|
|
|
Registros recuperados: 13 | |
|
|
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 |
| |
|
|
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 |
| |
|
|
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 |
| |
|
|
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 |
| |
|
| |
|
| |
|
|
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 |
| |
|
|
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 |
| |
|
|
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 |
| |
|
| |
|
| |
|
|
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 |
| |
|
|
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 |
| |
Registros recuperados: 13 | |
|
|
|