Elucidating the mechanism of laccase and tyrosinase in wheat bread making

Emilia Selinheimo (Corresponding Author), Karin Autio, Kristiina Kruus, Johanna Buchert

Research output: Contribution to journalArticleScientificpeer-review

68 Citations (Scopus)

Abstract

Cross-linking enzymes generate covalent bonds in and between food biopolymers. These enzymes are interesting tools for tailoring dough and bread structures, as the characteristics of the biopolymers significantly determine the viscoelastic and fracture properties of dough and bread. In this study, the influence of oxidative cross-linking enzymes, tyrosinase from the filamentous fungus Trichoderma reesei and laccase from the white rot fungus Trametes hirsuta, on dough and bread were examined. Oxidation of low molecular weight phenolic model compounds of flour, cross-linking of gluten proteins, dough rheology, and bread making were characterized during or after the enzymatic treatments. In the dough and bread experiments, laccase and tyrosinase were also studied in combination with xylanase. Of the model compounds tyrosine, p-coumaric acid, caffeic acid, ferulic acid, and Gly-Leu-Tyr tripeptide, tyrosinase oxidized all except ferulic acid. Laccase was able to oxidize each of the studied compounds. The phenolic acids were notably better substrates for laccase than L-tyrosine. When the ability of the enzymes to cross-link isolated gliadin and glutenin proteins was studied by the SDS-PAGE analysis, tyrosinase was found to cross-link the gliadin proteins effectively, whereas polymerization of the gliadins by laccase was observed only when a high enzyme dosage and prolonged incubation were used. Examination of large deformation rheology of dough showed that both laccase and tyrosinase made doughs harder and less extensible, and the effects increased as a function of the enzyme dosage. In bread making, interestingly, the pore size of the breads baked with tyrosinase turned out to be remarkably larger and more irregular when compared to that of the other breads. Nevertheless, both of the oxidative enzymes were found to soften the bread crumb and increase the volume of breads, and the best results were achieved in combination with xylanase.
Original languageEnglish
Pages (from-to)6357-6365
JournalJournal of Agricultural and Food Chemistry
Volume55
Issue number15
DOIs
Publication statusPublished - 2007
MoE publication typeA1 Journal article-refereed

Fingerprint

Laccase
Monophenol Monooxygenase
laccase
Bread
catechol oxidase
breads
Triticum
ferulic acid
dough
wheat
Gliadin
Enzymes
enzymes
Biopolymers
gliadin
crosslinking
Fungi
Rheology
Tyrosine
biopolymers

Keywords

  • Laccase
  • tyrosinase
  • cross-linking
  • wheat
  • dough
  • bread

Cite this

Selinheimo, Emilia ; Autio, Karin ; Kruus, Kristiina ; Buchert, Johanna. / Elucidating the mechanism of laccase and tyrosinase in wheat bread making. In: Journal of Agricultural and Food Chemistry. 2007 ; Vol. 55, No. 15. pp. 6357-6365.
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abstract = "Cross-linking enzymes generate covalent bonds in and between food biopolymers. These enzymes are interesting tools for tailoring dough and bread structures, as the characteristics of the biopolymers significantly determine the viscoelastic and fracture properties of dough and bread. In this study, the influence of oxidative cross-linking enzymes, tyrosinase from the filamentous fungus Trichoderma reesei and laccase from the white rot fungus Trametes hirsuta, on dough and bread were examined. Oxidation of low molecular weight phenolic model compounds of flour, cross-linking of gluten proteins, dough rheology, and bread making were characterized during or after the enzymatic treatments. In the dough and bread experiments, laccase and tyrosinase were also studied in combination with xylanase. Of the model compounds tyrosine, p-coumaric acid, caffeic acid, ferulic acid, and Gly-Leu-Tyr tripeptide, tyrosinase oxidized all except ferulic acid. Laccase was able to oxidize each of the studied compounds. The phenolic acids were notably better substrates for laccase than L-tyrosine. When the ability of the enzymes to cross-link isolated gliadin and glutenin proteins was studied by the SDS-PAGE analysis, tyrosinase was found to cross-link the gliadin proteins effectively, whereas polymerization of the gliadins by laccase was observed only when a high enzyme dosage and prolonged incubation were used. Examination of large deformation rheology of dough showed that both laccase and tyrosinase made doughs harder and less extensible, and the effects increased as a function of the enzyme dosage. In bread making, interestingly, the pore size of the breads baked with tyrosinase turned out to be remarkably larger and more irregular when compared to that of the other breads. Nevertheless, both of the oxidative enzymes were found to soften the bread crumb and increase the volume of breads, and the best results were achieved in combination with xylanase.",
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Elucidating the mechanism of laccase and tyrosinase in wheat bread making. / Selinheimo, Emilia (Corresponding Author); Autio, Karin; Kruus, Kristiina; Buchert, Johanna.

In: Journal of Agricultural and Food Chemistry, Vol. 55, No. 15, 2007, p. 6357-6365.

Research output: Contribution to journalArticleScientificpeer-review

TY - JOUR

T1 - Elucidating the mechanism of laccase and tyrosinase in wheat bread making

AU - Selinheimo, Emilia

AU - Autio, Karin

AU - Kruus, Kristiina

AU - Buchert, Johanna

PY - 2007

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N2 - Cross-linking enzymes generate covalent bonds in and between food biopolymers. These enzymes are interesting tools for tailoring dough and bread structures, as the characteristics of the biopolymers significantly determine the viscoelastic and fracture properties of dough and bread. In this study, the influence of oxidative cross-linking enzymes, tyrosinase from the filamentous fungus Trichoderma reesei and laccase from the white rot fungus Trametes hirsuta, on dough and bread were examined. Oxidation of low molecular weight phenolic model compounds of flour, cross-linking of gluten proteins, dough rheology, and bread making were characterized during or after the enzymatic treatments. In the dough and bread experiments, laccase and tyrosinase were also studied in combination with xylanase. Of the model compounds tyrosine, p-coumaric acid, caffeic acid, ferulic acid, and Gly-Leu-Tyr tripeptide, tyrosinase oxidized all except ferulic acid. Laccase was able to oxidize each of the studied compounds. The phenolic acids were notably better substrates for laccase than L-tyrosine. When the ability of the enzymes to cross-link isolated gliadin and glutenin proteins was studied by the SDS-PAGE analysis, tyrosinase was found to cross-link the gliadin proteins effectively, whereas polymerization of the gliadins by laccase was observed only when a high enzyme dosage and prolonged incubation were used. Examination of large deformation rheology of dough showed that both laccase and tyrosinase made doughs harder and less extensible, and the effects increased as a function of the enzyme dosage. In bread making, interestingly, the pore size of the breads baked with tyrosinase turned out to be remarkably larger and more irregular when compared to that of the other breads. Nevertheless, both of the oxidative enzymes were found to soften the bread crumb and increase the volume of breads, and the best results were achieved in combination with xylanase.

AB - Cross-linking enzymes generate covalent bonds in and between food biopolymers. These enzymes are interesting tools for tailoring dough and bread structures, as the characteristics of the biopolymers significantly determine the viscoelastic and fracture properties of dough and bread. In this study, the influence of oxidative cross-linking enzymes, tyrosinase from the filamentous fungus Trichoderma reesei and laccase from the white rot fungus Trametes hirsuta, on dough and bread were examined. Oxidation of low molecular weight phenolic model compounds of flour, cross-linking of gluten proteins, dough rheology, and bread making were characterized during or after the enzymatic treatments. In the dough and bread experiments, laccase and tyrosinase were also studied in combination with xylanase. Of the model compounds tyrosine, p-coumaric acid, caffeic acid, ferulic acid, and Gly-Leu-Tyr tripeptide, tyrosinase oxidized all except ferulic acid. Laccase was able to oxidize each of the studied compounds. The phenolic acids were notably better substrates for laccase than L-tyrosine. When the ability of the enzymes to cross-link isolated gliadin and glutenin proteins was studied by the SDS-PAGE analysis, tyrosinase was found to cross-link the gliadin proteins effectively, whereas polymerization of the gliadins by laccase was observed only when a high enzyme dosage and prolonged incubation were used. Examination of large deformation rheology of dough showed that both laccase and tyrosinase made doughs harder and less extensible, and the effects increased as a function of the enzyme dosage. In bread making, interestingly, the pore size of the breads baked with tyrosinase turned out to be remarkably larger and more irregular when compared to that of the other breads. Nevertheless, both of the oxidative enzymes were found to soften the bread crumb and increase the volume of breads, and the best results were achieved in combination with xylanase.

KW - Laccase

KW - tyrosinase

KW - cross-linking

KW - wheat

KW - dough

KW - bread

U2 - 10.1021/jf0703349

DO - 10.1021/jf0703349

M3 - Article

VL - 55

SP - 6357

EP - 6365

JO - Journal of Agricultural and Food Chemistry

JF - Journal of Agricultural and Food Chemistry

SN - 0021-8561

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