TY - JOUR

T1 - Cross-linking of wheat bran arabinoxylan by fungal laccases yields firm gels

AU - Khalighi, Sanaz

AU - Berger, Ralf G.

AU - Ersoy, Franziska

N1 - Funding Information: The publication of this article was funded by the Open Access fund of Leibniz Universit?t Hannover. The authors are grateful to U. Krings at the Institute of Food Chemistry, LU Hannover, for his skilful mass spectrometric analyses and help with the interpretation of the MS/MS data. We also thank D. Linke for helpful assistance. Funding Information: Funding: The publication of this article was funded by the Open Access fund of Leibniz Universität Hannover.

PY - 2019/12/30

Y1 - 2019/12/30

N2 - The native extractable arabinoxylans (AX) from wheat bran were cross-linked by the commercial laccase C (LccC) and self-produced laccases from Funalia trogii (LccFtr) and Pleurotus pulmonarius (LccPpu) (0.04 U/μg FA, each). Dynamic oscillation measurements of the 6% AX gels demonstrated a storage modulus of 9.4 kPa for LccC, 9.8 kPa for LccFtr, and 10.0 kPa for LccPpu. A loss factor ≤ 0.6 was recorded in the range from 20 to 80 Hz for all three laccases, and remained constant for four weeks of storage, when LccFtr and LccPpu were used. Arabinoxylan gel characteristics, including high water holding capacity, swelling ratio in saliva, and heat resistance indicated a covalently cross-linked network. Neither the mediator compounds caffeic acid and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS), nor citrus pectin, enhanced the elastic properties of the gels. Using laccases as an oxidant provided gels with a solid and stable texture, comparable in firmness to traditional gelatin gels. Thus, AX gels can be presented in the vegan, halal, and kosher food markets. They may also find use in pharmaceutical and other industrial applications.

AB - The native extractable arabinoxylans (AX) from wheat bran were cross-linked by the commercial laccase C (LccC) and self-produced laccases from Funalia trogii (LccFtr) and Pleurotus pulmonarius (LccPpu) (0.04 U/μg FA, each). Dynamic oscillation measurements of the 6% AX gels demonstrated a storage modulus of 9.4 kPa for LccC, 9.8 kPa for LccFtr, and 10.0 kPa for LccPpu. A loss factor ≤ 0.6 was recorded in the range from 20 to 80 Hz for all three laccases, and remained constant for four weeks of storage, when LccFtr and LccPpu were used. Arabinoxylan gel characteristics, including high water holding capacity, swelling ratio in saliva, and heat resistance indicated a covalently cross-linked network. Neither the mediator compounds caffeic acid and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS), nor citrus pectin, enhanced the elastic properties of the gels. Using laccases as an oxidant provided gels with a solid and stable texture, comparable in firmness to traditional gelatin gels. Thus, AX gels can be presented in the vegan, halal, and kosher food markets. They may also find use in pharmaceutical and other industrial applications.

KW - Arabinoxylan gel

KW - Cross-linking

KW - Laccase

KW - Viscoelastic properties

UR - http://www.scopus.com/inward/record.url?scp=85078410693&partnerID=8YFLogxK

U2 - 10.3390/pr8010036

DO - 10.3390/pr8010036

M3 - Article

AN - SCOPUS:85078410693

VL - 8

JO - Processes

JF - Processes

IS - 1

M1 - 36

ER -