The purpose of the present work was to evaluate both the antioxidant response system and oxidative stress in leaves from bitter gourd (Momordica charantia L) subjected to NaCl, UV-B and water stresses at three different stages of plant growth: pre-flowering, flowering and post-flowering. Except for peroxidase (POX), all enzyme activities including superoxide dismutase (SOD), catalase (CAT), pol...

Abstract The cereal aphids Rhopalosiphum padi L. are serious pests on grain crops, reducing the quality and yield by direct feeding damage virus transmission. changes in physiological biochemical parameters of two wheat cultivars under aphid stress were investigated to understand aphid-resistance mechanisms. activity levels phenylalanine ammonia-lyase (PAL), peroxidase (POD), tyrosine (TAL), Ca...

The ascorbate content declined rapidly in broccoli (Brassica oleracea L. var. italica) florets, but not in the stem tissue, during post-harvest senescence. Ascorbate peroxidase (APX), ascorbate oxidase (AO), l-galactono-1,4-lactone dehydrogenase (GLDH), monodehydroascorbate reductase (MDAR), dehydroascorbate reductase (DHAR), and glutathione reductase (GR) were investigated in gene expression a...

polyphenol oxidase (ppo) activity varied in differentiation from hyphae to rhizomorph and croute in a. mellea. in undifferentiated hyphae there was not any ppo activity, while croute showed the highest activity. electrophoresis in the presence of sds allows the detection of intensive enzyme forms of ppo, and can also convert slower migrating enzyme forms to faster ones. some fluorescent compoun...

30 This study aimed to improve the shelf life of Chinese red bayberries using vacuum impregnation. 31 Vacuum pressure of 5 kPa for 15 min, atmospheric pressure for 10 min, an impregnation temperature of 32 20 °C, alone or in combination with isotonic sucrose solution, 1% food-grade disodium stannous citrate 33 (DSC), and 2% food-grade calcium ascorbate were used for vacuum impregnation. Quality...

This research investigated the role of oxidative enzymes in the defense response of sorghum, Sorghum bicolor (L.) Moench (Poales: Poaceae), to the sorghum shoot fly, Atherigona soccata Rondani (Diptera: Muscidae). Changes in polyphenol oxidase and peroxidase activity and total protein content were observed in resistant and susceptible sorghum genotypes in response to A. soccata feeding. Resista...

The activities of polyphenol oxidase (PPO) and peroxidase (POD) in hot pepper (Capsicum annuum L.) pericarp were evaluated using spectrophotometric method. The enzymes were extracted from the pepper pericarp 5 g with 20 mL of 0.1 M phosphate buffer solution pH 7. PPO and POD activities were determined using catechol and guaiacol as a substrate, respectively. The effects of the amounts of enzyme...

in order to better understand how to prevent enzymatic greenning, it is important to understand  kinetic properties of polyphenol oxidase.  we investigated the effect of sds on the rate of catechol oxidation by small cherry tomato partial purified ppo. ppo activity increased with increasing sds concentration. the most effective concentration of sds was 0.8, 1 and 1.25 mm in according to ph and ...

The electrochemistry of banana tissues on a carbon paste electrode modified with multi-walled carbon nanotubes (MWCNTs) is presented. Cyclic voltammetry is applied to investigate the direct electrochemistry of banana tissues i.e. a source of polyphenol oxidase (PPO). A redox couple with an anodic and counterpart cathodic peak is obtained. The influence of various parameters such as pH,...

aril browning threatens production, consumption, and exports of pomegranates, because affected fruit cannot be externally distinguished from healthy fruit. this study compared the mineral, biochemical composition, and related enzyme activities in affected brown arils with healthy ones in ‘malase saveh’ pomegranates. the results indicated that concentrations of cu in the aril and k, mg, and mn i...