Aktywność antyoksydacyjna herbat dostępnych na polskim rynku, otrzymywanych z liści Camellia sinensis (L.) Kuntze podczas róznych procesów produkcyjnych

The leaves of Camellia sinensis (L.) Kuntze are used to produce many types of tea; this variety results from the production process. The extracts, especially from teas rich in polyphenols, are also used in the prevention and treatment of certain diseases, in addition to their application for consumption. The aim of the study was to compare the antioxidant activity and total phenolic content in extracts from the following types of tea: white, green, oolong, black and Pu-erh. The aqueous and methanolic extracts from the teas were analysed by spectrophotometric methods. The method with the Folin-Ciocalteu reagent was used to determine total phenolic content; the antioxidant activity was investigated by means of the reaction with the DPPH radical. Total phenolic content and the antioxidant activity of examined extracts differed significantly. The alcoholic and aqueous extracts from white and green tea of the highest content of polyphenols (97.1–84.4 mg GAE/g) showed the greatest antioxidant activity (IC50 0.263–0.329 mg/ml), similar to that of BHA. The methanolic extracts from black and Pu-erh tea demonstrated much weaker activity. The antioxidant activity of extracts from investigated teas is closely correlated with content of polyphenolic compounds, which depends on the type of tea and the solvent used for extraction.Liście Camellia sinensis (L.) Kuntze są używane do produkcji wielu rodzajów herbat, których różnorodność wynika z procesu produkcyjnego. Wyciągi, zwłaszcza z herbat bogatych w polifenole, poza zastosowaniem spożywczym, są wykorzystywane również w profilaktyce i wspomaganiu leczenia niektórych chorób. Celem pracy było porównanie aktywności antyoksydacyjnej i zawartości sumy polifenoli w wyciągach z herbaty: białej, zielonej, oolong, czarnej i Pu-erh. Wyciągi wodne i metanolowe z herbat analizowano metodami spektrofotometrycznymi. Do oznaczenia sumy polifenoli użyto metody z odczynnikiem Folin-Ciocalteu, aktywność antyoksydacyjną badano w oparciu o reakcję z rodnikiem DPPH. Zawartość sumy polifenoli i aktywność antyoksydacyjna badanych ekstraktów znacznie się różniły. Wyciągi alkoholowe i wodne z herbaty białej i zielonej, o najwyższej zawartości polifenoli (97,1-84,4 mg GAE/ g), wykazywały też najwyższą, zbliżoną do BHA, aktywność przeciwutleniającą (IC50 0,263-0,329 mg/ml). Ekstrakty metanolowe z herbaty czarnej i Pu-erh posiadały wielokrotnie słabsze działanie. Aktywność antyoksydacyjna wyciągów z badanych herbat jest ściśle skorelowana z zawartością w nich związków polifenolowych, która zależy od rodzaju herbaty i użytego do ekstrakcji rozpuszczalnika

DPPH radical scavenging activity and phenolic compound content in different leaf extracts from selected blackberry species

We used DPPH scavenging assays to study the antioxidant activity of three native Polish species of blackberry leaves (Rubus kuleszae Ziel., R. fabrimontanus (Sprib.) Sprib. and R. capitulatus Utsch.). All the studied extracts (methanolic, water, methanolic-water) showed high DPPH free radical scavenging activity (IC50 450.0–186.0 μg/ml). The most effective of the studied species was Rubus kuleszae. Total content of phenolic compounds (70.50–136.04 mg GAE/g) and phenolic acids (14.70–38.26 mg CAE/g) was determined spectrophotometrically. Antioxidant activity correlated positively with total content of phenolic compounds and phenolic acids

Dpph Radical Scavenging Activity and Phenolic Compound Content in Different Leaf Extracts from Selected Blackberry Species

We used DPPH scavenging assays to study the antioxidant activity of three native Polish species of blackberry leaves (Rubus kuleszae Ziel., R. fabrimontanus (Sprib.) Sprib. and R. capitulatus Utsch.). All the studied extracts (methanolic, water, methanolic-water) showed high DPPH free radical scavenging activity (IC50 450.0–186.0 μg/ml). The most effective of the studied species was Rubus kuleszae. Total content of phenolic compounds (70.50–136.04 mg GAE/g) and phenolic acids (14.70–38.26 mg CAE/g) was determined spectrophotometrically. Antioxidant activity correlated positively with total content of phenolic compounds and phenolic acids

Variability of leaf morphology from generative and vegetative shoots of Rubus capitulatus and R. kuleszae (Corylifolii section, Rosaceae)

Leaves from generative and vegetative shoots of Rubus capitulatus and R. kuleszae of Corylifolii section were investigated. The study was to demonstrate the variability of leaves of both types of shoots, and at the same time an examination on the contents of polyphenols and phenolic acids in their blades carried out. Selected blade traits, such as was: length, width, elongation, perimeter, dissection index, area, rectangularity and circularity were measured using computer program and statistically analysed. Additionally, fresh and dry leaves were weighed and the percentage of preserved mass of particular samples was calculated. A statistical analysis revealed the area to be the most variable feature in both species and both types of shoots. Leaves from vegetative shoots were the most similar to each other and the length, width, perimeter and area were the most strongly correlated traits to each other. The leaves of generative shoots of both species contained less water than the leaves of vegetative ones