Extraction conditions can greatly influence antioxidant capacity assays in plant food matrices

Evaluation of beetroot (Beta vulgaris L.) leaves during its developmental stages: a chemical composition study

“…The phenolic compounds may be responsible for the antioxidant activity; however, in the present study, this was not observed. In other studies on food matrices the relationship between phenolic compounds and antioxidant activity has been observed, as reported by Michiels et al (2012).…”

Anthocyanin profile of strawberry fruit as affected by extraction conditions

“…For extracting phenolic compounds, the most widely used solvents are water, ethanol, methanol, acetone, and their water mixtures, with or without acid. [25][26][27][28] In our study, anthocyanin contents of strawberry fruit were investigated for five different solvent types. The best anthocyanin content was found in acidified methanol.…”

Effect of freeze-drying and extraction solvents on the total phenolic contents, total flavonoids and antioxidant activity of different Rabbiteye blueberry genotypes grown in New Zealand

“…Kalt et al [13] found that acidification of extracting solvent by hydrochloric acid was not only enhancing extraction but also stabilized anthocyanin in the extracts and increased their antioxidant activity as measured by ORAC method. Recently, Michiels et al [25] showed that a small concentration of acetic acid in an extraction solvent had an influence on the total phenolic content and antioxidant activity of the plant extracts. Organic acids such as formic acid are more aggressive solvents than water alone and lead to higher extractability of phytochemicals.…”