The oxidation of starch to aldehyde starch opens up a wide range of further functionalization, e.g., via cross-linking. In investigating this oxidation, we found that classical analytical methods rely on time-consuming and work-intensive titration protocols. To accelerate the screening process we implemented a photometric assay based on the selective adduct-formation of 2 aminobenzamide oxime (ABAO) and aldehydes. The UV-active adduct can easily be quantified in a platereader, allowing for parallel processing of multiple samples with a readout in a fraction of the time and in consistency of conventional methods. We thank Lisa Riedlsperger for their technical support. The providence Lower Austria (BioSet, K3-F-603/003-2018) is gratefully acknowledged for financial support.