Niklas Broel

Mr. Niklas Broel


Research Focus & Metrics

Academic Career Length

5Years (2022-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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28 August 2022 in Foods
Verified
Journal Article
Open access
PDF file
NBNiklas Broel
Niklas Broel
MSMiriam A. Sowa
Miriam A. Sowa
JMJulia Manhard
Julia Manhard
ASAlexander Siegl
Alexander Siegl
EWEdgar Weichhard
Edgar Weichhard
MGMartin Gand
Martin Gand
In traditional cheese making, pregastric lipolytic enzymes of animal origin are used for the acceleration of ripening and the formation of spicy flavor compounds. Especially for cheese specialities, such as Pecorino, Provolone, or Feta, pregastric esterases (PGE) play an important role. A lipase from Pleurotus citrinopileatus could serve as a substitute for these animal-derived enzymes, thus offering vegetarian, kosher, and halal alternatives. However, the hydrolytic activity of this enzyme towards long-chain fatty acids is slightly too high, which may lead to off-flavors during long-term ripening. Therefore, an optimization via protein engineering (PE) was performed by changing the specificity towards medium-chain fatty acids. With a semi-rational design, possible mutants at eight different positions were created and analyzed in silico. Heterologous expression was performed for 24 predicted mutants, of which 18 caused a change in the hydrolysis profile. Three mutants (F91L, L302G, and L305A) were used in application tests to produce Feta-type brine cheese. The sensory analyses showed promising results for cheeses prepared with the L305A mutant, and SPME-GC-MS analysis of volatile free fatty acids supported these findings. Therefore, altering the chain length specificity via PE becomes a powerful tool for the replacement of PGEs in cheese making.