Enhancing nutritional quality and bioactivity of wheat bran through acid and alkaline pretreatments

Abstract

The effect of chemical processing, such as acid and alkaline pretreatments, on the phenolic profile, lipid components, and hydrosoluble protein content (HPC) in wheat bran (WB) was investigated. After acid pretreatment, the results provided an increase of over twofold in total reducing sugar (TRS). The sugars that have been identified are maltose, glucose, and fructose. After acid pretreatment, the total phenolic content increased by 41.95% compared with the untreated sample. Antioxidant potential, as assessed by the DPPH assay, significantly increased from 95.08 ± 1.13 μM TE/g DW in the untreated sample to 575.83 ± 2.41 μM TE/g DW following acid pretreatment. In the alkaline-treated sample, the total HPC increased to 16.58 ± 0.38 mg/100 g DW from 4.01 ± 0.17 mg/100 g DW. The fatty acid profile confirmed the presence of oleic acid (C18:1, n-9), linoleic acid (C18:2, n-6), and palmitic acid (16:0) as major components in analyzed samples. Chemical pretreatments significantly influenced all 13 identified phenolic compounds in WB, including avenanthramides, cinnamic acids (e.g., p-coumaric acid, ferulic acid, synaptic acid), and benzoic acids (e.g., vanillic acid). The study provides valuable insights into the development of sustainable approaches for using cereal bran to produce bioactive compounds with potential health benefits.