TY - JOUR

T1 - Laccase-catalysed cross-linking of a yoghurt-like model system made from skimmed milk with added food-grade mediators

AU - Struch, Marlene

AU - Linke, Diana

AU - Mokoonlall, Aryama

AU - Hinrichs, Jörg

AU - Berger, Ralf G.

N1 - Funding information: This project ( AIF 17475 N ) was supported by the Arbeitsgemeinschaft industrieller Forschungsvereinigungen “Otto von Guericke” e. V. (AiF) through FEI (Forschungskreis der Ernährungsindustrie e.V., Bonn) and ASA Spezialenzyme (Wolfenbüttel, Germany). Stefan Nöbels helpful advice is gratefully acknowledged. The authors thank Robin Leonhardt and Lucienne Giesler for proofreading the manuscript.

PY - 2015/10/1

Y1 - 2015/10/1

N2 - Lactic acid fermented foods, such as yoghurt, suffer from structural losses in post-processing steps due to their shear sensitivity. The acidic pH optimum of fungal laccases offers potential to compensate for these losses and enhance the textural characteristics by cross-linking of milk proteins. Physical properties of skimmed milk yoghurt, as measured by dynamic oscillation rheology, changed upon addition of laccase alone or in combination with food-grade mediators. Among seven mediators examined, vanillin, vanillic acid, and caffeic acid were found to be most efficient. Variation of enzyme activity, mediator type and concentration showed best viscoelastic properties for the combination of 3 U laccase per gram yoghurt and 5 mmol L-1 caffeic acid. Evaluation of the loss factor, tan δ, showed increased elastic properties. SDS-PAGE showed a changed pattern of protein bands after the treatments. Overall, the combination of laccase with common food components provides an alternative to improve yoghurt texture.

AB - Lactic acid fermented foods, such as yoghurt, suffer from structural losses in post-processing steps due to their shear sensitivity. The acidic pH optimum of fungal laccases offers potential to compensate for these losses and enhance the textural characteristics by cross-linking of milk proteins. Physical properties of skimmed milk yoghurt, as measured by dynamic oscillation rheology, changed upon addition of laccase alone or in combination with food-grade mediators. Among seven mediators examined, vanillin, vanillic acid, and caffeic acid were found to be most efficient. Variation of enzyme activity, mediator type and concentration showed best viscoelastic properties for the combination of 3 U laccase per gram yoghurt and 5 mmol L-1 caffeic acid. Evaluation of the loss factor, tan δ, showed increased elastic properties. SDS-PAGE showed a changed pattern of protein bands after the treatments. Overall, the combination of laccase with common food components provides an alternative to improve yoghurt texture.

UR - http://www.scopus.com/inward/record.url?scp=84930959264&partnerID=8YFLogxK

U2 - 10.1016/j.idairyj.2015.04.002

DO - 10.1016/j.idairyj.2015.04.002

M3 - Article

AN - SCOPUS:84930959264

VL - 49

SP - 89

EP - 94

JO - International dairy journal

JF - International dairy journal

SN - 0958-6946

ER -