Abstract:

Ultrasonic-assisted alkaline hydrolysis was used to release bound phenolic acids, the major antioxidant components in wheat bran. Some process conditions for the release of these antioxidant substances were optimized through single factor investigations and subsequent response surface analysis based on a three-factor, three-level Box-Behnken design. The optimal conditions for releasing bound phenolic acids from wheat bran were found as follows: material particle size, 0.5 mm; temperature, 60 ℃, NaOH concentration, 0.1 mol/L; solid/liquid ratio (g/mL), 2.5:100; and length of extraction time, 1 h. The total phenolic release under these optimal conditions was 3.687 mg/g, 7.23-fold higher than that obtained by the conventional methanol extraction method.

Key words: cereal bran, phenolic acids, response surface methodology, process optimization