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Activation of phenylalanine ammonia lyase as a key component of the antioxidative system of salt-challenged maize leaves Braz. J. Plant Physiol.
Gholizadeh,Ashraf; Kohnehrouz,B. Baghban.
Differential antioxidative activities were assessed in the leaves of two maize inbreds (A-180 and A-619) under salt stress and the subsequent recovery period. Total antioxidation test revealed that in both inbreds, this ability was sharply increased during stress period, but was slowly reverted back to the normal level during recovery. The enzymatic antioxidative analysis showed differential patterns in the activities of catalase, peroxidase and polyphenol oxidase in both maize inbreeds. Comparative analysis of the activity of phenylalanine ammonia lyase (PAL), a key enzyme at the gateway of propanoid biosynthetic pathway, suggested that propanoid compounds might be antioxidants of pivotal importance to the salt-challenged maize antioxidation system. As...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Antioxidation; Maize; Salt stress; PAL; Catalase; Peroxidase; Polyphenol oxidase.
Ano: 2010 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202010000400001
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Activity of enzymes associated with the enzymatic browning of minimally processed potatoes BABT
Vitti,Maria Carolina Dario; Sasaki,Fabiana Fumi; Miguel,Patrícia; Kluge,Ricardo Alfredo; Moretti,Celso Luiz.
The purpose of the present study was to evaluate the effect of different potato cultivars and storage temperatures on the specific activity of phenylalanine ammonia-lyase (PAL), polyphenol oxidase (PPO) and peroxidase (POD) in minimally processed potatoes. Potato cultivars Agata, Asterix and Monalisa were selected, washed, peeled, diced, sanitized, centrifuged, vacuum- packed and stored at 5 and 15°C for 9 and 5 days, respectively. There was an increase in the enzymatic activity in all the cultivars stored at 15°C. The cultivars 'Agata' and 'Asterix' stored at 5ºC did not differ significantly between them for the PAL, PPO and POD activities. The PAL, PPO and POD activities were also influenced by the storage temperature. The cultivars Agata and Asterix...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Solanum tuberosum L; Phenylalanine ammonia-lyase; Polyphenol oxidase; Peroxidase; Minimal processing.
Ano: 2011 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132011000500016
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Cultivar affects browning susceptibility of freshly cut star fruit slices Scientia Agricola
Teixeira,Gustavo Henrique de Almeida; Durigan,José Fernando; Mattiuz,Ben-Hur; Alves,Ricardo Elesbão; O'Hare,Timothy James.
Consumption of freshly-cut horticultural products has increased in the last few years. The principal restraint to using freshly-cut carambola is its susceptibility to tissue-browning, due to polyphenol oxidase-mediated oxidation of phenolic compounds present in the tissue. The current study investigated the susceptibility to browning of star fruit slices (Averrhoa carambola L.) of seven genotypes (Hart, Golden Star, Taen-ma, Nota-10, Malásia, Arkin, and Fwang Tung). Cultivar susceptibility to browning as measured by luminosity (L*) varied significantly among genotypes. Without catechol 0.05 M, little changes occurred on cut surface of any cultivars during 6 hour at 25°C, 67% RH. Addition of catechol led to rapid browning, which was more intense in cvs....
Tipo: Info:eu-repo/semantics/article Palavras-chave: Averrhoa carambola L.; Cathecol; Polyphenol oxidase; Minimally processed; Fresh-cut.
Ano: 2006 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162006000100001
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Effect of Blanching on Enzyme Activity and Bioactive Compounds of Blackberry BABT
Noreña,Caciano Zapata; Rigon,Renata Trindade.
ABSTRACT The inactivation of peroxidase and polyphenol oxidase and the degradation of phenolic compounds, anthocyanins, and antioxidant activity in blackberry were investigated during blanching in water at 80-90 °C, and in steam, from 0 to 10 minutes. The enzyme kinetics indicated the presence of two isoenzymes with different thermal stability, following two-phase model, in which the reaction rate constant increased with increasing temperature for both the heat labile and heat resistant component. The phenolic compounds also followed a biphasic pattern, indicating a more heat resistant fraction, and the rate constants increased with increasing temperature. For the antioxidant activity and anthocyanins, the first order kinetic model (R2>0.982) indicated...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Peroxidase; Polyphenol oxidase; Phenolic; Anthocyanins.
Ano: 2018 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132018000100501
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Effect of Harvest Time and L-Cysteine as an Antioxidant on Flesh Browning of Fresh-Cut Cherimoya (Annona cherimola Mill.) Chilean J. Agric. Res.
Campos-Vargas,Reinaldo; Defilippi,Bruno G; Romero Q,Paula; Valdés G,Héctor; Robledo M,Paula; Prieto E,Humberto.
Browning development is the most important factor limiting the quality of fresh-cut cherimoya (Annona cherimola Mill.). However, there is little information available about its causes and methods of control. The effectiveness of L-cysteine (0.125, 0.25 and 0.5%) in fresh-cut cherimoya harvested on two occasions (October and November) and stored for 6 and 12 days at 0 °C was studied. In order to understand the biological basis of browning, polyphenol oxidase (PPO) enzyme activity and total phenolic content in fresh-cut pieces were measured. Quality measurements and sensory analysis indicated that 0.5% L-cysteine was somewhat effective in reducing browning development, without affecting other quality attributes. In terms of physiological parameters, PPO...
Tipo: Journal article Palavras-chave: Antioxidants; Polyphenol oxidase; Phenolics; Sensorial evaluation.
Ano: 2008 URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392008000300001
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Foliar application of Burkholderia sp. strain TNAU-1 leads to activation of defense responses in chilli (Capsicum annuum L.) Braz. J. Plant Physiol.
Madhavan,Srinivasan; Paranidharan,Vaikuntavasan; Velazhahan,Rethinasam.
Induction of phenolics, peroxidase (PO), polyphenol oxidase (PPO), chitinase and thaumatin-like proteins (TLP) in leaves of chilli (Capsicum annuum L.) in response to foliar application with a biocontrol agent Burkholderia sp. strain TNAU-1 was studied. Chilli plants, when sprayed with Burkholderia sp. strain TNAU-1 showed increase in phenolic content one day after application and the maximum accumulation was observed seven days after treatment. Three new peroxidase isozymes (PO-1, PO-2 and PO-3) were induced in chilli leaves upon treatment with Burkholderia sp. strain TNAU-1. The activity of all the peroxidases was at the maximum level three days after treatment and subsequently decreased. Protein extracts obtained from Burkholderia sp. strain TNAU-1...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Capsicum annuum; Chitinase; Induced resistance; Peroxidase; Phenolics; Polyphenol oxidase; Thaumatin-like protein.
Ano: 2011 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202011000400003
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in vitro response of Colletotrichum to chitosan. Effect on incidence and quality on tropical fruit. Enzymatic expression in mango Acta Agron. (Palmira)
Gutiérrez-Martínez,Porfirio; Bautista-Baños,Silvia; Berúmen-Varela,Guillermo; Ramos-Guerrero,Anelsy; Hernández-Ibañez,Alba María.
Abstract: Colletotrichum is considered one of the fungal genera with the greatest diversity of species of phytopathogenic fungi and with a wide range of hosts including tropical fruits. In this study, the concentration of chitosan applied was a key factor in the in vitro inhibition of the three Colletotrichum isolates with the most sensitive being the one from banana. Germination was the development stage most affected by the application of this polymer. At the end of 10 days of storage, control of anthracnose in soursop, mango and banana fruit was considerable with the application of 1 % chitosan, with 80 to 100 % inhibition. Likewise, the ripening process of fruit with and without chitosan was generally similar. Activity of the peroxidase (POD) and...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Antracnose; Anonna muricata; Mangifera indica; Musa acuminata; Peroxidase; Polyphenol oxidase.
Ano: 2017 URL: http://www.scielo.org.co/scielo.php?script=sci_arttext&pid=S0120-28122017000200282
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Inactivation of oxidative enzymes from avocado Geada pulp by high hydrostatic pressure. Repositório Alice
ALVES, M.; LIMA, R.; ROSENTHAL, A..
Tipo: Separatas Palavras-chave: Avocado; Hight pressure; Polyphenol oxidase; Enzimas oxidativas; Polpa de abacate Geada; Alta pressão hidrostática.; Peroxidase..
Ano: 2014 URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/1005691
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Phenotypic Characterization and Synthesis of Extracellular Catecholase from a Newly Isolated Bacterium Pseudomonas sp. BSC-6 BABT
Lugani,Yogita; Kauldhar,Baljinder Singh; Kaur,Navneet; Sooch,Balwinder Singh.
Abstract Catecholase (EC 1.10.3.1), an oxidoreductase enzyme is a key member of polyphenol oxidase family which catalyze the degradation of catechol. This enzyme possesses vast applications in diverse areas and is found in bacteria, fungi, mushrooms, higher plants, arthropods, amphibians and mammals. Catechol, a phenolic compound, is used as a starting material in the synthesis of various industrial compounds such as inhibitors, antioxidants, pesticides etc. The release of this phenolic compound in the environment causes toxicity to both flora and fauna. In the present studies, emphasis has been laid on isolation, screening and characterization of catechol degrading bacterium coupled with synthesis of catecholase enzyme. Further, the selected isolated...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Catecholase; Catechol; Polyphenol oxidase; Pseudomonas sp. BSC-6; Bioremediation.
Ano: 2019 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132019000100216
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Prevention of enzymatic browning of yacon flour by the combined use of anti-browning agents and the study of its chemical composition Ciênc. Tecnol. Aliment.
Rodrigues,Oscar Romero Lopes; Asquieri,Eduardo Ramirez; Orsi,Daniela Castilho.
Yacon roots present functional properties because of the high levels of fructooligosaccharides (FOS), which are considered as prebiotic fibers. In addition, yacon roots are rich in phenolic compounds. During the processing of yacon, the freshly cut surface undergoes rapid enzymatic browning. Control of enzymatic browning during processing is very important to preserve the appearance of yacon flour. In this study, it was evaluated the combined effect of anti-browning agents (ascorbic acid, citric acid and L-cysteine) on the inhibition of enzymatic browning of yacon, using Response Surface Methodology. The yacon pre-treated with anti-browning agents in concentrations of 15.0 mM for ascorbic acid, 7.5 mM for citric acid and 10.0 mM for L-cysteine was used for...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Fructooligosaccharide; Polyphenol oxidase; Ascorbic acid; Cysteine; Citric acid.
Ano: 2014 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-20612014000200008
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Purification and characterization of polyphenol oxidase from purslane Ciênc. Tecnol. Aliment.
GUL GUVEN,Reyhan; GUVEN,Kemal; MATPAN BEKLER,Fatma; ACER,Omer; ALKAN,Hüseyin; DOGRU,Mehmet.
Abstract The polyphenol oxidase (PPO) is an enzyme that is responsible for the enzymatic browning of fruits and vegetables. This is generally undesired process and need to be prevented in food technology. PPO from purslane was purified, characterised and the kinetic parameters for three substrates namely, catechol, L-Dopa and 4-methylcatechol were determined. The optimum pH and temperature values were found to be pH 7.0 and 50 °C, respectively using the catechol as substrate. The apparent molecular weight of the PPO from purslane was determined as high as 163 kDa by partially denaturing SDS-PAGE. Moreover, the inhibition kinetics of the purified PPO were determined, using both synthetic and natural inhibitors. Among inhibitors tested, ascorbic acid was the...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Portulaca oleracea; Polyphenol oxidase; Purification; Kinetics; Inhibitors.
Ano: 2017 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-20612017000300356
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The effects of storage temperature on the quality and phenolic metabolism of whole and minimally processed kale leaves Agronomy
Simões, Adriano do Nascimento; Moreira, Silvino Intra; Mosquim, Paulo Roberto; Soares, Nilda de Fátima Ferreira; Puschmann, Rolf.
We studied the effects of storage temperature on the activities of phenylalanine ammonia-lyase (PAL), peroxidase (POD) and polyphenol oxidase (PPO) in minimally processed kale (Brassica oleracea var. acephala) that was stored for 15 and 9 days at 5 ± 1ºC and 10 ± 1ºC, respectively. The main visual evidence for quality loss in whole leaves was yellowing and loss of turgescence. Minimally processed leaves presented significant browning, indicating increased POD and PPO activities. The PAL activity in minimally processed leaves stored at 5ºC was fourfold higher than that of whole leaves after two days of storage. We showed that minimal processing influenced PAL, POD and PPO activities. The activity of all enzymes studied increased during storage, indicating...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Brassica oleraceae cv. acephala; Escurecimento enzimático; Peroxidase; Polifenol oxidase; Fenilalanina amônioliase Fisiologia Pós-colheita Ciências Agrárias: 50000004; Fisiologia de Plantas Cultivadas: 50103067 Brassica oleracea cv. acephala; Enzymatic browning; Peroxidase; Polyphenol oxidase; Phenylalanine ammonia-lyase Fisiologia Pós-Colheita.
Ano: 2014 URL: http://periodicos.uem.br/ojs/index.php/ActaSciAgron/article/view/18123
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Ultrafiltration performance of PVDF, PES, and cellulose membranes for the treatment of coconut water (Cocos nucifera L.) Ciênc. Tecnol. Aliment.
Debien,Isabel Cristina do Nascimento; Gomes,Maria Thereza de Moraes Santos; Ongaratto,Ricardo Schmitz; Viotto,Luiz Antonio.
Ultrafiltration (UF) inhibits the enzymatic activity which is responsible for color changes of coconut water without the need for heat treatment. In the present study, UF performance in terms of the permeate flux and enzymatic retention of the coconut water was evaluated at laboratory unit (LU) and pilot unit (PU). The membranes studied were polyethersulfone 150 kDa (UP150), polyvinylidene fluoride 150 kDa (UV150) and cellulose 30 kDa (UC030). The UP150 membrane showed the best permeate flux. The UC030 membrane showed the lowest flux, but it resulted in 100% enzymatic retention, while the other membranes showed enzymatic retentions between 71 and 85%. The application of the UC030 in the pilot unit (PU) resulted in a flux value higher than that obtained in...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Coconut water; Polyphenol oxidase; Peroxidase.
Ano: 2013 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-20612013000400012
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Unequal distribution of pH, polyphenol content and polyphenol oxidase activity within Japanese processing potato tubers OAK
Hironaka, Kazunori; Shimizu, Akira; Koaze, Hiroshi; Yamamoto, Kazuo; Sato, Tadatoshi; Kojima, Michiyuki; Mori, Motoyuki; Tsuda, Shogo; 弘中, 和憲; 清水, 明; 小疇, 浩; 山本, 和夫; 佐藤, 禎稔; 小嶋, 道之; 森, 元幸; 津田, 昌吾.
The pH, polyphenol content and polyphenol oxidase (PPO) activity in stem end, middle, and bud end of Norin No. 1 potatoes, one of processing varieties in Japan, were measured to investigate their respective distributions. The stem end area had a higher pH and PPO activity in the three areas. This result points out that careful harvesting and postharvest handling are needed especially at the stem end area of potatoes because of its high PPO activity.
Palavras-chave: 分布; ジャガイモ; PH; ポリフェノール; ポリフェノールオキシダーゼ; Distribution; Potato tuber; Polyphenol; Polyphenol oxidase.
Ano: 2008 URL: http://ir.obihiro.ac.jp/dspace/handle/10322/2271
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Validation of spectrophotometric microplate methods for polyphenol oxidase and peroxidase activities analysis in fruits and vegetables Ciênc. Tecnol. Aliment.
SIGUEMOTO,Érica Sayuri; GUT,Jorge Andrey Wilhelms.
Abstract Enzymes polyphenol oxidase (PPO) and peroxidase (POD) play important roles in the processing of fruits and vegetables, since they can produce undesirable changes in color, texture and flavor. Classical methods of activity assessment are based on cuvette spectrophotometric readings. This work aims to propose, to validate and to test microplate spectrophotometric methods. Samples of apple juice and lyophilized enzymes from mushroom and horseradish were analyzed by the cuvette and microplate methods and it was possible to validate the microplate assays with satisfactory results regarding linearity, repeatability, accuracy along with quantitation and detection limits. The proposed microplate methods proved to be reliable and reproducible as the...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Microplate; Polyphenol oxidase; Peroxidase; Enzymatic assay; Apple juice.
Ano: 2017 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-20612017000500148
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