No abstract

No abstract

No abstract

In this study, the extraction of phenolic antioxidants from red corn cob was carried out using ultrasound-assisted extraction (UAE). The solid:liquid ratio and extraction time were evaluated when obtaining these bioactive compounds. The total phenolic contents were evaluated using the Folin Ciocalteu method, while the antioxidant activity was measured by ABTS•+ and DPPH• assays. The amount of phenolic compounds ranged from 215.17 ± 33.49 to 527.33 ± 103.79 GAE mg/100 g and, overall, high solid:liquid ratios and time periods release more phenolic compounds. Moreover, the red corn cob extracts showed higher radical scavenging capacity according to the results obtained using the ABTS•+ technique compared to the DPPH• test. The coupling of liquid chromatography and mass spectrometry assay allowed the determination of 11 phenolic compounds, including phenolic acids and flavonoids. Thus, our results demonstrated for the first time the potential of red corn cob as a source of bioactive compounds, which might be included in food and pharmacological preparations.

'Tar bush' and 'creosote bush' were substrates of fungal cultivation for tannase production and gallic acid and pyrocatechol accumulation. Aspergillus niger GH1 grew similarly on both plant materials under solid state culture conditions, reaching maximal levels after 4 d. Fungal strain degraded all tannin content of creosote bush after 4 d of fermentation and >75 % of tar bush after 5 d. Higher level of tannase activity was detected in tar bush fermentation. Biotransformation of tannins to gallic acid was high (93 % in creosote bush and 89 % in tar bush). Pyrocatechol was released poorly. Kinetic parameters of tannin conversion were calculated.