ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Different immobilized feruloyl esterase preparations for production of ferulic acid from buckwheat and white wheat brans

Çiğdem Çetin, Ali Toprak, Deniz Yildirim, and Ramazan Bilgin

Chemistry Department, Sciences and Letters Faculty, Cukurova University, Adana, Turkey

E-mail: rbilgin@cu.edu.tr

Received: 8 May 2025  Accepted: 26 June 2025

Abstract:

Ferulic acid is an important bioactive compound used in agricultural, cosmetic, food, pharmaceutical industries. In this study, feruloyl esterase (FAE) from Clostridium thermocellum was covalently immobilized using a glutaraldehyde spacer arm on 3-aminopropyl silica gel support (Si-Glu@FAE), in PVA (PVA@FAE), and in sol–gel (sol–gel@FAE) to produce ferulic acid from de-starched buckwheat and white wheat brans. The optimum pH and temperature, thermal stability, and kinetic parameters were determined for the free and immobilized FAEs. The optimum pH for free FAE, Si-Glu@FAE, PVA@FAE, and sol–gel@FAE was 6.5, 6.5, 7.0, and 7.0, respectively. The optimum temperature was 40 °C for free FAE, Si-Glu@FAE and PVA@FAE, while the optimum temperature shifted to 60 °C for sol–gel@FAE. The catalytic efficiency of Si-Glu@FAE and sol–gel@FAE increased by 2.1-fold, and 1.3-fold, respectively, compared to free FAE. Si-Glu@FAE, sol–gel@FAE and PVA@FAE were stabilized by 4.6-fold, 4.2-fold, and 2.6-fold, respectively, compared to free FAE at 40 °C. The highest amounts of ferulic acid were obtained as 61.3 and 91.9 mg per gram of dry white wheat bran and buckwheat bran for Si-Glu@FAE, respectively. Our results demonstrate that Si-Glu@FAE has a superior performance compared to sol–gel@FAE and PVA@FAE in terms of catalytic efficiency, thermal stability, and ferulic acid production, making it a promising candidate for industrial applications involving biomass valorization.

Keywords: Feruloyl esterase; Ferulic acid; Immobilization; Buckwheat bran; White wheat bran

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-025-04220-3

Chemical Papers 79 (10) 6751–6761 (2025)