Antioxidant capacity of extracts from amaranth (Amaranthus hypochondriacus L.) seeds or leaves

ArticleinIndustrial Crops and Products 53:55–59 · February 2014with 377 Reads
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  • Article
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    Amaranthus plants, or spinach, are used extensively as a vegetable and are known to possess medicinal properties. Neuroinflammation and oxidative stress play a major role in the pathogenesis of many neurodegenerative diseases, such as Alzheimer's disease and Parkinson's disease. Advanced glycation end-products (AGEs) cause cell toxicity in the human neuronal cell line, SH-SY5Y, through an increase in oxidative stress, as shown by reducing cell viability and increasing cell toxicity in a dose-dependent manner. We found that preincubation of SH-SY5Y cells with either petroleum ether, dichloromethane or methanol extracts of A. lividus and A. tricolor dose-dependently attenuated the neuron toxicity caused by AGEs treatment. Moreover, the results showed that A. lividus and A. tricolor extracts significantly downregulated the gene expression of the pro-inflammatory cytokines, TNF-α, IL-1 and IL-6 genes in AGEs-induced cells. We concluded that A. lividus and A. tricolor extracts not only have a neuroprotective effect against AGEs toxicity, but also have anti-inflammatory activity by reducing pro-inflammatory cytokine gene expression. This suggests that Amaranthus may be useful for treating chronic inflammation associated with neurodegenerative disorders.
  • Article
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    The antioxidant activity and phenolic composition of the aerial part of Amaranthus caudatus at seven stages of development were investigated. Total phenolic content, ABTS•+, DPPH•, and O2•− scavenging activity, ferric-reducing antioxidant power (FRAP), and Fe2+ chelating ability were evaluated. The phenolic profile was characterized by 17 compounds. Rutin was predominant in all growth stages, although its content, similar to the quantity of other phenolics, changed during the growth cycle. Flavonols were most abundant in the plants of early flowering and grain fill stages. In contrast, the highest content of hydroxycinnamic acid derivatives was found in the early vegetative stage. The results of antioxidant assays also showed significant differences among plant stages. Generally, the lowest antioxidant activity was found in the shooting and budding stages. Significantly higher activity was observed in amaranths in earlier (vegetative) and later (early flowering and grain fill) stages, suggesting that plants in these stages are valuable sources of antioxidants.
  • Chapter
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    Cultivated amaranths are crops with an unrealized agronomical potential despite their high nutritional value and nutraceutic properties of their seeds and/ or leaves. They tolerate growing conditions unsuitable for cereals, and are tolerant to biotic aggressors. Several Amaranthus species are abundant of sources of secondary metabolites, mostly phenylpropanoids, predominantly in seeds and leaves, many of which may confer health benefits associated with their antioxidant properties. They could also act as defensive compounds against predators or pathogens. Recent biochemical and molecular approaches partly defined the mechanisms responsible for grain amaranth´s tolerance against biotic stress. However, the role played by secondary metabolites in (a)biotic stress amelioration in amaranth is practically unknown. Our group has identified several genes coding for enzymes involved in secondary metabolism pathways in A. hypochondriacus, in addition to related regulatory transcription factors. More than 50% of these genes involve the phenyl‐ propanoid pathway. In this chapter, the role played by this pathway in (a)biotic stress amelioration in plants will be briefly reviewed, followed by an examination of its involvement in the conferral of nutraceutic properties to amaranth plants. A descrip‐ tion of the progress obtained so far regarding the characterization of phenylpropanoid genes in grain amaranth will close this chapter.
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    Amaranthus plants, or spinach, are used as food sources worldwide. Amaranthus leaves are rich in antioxidant compounds, which act as free radical scavengers. Oxidative stress caused by the aberrant production of reactive oxygen species (ROS) represents an important mechanism for neuronal dysfunction and cell loss in different neurodegenerative disorders. The neuroprotective effects of antioxidant-containing plants have been extensively demonstrated in different models of neurotoxicity. However, few studies have investigated the antioxidant properties of Amaranthus extracts and their effect on the nervous system. In the present study, the leaves of Amaranthus lividus and Amaranthus tricolor were extracted using petroleum ether, dichloromethane, and methanol. Results indicated that antioxidant activities were the highest in methanol extracts from both kinds of Amaranthus leaves. In addition, oxidative stress was induced in human neuroblastoma cell lines (SH-SY5Y) by using H2O2. Intracellular oxidative stress, cytotoxicity, and gene expression of RAGE were then determined. In vitro results demonstrated that pretreatment with A. lividus and A. tricolor extracts can significantly decrease cell toxicity and intracellular ROS production in SH-SY5Y cells. Interestingly, the extracts also significantly downregulated the expression of oxidative stress genes such as HMOX-1, RAGE, and RelA/ NF-κB. Our results suggested that Amaranthus leaves may be useful for reducing oxidative stress and may be beneficial for age-related diseases and neurodegenerative disorders.
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    Synthetic and natural food antioxidants are used routinely in foods and medicine especially those containing oils and fats to protect the food against oxidation. Many antioxidant compounds, naturally occurring in plant sources have been identified as free radical scavengers. Hence the plant nutrition plays a crucial role in the prevention of chronic diseases, as most of them can be related to diet. As the studies on the nutritional composition of wild food plants are limited and incomplete, and it is an area that demands. The present study is focused on the indigenous and underutilized plants Amaranthus dubius and Allmania nodiflora. The raw and processed samples were extracted using 70% acetone and 80% methanol. The samples were analyzed for the proximate composition, total phenolics and tannins content, flavonoid characterization, FRAP assay, Metal chelating activity, DPPH • , ABTS •+ , Hydroxyl, Nitric oxide, Superoxide radical scavenging activities. Both the samples are highly rich in protein, dietary fiber, starch, micronutrients and bioactive compounds with low level of fat.
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    Objective: The aim of this study was to obtain protein isolate from amaranth using alkaline method at extraction pH 8 and extraction pH 12 with different precipitation pHs and to analyze protein isolate with electrophoresis. Methods: Amaranth protein isolates were obtained using isoelectric precipitation method at different pHs. Proteins were analyzed using sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Results: A yield of 20.52% of protein isolate of defatted amaranth at pH 4.0 was obtained. The content of protein isolate was higher than 53% in all pH assays. Globulins and albumins in protein isolate at different pHs were observed. A band with 50 kDa corresponding to 7S globulin was found. The bands 36-38 kDa and 18-20 kDa correspond to 11S globulin. Bands less to 14.4 kDa correspond to albumins. Conclusions: Amaranth protein isolate is possible to obtain in extreme conditions of pH. The treatment with water was optimum to obtain amaranth protein isolate. © 2016, Innovare Academics Sciences Pvt. Ltd. All rights reserved.
  • Article
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    Abstract Synthetic and natural food antioxidants are used routinely in foods and medicine especially those containing oils and fats to protect the food against oxidation. Many antioxidant compounds, naturally occurring in plant sources have been identified as free radical scavengers. Hence the plant nutrition plays a crucial role in the prevention of chronic diseases, as most of them can be related to diet. As the studies on the nutritional composition of wild food plants are limited and incomplete, and it is an area that demands. The present study is focused on the indigenous and underutilized plants Amaranthus dubius and Allmania nodiflora. The raw and processed samples were extracted using 70% acetone and 80% methanol. The samples were analyzed for the proximate composition, total phenolics and tannins content, flavonoid characterization, FRAP assay, Metal chelating activity, DPPH• , ABTS•+, Hydroxyl, Nitric oxide, Superoxide radical scavenging activities. Both the samples are highly rich in protein, dietary fiber, starch, micronutrients and bioactive compounds with low level of fat.
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    Twenty stem amaranth genotypes collected previously from different eco-geographic regions of Bangladesh were assessed to evaluate variations in mineral compositions, yield and yield components, their interrelationships and direct and indirect effects on biological yield. Analysis of variance revealed significant difference among the genotypes for all the characters studied. Considering mean, range and all genetic parameters, selection could be performed on the basis of leaves per plant, leaf area, shoot weight, root weight, stem weight, Zn, Mn, Cu, Fe and biological yield for significant improvement of stem amaranth genotypes. Correlation revealed that stem base diameter, shoot weight, root weight, stem weight and leaves plant-1 could significantly improve the biological yield of stem amaranth. Insignificant associations amongst mineral compositions indicated that improvement of mineral compositions was possible without compromising the loss of biological yield of stem amaranth. Path analysis revealed that direct selection based on shoot weight and root weight would be effective for yield improvement of stem amaranth. SA8 had higher yield along with calcium, magnesium, potassium, iron, manganese and zinc content and could be utilized as high yield potential mineral enriched variety. The genotypes SA1, SA2, SA3, SA5, SA7, SA8, SA13, SA18 and SA20 could be utilized in future breeding program for improvement of stem amaranth. The genotypes SA6 and SA11 might also be selected as a donor parent for introgression of potential genes of high minerals into other genotypes.
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    This study examined the optimization of hot-water extraction conditions for maximizing the total polyphenol compounds (TPC) extracted from amaranth leaf. The effects of three independent variables, including extraction temperature, extraction time and ethanol concentration on TPC were investigated using central composite design (CCD). The concentration of TPC increased with increased levels of extraction temperature and time. The extraction temperature and the ethanol concentration showed the significant effect on TPC production (p<0.05). The predicted values at the optimized condition were acceptable when compared to the experimental values (R2=0.9566). The optimum extraction conditions were as follows: temperature of 90.1 °C, time of 50 min and ethanol concentration of 61.6% (v/v) for the maximum TPC of 12.6 mg GAE/g DM.
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    The present study was aimed to evaluate the efficacy of Eucalyptus camaldulensis leaf hexane, acetone and methanol extracts against Callosobruchus maculatus and their impact on biochemical, sensorial and microbiological properties of the treated Vigna subterranea grains in the laboratory. Each plant extract was applied at doses of 5, 10, 15 and 20g/kg on the bambara groundnut grains and pea beetles were released in each concentration test and C. maculatus was monitored 1, 3 and 6 days post-exposure. Effects of the plant products on progeny production F1 and damages caused by C. maculatus after three months post-storage were evaluated. Biochemical, sensorial and microbiological characteristics of the preserved seeds were also assessed. Plant extracts tested caused a significant mortality and reduced progeny production F1 of C. maculatus. Hexane extract (5g/kg) was most effective causing 78.75% mortality of insect, completely inhibited progeny production F1 and protected seeds for 3 months from insect attack. Kodek bambara groundnut variety was rich in proteins (21.53%), carbohydrates (61.24%) and minerals (3.54%). Antinutrients in treated grains increased but remained below the threshold values. The preservation of bambara groundnut grains with the plant extracts improved the organoleptic properties but affected the taste, tender and the crisp of the derived products. The plant extracts also protected V. subterranea flour against the micro-organisms.
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    The aim of this work was the characterization of three endemic plant species [quelite cenizo and quintonil (quelites), and purslane], from Mexico, in terms of their physicochemical, nutritional and antioxidant properties. These species are highly used by rural populations in their local dishes. Nevertheless, scarce information exists about their nutritional and functional properties. The experimental included physicochemical properties, nutrimental composition, qualitative and quantitative analysis of antioxidants by HPLC. The results showed that purslane was the sample with the highest concentration of total carotenoids (2.85 mg/g DW), and with the highest antioxidant activity by DPPH and FRAP methods. Quelite cenizo and purslane displayed similar values for antioxidant activity by ABTS method, nevertheless, the former showed higher values for total phenolics (10.24 mg GAE/g DW) and flavonoids (17.57 mg QE/g DW) content than the latter. Finally, quintonil showed similar results for total chlorophyll (70.50 mg/g DW) and protein (3.65 g/100 g FW) to those found in quelite cenizo. The contents of Fe, Ca, and Mg were higher in quintonil, meanwhile the contents of P, K and Zn were higher in quelite cenizo. The analysis by HPLC also showed the presence of ferulic, and chlorogenic acids as the most abundant phenolic acids, meanwhile rutin and phloridzin were the main flavonoids in the quelites, displaying higher contents than in the purslane. Therefore, it can be assumed that these samples possess high nutritional quality and could be considered for their use in strategies to improve food security in rural populations.
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    The influence of stimulation with He-Ne laser light, alternating magnetic field and the combination of these factors on germination parameters of amaranth seeds and on the chlorophyll and carotenoid content in seedlings was investigated. During the stimulation the amaranth seeds had a different initial moisture content. From the germination characteristics of the seeds as the function of humidity, three maxima and one minimum value of the germination parameters (the relative germination capacity NK REL, the relative maximum germination rate SK MAX REL and the maximum germination index WK MAX) were obtained. In the majority of cases, the extremities coincided with the changes in the chlorophyll and carotenoid content in the seedlings. The presented research is innovative in the field of seed biology since no similar studies have been conducted before. It is difficult to interpret the results referring to the literature on this subject. The results can be explained as follows: the observed effect must be related to the stages of the water uptake by the seeds. The three stages of the water uptake associated with the seed germination process coincide with the maximum values in the germination parameters and with the change in the photosynthetic pigment content in seedlings.
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    Kiwicha has significant nutritional characteristics. It is commonly used as a puffed product, but there is little research on the lamination process. In this paper, the physical, functional properties, chemical composition and acceptability of the precooked kiwicha grains were studied. Puffed (PK) and laminated kiwicha (LK) were made. Puffed amaranth (CPA) was used as a commercial reference standard. The raw grain (RG) showed a higher bulk density (0.85 g/ml) than in PK (0.18 g/ml) and LK (0.38 g/ml). Both products had a good expansion. The yellow index decreased in PK (50.92) and LK (45.87) respect to RG (65.64). The largest was CPA (58.54). In all the products, the precooking increased the index of absorption, solubility and swelling power. Also, they showed major pasting temperature, low peak viscosity and breakdown viscosity. In both formulated products, the content of total, soluble and insoluble dietary fibre decreased during the precooking process. The content of protein was optimal (between 14.57-14.59 g/100g). PK had high acceptability (5.84), preference (84.48%), purchase (38.79%) and consumption (43.96%) intention. The lowest was CPA. This work demonstrates that it’s feasible to make precooked products with good quality characteristics, chemical composition and acceptability for the development of new products. © 2015, Sociedade Brasileira de Ciencia e Tecnologia de Alimentos, SBCTA. All rights reserved.
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    Spectrophotometric and chromatographic analysis of phenolics in water and ethanolic extracts of wild asparagus, butcher’s broom and black bryony from Croatia was conducted. Their antioxidant capacity (ABTS, DPPH and FRAP assay) and energy content were determined. The gastrointestinal stability of detected phenolics was determined using a two-phase in vitro digestion method with human enzymes. The highest phenolics yield, radical scavenging activity and ferric reducing antioxidant potential were recorded in 40 % ethanolic extract of black bryony, with glycosylated forms of kaempferol as dominant components. Quercetin-3-O-rutinoside and isorhamnetin-3-Orutinoside were dominant phenolics in all wild asparagus extracts, and salicylic acid was predominant in butcher’s broom 40 % ethanolic extract. Phenolic acids of the three species were not stable during gastric and duodenal phases of simulated digestion. Two main black bryony kaempferol glycosides were best preserved after digestion (50 % of each). Black bryony contains more energy than wild asparagus and butcher’s broom. Accordingly, we propose black bryony as a valuable source of antioxidant kaempferol glycosides with relevant gastrointestinal stability and higher energy content than so far more conventional vegetable wild asparagus.
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    Gynura procumbens has been consumed for a longtime in tropical regions as a vegetable with health promoting activities. We investigated phenolic antioxidants that were fractionated from the crude extract of G. procumbens leaves by Sephadex LH-20 column chromatography. Sub-fraction 3 had the highest antioxidant activity as well as its total phenolic and flavonoid contents. The IC50 values of sub-fraction 3 were 19 and 12 µg/ml, which were lower than those of ascorbic acid and trolox for DPPH• and ABTS•+ assays, respectively. The major phenolic acids identified in sub-fraction 3 were ferulic acid and sinapic acid, whereas predominant flavonoids were myricetin and kaempferol. There was a strong positive correlation between antioxidant activity and total flavonoid content; however, no correlation existed between those and total phenolic content. Our findings suggest that the strongest antioxidant activity in sub-fraction 3 came from the flavonoids, especially myricetin and kaempferol, rather than phenolic acids.
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    Food industries are looking for natural antioxidant to replace synthetic because these last ones are questioned due to healthy reasons. Essential oils are natural products that can have antioxidant activity, but their composition and antioxidant activity could change for thermal storage condition. The objective of this study was to evaluate the antioxidant effect and thermal stability of rosemary, oregano and laurel essential oils (EO). The major components of the essential oils were terpineol (E) Beta (55.5%), terpinen-4-ol (15.9%), and thymol (12.9%) in oregano; camphor (35.7%), verbenone (26.6%), and β-caryophyllene (15.8%) in rosemary EO; and linalool (45.0%), sabinene (31.9%), and methyl eugenol (14.3%) in laurel EO. The volatile composition of the EO changed during the thermal stability study. The antioxidant activity of the essential oils was analyzed measuring free-radical scavenging activity (FRSA) and total phenolic content; and performing a storage study of sunflower oil measuring the formation of peroxide and volatile oxidation compounds. The FRSA showed that laurel (61.74%), oregano (59.97%), and rosemary (48.23%) EOs showed better percentage inhibitions than BHT (8.76%). In the storage study of sunflower oil, samples with 0.10% oregano EO, 0.02% oregano EO, 0.02% laurel EO, and 0.10% rosemary EO showed better antioxidant properties, exhibiting less peroxide and anisidine values during storage. Also, 0.02% oregano EO in the storage study showed reduced formation of volatile compounds like hexanal, 2-heptenal, and 2,4-decadienal. The studied EOs have antioxidant activity and constitute natural potential agents that could be used as antioxidants in food products. Also, the studied EOs are compounds that change under high temperature conditions during storage, which could affect their potential antioxidant activity.
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    Amaranth (Amaranthus hypochondriacus) is a pseudocereal with higher protein concentration than most cereal grains. Enzymatic hydrolysis and food processing could produce biopeptides from amaranth proteins; however, there is limited information about the bioactivity of peptides from amaranth proteins. The objective of this comprehensive review was to determine bioactive peptide sequences in amaranth proteins that may prevent cardiovascular disease, cancer, and diabetes. Amaranth proteins, reported in UniProt database, were evaluated for potential bioactive peptide using BIOPEP database. The 15 main proteins present in amaranth seed are 11S globulin, 7S globulin, α-amylase inhibitor, trypsin inhibitor, antimicrobial proteins, nonspecific lipid-transfer-protein-1, superoxide dismutase, ring-zinc finger protein, prosystemin, amaranth albumin 1, glucose-1-phosphate adenyltransferase, glucosyltransferase, polyamine oxidase, granule-bound starch synthase 1, and acetolactate synthase. All proteins showed high occurrence frequencies of angiotensin-converting enzyme-inhibitor peptides (A = 0.161 to 0.362), as well as of dipeptidyl peptidase IV inhibitor (A = 0.003 to 0.087). Other proteins showed antioxidative (A = 0.012 to 0.063) and glucose uptake-stimulating activity (A = 0.023 to 0.042), and also antithrombotic (A = 0.002 to 0.031) and anticancer sequences (A = 0.001 to 0.042). The results of this study support the concept that amaranth grain could be part of a “healthy” diet and thereby prevent chronic human diseases.
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    Mediterranean countries contribute highly on world peach production and tonnes of waste leaves are released due to pruning. The aim of this study was to investigate the utilization possibilities of the leaves by supercritical fluid extraction. A statistical design was used to evaluate the effect of temperature (40-80 degrees C), pressure (150-300 bar) and concentration of ethanol as co-solvent (6-20%) at a flow rate of 15 g/min and for a duration of 60 min. The most effective variables were found as pressure and co-solvent ratio (p < 0.005). Optimum extraction conditions were elicited as 60 degrees C, 150 bar and 6% co-solvent yielding a total phenol content of 79.92 mg GAE/g extract, EC50 value of 232.20 mu g/ml and a radical scavenging activity of 53.25% which was higher than the value obtained by conventional solvent extraction method (32.23%). Consequently, Prunus persica L. leaves were found as a potential phenolic source for industrial applications.
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    A universal set of equations for determining chlorophyll (Chl) a, accessory Chl b, c, and d, and total Chl have been developed for 90 % acetone, 100 % methanol, and ethanol solvents suitable for estimating Chl in extracts from natural assemblages of algae. The presence of phaeophytin (Ph) a not only interferes with estimates of Chl a but also with Chl b and c determinations. The universal algorithms can hence be misleading if used on natural collections containing large amounts of Ph. The methanol algorithms are severely affected by the presence of Ph and so are not recommended. The algorithms were tested on representative mixtures of Chls prepared from extracts of algae with known Chl composition. The limits of detection (and inherent error, ±95 % confidence limit) for all the Chl equations were less than 0.03 g m−3. The algorithms are both accurate and precise for Chl a and d but less accurate for Chl b and c. With caution the algorithms can be used to calculate a Chl profile of natural assemblages of algae. The relative error of measurements of Chls increases hyperbolically in diluted extracts. For safety reasons, efficient extraction of Chls and the convenience of being able to use polystyrene cuvettes, the algorithms for ethanol are recommended for routine assays of Chls in natural assemblages of aquatic plants.
  • Sistema Mexicano de Alimentos Equivalentes
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  • Amaranto: historia y promesa
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    Hernández, G.R., Herrerías, G.G., 1998. Amaranto: historia y promesa. Horizonte del Tiempo. Tehuacán: Horizonte del Tiempo, vol. 1. Patrimonio Histórico de Tehuacán A.C., México, pp. 529–546.
  • El Amaranto El cultivo del Amaranto (Amaranthus spp.): producción, mejoramiento genético y utilización
    • G J C Morales
    • M N Vázquez
    • C R Bressani
    Morales, G.J.C., Vázquez, M.N., Bressani, C.R., 2009. El Amaranto. Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, D.F., México. Mujica-Sánchez, A., Berti, M., 1997. El cultivo del Amaranto (Amaranthus spp.): producción, mejoramiento genético y utilización. FAO, Oficina Regional para América Latina y el Caribe.
  • El cultivo del Amaranto (Amaranthus spp.): producción, mejoramiento genético y utilización
    • A Mujica-Sánchez
    • M Berti
    Mujica-Sánchez, A., Berti, M., 1997. El cultivo del Amaranto (Amaranthus spp.): producción, mejoramiento genético y utilización. FAO, Oficina Regional para América Latina y el Caribe.
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    USDA, 2011. National Nutrient Database for Standard. United States Department of Agriculture, http://www.nal.usda.gov/fnic/foodcomp/search/ (accessed 24.09.13).
  • Adding Value to Holy Grain
    • A C Fomento De Nutrición Y Salud
    • Df Mexico
    • Mexico
    • I S Fomsgaard
    • M C Non
    • A P Barba De La Rosa
    • C Christophersen
    • K Dusek
    • J Délano-Frier
    • J Espinoza Pérez
    • A Fonseca
    • D Janovská
    • P Kudsk
    • R S Labouriau
    • Lacayo Romero
    • M L Martínez
    • N Matus
    • F Matusová
    • K Mathiassen
    • S K Noellemeyer
    • E J Pedersen
    • H A Stavelikova
    • H Steffensen
    • S K De Troiani
    • R M Taberner
    Fomento de Nutrición y Salud A.C. (FNSAC), 2009. Sistema Mexicano de Alimentos Equivalentes. Impresos Trece, Mexico DF, Mexico. Fomsgaard, I.S., A ˜ non, M.C., Barba de la Rosa, A.P., Christophersen, C., Dusek, K., Délano-Frier, J., Espinoza Pérez, J., Fonseca, A., Janovská, D., Kudsk, P., Labouriau, R.S., Lacayo Romero, M.L., Martínez, N., Matus, F., Matusová, K., Mathiassen, S.K., Noellemeyer, E.J., Pedersen, H.A., Stavelikova, H., Steffensen, S.K., de Troiani, R.M., Taberner, A., 2010. Adding Value to Holy Grain: Providing the Key Tools for the Exploitation of Amaranth – The Protein-rich Grain of the Aztecs. Results from a Joint European – Latin American Research Project. Department of Integrated Pest Management, Aarhus University, Faculty of Agricultural Sciences, Denmark.
  • Article
    A review on the use of supercritical carbon dioxide as a solvent for the bioactive compounds extraction present in vegetables of current and potential use in agroindustrial processes is presented. A description of the extraction with soxhlet, which is used to evaluate the yield in extract and in extraction time of traditional and modern extraction methods is done. Extraction with supercritical fluids is described, operation conditions are showed and bioactive principles extracted from different vegetables raw material reported in the international literature are described. To better described the applications of supercritical fluids in the agroindustry, these are classified in five well defined groups. This allows to get a clear global idea about the possibilities offered by the supercritical fluids to improve the competitiveness of the agroindustry.
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    Full-text available
    Amaranth is a commonly consumed vegetable in households in Southwestern Nigeria. Raw amaranth is known to be rich in micronutrients particularly Iron and Vitamin C, which are lost during cooking due to the method of preparation. Hence, this study was conducted to determine the method of preparation that best retains nutrients. Three common me-thods of preparing amaranth were identified; method 1 in which no heat was applied but amaranth leaves were finely chopped (samples A), method 2 which was steaming before chopping the leaves (sample B) and method 3 involved chopping of leaves before blanching (sample C). These three samples were subjected to proximate analysis and micro-nutrient determinations. Results were mean of three determinations. Result of proximate analysis showed that sample B method of preparation has highest percentage of crude fat per gram of sample (2.31 ± 0.45), protein (4.35 ± 0.15) and fibre (1.09 ± 0.06). Sample A has highest percentage of moisture (90.35 ± 0.27) and ash content (1.36 ± 0.28) while sample C has highest percentage per gram of sample in carbohydrate (4.89 ± 1.21) only. Micronutrient determination results showed that sample A was highest in Vitamin C (1.57 mg ± 0.06) and Iron (535.84 ppm ± 123.42), followed by sample C (1.21 ± 0.07) and (501.88 ± 215.19) respectively while sample B had the least vitamin C (0.79 ± 0.06) and Iron (354.18 ± 121.84). The study showed that samples A best retained the nutrient contents of Amaranth leaves after preparation.
  • Article
    Full-text available
    The aim of this work was to assess the following plants as functional foods that can be found in Mexico: white sapote (Casimiroa edulis), jicama (Pachyrhizus spp.), amaranth (Amaranthus hypochondriacus), sweet fennel (Foeniculum vulgare), oregano (Lippia graveolens), pitahaya (Hylocereus sp.), agave (Agave americana), pelitre (Heliopsis longipes), and purslane (Portulaca oleracea L). The main characteristics, components and active substances, forms of use in traditional medicine, nutritional properties, evaluation of biological assays, and the potential possibilities of research with the plants and/or extracts were reviewed.
  • Article
    RESUMEN. Seis variedades de Amaranto fueron procesadas para dar una harina cruda, una nixtamalizada, una cocida en agua, otra expandida, una malteada y una laminada después de un tratamiento térmico. Los valores analíticos en estas muestras se compararon con los valores en una muestra cruda. Los granos crudos contenían de 14.5% a 15.1% de proteína, 5.9 a 6.7 de grasa, y 2.3% a 3.2% de cenizas. Las harinas de las variedades de diferentes procesos dieron un contenido de grasa que varía entre 6.4% - 7.0%. Las harinas de procesos en seco contenían mas aceite que las de procesos en húmedo SUMMARY. The oil, fatty acid and squalene content of variet- ies of raw and processed grain amaranth. Six amaranth grain varieties were processed to yield a nixtamalized flour, one cooked in water, one expanded, a malted one and a laminate samples after a thermic treatment. The chemical values of the raw samples con- tained from 14.5% to 15.1% protein, 5.9 to 6.7% ether extract and from 2.3% to 3.2% ash on a dry weight basis. The flours from the different processes yield products with a fat content which varied from 6.4% to 7.0% for the 6 varieties. The flours coming from dry heat processing contained higher oil levels than those flours coming from wet processes. The oil from only 3 varieties and from 4 processes were analyzed from its fatty acid composition. The oil contained on the average 17.85% of C16:0, 68.1% of stearic, olic and linoleic acids, 3.86% of C18:3, 5.1% of C20:0 and small amounts of C20:1 and C22:0. The squalene content in the oil of the pro- cessed flours varied from 7.0 to 9.6 g/100 g for the raw flour, 8.1 - 12.6 g/100 g for the flour from wet cooking in water, 9.0 -12.7g/ 100 g for the flour from the nixtamalization process, 10.1-12.8g/ 100 g for the expanded grain flour, 9.0 to 11.2 g/100 g for the malted flour and 6.0 -9.5 g/100 g for the laminated grain flour. The squalene averages per process showed statistical significant differences.
  • Article
    The protein profile and the amino acid composition of eleven amaranth species have been studied. The following species were taken into account: A. viridis, A. powellii, A. muricatus, A. deflexus, A. graecizans, A. blitoides, A. retroflexus, A. blitum, A. albus, A. cruentus and A. hypochondriacus. Seed samples were obtained from wild populations located in the southwest of Spain. The protein profile was studied by gel filtration chromatography and denaturing electrophoresis. Profiles were similar in all taxa, with small variations in the molecular weights and amounts of the main seed proteins. Thus, after gel filtration chromatography six main fractions of around 300 kDa, 180 kDa, 120 kDa, between 40 and 50 kDa, 20 and 30 kDa and below 10 kDa were observed. On the other hand, the electrophoretic analysis showed peptides grouped into three main fractions, between 50 and 64 kDa, 33 and 37 kDa and 18 and 25 kda. The most balanced amino acid compositions were observed in the wild taxa A. muricatus, A. blitum and A. powellii showed the most equilibrated amino acid composition. A. hypochondriacus and A. graecizans showed the most deficient amino acid composition with limitations in five essential amino acids. These results show the potential of wild amaranthus taxa for their introduction as crops or their use in the improvement by hybridization mechanisms of other crops such as A. hypochondriacus.
  • Article
    Full-text available
    A review on the use of supercritical carbon dioxide as a solvent for the bioactive compounds extraction present in vegetables of current and potential use in agroindustrial processes is presented. A description of the extraction with soxhlet, which is used to evaluate the yield in extract and in extraction time of traditional and modern extraction methods is done. Extraction with supercritical fluids is described, operation conditions are showed and bioactive principles extracted from different vegetables raw material reported in the international literature are described. To better described the applications of supercritical fluids in the agroindustry, these are classified in five well defined groups. This allows to get a clear global idea about the possibilities offered by the supercritical fluids to improve the competitiveness of the agroindustry.
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    Full-text available
    Entada africana is an endangered West African medicinal plant because of a large scale use of its roots. To evaluate and compare the medicinal potential of all plant parts for a sustainable use the radical scavenging activity (DPPH method) and the phenolic compound contents (Folin-Ciocalteu method) of aerial parts and roots were investigated. Aqueous extracts of leaves, stem barks and roots were used for this investigation. Methanol extract was also used for the roots. The fourth extracts showed high radical scavenging activity (ranging from 1.27-3.36 μg LL-1) similar to those of quercetin, rutoside and ascorbic acid (0.8, 5.20 and 5.32 μg mL-1, respectively). Fractions obtained from the four extracts with chloroform, ethyl acetate, methanol and water also showed high activity with EC, ranging from 3.39-16.72 pg mL-1 except chloroform fractions (EC50>36 μg mL-1). The total phenolic and flavonoid contents of the four extracts and their twelve fractions were quite high, ranging from 17.10-43.50% TAE. The leave extracts showed an interesting free radical scavenging activity and phenolic content as to be preconized for use instead of the roots.
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    Full-text available
    The objective of the present study was to investigate the effect of phenolic substances and proteins on the antioxidant potentials in some cereals and pseudocereals and to compare their bioability. The polyphenol dry matter extracts (PDME) from the investigated seeds of buckwheat, rice, soybean, amaranth and quinoa with 1.2M HCl in 50%methanol/water (PDME50%Met/HCl) exhibited higher inhibition of lipid peroxidation than the ones extracted with 50%methanol/water (PDME50%Met) and were comparable to the antioxidant activity of butylated hydroxyanisole at concentration of 0.2mgmL−1. The antioxidant activities of these seed extracts determined by 2,2′-azinobis (3-ethylbenzothiazoline-6-sulfonate)-ABTS●+/K2S2O8, β-carotene bleaching (β-carotene), and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging methods showed high correlation coefficients (R 2) such as 0.9515, 0.9058 and 0.8723, respectively, with the presence of total polyphenols estimated by Folin-Ciocalteu assay. These results indicate that the major antioxidant components in these extracts mostly derived from the polyphenols, and proteins showed only minimal values of bioactivity. Based on high contents of polyphenols, anthocyanins, flavonoids and their antioxidant activities pseudocereals such as buckwheat, quinoa and amaranth can be a substitute for cereals for common and atherosclerotic diets and sometimes in the allergic cases.
  • Adding Value to Holy Grain: Providing the Key Tools for the Exploitation of Amaranth – The Protein-rich Grain of the Aztecs
    • I S Fomsgaard
    • A Non
    • M C Barba
    • A P La Rosa
    • C Christophersen
    • K Dusek
    • J Délano-Frier
    • Espinoza Pérez
    • J Fonseca
    • A Janovská
    • D Kudsk
    • P Labouriau
    • R S Lacayo Romero
    • M L Martínez
    • N Matus
    • F Matusová
    • K Mathiassen
    • S K Noellemeyer
    • E J Pedersen
    • H A Stavelikova
    • H Steffensen
    • S K Troiani
    • R M Taberner
    Fomsgaard, I.S., A ˜ non, M.C., Barba de la Rosa, A.P., Christophersen, C., Dusek, K., Délano-Frier, J., Espinoza Pérez, J., Fonseca, A., Janovská, D., Kudsk, P., Labouriau, R.S., Lacayo Romero, M.L., Martínez, N., Matus, F., Matusová, K., Mathiassen, S.K., Noellemeyer, E.J., Pedersen, H.A., Stavelikova, H., Steffensen, S.K., de Troiani, R.M., Taberner, A., 2010. Adding Value to Holy Grain: Providing the Key Tools for the Exploitation of Amaranth – The Protein-rich Grain of the Aztecs. Results from a Joint European – Latin American Research Project. Department of Inte-grated Pest Management, Aarhus University, Faculty of Agricultural Sciences, Denmark.
  • Article
    The demand for food is increasing, not only to meet food security for growing populations, but also to provide more nutritious food, rich in good quality proteins and nutraceutical compounds. The amaranth (Amaranthus hypochondriacus) plant, in addition to its high nutritive and nutraceutical characteristics, has excellent agronomic features. The objective of the present study was to analyze some physical and proximal-nutritional properties of amaranth seeds obtained from different varieties grown in arid zones and characterize their phenolic acids and flavonoids. Two commercial (Tulyehualco and Nutrisol) and two new (DGETA and Gabriela) varieties of A. hypochondriacus were grown at the Mexican Highlands zone. Tulyehualco and DGETA varieties had higher seed yield of 1475 and 1422 kg ha−1, respectively, comparable to corn and soybean production in agricultural areas. Gabriela had the highest protein content of 17.3%, but all varieties had an adequate balance of essential amino acids. Polyphenols as rutin (4.0–10.2 μg g−1 flour) and nicotiflorin (7.2–4.8 μg g−1 flour) were detected. Amaranth can be cultivated in arid zones where commercial crops cannot be grown; the seeds besides their well known nutritive characteristics could be a source of phenolic compounds of high antioxidant properties.
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    Full-text available
    Water, methanol and ethyl acetate extracts from stems with leaves and flowers of Amaranthus lividus L., one of the most popular leafy vegetable consumed in the west Black Sea region of Turkey, were tested in vitro for their ability to inhibit peroxidation of phosphatidylcholine liposomes induced with Fe3+/ascorbate, to scavenge ABTS+, DPPH and hydroxyl radicals, to reduce Fe (III) to Fe (II) and to chelate Fe (II) ions. The results showed that amaranth vegetable contained naturally occuring antioxidant components and possessed antioxidant activity which may be attributed to its lipid peroxidation inhibitory, radical scavenging and metal chelating activities. The antioxidant activities of the water and ethyl acetate extracts were not concomitant with the development of their reducing power. It was concluded that A. lividus might be a potential source of antioxidants.
  • Article
    Pomegranate peels (PP) are underestimated as an agricultural waste. In this work, antioxidant efficacy of PP extracts has been estimated in stabilization of sunflower oil. Methanolic extract was found to be highest in yield, i.e. 29.16% and antioxidant activity 92.69% as compared to other solvents ranging in yield 13.96–21.14% and antioxidant activity 42.11–89.23%. Thermal stability of methanolic extracts was evaluated by heating the extract at 185 °C up to 80 min and evaluating the antioxidant activity of extract for different intervals during storage period and exhibited 66.23% inhibition of peroxidation after 80 min heating time. Methanolic extracts of PP at three concentrations, i.e. 250 (SFO-250), 500 (SFO-500) and 1000 ppm (SFO-1000) were added to preheated RBD sunflower oil. BHT at 200 ppm (SFO-BHT) served as standard besides a control (ctrl). Weight gain (WG), antioxidant activity index (AAI), peroxide value (PV), conjugated dienes (CD), conjugated trienes (CT) and thiobarbituric acid reactive substances (TBARS) were taken as the parameters for evaluation of stabilization efficacy of methanolic extracts of PP. Results from different parameters were in agreement with each other, suggesting higher efficiency of SFO-1000 followed by SFO-BHT, SFO-500, SFO-250 and Ctrl samples, respectively, with the exception of CD; which suggested higher efficiency of SFO-500 over SFO-BHT. Results reveal PP to be a potent antioxidant for the stabilization of sunflower oil.
  • Article
    The antiradical activities of various antioxidants were determined using the free radical, 2,2-Diphenyl-1-picrylhydrazyl (DPPH*). In its radical form. DPPH* has an absorption band at 515 nm which dissappears upon reduction by an antiradical compound. Twenty compounds were reacted with the DPPH* and shown to follow one of three possible reaction kinetic types. Ascorbic acid, isoascorbic acid and isoeugenol reacted quickly with the DPPH* reaching a steady state immediately. Rosmarinic acid and δ-tocopherol reacted a little slower and reached a steady state within 30 min. The remaining compounds reacted more progressively with the DPPH* reaching a steady state from 1 to 6 h. Caffeic acid, gentisic acid and gallic acid showed the highest antiradical activities with a stoichiometry of 4 to 6 reduced DPPH* molecules per molecule of antioxidant. Vanillin, phenol, γ-resorcylic acid and vanillic acid were found to be poor antiradical compounds. The stoichiometry for the other 13 phenolic compounds varied from one to three reduced DPPH* molecules per molecule of antioxidant. Possible mechanisms are proposed to explain the experimental results.
  • Article
    There is strong epidemiological evidence that whole-grain cereals protect the body against age-related diseases such as diabetes, cardiovascular diseases and some cancers. This may be due to the fibre and micronutrients in the outer layer and germ fractions of the grain acting together to combat oxidative stress, inflammation, hyperglycaemia and carcinogenesis. Oxidative stress is associated with these metabolic diseases. Whole-grain cereals are a good source of vitamin E, folates, phenolic acids, zinc, iron, selenium, copper, manganese, carotenoids, phytic acid, lignins, lignans, and alkylresorcinols, all of which have significant antioxidant potential in vitro. Phenolic acids such as ferulic acid are characteristic of cereals. They may scavenge free-radical oxygen species both in vitro and in vivo. Phenolics may also act in vivo by triggering gene induction/repression via cell signalling through transcription factors. Whole-grain cereals are also a good source of betaine, choline and sulphur amino acids that can improve antioxidant status. Betaine, which accounts for about 1% (w/w) of the bran fraction in wheat, acts as a methyl donor that may decrease hyperhomocysteinaemia, a cardiovascular risk factor, but it has been neglected. Cereals and cereal products are antioxidative in vitro, as are most fruits and vegetables. The in vitro antioxidant capacity of cereals and their constituent fractions is significantly correlated with their polyphenol content, except for maize. However, the in vitro antioxidant capacity of cereals is only an approximate reflection of their in vivo antioxidant effect due to differences in antioxidant solubility/bioavailability within the digestive tract and the metabolism/conjugation of compounds such as polyphenols. During digestion, the antioxidant capacity of cereals is increased and is likely to provide a favourable antioxidative environment for the epithelium tract, notably in the large intestine. Most of the studies performed on animals have been concerned with the antioxidant property of coloured rice, especially black rice and its anthocyanin fraction, showing a positive effect on some antioxidant biomarkers. Those very few studies that have been done on humans have shown that wheat bran and rye product supplements have no effect on antioxidant status, while a black rice pigment fraction and an avenanthramide-enriched mixture extracted from hulled oats have a positive effect. In vivo studies are therefore needed to further explore the real antioxidant potential of cereals.
  • Article
    The amount of phenolic acids, flavonoids and betalains in Andean indigenous grains, quinoa (Chenopodium quinoa), kañiwa (Chenopodium pallidicaule) and kiwicha (Amaranthus caudatus), was determined. The total amount of phenolic acids varied from 16.8 to 59.7 mg/100 g and the proportion of soluble phenolic acids varied from 7% to 61%. The phenolic acid content in Andean crops was low compared with common cereals like wheat and rye, but was similar to levels found in oat, barley, corn and rice. The flavonoid content of quinoa and kañiwa was exceptionally high, varying from 36.2 to 144.3 mg/100 g. Kiwicha did not contain quantifiable amounts of these compounds. Only one variety of kiwicha contained low amounts of betalains. These compounds were not detected in kañiwa or quinoa. Our study demonstrates that Andean indigenous crops have excellent potential as sources of health-promoting bioactive compounds such as flavonoids.
  • Article
    This study examined the polyphenol composition and antioxidant properties of methanolic extracts from amaranth, quinoa, buckwheat and wheat, and evaluated how these properties were affected following two types of processing: sprouting and baking. The total phenol content amongst the seed extracts were significantly higher in buckwheat (323.4 mgGAE/100 g) and decreased in the following order: buckwheat > quinoa > wheat > amaranth. Antioxidant capacity, measured by the radical 2,2-diphenyl-1-picylhydrazyl scavenging capacity and the ferric ion reducing antioxidant power assays was also highest for buckwheat seed extract (p < 0.01). Total phenol content and antioxidant activity was generally found to increase with sprouting, and a decrease in levels was observed following breadmaking. Analysis by liquid chromatography coupled with diode array detector revealed the presence of phenolic acids, catechins, flavanol, flavone and flavonol glycosides. Overall, quinoa and buckwheat seeds and sprouts represent potential rich sources of polyphenol compounds for enhancing the nutritive properties of foods such as gluten-free breads.
  • Article
    This study examined extraction of pomegranate seed oil by using supercritical carbon dioxide. Response surface methodology was used to evaluate the effects of the process parameters, namely extraction pressure, temperature and CO2 flow rate on the yield of pomegranate seed oil. The extraction parameters were optimized with a central composite design experiment. The linear term of pressure, followed by the linear term of CO2 flow rate, the quadratic terms of pressure, temperature and CO2 flow rate and the interactions between pressure and temperature, as well as CO2 flow rate and temperature, had significant effects on the oil yield (p < 0.05). Maximum yield of pomegranate seed oil from the mathematical model was predicted to be 156.3 g/kg dry basis under the condition of pressure 37.9 MPa and temperature 47.0 °C with CO2 flow rate of 21.3 L/h. The fatty acid composition and the tocopherols' content of pomegranate seed oil extracted using supercritical CO2 were compared with those obtained by Soxhlet method. Minor difference was found in the fatty acid composition of the oils extracted by the two methods. The content of total tocopherols was about 14% higher in the oil extracted with supercritical CO2 than that obtained by Soxhlet extraction.
  • Article
    The antioxidant activity of peptides present in the phosphate buffer-soluble fraction of: – Amaranthus mantegazzianus protein isolates (Is), – protein fractions (Albs, Globs, GlobPs and Gluts), alcalase hydrolysates of isolates (hydrolysis degree –HD-: 2.4% (IHls) and 30% (IHhs) and protein fractions (AlbHs, GlobHs, GlobPHs, and GlutHs) was investigated. Fractions separated by molecular exclusion chromatography were also analyzed. ABTS+. scavenging method showed the presence of antioxidant peptides in Is, Albs, Globs, and Gluts, being the last the one with the highest activity. No activity was detected in the GlobPs. After hydrolysis, the scavenging activity of all samples increased, especially at high HD. The GlobPs fraction presented the highest scavenging capacity after hydrolysis. Naturally-occurring peptides and polypeptides presented also the capacity to inhibit the linoleic acid oxidation, which was partially lost after hydrolysis. FPLC fractionation evidenced the appearance of <0.5 kDa active peptides due to the hydrolysis process. Results suggest the presence in the Is and IHhs of several peptides and polypeptides which can act as antioxidants by different mechanisms.
  • Article
    Full-text available
    Total antioxidant capacity, total phenolic contents (TP) and anthocyanins contents (ANT) were determined in Amaranthus cruentus and Chenopodium quinoa seeds and sprouts. Antioxidant activity of the investigated seeds decreased in the following order: quinoa, amaranth v. Rawa, amaranth v. Aztek for FRAP and quinoa, amaranth v. Aztek, amaranth v. Rawa for both ABTS and DPPH. Sprouts activity depended on the length of their growth, and the peak values were reached on the fourth day in the case of amaranth and on the sixth day in the case of quinoa. The data obtained by the three methods showed significant correlation between TP content in seeds and sprouts. In sprouts grown in the daylight and in the darkness we observed some significant changes of TP, ANT and antioxidant activity. Amaranth and quinoa seeds and sprouts can be used in food, because it is a good source of ANT and TP with high antioxidant activity.
  • Article
    The antioxidant activity of six natural isolated chlorophyll derivatives and Cu-chlorophyllin was investigated by measuring their protective action against lipid oxidation. For this, the β-carotene bleaching method and the stable radical 2,2-diphenyl-1-picryldrazyl (DPPH) scavenging assay were employed. The results obtained by the β-carotene bleaching method showed that all chlorophyll derivatives presented a dose-dependent response. Pheophorbide b and pheophytin b were the strongest natural antioxidant compounds, whose activities were comparable to BHT. The high antioxidant activity found for pheophorbide b, in comparison to pheophorbide a, demonstrated the importance of the aldehyde group for functionality. On the other hand, by the DPPH assay, all natural pigments showed low antioxidant activity when compared to Trolox. Cu-chlorophyllin, tested by both methods, presented a higher antioxidant activity than that of natural chlorophylls, showing the importance of the nature of the chelated metal in the porphyrin ring. The mechanism of antioxidant activity displayed by the natural chlorophyll derivatives does not seem to be based on the ability to donate hydrogen but maybe, on the protection of linoleic acid against oxidation and/or preventing decomposition of hydroperoxides.
  • Article
    The oil fractions of Amaranthus caudatus L. and Amaranthus cruentus L. seeds were studied after different treatments of the seeds. The oil contents were 7.1 and 8.5% for raw A. caudatus L. and A. cruentus L. seeds, and consisted of 80.3–82.3% of triacylglycerols (TAGs). Phospholipids represented 9.1–10.2% of the oil. The squalene content was 4.8–4.9% in both types of oil. Air classification increased the lipid content and decreased the content of squalene, while heating (popping and cooking) increased the squalene content. After germination, the lipid fraction was decreased in their TAGs and increased in their phospholipids. The main fatty acid composition (palmitic, linoleic and oleic) was not affected by thermal treatments or by germination of the seeds. The hydroperoxide stability test showed that the stability of amaranth oil was more than that of sunflower oil. This research provides some information about the effect of different treatments – including heat treatments, germination and air classification – on the oil characteristics of two species of amaranth seeds. Fatty acids and triacylglycerol profiles, lipid fractions and squalene content were the main characteristics studied during this research. The stability of the oil against oxidation is also presented as compared with sunflower oil. The results of this research provide a clearer picture for the potential use of amaranth oil on an industrial scale and its characteristic stability under different process conditions.
  • Article
    Full-text available
    The protein profile and the amino acid composition of eleven amaranth species have been studied. The following species were taken into account: A. viridis, A. powellii, A.muricatus, A. deflexus, A. graecizans, A. blitoides, A. retroflexus, A. blitum, A. albus, A. cruentus and A. hypochondriacus . Seed samples were obtained from wild populations located in the southwest of Spain. The protein profile was studied by gel filtration chromatography and denaturing electrophoresis. Profiles were similar in all taxa, with small variations in the molecular weights and amounts of the main seed proteins. Thus, after gel filtration chromatography six main fractions of around 300 kDa, 180 kDa, 120 kDa, between 40 and 50 kDa, 20 and 30 kDa and below 10 kDa were observed. On the other hand, the electrophoretic analysis showed peptides grouped into three main fractions, between 50 and 64 kDa, 33 and 37 kDa and 18 and 25 kda. The most balanced amino acid compositions were observed in the wild taxa A. muricatus, A. blitum and A. powellii showed the most equilibrated amino acid composition. A. hypochondriacus and A. graecizans showed the most deficient amino acid composition with limitations in five essential amino acids. These results show the potential of wild amaranthus taxa for their introduction as crops or their use in the improvement by hybridization mechanisms of other crops such as A. hypochondriacus. El objetivo de este estudio fue determinar la composición aminoacídica y el perfil proteico de las semillas de once especies de amaranto. Las especies estudiadas fueron A. viridis, A. powellii, A. muricatus, A. deflexus, A. graecizans, A. blitoides, A. retroflexus, A. blitum, A. albus, A. cruentus y A. hypochondriacus . Se estudiaron poblaciones silvestres de estos taxones localizadas en el suroeste de España. El perfil proteico se estudió mediante cromatografía de filtración en gel y electroforesis desnaturalizante. Este perfil fue similar en todas las especies, con ligeras variaciones en los pesos moleculares y abundancia de las principales proteínas. Así, mediante cromatografía de filtración en gel se apreciaron seis fracciones mayoritarias de alrededor de 300 kDa, 180 kDa, 120 kDa, entre 40 y 50 kDa, entre 20 y 30 kDa y menores de 10 kDa. Por otro lado, el estudio electroforético mostró tres grupos de péptidos mayoritarios con pesos comprendidos entre 50 y 64 kDa, entre 33 y 37 kDa y entre 18 y 25 kDa. Las especies con la composición aminoacídica más equilibrada correspondieron a taxones no cultivadas. A. muricatus, A. blitum y A. powellii mostraron la composición aminoácidica más equilibrada. A. hypochondriacus y A. graecizans mostraron la composición aminoacídica más deficitaria, con carencias en cinco aminoácidos esenciales. Estos resultados muestran el potencial de los taxones silvestres de amaranto para su introducción como cultivos o su uso para la mejora mediante hibridación de otros cultivados, como A. hypochondriacus .
  • Article
    Antioxidant-rich fractions were extracted from pomegranate (Punica granatum) peels and seeds using ethyl acetate, methanol, and water. The extracts were screened for their potential as antioxidants using various in vitro models, such as beta-carotene-linoleate and 1,1-diphenyl-2-picryl hydrazyl (DPPH) model systems. The methanol extract of peels showed 83 and 81% antioxidant activity at 50 ppm using the beta-carotene-linoleate and DPPH model systems, respectively. Similarly, the methanol extract of seeds showed 22.6 and 23.2% antioxidant activity at 100 ppm using the beta-carotene-linoleate and DPPH model systems, respectively. As the methanol extract of pomegranate peel showed the highest antioxidant activity among all of the extracts, it was selected for testing of its effect on lipid peroxidation, hydroxyl radical scavenging activity, and human low-density lipoprotein (LDL) oxidation. The methanol extract showed 56, 58, and 93.7% inhibition using the thiobarbituric acid method, hydroxyl radical scavenging activity, and LDL oxidation, respectively, at 100 ppm. This is the first report on the antioxidant properties of the extracts from pomegranate peel and seeds. Owing to this property, the studies can be further extended to exploit them for their possible application for the preservation of food products as well as their use as health supplements and neutraceuticals.