represented by oleic acid. The results showed close agreement between density and viscosity of buriti and olive oils. The crystallization and melting peaks occurred at -43.06 °C and -2.73 °C, respectively. These properties enable Buriti oil to be recommended as an excellent alternative for enriching foods with bioactive compounds.

Isolation of High Carotenoid-producing Aurantiochytrium sp. Mutants and Improvement of Astaxanthin Productivity Using Metabolic Information.

The marine eukaryotic microheterotroph thraustochytrid genus Aurantiochytrium is a known producer of polyunsaturated fatty acids, carotenoids, and squalene. We previously constructed a lipid fermentation system for Aurantiochytrium sp. strains using underutilized biomass, such as canned syrup and brown macroalgae. To improve the productivity, in this study, Aurantiochytrium sp. RH-7A and RH-7A-7 that produced high levels of carotenoids, such as astaxanthin and canthaxanthin, were isolated through chemical mutagenesis. Moreover, metabolomic analysis of the strain RH-7A revealed that oxidative stress impacts carotenoid accumulation. Accordingly, the addition of ferrous ion (Fe2+), as an oxidative stress compound, to the culture medium significantly enhanced the production of astaxanthin by the mutants. These approaches improved the productivity of astaxanthin up to 9.5 mg/L/day at the flask scale using not only glucose but also fructose which is the main carbon source in fermentation systems with syrup and brown algae as the raw materials.

Colonic Mucosal Bacteria Are Associated with Inter-Individual Variability in Serum Carotenoid Concentrations

BackgroundRelatively high serum carotenoid levels are associated with reduced risks of chronic diseases, but inter-individual variability in serum carotenoid concentrations is modestly explained by diet. The bacterial community in the colon could contribute to the bioaccessibility of carotenoids by completing digestion of plant cells walls and by modulating intestinal permeability. ObjectiveTo evaluate whether colonic bacterial composition is associated with serum and colon carotenoid concentrations. DesignThe study was a randomized dietary intervention trial in healthy individuals who were at increased risk of colon cancer. Colon mucosal biopsy samples were obtained before and after 6 months of intervention without prior preparation of the bowels. Participants/settingParticipants were recruited from Ann Arbor, MI, and nearby areas from July 2007 to November 2010. Biopsy data were available from 88 participants at baseline and 82 participants after 6 months. MethodsStudy participants were randomized to counseling for either a Mediterranean diet or a Healthy Eating diet for 6 months. ResultsAt baseline, bacterial communities in biopsy samples from study participants in the highest vs the lowest tertile of total serum carotenoid levels differed by several parameters. Linear discriminant analysis effect size identified 11 operational taxonomic units that were significantly associated with higher serum carotenoid levels. In linear regression analyses, three of these accounted for an additional 12% of the variance in serum total carotenoid concentrations after including body mass index, smoking, and dietary intakes in the model. These factors together explained 36% of the inter-individual variance in serum total carotenoid concentrations. The bacterial community in the colonic mucosa, however, was resistant to change after dietary intervention with either a Mediterranean diet or Healthy Eating diet, each of which doubled fruit and vegetable intakes. ConclusionsThe colonic mucosal bacterial community was associated with serum carotenoid concentrations at baseline but was not appreciably changed by dietary intervention.

The Silencing of Carotenoid β-Hydroxylases by RNA Interference in Different Maize Genetic Backgrounds Increases the β-Carotene Content of the Endosperm.

Maize (Zea mays L.) is a staple food in many parts of Africa, but the endosperm generally contains low levels of the pro-vitamin A carotenoid β-carotene, leading to vitamin A deficiency disease in populations relying on cereal-based diets. However, maize endosperm does accumulate high levels of other carotenoids, including zeaxanthin, which is derived from β-carotene via two hydroxylation reactions. Blocking these reactions could therefore improve the endosperm β-carotene content. Accordingly, we used RNA interference (RNAi) to silence the endogenous ZmBCH1 and ZmBCH2 genes, which encode two non-heme di-iron carotenoid β-hydroxylases. The genes were silenced in a range of maize genetic backgrounds by introgressing the RNAi cassette, allowing us to determine the impact of ZmBCH1/ZmBCH2 silencing in diverse hybrids. The β-carotene content of the endosperm increased substantially in all hybrids in which ZmBCH2 was silenced, regardless of whether or not ZmBCH1 was silenced simultaneously. However, the β-carotene content did not change significantly in C17 hybrids (M7 × C17 and M13 × C17) compared to C17 alone, because ZmBCH2 is already expressed at negligible levels in the C17 parent. Our data indicate that ZmBCH2 is primarily responsible for the conversion of β-carotene to zeaxanthin in maize endosperm.

The genetic diversity of leaf vegetable jute mallow (Corchorus spp.): A review

Corchorus spp. is among traditional vegetable which is very nutritious and has been in use in many households in Africa. It contains high level of carotenoids (150µg/100g), vitamin C, Iron (190µg/g), 1.3% Calcium and 25.0% protein. The leaves are used in treatment of diseases and have wide antibacterial properties. It is semidomesticated and sometimes grows as a volunteer crop. Its status in some parts of Tanzania as a wild plant renders it unappealing for consideration in crop development programs.There is limited scientific information on its diversity for use as a vegetable in crop improvement and is a potential area for research. Variations exist among different accessions based on leaf shapes and color. Diversity studies by using molecular markers, proteins and isozymes are reported by several authors. There is low variation within species and high among species. Most of released varieties have a narrow genetic base. Conservation of this species in Africa is scarcely reported.

Biochemical profile and in vitro neuroprotective properties of Carpobrotus edulis L., a medicinal and edible halophyte native to the coast of South Africa

This work reports the nutritional profile and in vitro neuroprotective properties of leaves of Carpobrotus edulis L., a medicinal and edible succulent species native to the coast of South Africa. Biomass was evaluated for proximate composition and for contents in carotenoids, liposoluble pigments and minerals. Hexane, dichloromethane, ethyl acetate and methanol extracts were prepared by Soxhlet extraction from dried biomass and evaluated for in vitro inhibition of acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE), capacity to attenuate hydrogen peroxide (H2O2)-induced injury in the human dopaminergic cell line SH-SY5Y and for anti-neuroinflammatory potential on lipopolysaccharide (LPS)-stimulated microglia cells. Extracts were evaluated for antioxidant activity by four complementary methods, total content of phenolics, tannins and flavonoids. Finally the profile of the main phenolic compounds was determined by high performance liquid chromatography with diode array detection (HPLC-DAD). C. edulis has a high moisture content, high levels of crude protein, fibre, ash, carotenoids, calcium and iron and a low fat level. The extracts were able to efficiently scavenge the free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH), reduce iron and chelate copper and iron ions, and exhibited different levels of phenolic compounds in the order ethyl acetate>methanol>dichloromethane>hexane. The main compounds detected were gallic and salicylic acids and quercetin, all in the ethyl acetate extract. The extracts allowed a dual and potent inhibition of AChE and BuChE. The dichloromethane and methanol extracts had the strongest capacity to prevent cell death induced by H2O2, and the methanol extract had anti-neuronflammatory properties. All together our results suggest that consumption of leaves of C. edulis can contribute for a balanced diet, and that they may add to the improvement of cognitive functions. It also suggests possible novel biotechnological applications of C. edulis such as source of molecules and/or products for the food and/or pharmaceutical industries. Studies aiming to the isolation and identification of the bioactive compounds are already in progress.

Selenium ameliorates salinity stress in Petroselinum crispum by modulation of photosynthesis and by reducing shoot Na accumulation

This study was performed to understand the mechanisms for Se-enhanced resistance of parsley (Petroselinum crispum L.) plants to salinity stress. Plant growth was negatively affected by salt stress; however, Se treatments at 1 mg/L significantly improved the growth rate and enhanced the salt tolerance of seedlings. This increased tolerance in Se-supplied plants was obtained by reduced damaging effect on maximal quantum yield of photosystem II (PSII) (F v/F m) coupled with higher levels of carotenoids and non-photochemical quenching (NPQ). The performance index (PIABS), as evidence for modulation of PSII function, was downregulated by salt stress; while Se mitigated this effect. Moreover, analysis of OJIP transients demon-strated that Se reduced salt damaging effect on PSII function through improvement of excitation energy trapping (TR0/CS) and electron transport (ET0/CS) per excited cross-section of leaf. The Na concentrations in shoots and roots of parsley seedlings considerably enhanced after NaCl treatment. Interestingly, treatment of salt-stressed plants with Se decreased the Na contents in shoots via the limitation of the root-to-shoot translocation of Na and exclusion of Na from cell sap, as well as the retention of K/Na and Ca/Na ratios. These data provide the first evidence that the Se application alleviates salinity stress by enhancing PSII function and by decreasing Na content in the shoot via binding of Na to the root cell wall.

Revealing the Biochemical and Genetic Basis of Color Variation in a Polymorphic Lizard.

Determining the mechanistic and genetic basis of animal coloration is essential to understand the costs and constraints on color production, and the evolution and maintenance of phenotypic variation. However, genes underlying structural color and widespread pigment classes apart from melanin remain largely uncharacterized, in part due to restricted taxonomic focus. We combined liquid chromatography-mass spectrometry and RNA-seq gene expression analyses to characterize the pigments and genes associated with skin color in the polymorphic lizard, Ctenophorus decresii. Throat coloration in male C. decresii may be a combination of orange, yellow, grey, or ultra-violet blue. We confirmed the presence of two biochemically different pigment classes, pteridines (self-synthesized) and carotenoids (acquired through the diet), in all skin colors. Orange skin had the highest levels of pteridine pigments while yellow skin tended to have higher levels of carotenoids, of which the vitamin A precursors β-carotene and β-cryptoxanthin have not been previously confirmed in reptiles. These results were confirmed by gene expression analyses, which detected 489 genes differentially expressed between the skin colors, including genes associated with pteridine production, provitamin A carotenoid metabolism, iridophore-specific synthesis, melanin synthesis, and steroid hormone pathways. For the majority of these 489 genes, however, our study reveals a new association with color production in vertebrates. These data represent a significant contribution to understanding the genetic basis of color variation in vertebrates and a rich resource for further studies.

Calabrian Goji vs. Chinese Goji: A Comparative Study on Biological Properties.

Lycium barbarum (Goji) fruits are mainly cultivated in northwestern China and are well known for their beneficial and healthy effects. In this work, the biological and functional properties of Calabrian Goji extract, obtained from Goji berries cultivated in the Sibari Plain (in the Italian region of Calabria), were demonstrated. In order to evaluate the use of this extract as a food supplement for cognitive and mental disorders, the quantification of Carotenoids as Zeaxanthin equivalents was made. The antioxidant activity was investigated by evaluating the scavenging properties against 2,2′-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-Azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radicals and by performing the ORAC (Oxygen Radical Absorbance Capacity) assay. The inhibition of lipid peroxidation was quantified by bleaching test and the ability to inhibit acetylcholinesterase enzyme and to scavenge nitric oxide radical was also evaluated. All the results were compared to those obtained from a Chinese Goji extract used as a reference. Based on the reported data, Calabrian Goji might be used as a food supplement with a possible application in cognitive disorders, mental impairments and other neurodegenerative diseases, due to its biological properties and the high levels of Carotenoids.

The Arabidopsis ORANGE (AtOR) gene promotes carotenoid accumulation in transgenic corn hybrids derived from parental lines with limited carotenoid pools.

The AtOR gene enhances carotenoid levels in corn by promoting the formation of plastoglobuli when the carotenoid pool is limited, but has no further effect when carotenoids are already abundant. The cauliflower orange (or) gene mutation influences carotenoid accumulation in plants by promoting the transition of proplastids into chromoplasts, thus creating intracellular storage compartments that act as metabolic sink. We overexpressed the Arabidopsis OR gene under the control of the endosperm-specific wheat LMW glutenin promoter in a white corn variety that normally accumulates only trace amounts of carotenoids. The total endosperm carotenoid content in the best-performing AtOR transgenic corn line was 32-fold higher than wild-type controls (~25µg/g DW at 30 days after pollination) but the principal carotenoids remained the same, suggesting that AtOR increases the abundance of existing carotenoids without changing the metabolic composition. We analyzed the expression of endogenous genes representing the carotenoid biosynthesis and MEP pathways, as well as the plastid fusion/translocation factor required for chromoplast formation, but only the DXS1 gene was upregulated in the transgenic corn plants. The line expressing AtOR at the highest level was crossed with four transgenic corn lines expressing different carotenogenic genes and accumulating different carotenoids. The introgression of AtOR increased the carotenoid content of the hybrids when there was a limited carotenoid pool in the parental line, but had no effect when carotenoids were already abundant in the parent. The AtOR gene therefore appears to enhance carotenoid levels by promoting the formation of carotenoid-sequestering plastoglobuli when the carotenoid pool is limited, but has no further effect when carotenoids are already abundant because high levels of carotenoids can induce the formation of carotenoid-sequestering plastoglobuli even in the absence of AtOR.

Functional pasta with tomato by-product as a source of antioxidant compounds and dietary fibre

Tomato peels are abundant by-products of tomato processing and therefore represent a cost of disposal and an impact on the environment. For this reason, the aim of the present study was to valorise tomato peels to enrich pasta, being these ingredients still rich in antioxidants like carotenoids that are well-known to protect against degenerative diseases. To the aim of the work, in the first step, tomato peel flour was added to wholemeal flour in different amounts until the overall quality of cooked pasta reached its acceptability threshold (tomato peel flour at 15% w/w of semolina weight). Even though the pasta enriched with tomato peels showed high levels of carotenoids and dietary fibre, lower sensory scores for elasticity, odour, and firmness were recorded than in the control. Therefore, the second step was aimed to improve the sensory quality of the 15% enriched spaghetti by means of proper addition of hydrocolloids. Final results confirmed the ability of the structuring agents to enhance adhesiveness and bulkiness of pasta, without compromising other physical and chemical properties.

Effects of pretreatments and air drying temperatures on the carotenoid composition and antioxidant capacity of dried gac peel

Gac fruit contains a high level of carotenoids in the seed membrane (aril), pulp, and peel. However, only the aril is commercially processed and the peel is currently discarded. This study investigated different pretreatments and drying temperatures on the colour, content of carotenoids and antioxidant activity of air-dried Gac peel. The results showed that pre-treatments of Gac peel prior to drying and the drying temperature significantly affected the colour, carotenoid content and antioxidant capacity of the dried peel. Peel treated with ascorbic acid and dried at 70°C retained the highest levels of carotenoids and ABTS antioxidant capacity. These results suggest that the pre-treatment with ascorbic acid solution can be applied to prevent the loss of carotenoids and antioxidant capacity caused by drying of Gac peel. Practical applications Gac peel contains high levels of carotenoids but thousands tons of the peel are currently discarded as waste of the Gac processing industry. The results of this study showed that the combination of the pre-treatment of Gac peel with ascorbic acid solution with air drying at 70°C is an effective way to preserve carotenoids and antioxidant capacity of dried Gac peel, which can be utilised as a material for extraction of carotenoids.

Optimisation of extraction conditions for recovering carotenoids and antioxidant capacity from Gac peel using response surface methodology

SummaryThe peel of Gac fruit is regarded as waste product in the processing of Gac although it contains high level of carotenoids and possesses a significant antioxidant capacity. This study optimised the extraction yields of carotenoids and antioxidant capacity from Gac peel. Different organic solvents were examined to determine the most suitable solvent for the extraction. The extraction conditions including time, temperature and solvent–solid ratio were then optimised for maximising extraction yields of carotenoids and antioxidant capacity from Gac peel using response surface methodology. Ethyl acetate was identified as the most suitable solvent. The optimal extraction time, temperature and solvent–solid ratio were 150 min, 40.7 °C and 80 mL g−1, respectively. The carotenoid extraction yield and the antioxidant capacity extraction yield were 271 mg/100 g DW and 737 μm TE/100 g DW, respectively. Thus, the extraction using ethyl acetate with the ratio of 80:1 (mL solvent per g Gac peel) for 150 min at 40.7 °C is suggested for recovering carotenoids and antioxidant capacity from Gac peel.

Biomass and terpenoids produced by mutant strains of Arthrospira under low temperature and light conditions.

The filamentous Cyanobacterium Arthrospira is commercially produced and is a functional, high-value, health food. We identified 5 low temperature and low light intensity tolerant strains of Arthrospira sp. (GMPA1, GMPA7, GMPB1, GMPC1, and GMPC3) using ethyl methanesulfonate mutagenesis and low temperature screening. The 5 Arthrospira strains grew rapidly below 14 °C, 43.75μmol photons m-2s-1 and performed breed conservation at 2.5 °C, 8.75μmol photons m-2s-1. We used morphological identification and molecular genetic analysis to identify GMPA1, GMPA7, GMPB1 and GMPC1 as Arthrospira platensis, while GMPC3 was identified as Arthrospira maxima. Growth at different culture temperatures was determined at regular intervals using dry biomass. At 16 °C and 43.75μmol photons m-2s-1, the maximum dry biomass production and the mean dry biomass productivity of GMPA1, GMPB1, and GMPC1 were 2057 ± 80 mgl-1, 68.7 ± 2.5 mgl-1day-1, 1839 ± 44 mgl-1, 60.6 ± 1.8 mgl-1day-1, and 2113 ± 64 mgl-1,77.7 ± 2.5 mgl-1day-1 respectively. GMPB1 was chosen for additional low temperature tolerance studies and growth temperature preference. In winter, GMPB1 grew well at mean temperatures <10 °C, achieving 3258mg dry biomass from a starting 68mg. In summer, GMPB1 grew rapidly at mean temperatures more than 28 °C, achieving 1140 mgl-1 dry biomass from a starting 240mg. Phytonutrient analysis of GMPB1 showed high levels of C-phycocyanin and carotenoids. Arthrospira metabolism relates to terpenoids, and the methyl-D-erythritol 4-phosphate pathway is the only terpenoid biosynthetic pathway in Cyanobacteria. The 1-deoxy-D-xylulose 5-phosphate reductoisomerase (DXR) gene from GMPB1 was cloned and phylogenetic analysis showed that GMPB1 is closest to the Cyanobacterium Oscillatoria nigro-viridis PCC711. Low temperature tolerant Arthrospira strains could broaden the areas suitable for cultivation, extend the seasonal cultivation time, and lower production costs.

Hydroponic production of vegetable Amaranth (Amaranthus cruentus) for improving nutritional security and economic viability in Kenya

AbstractThis study used a multidisciplinary approach to evaluate the potential for hydroponic production of vegetable amaranth (Amaranthus cruentus) in Kenya. Hydroponic systems have potential for increased efficiency in water and land use, but their potential has not been critically evaluated in many developing countries. To address this gap in knowledge, this study assessed the nutritional density and economic viability of hydroponic systems built from local materials. Specifically, vegetable amaranth was grown hydroponically and evaluated for increased nutritional density of key micronutrients. Manipulation of the nutrient solution used in hydroponic systems changed the bioaccumulation of zinc, iron and carotenoids, which are three of the most common micronutrients lacking in Kenyan diets. Economic viability was assessed with a benefit-cost analysis that compared three different hydroponic systems to soil-based production and purchasing vegetables from local markets. This analysis showed that none of the hydroponic systems were profitable under current conditions, but sensitivity analyses revealed certain scenarios where they could become so. Overall, hydroponic production has the potential to create nutrient-dense crops with high levels of zinc, iron, or carotenoids. However, hydroponic systems may be better suited to crops of higher value than amaranth, areas where soil-based production is not an option, or regions where vegetable markets are not available.

A Comparative Study on Antioxidant Potential of Selected African and Exotic Leafy Vegetables

African leafy vegetables (ALVs) are thought to contain an immense variety of antioxidants, which may provide nutritional and health benefits. However, there is limited, robust, and comparable information describing their nutritional composition. The aim of this study is to determine the antioxidant potential of selected ALVs [black jack (Bidens pilosa L.) and amaranth (Amaranthus hybridus L.)] in comparison with exotic leafy vegetables (ELVs) [lettuce (Lactuca sativa L.), green cabbage (Brassica oleracea), red cabbage (B. oleracea var. capitata)]. Different nonenzymatic and enzymatic antioxidant assays were used to determine plant carbohydrates (CHOs) using high-performance liquid chromatography (HPLC), phenols (Folin–Ciocalteu), ascorbic acid, carotenoids, total antioxidant capacity (TAOC) using reducing ferric ion antioxidant potential (FRAP) and 1,1-diphenyl-2-picrylhydrazyl free radical (DPPH) assays, super oxide dismutase (SOD), catalase (CAT), and peroxidase (POD). Both amaranth and black jack produced high levels of CHOs, carotenoids, ascorbic acid, and phenols during early vegetative growth [4 weeks after transplanting (WAT)]. Similarly, SOD, CAT, and POD activity for amaranth and black jack also increased during early vegetative development. Conversely, exotic vegetables (lettuce and cabbages) only increased these antioxidants toward maturity. Overall, ALVs have produced higher concentrations of antioxidants specifically during early vegetative growth stage than the exotic vegetables. The promotion of ALVs could promote a healthy alternative especially in poor rural households.

Biochemical leaf traits as indicators of tolerance potential in tree species from the Brazilian Atlantic Forest against oxidative environmental stressors

The tolerance potential against the oxidative injury in native plants from forest ecosystems affected by environmental stressors depends on how efficiently they keep their pro-oxidant/antioxidant balance. Great variations in plant tolerance are expected, highlighting the higher relevance of measuring biochemical leaf trait indicators of oxidative injury in species with similar functions in the forest than in single species. The use of this functional approach seems very useful in the Brazilian Atlantic Forest because it still holds high plant diversity and was the focus of this study. We aimed at determining the tolerance potential of tree species from the Atlantic Forest remnants in SE Brazil against multiple oxidative environmental stressors. We assumed that pioneer tree species are more tolerant against oxidative stress than non-pioneer tree species and that their tolerance potential vary spatially in response to distinct combined effects of oxidative environmental stressors. The study was carried out in three Atlantic Forest remnants, which differ in physiognomy, species composition, climatic characteristics and air pollution exposure. Leaves of three pioneer and three non-pioneer species were collected from each forest remnant during wet (January 2015) and dry periods (June 2015), for analyses of non-enzymatic and enzymatic antioxidants and oxidative injury indicators. Both hypotheses were confirmed. The pioneer tree species displayed biochemical leaf traits (e.g. high levels of ascorbic acid, glutathione and carotenoids and lower lipid peroxidation) that indicate their higher potential tolerance against oxidative environmental stressors than non-pioneer species. The biochemical leaf traits of both successional groups of species varied between the forest remnants, in response to a linear combination of oxidative environmental stressors, from natural (relative humidity and temperature) and anthropogenic sources (ozone and nitrogen dioxide).

Improvement of the content in bioaccessible lipophilic micronutrients in raw and processed drumstick leaves (Moringa oleifera Lam.)

Our objective was to evaluate the influence of cooking (boiling, steaming, frying) and processing (freezing, freeze-drying, sun drying, oven drying, sterilization or powdering) on the micronutrient profile of drumstick leaves (β-carotene, lutein, α-tocopherol) and the bioaccessibility of the latter after in vitro digestion.Fresh drumstick leaves contain a high level of carotenoids and α-tocopherol with a very low bioaccessibility (<1%). Freezing, steaming and sterilization preserve the more the micronutrients and most of the processing methods improve the contents in bioaccessible β-carotene, lutein and α-tocopherol. Among the cooking practices, only steaming was efficient to increase the compound release. The structural changes of the leaf tissue during processing partially explain the modulation of the bioactive compound release during the course of in vitro digestion. After boiling and steaming, the cells of epidermis and mesophyll were slightly disorganized while frying induced a deep destructuration of the overall tissue with cell wall rupture.