Effect of nitrogen fertilisation and irrigation on phenolic content, phenolic acid composition, and antioxidant activity of winter wheat grain

The antioxidant activity and content of phenolic substances in vegetable broths were determined. Green beans, beetroots, courgettes, onions, parsley, carrots, cabbages, celery, broccoli, spinach, cauliflowers, and tomatoes were subjected to boiling. Fresh vegetables and vegetable broths were analysed for ascorbic acid content, total phenolic content, ORAC and TEAC values. Phenolic acids were quantified using HPLC. The ascorbic acid content of vegetables ranged from 5–109 mg/100 ml, while no ascorbic acids could be detected in vegetable broths. Total phenolic content was between 17–1729 mg GAE/l for all samples. ORAC and TEAC values of vegetable broths were between 0–3 µmol TE/ml and 0–2 µmol TE/ml, respectively. Gallic, chlorogenic, caffeic, p-coumaric, and ferulic acid were detected in both fresh vegetables and vegetable broths. The highest phenolic acid content was observed in water in which beetroots were boiled. It was found that the vegetable broths of beetroots, celery stalks, cabbages, parsley and broccoli harboured remarkable antioxidant activity.

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Antioxidant activity and phenolic acid composition of South African herbal remedies

Toxicology Letters ◽

10.1016/j.toxlet.2010.03.533 ◽

2010 ◽

Vol 196 ◽

pp. S155

Author(s):

M. Gulumian ◽

O. Nkwaner ◽

J. Van Tonder ◽

V. Steenkamp

Keyword(s):

Antioxidant Activity ◽

South African ◽

Acid Composition ◽

Phenolic Acid ◽

Herbal Remedies

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ANTIOXIDANT ACTIVITY AND PHENOLIC COMPOSITION CHANGES IN SWEETPOTATO ROOT AND LEAF TISSUE DURING DEVELOPMENT

HortScience ◽

10.21273/hortsci.41.3.498c ◽

2006 ◽

Vol 41 (3) ◽

pp. 498C-498

Author(s):

M.S. Padda ◽

D.H. Picha

Keyword(s):

Antioxidant Activity ◽

Chlorogenic Acid ◽

Phenolic Acid ◽

Total Phenolic Content ◽

Phenolic Content ◽

Total Phenolic ◽

Root Weight ◽

Tissue Weight ◽

Stage Of Development ◽

Leaf Tissues

Antioxidant activity and phenolic content of sweetpotato root and leaf tissues were quantified at different developmental stages. 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical method was used to measure antioxidant activity and total phenolic content was quantified by spectrophotometry using Folin-Denis reagent. Individual phenolic acids were quantified using reversed phase high performance liquid chromatography. Antioxidant activity and phenolic content decreased with root development and leaf maturity. Roots at the initial stages of development (about 4.0 g root weight) had a higher antioxidant activity and phenolic content compared to fully developed roots. Phenolic content in fully developed roots was significantly higher in the cortex tissue than internal pith tissue. The highest total phenolic content and antioxidant activity was found in cortex tissue at the initial stage of development (10.3 mg chlorogenic acid eq/g dry tissue weight and 9.7 mg Trolox eq/gdry tissue weight, respectively). Sweetpotato leaves had a significantly higher phenolic content and antioxidant activity than roots. Immature unfolded leaves had the highest total phenolic content (88.5 mg chlorogenic acid eq/g dry tissue weight) and antioxidant activity (99.6 mg Trolox eq/g dry tissue weight). Chlorogenic acid was the major phenolic acid in root and leaf tissues with the exception of young immature leaves in which the predominant phenolic acid was 3,5-dicaffeoylquinic acid.

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