Search results for "Catechol oxidase"
showing 4 items of 44 documents
SALINITY EFFECTS ON ENZYMATIC BROWNING AND ANTIOXIDANT CAPACITY OF FRESH-CUT BABY ROMAINE LETTUCE (LACTUCA SATIVA L. CV. DUENDE)
2010
Abstract Enzymatic browning is a main problem encountered in minimal processing and further storage of leafy vegetables, leading to shorter shelf-life of products. Changes in the two oxidative activities, polyphenol oxidase (PPO) and peroxidase (POD), as well as in total phenolic content, colour parameters and antioxidant capacity (assayed with ORAC method), were monitored during 10 days of storage at 4 °C of minimally processed baby Romaine lettuce ( Lactuca sativa L. cv. Duende) cultivated under three different salinity conditions (2.8, 3.8 and 4.8 dS m −1 ), in order to determine the most suitable condition for further processing. Increasing levels of salinity reduced both oxidases activ…
Wound-induced responses in leaves of strawberry cultivars differing in susceptibility to spider mite
2002
Summary The effect of leaf detachment and wounding on the activities of oxidative enzymes and ethylene production was studied in strawberry (Fragaria × ananassa) cultivars, differing in susceptibility to the spider mite (Tetranychus urticae Koch.). Strawberry plants were cultivated during winter in two growth conditions - with and without overwintering, in greenhouse and laboratory, respectively. Polyphenol oxidase activity, peroxidase activity and catalase activity in strawberry leaves depended on the cultivar analysed, type of treatment (detachment or detachment and wounding), as well as on plant growth conditions. Activities of all analysed enzymes were higher in control plants grown in …
Changes of morphogenic competence in mature Pinus sylvestris L. buds in vitro.
2002
The effects of season and cold storage on morphogenic competence in mature Pinus sylvestris buds were investigated. Peroxidase and polyphenol oxidase activity were measured as markers of oxidative metabolism. No growth in vitro was observed on explants detached from the end of January until the beginning of March. Brachioblasts, each with a couple of needles, formed on 11 % of the buds without macrostrobili that were detached in early April and introduced immediately into culture. Of the explants detached in late July, 15 % formed shoots with brachioblasts and needles. The lowest activity of peroxidase and polyphenol oxidase in pine buds was observed from the end of April until the beginnin…
Kinetic properties of catecholoxidase activity of tarantula hemocyanin
2008
Phenoloxidases occur in almost all organisms, being essentially involved in various processes such as the immune response, wound healing, pigmentation and sclerotization in arthropods. Many hemocyanins are also capable of phenoloxidase activity after activation. Notably, in chelicerates, a phenoloxidase has not been identified in the hemolymph, and thus hemocyanin is assumed to be the physiological phenoloxidase in these animals. Although phenoloxidase activity has been shown for hemocyanin from several chelicerate species, a characterization of the enzymatic properties is still lacking. In this article, the enzymatic properties of activated hemocyanin from the tarantula Eurypelma californi…