Details
| Original language | English |
|---|---|
| Pages (from-to) | 563-570 |
| Number of pages | 8 |
| Journal | Innovative Food Science and Emerging Technologies |
| Volume | 33 |
| Publication status | Published - 2 Nov 2015 |
Abstract
Laccases are a promising candidate for crosslinking milk proteins in stirred fermented milks. It was applied in a post-processing step due to its acidic pH optimum reported in literature for rebodying of the gel and an improvement in structure. A laccase preparation from Trametes versicolor had a lower oxidation activity in ultrafiltration permeate than in model buffer systems, and a pH optimum of 4.5. It was applied to stirred skim milk gels but no significant change in the storage modulus or apparent viscosity of yoghurt occurred. Confocal laser scanning micrographs showed a more porous structure of the milk gel. Some fresh cheese samples had improved rheological properties. A competing crosslinking activity and peptidolytic activity was assumed and smaller peptides were detected in acidified milk by fluorescence. Mass spectrometry of the laccase preparation returned mainly laccase sequences. Although this does not exclude proteases, it indicates that the radical mechanism of laccases may lead to protein degradation. Industrial Relevance: Enzymatic modification of milk proteins can alter the structure of fermented milk gels and even create new structures. Rheological properties can be improved via crosslinking, thus reducing costs due to the addition of protein powders or stabilisers. An innovative approach to combining biotechnology and food science and engineering is investigated. The study is interesting for both enzyme manufacturers and dairy companies as it aims to at least partially fill the knowledge gap between enzymology and their real-world application in dairy products. However, enzymatic treatment is an additional step and also incurs costs which should be taken into account.
Keywords
- Fermented milks, Laccase, Post-processing, Protein modification
ASJC Scopus subject areas
- Agricultural and Biological Sciences(all)
- Food Science
- Chemistry(all)
- Engineering(all)
- Industrial and Manufacturing Engineering
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In: Innovative Food Science and Emerging Technologies, Vol. 33, 02.11.2015, p. 563-570.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Structure modification of stirred fermented milk gel due to laccase-catalysed protein crosslinking in a post-processing step
AU - Mokoonlall, Aryama
AU - Pfannstiel, Jens
AU - Struch, Marlene
AU - Berger, Ralf Günter
AU - Hinrichs, Jörg
N1 - Funding information: This research project was supported by the German Ministry of Economics and Technology (via AiF) and the FEI (Forschungskreis der Ernährungsindustrie e.V., Bonn) Project AiF 17475 N . The authors thank Stefan Nöbel for his invaluable comments, Lin Du for performing part of the experiments and Luc Mertz and Berit Würtz for their technical assistance.
PY - 2015/11/2
Y1 - 2015/11/2
N2 - Laccases are a promising candidate for crosslinking milk proteins in stirred fermented milks. It was applied in a post-processing step due to its acidic pH optimum reported in literature for rebodying of the gel and an improvement in structure. A laccase preparation from Trametes versicolor had a lower oxidation activity in ultrafiltration permeate than in model buffer systems, and a pH optimum of 4.5. It was applied to stirred skim milk gels but no significant change in the storage modulus or apparent viscosity of yoghurt occurred. Confocal laser scanning micrographs showed a more porous structure of the milk gel. Some fresh cheese samples had improved rheological properties. A competing crosslinking activity and peptidolytic activity was assumed and smaller peptides were detected in acidified milk by fluorescence. Mass spectrometry of the laccase preparation returned mainly laccase sequences. Although this does not exclude proteases, it indicates that the radical mechanism of laccases may lead to protein degradation. Industrial Relevance: Enzymatic modification of milk proteins can alter the structure of fermented milk gels and even create new structures. Rheological properties can be improved via crosslinking, thus reducing costs due to the addition of protein powders or stabilisers. An innovative approach to combining biotechnology and food science and engineering is investigated. The study is interesting for both enzyme manufacturers and dairy companies as it aims to at least partially fill the knowledge gap between enzymology and their real-world application in dairy products. However, enzymatic treatment is an additional step and also incurs costs which should be taken into account.
AB - Laccases are a promising candidate for crosslinking milk proteins in stirred fermented milks. It was applied in a post-processing step due to its acidic pH optimum reported in literature for rebodying of the gel and an improvement in structure. A laccase preparation from Trametes versicolor had a lower oxidation activity in ultrafiltration permeate than in model buffer systems, and a pH optimum of 4.5. It was applied to stirred skim milk gels but no significant change in the storage modulus or apparent viscosity of yoghurt occurred. Confocal laser scanning micrographs showed a more porous structure of the milk gel. Some fresh cheese samples had improved rheological properties. A competing crosslinking activity and peptidolytic activity was assumed and smaller peptides were detected in acidified milk by fluorescence. Mass spectrometry of the laccase preparation returned mainly laccase sequences. Although this does not exclude proteases, it indicates that the radical mechanism of laccases may lead to protein degradation. Industrial Relevance: Enzymatic modification of milk proteins can alter the structure of fermented milk gels and even create new structures. Rheological properties can be improved via crosslinking, thus reducing costs due to the addition of protein powders or stabilisers. An innovative approach to combining biotechnology and food science and engineering is investigated. The study is interesting for both enzyme manufacturers and dairy companies as it aims to at least partially fill the knowledge gap between enzymology and their real-world application in dairy products. However, enzymatic treatment is an additional step and also incurs costs which should be taken into account.
KW - Fermented milks
KW - Laccase
KW - Post-processing
KW - Protein modification
UR - http://www.scopus.com/inward/record.url?scp=84961878117&partnerID=8YFLogxK
U2 - 10.1016/j.ifset.2015.10.006
DO - 10.1016/j.ifset.2015.10.006
M3 - Article
AN - SCOPUS:84961878117
VL - 33
SP - 563
EP - 570
JO - Innovative Food Science and Emerging Technologies
JF - Innovative Food Science and Emerging Technologies
SN - 1466-8564
ER -