Antioxidant effect of various rosemary (Rosmarinus officinalis L.) clones

The antioxidant effects, the levels of total phenol and the total phenol contents of volatile oils and plant extracts were determined in eight various Rosemary (Rosmarinus officinalis L.) clones. Antioxidant acitvities and the total phenol contents were measured by spectophotometric method as well as the volatile oil content of the fresh plants with gas chromatograph. Our preliminary results clearly indicate that the antioxidant capacity of volatile oils and plant extracts closely related to the total phenol contents. Reason of the observed differences should be revealed by the determination of the quantity and quality of the individual volatile oil components

Morphological, chemical and biochemical characterization of St. John's Wort (Hypericum perforatum L.) hybrids

After several years of inbreeding, we concluded that combination of advantageous properties of Hypericum perforatum lines is necessary. Two hybrids were established by reciproc crossing a d their populations have been tested in the second year. Concerning drug production, hybrid F9 exceeded both parents. In the case of hypericin content, crossing resulted in the manifestation of mother's effect. Hypericin content was higher in flowers, while POD accumulated mainly in leaves. Alterations of them in the mentioned parts proved to be inverse: the level of hypericin increased and that of the POD decreased from vegetative to flowering phase. The content of glucose and fructose changed by organs during ontogenesis, their ratio in flowers increased. There were significant differences among taxa investigated: parent 35 and hybrid F16 showed lower values of POD and glucose in average, which may be in connection with their weaker tolerance against wilt disease

Correlation between antioxidant capacity and total polyphenol content in fruit juice concentrates

In our current research, the total polyphenol content and antioxidant capacity of 6 types of 65% fruit juice concentrates (pomegranate, red grapes, oranges, lemons, apples, pineapples) were investigated and compared with TEAC and FRAP methods. For each juice concentrate, a significant relationship was found between the total polyphenol content and the antioxidant capacity: the most outstanding values were measured for pomegranates, followed by red grapes, followed by oranges and lemons. At the same time, the TPC and FRAP values of apple and pineapple were significantly lower compared to the other 4 types of juice concentrates

A review of nutritional value and putative health-effects of quince (Cydonia oblonga Mill.) fruit

Quince (Cydonia oblonga Mill.) has been long regarded to be a health-promoting fruit. Although it is mainly consumed in processed form, its relatively heat-stable polyphenolics were confirmed to be responsible for most of the beneficial effects. This review aims to show basic nutritional information on quince fruit such as carbohydrate, fibre, pectin and mineral element contents. In addition, vitamin and polyphenolic contents and composition as well as the physiological effects of quince consumption were also surveyed. Information on presumable protective effects against several diseases including inflammation, atopic dermatitis, ulcers and cancer is summarized. Potential antibacterial effects of quince polyphenolics were also considered. Polyphenolics are supposed to be responsible for the major part of beneficial health-effects, and phenolic compounds predominantly accumulate in peel. There exists a considerable extent of genetic variation in phytochemical composition among cultivars, which might be exploited in designing future breeding programs for quince improvement and opening new ways for health-related uses

Presumable protective role of peroxidase and polyphenol oxidase enzymes against freezing stress in peach (Prunus persica /L./ Batsch)

Antioxidant enzymes have important roles in inactivation of the active oxygen forms induced by the different stresses. During winter, the over-wintering organs of peach are exposed to severe chilling temperatures. Our aim was to study the role of two antioxidant enzymes in the protection mechanisms against freezing injuries in three peach genotypes representing contrasting levels of cold hardiness. The activity of these two antioxidant enzymes in the different plant tissues increased during the first half, while decreased during the second half of the dormancy period. Due to the cold spells during ecodormancy the activity of antioxidant enzymes increased again in some sample. This phenomenon was mostly characteristic to the cold tolerant genotypes. In floral buds the activity of polyphenol-oxidase changed to a greater extent, while in the vegetative tissues it was the peroxidase enzyme showing a greater change. Thus to establish the exact role of antioxidant enzymes in abiotic stress tolerance requires further detailed investigations

Change of peroxidase enzyme activities in annual cuttings during rooting

The peroxidase enzyme (POD) activities (U/mg protein) were measured by spectrophotometric method in different organs of some annual ornamental plant cuttings during rooting period. The examined species were Lantana camara L. "Schneewittchen", Lantana camara L "Prof. Raoux", Heliotropium arborescens L. an d Helichrysum stoechas (L.) Moench. Rooting of cuttings was more than 90% at all species. The POD enzyme activities increased from the top towards the base of cuttings at all species and in all measuring dates. The highest POD activities were in the base measured one week after cutting, these values decreased in connection with the root formation in all cases. In the case of Helichrysum stoechas the rooting took much longer time while it was shown in the ten times lower POD enzyme activities in all measuring dates