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Effect of variety and cultivation technology on phenols and antioxidant activity of sweet and sour cherry
59-61.Views:1241The goal of the present work was to compare different sweet and sour cherry cultivars and cultivation methods (bio/integrated) with respect to polyphenol content and antioxidant activity. The concentration of total polyphenols ranged between 880–1050 mg kg-1 of fresh fruit, whereas antioxidant activity expressed as TEAC was found to be between 5.4 and 10.3 mmol kg-1 for the sweet cherry cultivars examined. In case of sour cherry the level of polyphenols ranged between 1283 and 3490 mg/kg fresh edible part of the fruit. Antioxidant activity was recorded between 15–32 mmol kg-1 for the different sour cherry cultivars included in this work. After one-month storage at low temperature, the total phenols and antioxidant activity decreased by 2–40% in the sour cherry cultivars studied. The anthocyanin content in cherry cultivars was less (131–312 mg kg-1) than the135–1893 mg kg-1 found in sour cherries. Anthocyanin level was higher in samples produced under organic farming conditions than in those produced with integrated cultivation.
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Bioactive phenols in leaves of Forsythia species
57-59.Views:428Nowadays a number of lignans (arctigenin, matairesinol, pinoresinol and phillygenin) have come to the fore in research due to their various biological activities. In this paper the accumulation of these constituents in leaf extracts of Forsythia plants (F. intermedia, F. ovata 'Robusta’ and `Tetragold', F. suspensa, F. viridissima) was quantified using a new isolation method, supercritical CO2 fluid extraction. The total phenolic and flavonoid contents, the antioxidant capacity and the aglycone lignan profile were determined in leaf extracts of Forsythia species. Within the phenols, the flavonoids were only present in small quantities, but the amount of aglycone lignans was extremely high. F. ovata `Robusta' had the highest total lignan content (103.8 mg/g) of all the Forsythia species. The main lignan in this species is arctigenin, which normally makes up about 60% of the total lignan content, but in the case of F. ovata `Robusta' this value was 96.1%. Since this arctigenin content is outstanding compared to that of other Forsythia species, it could be promising to develop a fermentation technology for the production of this natural compound.
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Comparative study of three rosemary (Rosmarinus officinalis L.) clones during the growing season
67-72.Views:597The growth rate of three rosemary clones, `Harmat', 'Salem' and `Horvát', their essential oil content and its components as well as the total phenol content and total antioxidant capacity in their aqueous and ethanolic extracts were compaired. Total phenol content (determined by Folin-Ciocalteau reagent) and antioxidant power (FRAP-value) of aqueous and ethanolic rosemary extracts were measured by spectrophotometric method. The essential oil content was determined from drug by water-steam distillation. `Harmat' showed the most intensive growth through the vegetation period. The total antioxidant power of the ethanolic extracts from all the three clones was similar: a decrease was observed at the end of the season. In most cases more antioxidant compounds were dissolved in the aqueous extracts. The total quantity of phenolic compounds shows a good correlation with the potential extent of stress effects. The difference among the phenol contents of the various clones can be derived from the difference in their tolerance, because phenols have antioxidant effects contributing to protection against harmful impacts. Difference between the two extraction methods (aqueous and ethanolic) is due to the distinct solubility of compounds. Some other components, like essential oil compounds also possess antioxidant effect and in this way they may influence the antioxidant power of extracts.
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Varietal variations in fruit quality parameters in strawberry (Fragaria×ananassa) harvested at different stages of color development
102-114.Views:32Present investigation reports the fruit quality of five strawberry cultivars (‘Rania’, ‘Winter Dawn’, ‘Winter Star’, ‘Camarose’ and ‘Navelia’) harvested at different stages of color development. These cultivars showed significant variations in their chemical composition. The highest and significant values of fruit weight, hue angle and total sugars were recorded in ‘Winter Star’ cultivar at full red stage. Total phenolics and ascorbic acid content were higher in ‘Camarose’ as compared to other cultivars. These parameters and reducing sugar content in strawberry fruits showed a direct relationship with DPPH radical scavenging activity. ‘Winter Star’ exhibited highest anthocyanin content form 25% red to full ripe red stage of fruit color development with most intensive color. Total soluble sugars, reducing sugars, pH, °Brix values increased from green to full red stage whereas titratable acidity showed the reverse trend. These cultivars showed significant differences in their physicochemical and biochemical composition at different stages of ripening in agroclimatic conditions of Punjab area of northwest India.
