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Registros recuperados: 24 | |
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Pérez Prado, José Adán. |
El plátano es el frutal en segundo lugar en importancia económica en México, el 95% se destina al consumo nacional y el 5% restante a la exportación. No obstante, las pérdidas por manejo postcosecha justifican buscar métodos para conservarlo. El plátano presenta cambios en volumen debido al intercambio de calor y masa, por lo que decrece su superficie bajo la contracción de los tejidos por pérdida parcial de agua. En consecuencia, todos los parámetros que dependen de cambios de dimensión interna y externa, requieren del uso de modelos de simulación mediante curvas de secado que nos permitan describir dicho comportamiento en los alimentos. Por lo anterior, el presente trabajo presenta una serie de modelos de regresión (exponencial, lineal, logarítmico y... |
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Palavras-chave: Acido cítrico; Enzimas; Obscurecimiento; Harina; Madurez; Citric acid; Enzyme; Darkening; Flour; Ripening; Maestría Tecnológica; Agroindustria. |
Ano: 2010 |
URL: http://hdl.handle.net/10521/331 |
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Rywinska,Anita; Rymowicz,Waldemar; Marcinkiewicz,Marta. |
In the present report, citric acid production from raw glycerol in two fed-batch systems by acetate negative-mutants of Yarrowia lipolytica: Wratislavia 1.31 and Wratislavia AWG7 was compared. In the system, in which the total glycerol concentration was 200 g∙L-1, the substrate was added by pulsed additions, and in the other, in which the total glycerol concentration was 300 g∙L-1, the substrate was added at a constant feeding rate of 1.4 g∙h-1. Despite high citric acid concentrations (155.2 and 157.5 g∙L-1 with Y. lipolytica Wratislavia 1.31 and Y. lipolytica Wratislavia AWG7, respectively) obtained from 300 g∙L-1 of glycerol, the yield of citric acid was similar, i.e. about 0.6 g∙g-1. The... |
Tipo: Journal article |
Palavras-chave: Citric acid; Fed-batch culture; Yarrowia lipolytica; Raw glycerol. |
Ano: 2010 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582010000400009 |
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Anastassiadis,Savas; Rehm,Hans-Jürgen. |
The effect of air saturation on citric acid production in batch, repeated batch and chemostat cultures has been studied. It was shown that, under continuous fermentation (chemostat mode), the highest concentration of citric acid equal of 98 g/l was produced at 20% of air saturation. In contrary to continuous fermentation, displaying an optimum at 20%, 80% air saturation yielded higher values in repeated batch fermentation process. 167 g/l citric acid were produced continuously with the fill and drain technique at 4.85 days, at 80% air saturation, compared with 157.6 g/l achieved within 5.4 days at 20%. Under repeated batch fermentation, the formation rate of the generic product (Rj) as well as the specific citric acid productivity (m p) reached a maximum... |
Tipo: Journal article |
Palavras-chave: Air saturation influence; Chemostat; Citric acid; Citric acid fermentation; Repeated batch; Oxygen influence. |
Ano: 2006 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582006000100005 |
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Anastassiadis,Savas; Rehm,Hans-Jürgen. |
The influence of air saturation and temperature on continuous citric acid secretion was studied in chemostat cultures of Candida oleophila ATCC 20177 (var.). Simultaneous measurements of intra- and extracellular concentration of glucose, citric and isocitric acid confirmed the involvement of a specific active transport system in citrate secretion, favouring citric acid over isocitrate. An optimum air oxygen saturation of 20% and temperature of 30-31ºC were determined for the continuous citric acid secretion. The highest values of citric acid concentration (98 g/L), citrate to isocitrate ratio (33.3:1), volumetric citric productivity (1.8 g/(L x h)), and specific citric acid productivity (0.1 g/(g x h)), were reached at 20% air saturation at a... |
Tipo: Journal article |
Palavras-chave: Candida oleophila; Citric acid; Citric acid secretion. |
Ano: 2006 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582006000400010 |
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Çevrml,Bekir Stk; Karipta,Ergin; Yaar,Ahmet; Ytolu,Mustafa. |
Influences of phenol, ?-naphtol and ?-naphtol, which are toxic chemicals, on citric acid biosynthesis and biomass in the artificial culture setting of Aspergillus niger using batch fermenter are examined in the most favorable fermentation conditions, and a model is proposed. Addition of certain concentrations of phenol, ?-naphtol and ?-naphtol to the culture increases the citric acid production. According to this model, maximum citric acid concentration is 48.3 g L-1 in a culture that does not contain any toxic chemicals, whereas the maximum concentrations obtained in cultures containing 25 mg L-1 phenol, 25 mg L-1 alpha-naphtol and 15 mg L-1 beta-naphtol are 62.5 g L-1, 78.1 g L-1 and 86.0 g L-1, respectively. Moreover, addition of toxic chemicals to the... |
Tipo: Journal article |
Palavras-chave: A. niger; Citric acid; Fermenter; Toxic chemicals (phenols). |
Ano: 2010 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582010000600008 |
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Drouillon,M.; Merckx,R.. |
Exudation of low molecular weight carboxylates is an important phosphorus (P) acquisition strategy for plants in strongly P-fixing soils. The effect of citrate exudation on P availability was studied in five acid soils with a large organic matter content and a low available P pool. The amount of molybdate reactive P extracted by citric acid 10 mM (0.1-2 mg kg-1) was larger than the molybdate reactive P (MRP) extracted by CaCl2 10-3 M (0.007-0.07 mg kg-1). Both extractants were adjusted to soil pH prior to extraction. Also, the total P content of citric acid extracts (2-44 mg kg-1) far exceeded the total P content of CaCl2 (0.2-1.5 mg kg-1). However, ratios of MRP to total dissolved P (TDP) remained constant. When citric acid was added to the CaCl2-extracts... |
Tipo: Journal article |
Palavras-chave: Andosols; Citric acid; Phosphorus availability. |
Ano: 2003 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-66432003000100009 |
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Pino, J. A.; Sauri-Duch, E.; Cuevas-Glory, L.. |
En el presente trabajo se estudiaron los cambios de los componentes volátiles de un concentrado de sabor limón para preparar bebidas de limón durante 6 meses de conservación a 40 ºC. Se identificaron 44 compuestos aislados mediante microextracción en fase sólida del espacio de cabeza en combinación con la cromatografía de gases- espectrometría de masas. El limoneno, γ-terpineno, acetato de citronelilo, acetato de nerilo y acetato de geranilo, disminuyeron su contenido significativamente, mientras que el 1,4-cineol, 1,8-cineol, p-cimeno, p-cimeneno, p-menta-1,3- dien-8-ol, α-terpineol, trans-α-bergamoteno, ar-curcumeno, (E,E)-α-farneseno y β-bisaboleno la incrementaron. El neral y geranial parecen disminuir su contenido, pero estos cambios no explican todo... |
Tipo: Journal Contribution |
Palavras-chave: Volatile compounds; Stability; Flavourings; Concentrates; Lemons; Spoilage; Citric acid. |
Ano: 2008 |
URL: http://hdl.handle.net/1834/4893 |
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Andrade,Felipe Vaz; Mendonça,Eduardo de Sá; Silva,Ivo Ribeiro da. |
Organic acids play an important role in the nutritional conditions of plants. Their relevance is related to their formation dynamics, mineralization rate and adsorption by soil colloids. This study was carried out to evaluate the dynamics of mineralization and adsorption of organic acid (acetic acid - AA, citric acid - CA and humic acid - HA) applied to the soil. Samples of two Oxisols were used: Rhodic Haplustox (LV) and Typic Haplustox (LVA). The mineralization experiment was arranged in a 2 x 3 x 5 factorial design, based on the factors: two soils (LV and LVA) x three organic acid (OA) types (AA, CA and HA) x five OA rates (0, 1, 2, 4, and 8 mmol dm-3). Organic carbon mineralization in samples was measured by the C-CO2 efflux, produced by the microbial... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Citric acid; Humic acids; Sorption; Biodegradation. |
Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832013000400015 |
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Santos,Wedisson Oliveira; Mattiello,Edson Marcio; Barreto,Matheus Sampaio Carneiro; Cantarutti,Reinaldo Bertola. |
ABSTRACT: There are several globally accepted methods to chemically characterize P-fertilizers, but not all are suitable to predict the agronomic efficiency of the P sources in terms of plant nutrition. Our aim was to investigate the performance of P extractors for fertilizers, investigating the consistency of different methods for P sources of varying properties and the related plant responses. The experiment was carried out in a greenhouse, using corn as a model plant. Phosphorus values extractable in water, 2 % citric acid, 2 % formic acid, ammonium neutral citrate + water, and acid ammonium citrate were evaluated for eight P fertilizers of varied solubility and correlated with P uptake by corn. The extractors citric acid and formic acid recovered no... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Phosphorus fertilizers; Citric acid; Ammonium neutral citrate. |
Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832019000100503 |
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Machado,Ramires Ventura; Andrade,Felipe Vaz; Passos,Renato Ribeiro; Ribeiro,Roberto Carlos da Conceição; Mendonça,Eduardo Sá; Mesquita,Luiz Felipe. |
ABSTRACT Organic acids present in organic matter and, or, exudates by microorganisms and plants can increase the liberation of potassium present in minerals. The objective of this study was to characterize the residue from ornamental rocks and evaluate the release of K from these residues after the application of organic acids. The experiment was conducted under laboratory conditions and followed a 2 × 3 × 5 factorial design with three replicates. The studied factors were: two organic acids (citric acid and malic acid), three ornamental rock residues (R1, R2 and R3) and five organic acid rates (0, 5, 10, 20 and 40 mmol L-1). After agitation, K concentrations were determined in the equilibrium solution. Successive extractions were performed (1, 5, 10, 15,... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Stonemeal; Fertilization; Citric acid; Silicate rocks. |
Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832016000100505 |
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Martins,Ramilo Nogueira; Mattiuz,Ben-Hur; Santos,Leandra Oliveira; Morgado,Cristiane Maria Ascari; Mattiuz,Claudia Fabrino Machado. |
'Aurora-1' peaches establishes an interesting alternative as a minimally processed product, due to its characteristics like flavor, color, smell, and also because of its handling resistance. However, it has a short shelf life after a fresh-cut due to enzymatic browning and stone cavity collapse. The main purpose of this research was to test the additive with antioxidant effect to prevent browning in minimally processed 'Aurora-1' peaches. The minimal processing consists of washing, sanitizing, peelings and fruit stone extraction. After that, longitudinal cuts were made to obtain eight segments per fruit. The slices were immersed into the following treatment solutions: control (immersion in 2% ascorbic acid); 2% ascorbic acid + 2% calcium chloride; 1%... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Ascorbic acid; Calcium chloride; Cysteine; Citric acid; Isoascorbate. |
Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-29452011000400023 |
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Dawood, Mona Gergis. |
Ascobin had a promotion effect on growth and active constituents’ compounds of various plants under normal and stressed conditions. The physiological response of sunflower plant to foliar application of ascobin treatments (200,400,600 ppm) was investigated either under normal or salinity stressed conditions (5000 ppm NaCl solution) in pot experiments at the wire-house of the National Research Centre, Dokki, Cairo, Egypt. Data revealed that salinity stress caused significant decreases in shoot height, leaf area chlrorophyll b, carotenoids, total photosynthetic pigments, seed yield, yield components, oil and protein content of the yielded seeds relative to control. The decrease in oil percentage was more obvious by salinity than protein percentage. Since... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Helianthus annuus L.; Ascorbic acid; Citric acid; Seed quality; Antioxidant enzymes. |
Ano: 2018 |
URL: http://www.cigrjournal.org/index.php/Ejounral/article/view/4375 |
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Vandenberghe,Luciana P. S; Soccol,Carlos R; Pandey,Ashok; Lebeault,Jean-Michel. |
Citric acid is the most important organic acid produced in tonnage and is extensively used in food and pharmaceutical industries. It is produced mainly by submerged fermentation using Aspergillus niger or Candida sp. from different sources of carbohydrates, such as molasses and starch based media. However, other fermentation techniques, e.g. solid state fermentation and surface fermentation, and alternative sources of carbon such as agro-industrial residues have been intensively studied showing great perspective to its production. This paper reviews recent developments on citric acid production by presenting a brief summary of the subject, describing micro-organisms, production techniques, and substrates, etc. |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Citric acid; Aspergillus niger; Submerged fermentation; Solid state fermentation; Substrates. |
Ano: 1999 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89131999000300001 |
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Torrado,Ana María; Cortés,Sandra; Salgado,José Manuel; Max,Belén; Rodríguez,Noelia; Bibbins,Belinda P; Converti,Attilio; Domínguez,José Manuel. |
Valencia orange (Citrus sinensis) peel was employed in this work as raw material for the production of citric acid (CA) by solid-state fermentation (SSF) of Aspergillus niger CECT-2090 (ATCC 9142, NRRL 599) in Erlenmeyer flasks. To investigate the effects of the main operating variables, the inoculum concentration was varied in the range 0.5·10³ to 0.7·10(8) spores/g dry orange peel, the bed loading from 1.0 to 4.8 g of dry orange peel (corresponding to 35-80 % of the total volume), and the moisture content between 50 and 100 % of the maximum water retention capacity (MWRC) of the material. Moreover, additional experiments were done adding methanol or water in different proportions and ways. The optimal conditions for CA production revealed to be an... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Orange peel; Citric acid; Aspergillus niger; Solid-state fermentation. |
Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822011000100049 |
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Registros recuperados: 24 | |
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