Wyniki wyszukiwania - AGRO

1

Antioxidant activity of gallocatechin gallate and epigallocatechin gallate

100%

Muzolf-Panek M., Gliszczynska-Swigło A., Szymusiak H., Tyrakowska B.

Polish Journal of Food and Nutrition Sciences

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2011

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tom 61

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nr Suppl.1

2

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Phenolic compounds and antioxidant activity of Nepeta nuda subsp. Albiflora

100%

Teber I., Bursal E.

International Letters of Natural Sciences

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2020

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tom 79

Phenolic content and antioxidant activity of Nepeta nuda subsp. albiflora Boiss. were reported in this study. The ethanol and water extracts of Nepeta nuda subsp. albiflora were prepared and used for biochemical analyses. Antioxidant capacities of the extracts were evaluated by three different in vitro bioanalytical methods including a reducing antioxidant method and two radical scavenging antioxidant methods. The water and ethanol extracts of the plant sample were found to have effective antioxidant potentials. Phenolic content of Nepeta nuda subsp. albiflora was determined by high performance liquid chromatography (HPLC). Rosmarinic acid (182.0±4.5 µg/g), apigenin (84.5±57.6 µg/g), and quercetin (44.5±62.9 µg/g) were identified as major compounds in the ethanol extract of the plant sample. This study has a potential scientific base for further studies about Nepeta nuda subsp. albiflora related to plant biochemistry and plant based pharmacological industry.

3

Antioxidant activities of cinnamic and benzoic acid derivatives

100%

Szwajgier D., Pielecki J., Targonski Z.

Acta Scientiarum Polonorum. Technologia Alimentaria

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2005

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tom 04

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nr 2

Antioxidant and antiradical activities of cinnamic and benzoic acid derivatives, using different methods, were investigated. The total antioxidant effect was evaluated using method with linoleic acid-water emulsion. The ability to scavenge free radicals was checked using 2,2 -azinobis-3-ethylbenzothiazoline-6-sulphonic acid (ABTS*) or 2,2-di- phenyl-1-picrylhydrazyl radical (DPPH*). The reducing power of the studied compounds solutions was also evaluated. It was stated, that the applied measuring method strongly influenced the obtained result, because in the system with ABTS* free radicals, the highest antioxidant activities possessed vanillic, sinapic and protocatechuic acid, whereas the most effective DPPH* radical scavengers were methyl ferulate, methyl syringate, syringaldéhyde and vanillic acid. In another method, linoleic acid peroxidation was effectively inhibited by the caffeic, sinapic and syringic acid. The highest reducing powers possessed protocatechuic acid, caffeic, sinapic and ferulic acid, higher than BHT and comparable to Trolox. Methylated derivatives of coumaric acid, caffeic acid, vanillic acid and syringic acid turned out to be weaker antioxidants and reducing agents than the free forms, except methyl ferulate, which possessed only slightly lower antioxidant activity than free ferulic acid, and in some measuring systems was a more effective antioxidant than ferulic acid.

4

Antioxidant activity of berry fruits and beverages

100%

Borowska J., Szajdek A.

Polish Journal of Natural Sciences

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2003

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tom 14

5

Antioxidant activity of hemoglobin

100%

Falcioni G., Caulini G. C., Fedeli D., Santroni A. M., Gabbianelli R., Kantar A.

Polish Journal of Environmental Studies

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1998

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tom 07

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nr 6

6

Plant extracts as cosmetic ingredients

88%

Malinowska P., Szymusiak H.

Towaroznawcze Problemy Jakości. Polskie Towarzystwo Towaroznawcze

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2008

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nr 2

33-40

7

Antioxidant activities and polyphenolics content of Flammulina velutipes mushroom extracts

88%

Slawinska A., Radzki W., Kalbarczyk J.

Herba Polonica

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2013

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tom 59

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nr 3

A study was conducted in order to determine the content of phenolic compounds and antioxidative activity of extracts from Flammulina velutipes. Water and ethanolic, methanolic, acetone (70% v/v) extracts were prepared from lyophilized fruiting bodies of mushrooms. Different extraction techniques were used: ultrasonication and stirring by a rotary shaker at ambient temperature and at 50oC, and at boiling point for each solvent. Next, total phenolics by Folin-Ciocalteu method, antioxidant capacity (EC) by ferric reducing antioxidant power assay (FRAP) and scavenging ability on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals were analysed in these extracts. It was observed that the extraction method and the kind of solvent influenced the antioxidant activity and concentration of total phenolics in the extracts. The highest concentration of phenolic compounds (7.58±0.17 mg GAE/g extract) were observed for water extract prepared with use of ultrasonification method (at 50oC for 1h). Results showed that water extracts possessed high equivalent capacity (EC) for all applied extraction methods. The highest EC value (9.2±0.18 mM Fe2+/g extract) was observed in water extract prepared by stirring at ambient temperature for 1 h. This extract was characterized by high level of total phenolics. The acetone extracts, prepared by ultrasonic extraction at 50oC for 1 h, at 10 mg/ml showed the highest scavenging activity (57.53±1.18%), although, the value was lower than that of ascorbic acid at 10 mg/ml (60.50±1.32%).

8

Antiradical activity of ciders

88%

Foltyniewicz M., Kiewlicz J., Zielinski R.

Towaroznawcze Problemy Jakości. Polskie Towarzystwo Towaroznawcze

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2017

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nr 3

9

Fruit maturity phenolic content and antioxidant activity of Eugenia jambolana Lam. fruit

88%

Balamurugan S.

International Letters of Natural Sciences

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2014

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tom 08

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nr 1

Fruits of Eugenia jambolana were analysed for total phenolics and antioxidant activity of three successive development stages viz. 1. Mature green 2. Half - ripened and 3. Fully ripened. The total anthocyanin concentrations were higher in fully ripened stage, the total phenolic content was maximum achieved in mature green stage (354 mg L-1). Antioxidant activity also strongly depended on ripening stages, showing completely opposite compared to that of total phenolics. Since total phenolics and antioxidant activity performed nearly “Object and its reflection in the mirror” trend.

10

Effect of long-term storage on antioxidant activity of walnut cake

88%

Binczak O., Samotyja U.

Towaroznawcze Problemy Jakości. Polskie Towarzystwo Towaroznawcze

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2018

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nr 2

11

Antioxidant activity and total phenolic content of Rheum palmatum roots

88%

Sokol-Letowska A., Kucharska A. Z., Biesiada A.

Herba Polonica

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2009

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tom 55

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nr 3

200-205

The aim of our work was to investigate the antioxidant activity of Rheum palmatum extracts. Antiradical activity against DPPH and ABTS radicals, reducing power FRAP and total phenolic contents, were investigated in one-, two- and three-year-old roots of rhubarb fertilized with nitrogen at the rates of 50, 100 and 200 kg N/ha. It was proved that nitrogen dose as well as the age of plantation did significantly influence antioxidant activity and total phenolic of root extracts. The highest values were determined in one-year-old plants, antioxidant activity ranged the level of 112–203 µM Trolox/g and total phenolic compounds average content was 22 mg GAE/g FW. Two-year-old roots were characterized by 3–11%, and three-year-old ones by 15–23% lower antioxidant activity and phenolic compounds content. When nitrogen dose increased, polyphenols content, DPPH and FRAP values increased as well, although, ABTS showed a different tendency.

12

Assessing polyphenols content and antioxidant activity in coffee beans according to origin and the degree of roasting

88%

Dybkowska E., Sadowska A., Rakowska R., Debowska M., Swiderski F., Swiader K.

Roczniki Państwowego Zakładu Higieny

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2017

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tom 68

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nr 4

Background. The roasting stage constitutes a key component in the manufacturing process of natural coffee because temperature elicits changes in bioactive compounds such as polyphenols and that Maillard-reaction compounds appear, thus affecting the product’s sensory and antioxidant properties. Actual contents of these compounds may depend on which region the coffee is cultivated as well as the extent to which the beans are roasted. Objectives. To determine polyphenols content and antioxidant activity in the ‘Arabica’ coffee type coming from various world regions of its cultivation and which have undergone industrial roasting. Also to establish which coffee, taking into account the degree of roasting (ie. light, medium and strong), is nutritionally the most beneficial. Materials and Methods. The study material was natural coffee beans (100% Arabica) roasted to various degrees, as aforementioned, that had been cultivated in Brazil, Ethiopia, Columbia and India. Polyphenols were measured in the coffee beans by spectrophotometric means based on the Folin-Ciocalteu reaction, whereas antioxidant activity was measured colourimetrically using ABTS+ cat-ionic radicals. Results. Polyphenol content and antioxidant activity were found to depend both on the coffee’s origin and degree of roasting. Longer roasting times resulted in greater polyphenol degradation. The highest polyphenol concentrations were found in lightly roasted coffee, ranging 39.27 to 43.0 mg/g, whereas levels in medium and strongly roasted coffee respectively ranged 34.06 to 38.43 mg/g and 29.21 to 36.89 mg/g. Antioxidant activity however significantly rose with the degree of roasting, where strongly roasted coffee had higher such activity than lightly roasted coffee. This can be explained by the formation of Maillard-reaction compounds during roasting, leading then to the formation of antioxidant melanoidin compounds which, to a large extent, compensate for the decrease in polyphenols during roasting. Conclusions. Polyphenols levels and antioxidant activities in the studied Arabica coffee beans that had undergone roasting depended on the cultivation region of the world. Longer roasting caused a significant decline in polyphenols compound levels (from 7.3% to 32.1%) in the coffee beans. Antioxidant activities of coffee increased with roasting, despite reduced levels of natural antioxidants. From a nutritional standpoint, the most favoured coffees are those lightly or medium roasted.

13

Comparison of antioxidant activity of selected commercial cosmetic plant roots extracts

88%

Malinowska P., Kiewlicz J.

Towaroznawcze Problemy Jakości. Polskie Towarzystwo Towaroznawcze

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2017

|

nr 2

14

Effect of flavonoids content on antioxidant activity of commercial cosmetic plant extracts

88%

Malinowska P.

Herba Polonica

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2013

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tom 59

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nr 3

The aim of this work was to evaluate the antioxidant capacity and flavonoids content in 10 commercial cosmetic plant extracts used in cosmetics industry. Antioxidant activity of plant extracts were measured using two methods: FRAP (Ferric Reducing Antioxidant Power) and TEAC (Trolox Equivalent Antioxidant Capacity). The relationship between flavonoids content and antioxidant capacity of plant extracts were checked. As a result of this research it was found that FRAP and TEAC values of plant extracts significantly depend on the flavonoids content. The highest antioxidant activity, both in FRAP and TEAC assays, was observed for arnica flowers, hawthorn flowers and lungwort herb extracts. These extracts can be used as source of natural antioxidants for the prolongation of the oxidative stability of cosmetic products. Additionally, they can replace synthetic antioxidants.

15

Evaluation of the effect of roasted constituents on the antioxidant activity of cereal coffee

88%

Klensporf-Pawlik D., Majcher M., Frackowiak K.

Towaroznawcze Problemy Jakości. Polskie Towarzystwo Towaroznawcze

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2017

|

nr 1

16

The antioxidant activity of new ammonium salts

88%

Gabrielska J., Przestalski S., Witek S.

Biophysics of Membrane Transport

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1994

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tom 12

|

nr 2

17

Antimicrobial and antioxidant activity of the polyphenol mangiferin

88%

Stoilova I., Gargova S., Stoyanova A., Ho I.

Herba Polonica

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2005

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tom 51

|

nr 1-2

The antimicrobial effect of the polyphenol mangiferin obtained from leaves of mango tr was studied according to the diffusion method. The solutions of mangiferin in polyetl ene glycol-400 showed an activity with regard to seven bacterial and five fungal spec - Bacillus pumilus, Bacillus cereus, Staphylococcus aureus, Staphylococcus citreus, Escherichia ( Salmonella agona, Klebsiella pneumoniae, Saccharomyces cerevisiae, Thermoascus aurantiai Trichoderma reesei, Aspergillus ßavus and Aspergillus fiimigatus. Its antioxidant activity w regard to the free radical 2,2-diphenyl-l-picrylhydrazyl (DPPH) was also studied, as concentration of mangiferin causing 50% inhibition of the free radical (ICS0) was assa; to be 7.5 ± 0.0075 jug/ml.

18

The influence of chosen isoflavones on the properties of model bilayers

88%

Lania-Pietrzak B., Zugaj J., Shirataki Y., Michalak K.

Cellular and Molecular Biology Letters

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2002

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tom 07

|

nr Suppl.

19

Grapevine leaves as a source of natural antioxidants

88%

Amarowicz R., Narolewska O., Karamac M., Kosinska A., Weidner S.

Polish Journal of Food and Nutrition Sciences

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2008

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tom 58

|

nr 1

The crude extracts of phenolic compounds were obtained from grapevine leaves using 80% acetone and 80% methanol (v/v). The content of total phenolic and condensed tannins was determined using Folin & Ciocalteau’s phenol reagent, vanillin/HCl reagent, and protein precipitation method. The antioxidant properties of the extracts were investigated using the total antioxidant activity (TAA), DPPH radical scavenging activity and reducing power. The content of individual phenolic acids was determined using the HPLC method. The content of total phenolics in grapevine leaves and their extracts determined in this study was high (257 mg/g acetone extract and 232 mg/g methanolic extract). The content of condensed tannins in acetone extract was higher than in the methanolic one. Antiradical activity of both extracts against DPPH radical and reducing power were similar and strong. The acetone and methanolic extracts exhibited TAA of 1.37 and 1.44 mmol Trolox/g, respectively. Vitis vinifera leaves extracts were observed to contain gallic, caffeic, and p-coumaric acid. Gallic acid was a dominant phenolic acid. The majority of phenolic acids were found in the form of esters.

20

Effect of storage conditions on antioxidant activity of bee pollen extracts

75%

Rzepecka-Stojko A., Drzal A., Stojko J., Buszman E.

Medycyna Weterynaryjna

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2014

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tom 70

|

nr 12

Bee pollen is a product of rich and varied chemical composition, and its biological activities are diverse. Many of these activities are related to the antioxidant effect of bee pollen. The aim of this study was to determine the effect of storage conditions on the antioxidant activity of bee pollen extracts. The study was conducted on three types of bee pollen extracts, namely, ethanol and pepsin extracts of bee pollen, as well as on ethanol extracts of pepsin-digested bee pollen. Antioxidant activity was determined by a DPPH method, directly after obtaining the extracts and after storing them for twelve months under various conditions, i.e. at –18°C in the dark, at 4-8°C in the dark, at room temperature in the dark, and at room temperature in the light. It was concluded that the 12-month storage of bee pollen extracts caused a decrease in the antioxidant activity of all extracts examined, and the decrease depended on storage conditions. The highest decrease in antioxidant activity was observed in all types of extracts stored at room temperature in the light. The lowest decrease in antioxidant activity was found in ethanol extracts of pepsin-digested bee pollen.

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