Professor Frank heads the division Biofunctionality and Safety of Food at the Institute of Biological Chemistry and Nutrition at the University of Hohenheim

His research interests lie in factors that determine the absorption, metabolism, and elimination of the different vitamin E congeners and phytochemicals (such as curcuminoids and flavonoids) and in developing novel strategies to overcome the low intrinsic oral bioavailability of phytochemicals, as well as in understanding the biological activities of these potentially health-beneficial bioactives.

The first nutrition and food science journal to offer Registered Reports

NFS Journal is the new peer-reviewed, open access scientific journal published by the Society of Nutrition and Food Science in cooperation with Elsevier.

The journal invites submission of high-quality original research articles and methods papers presenting cutting-edge scientific advances as well as review articles on current topics in all areas of nutrition and food science. The journal particularly invites submission of articles that deal with research at the interface of nutrition and food science and thus connects both disciplines. 

Submit your work to NFS Journal to receive global visibility of your research.

Registered Reports

The open-access journal features a new article format Registered Reports, which allows researchers to submit their innovative hypotheses and experimental procedures for testing them, and have them evaluated by members of the editorial board and outside expert reviewers before they begin their laboratory work. This creates the opportunity to receive feedback from peers, correct mistakes and optimise experiments, which in turn enhances the quality of the generated data.

If the pre-registered hypotheses and procedures adhere to the highest scientific standards, are positively evaluated by the peers, and the registered procedures are followed strictly, the acceptance of the Registered Report is guaranteed irrespective of the outcome of the study, thus eliminating publication bias once and for all.

When analysing your data, you may discover novel aspects that are exciting, but were not part of the pre-registered procedures. In order for authors to react to such unforeseen and exciting results and to explore new paths that have not been anticipated, it is possible to include additional exploratory analyses in a special section of the Registered Reports.

Selected recent publications


The oral bioavailability of 8-prenylnaringenin from hops (Humulus lupulus L.) in healthy women and men is significantly higher than that of its positional isomer 6-prenylnaringenin in a randomized crossover trial. 

Mol Nutr Food Res (accepted for publication)


Natural 6-hydroxy-chromanols and -chromenols: structural diversity, biosynthetic pathways and health implications.

RSC Advances 8: 4803-4841


Tocopherols, tocomonoenols and tocotrienols in oils of Costa Rican palm fruits: a comparison between six varieties and chemical vs. mechanical extraction.

J Agric Food Chem 65: 7476–7482


Validation of a rapid and sensitive reversed- phase liquid chromatographic method for the quantification of prenylated chalcones and flavanones in plasma and urine. 

NFS Journal 10: 1-9

Dietary flavonoids and modulation of natural killer cells: Implications in malignant and viral diseases. 

J Nutr Biochem 2017; 46: 1-12


Vitamin E: emerging aspects and new directions.

Free Radical Biology & Medicine 2017; 102:16-36

The long chain α–tocopherol metabolite α-13’-COOH and γ-tocotrienol induce P-glycoprotein expression and activity by activation of the pregnane X receptor in the intestinal cell line LS 180. 

Mol Nutr Food Res 61: 1600605

Planet Wissen: Vitamine - wie viele brauchen wir wirklich?

Professor Frank was invited to appear as a nutrition expert on the German TV program planet wissen

IMG 6526 Kopie


Impressions from the joint conference REDOX BIOLOGY MEETS NUTRITION of the Society for Free Radical Research - Europe and the Society of Nutrition and Food Science, which was organised and chaired by Prof Frank. The conference program featured award lectures by Prof Barry Halliwell, the first scientist to give the SNFS Advances in Nutrition Research Lecture, Prof Enrique Cadenas, Prof Randal Kaufman and many more esteemed scientists.  

SFRR-E/SNFS Meeting at Hohenheim PalaceSFRR-E/SNFS Meeting at Hohenheim PalaceEnrique Cadenas - SFRR-E Award lectureKelvin Davies and Enrique CadenasDr Antonio Ruíz-Martinez’ Catherine Pasquier Memorial Award LectureCatherine Pasquier Memorial AwardSession 2Session 2Session 2 - Verena EllerkampMassimo Delledonne - Symposium 2: Plant Redox SystemsRandal Kaufman - SFRR-E Clinical Science LectureHelmut Sies and Barry HalliwellBarry Halliwell - SNFS Advances in Nutrition Research LectureHohenheim Palace

Paper of the year 2014

Our paper The oral bioavailability of curcumin from micronized powder and liquid micelles is significantly increased in healthy humans and differs between sexes was the article with the most downloads from the website of Molecular Nutrition and Food Research in 2014 and therefore selected as the journal’s Paper of the year 2014. Even in the years 2015 and 2016, the paper remained at the top of the list of highly accessed articles published in Molecular Nutrition and Food Research and led the list again in 2017.


In this article, the lead authors Christina Schiborr and Alexa Kocher report the results of a crossover human trial identifying micellar solubilisation as a technique to increase the oral bioavailability of curcumin 185-fold over native curcumin.