Siemer  Claudia

Siemer Claudia


Research Focus & Metrics

Academic Career Length

6Years (2021-Present)

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

Representative Publications

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18 May 2021 in Applied Sciences
Verified
Journal Article
Open access
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DMDana Middendorf
Dana Middendorf
UBUte Bindrich
Ute Bindrich
SCSiemer Claudia
Siemer Claudia
Stefan ToepflStefan Toepfl
Stefan Toepfl
Volker HeinzVolker Heinz
Volker Heinz
The increased consumption of reduced-fat or non-fat products leads to a reduced intake of fat-soluble bioactive substances, such as fat-soluble vitamins. Due to their natural role as transport systems for hydrophobic substances, casein micelles (CM) might depict a viable system. The structure of CM is characterized by a lipophilic core stabilized by an electric double layer-like structure. Modification allows accessibility of the core and, therefore, the inclusion of fat-soluble bioactive substances. Well-known modifications are pH reduction and use of rennet enzyme. A completely new procedure to modify CM structure is offered by pulsed electrical fields (PEF). The principle behind PEF is called electroporation and affects the electric double layer of CM so that it is interrupted. In this way, lipophilic substances can be incorporated into CM. In this work, we evaluated integration of β-carotene into native CM by an industry-compatible process to overcome disadvantages associated with the use of Na-caseinate and avoid great technical effort, e.g., due to treatment with high hydrostatic pressure. Our research has shown that PEF can be used for disintegration of CM and that significant amounts of β-carotene can be incorporated in CM. Furthermore, after disintegration using PEF, a combination of another PEF and thermal treatment was applied to restructure CM and trap significant amounts of β-carotene, permanently, ending up with an encapsulation efficiency of 78%.

17 May 2023 in Journal of Food Processing and Preservation
Verified
Journal Article
Open access
PDF file
Ivan ShorstkiiIvan Shorstkii
Ivan Shorstkii
CSCorinna Stühmeier-Niehe
Corinna Stühmeier-Niehe
MSMaxim Sosnin
Maxim Sosnin
Emad Hussain Ali MunassarEmad Hussain Ali Munassar
Emad Hussain Ali Munassar
MCMartina Comiotto-Alles
Martina Comiotto-Alles
Stefan ToepflStefan Toepfl
Stefan Toepfl
The kiwifruit processing industry is focused on product yield maximization and keeping energy costs and waste effluents to a minimum while maintaining high product quality. In our study, pulsed electric field (PEF) pretreatment enhanced kiwifruit processing to facilitate peelability and specific peeling process and enhanced valorization of kiwifruit waste. PEF optimization was applied to obtain the best treatment parameters. A 32 factorial design of response surface methodology was applied to find the effect of time elapsed after PEF treatment and the PEF-specific energy input on specific peeling force and kiwifruit firmness as response criteria. Under the optimized condition, the specific peeling force decreased by 100, and peelability increased by 2 times. The phenolic content and antioxidant capacity of PEF-treated kiwifruit bagasse were 5.1 and 260 richer than the control sample. Overall, the optimized PEF pretreatments incorporated into kiwifruit processing led to decreased energy demand and increased productivity.

1 January 2022
Verified
Book Chapter
Closed access
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SCSiemer Claudia
Siemer Claudia
JGJim Gratzek
Jim Gratzek
VHVolker Heinz
Volker Heinz
STStefan Toepfl
Stefan Toepfl