Acta Agriculturae Zhejiangensis ›› 2025, Vol. 37 ›› Issue (9): 1958-1968.DOI: 10.3969/j.issn.1004-1524.20240542

• Food Science • Previous Articles     Next Articles

Optimization of the preparation process and separation purification of antioxidant peptides from oat bran protein

LI Huaxin1,2(), YANG Xuankang1, CHEN Ying1,2, WU Xiaoting2, LIU Silian2, YANG Zhong3, ZHOU Chenggang3, GAO Dandan1,2,*()   

  1. 1 China-Malaysia National Joint Laboratory, Biomedical Research Center, Northwest Minzu University, Lanzhou 730030, China
    2 College of Life Science and Engineering, Northwest Minzu University, Lanzhou 730124, China
    3 The No.2 People's Hospital of Lanzhou, Lanzhou 730046, China
  • Received:2024-06-22 Online:2025-09-25 Published:2025-10-15
  • Contact: GAO Dandan

Abstract:

To enhance the comprehensive application value of oat bran protein, this study prepared antioxidant peptides by enzymatic hydrolysis of oat bran protein with neutral protease. The DPPH free radical scavenging rate was used as an indicator to investigate the effects of enzymolysis time, enzymolysis temperature, pH value, and mass fraction of oat bran protein on the hydrolysis efficiency. Based on single-factor experiments, response surface methodology was employed to optimize the process conditions. The results showed that when the mass fraction of oat bran protein was 6.0%, pH value was 7.5, the enzymolysis temperature was 45 ℃, and the enzymolysis time was 4.5 h, the DPPH free radical scavenging rate was (73.78±0.67)%. The enzymatic hydrolysates were separated into four fractions by ultrafiltration, with the F4 fraction exhibiting the highest scavenging ability. Further purification using Sephadex G-25 gel filtration chromatography yielded three sub-fractions, which were assessed for their antioxidant activities based on their abilities to scavenge DPPH free radicals, hydroxyl radicals(·OH), and superoxide radicals (${O}_{2}^{·-}$). The study found that the E2 sub-fraction separated by Sephadex G-25 had the highest antioxidant activity, with the scavenging ability of DPPH radicals, hydroxyl radicals(·OH), and superoxide radicals (${O}_{2}^{·-}$) were (84.8±0.5)%, (81.6±0.7)%, and (80.1±0.7)%. These findings indicate that neutral protease can effectively hydrolyze oat bran protein to produce antioxidant peptides, and the antioxidant activity of these peptides can be significantly enhanced through separation and purification processes. This study provides a reference for the preparation of bioactive peptides from oat bran protein and offers a basis for enhancing their functional value.

Key words: neutral protease, oat bran protein, antioxidant peptides, DPPH free radical

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