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Thermodynamic properties of water sorption isotherms of grape seed

100%

Majd K. M., Karparvarfard S. H., Farahnaky A., Ansari S.

International Agrophysics

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2014

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tom 28

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nr 1

In this study the moisture sorption isotherm of grape seed was determined by using a static gravimetric method at 35-65°C and 0.108-0.821 water activity range. The sorption isotherms were found to be typical sigmoid shape of most food materials. Five models including the Brunauer-Emmett-Teller (2-parameter), Guggenheim, Anderson and De Boer (3-parameter), Oswin (2-parameter), Ferro-Fontan (3-parameter) and Peleg (4-parameter) models were considered to fit the experimental data. The Ferro- Fontan and Peleg equations (at three temperatures 35, 45, 65°C) having R2 greater than 0.97 and lower values of standard error of estimate and deviation modulus gave the best fit of the experimental data throughout the entire range of water activity. The net isosteric heat of sorption, calculated by Calusius-Clapeyron equation on experimental data, was found to be a polynomial and exponential function of equilibrium moisture content within the temperature range investigated.

2

Protective effect of grape seed and skin extract on garlic-induced erythrocyte oxidative stress

84%

Hamlaoui S., Mokni M., Limam N., Zouaoui K., Ben Rayana M. C., Carrier A., Limam F., Amri M., Marzouki L., Aouani E.

Journal of Physiology and Pharmacology

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2012

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tom 63

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nr 4

3

Assessment of antioxidants by HPLC-MS in grapevine seeds

67%

Sochorova L., Klejdus B., Mojmir B., Tunde J., Mlcek J., Sochor J., Ercisli S., Kupe M.

Acta Scientiarum Polonorum. Hortorum Cultus

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2019

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tom 18

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nr 6

It is well known, that grapevine seeds are rich in significant antioxidants. However, the issue of dealing with the analysis and comparison of antioxidant components in the seeds of Vitis vinifera L. in individual cultivars has not yet been sufficiently studied. The experiment was performed with extracts of three varieties (Blaufränkish, Italian Riesling and Cabernet Moravia) and three interspecific cultivars (Nativa, Marlen and Kofranka). Contents of nine major flavonoids (apigenin, astragalin, hyperoside, isorhamnetin, kaempferol, myricetin, quercetin, quercitrin and rutin) and two procyanidins (procyanidin A2 and procyanidin B1) were assessed by the HPLC/MS method. The highest contents of antioxidants were found out in interspecific cultivars Marlen and Nativa while the lowest one was assessed in the cultivar Cabernet Moravia. The most represented flavonoid was hyperoside (cultivar Marlen – 15.66 mg∙l–1), least represented was kaempferol (cultivar Cabernet Moravia – 1.81 µg∙l–1).

4

Stabilization of erythrocytes against oxidative and hypotonic stress by tannins isolated from sumac leaves (Rhus typhina L.) and grape seeds (Vitis vinifera L.)

67%

Olchowik E., Lotkowski K., Mavlyanov S., Abdullajanova N., Ionov M., Bryszewska M., Zamaraeva M.

Cellular and Molecular Biology Letters

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2012

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tom 17

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nr 3

Erythrocytes are constantly exposed to ROS due to their function in the organism. High tension of oxygen, presence of hemoglobin iron and high concentration of polyunsaturated fatty acids in membrane make erythrocytes especially susceptible to oxidative stress. A comparison of the antioxidant activities of polyphenol-rich plant extracts containing hydrolysable tannins from sumac leaves (Rhus typhina L.) and condensed tannins from grape seeds (Vitis vinifera L.) showed that at the 5–50 μg/ml concentration range they reduced to the same extent hemolysis and glutathione, lipid and hemoglobin oxidation induced by erythrocyte treatment with 400 μM ONOO− or 1 mM HClO. However, extract (condensed tannins) from grape seeds in comparison with extract (hydrolysable tannins) from sumac leaves stabilized erythrocytes in hypotonic NaCl solutions weakly. Our data indicate that both hydrolysable and condensed tannins significantly decrease the fluidity of the surface of erythrocyte membranes but the effect of hydrolysable ones was more profound. In conclusion, our results indicate that extracts from sumac leaves (hydrolysable tannins) and grape seeds (condensed tannins) are very effective protectors against oxidative damage in erythrocytes.

5

Metabolism of phenolic compounds in Vitis riparia seeds during stratification and during germination under optimal and low temperature stress conditions

67%

Wrobel M., Karamac M., Amarowicz R., Fraczek E., Weidner S.

Acta Physiologiae Plantarum

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2005

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tom 27

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nr 3A

We studied the alterations in phenolic compounds in grape seeds during their stratification and germination under optimal conditions (+25 °C) and at low temperature (+10 °C). Biological materials in the study were seeds of Vitis riparia. Phenolic compounds were extracted from defatted seeds using 80 % methanol or 80 % acetone. The content of total phenolics was determined with the Folin-Ciocalteau reagent, while the content of tannins was determined by vanillin assay and the protein (BSA) precipitation method. The RP - HPLC method was used to determine phenolic compounds (phenolic acids, catechins) in the extracts. High amounts of tannins, catechins, gallic acid and lesser amounts of p-coumaric acid were found in the seeds. The content of total phenolics in acetone extracts was higher than that obtained using methanol. The amounts of phenolic acids and tannins found in V. riparia seeds after stratification were much lower. It may confirm a possible role of these compounds in dormancy of V. riparia seeds. After 72 h of low temperature treatment, inhibition of grape root growth and biochemical changes in seeds were detected. The chilling stimulated increased accumulation of some phenolic compounds (free gallic acid and catechins) in the seeds. These substances can protect plants against some abiotic stressors.

Ograniczanie wyników

Thermodynamic properties of water sorption isotherms of grape seed

Protective effect of grape seed and skin extract on garlic-induced erythrocyte oxidative stress

Assessment of antioxidants by HPLC-MS in grapevine seeds

Stabilization of erythrocytes against oxidative and hypotonic stress by tannins isolated from sumac leaves (Rhus typhina L.) and grape seeds (Vitis vinifera L.)

Metabolism of phenolic compounds in Vitis riparia seeds during stratification and during germination under optimal and low temperature stress conditions