Background

Various plant substitutes are now widely available on the market. Especially in the case of milk substitutes, there is a wide range of alternatives to conventional cow's milk. One nutrient-rich protein source from which a substitute milk can be obtained is the yellow split pea. It is characterized by a high protein content and environmentally friendly cultivation. Although pea milk is now established on the market, there are still disturbing flavors that make this product less attractive to the market. For example, the taste of this is often described as beany and bitter. To further improve the taste of these products, it is necessary to identify the substance classes responsible for these interfering notes by mass spectrometry and to degrade them enzymatically.

Tasks

Within the scope of this work, the sample processing of various substitute milk products is to be standardized and largely automated by applying filtration or precipitation and centrifugation steps followed by preparative chromatography or extraction. At the end of the processing sequence, small aliquots of the obtained fractions will be automatically pipetted onto measurement plates for Matrix Assisted Laser Desorption/Ionization (MALDI) analysis and the spectra of the samples will be determined. Automation allows efficient testing and optimization of various parameters of the sample processing steps as well as the MALDI analysis. After defining a standardized procedure (SOP), the analysis data of the fractions of different substitute milk products are to be determined and compared with each other. The focus will not be on individual substances, but on algorithms for pattern recognition that identify differences in the identified proteins and substance classes of the complex natural products, thereby allowing initial correlations between flavor notes and analysis data.

Practical sub-aspects of the work are:

Development of a protocol for the preparation of samples of substitute dairy products.

Partial automation of the sample preparation for MALDI-TOF-MS analysis using a pipetting station with connected robotics

Determination of measurement parameters for mass spectrometric measurements (measurement mode, solvent content, matrices ...)

Characterization of the most important substance classes and proteins of different substitute milk products

Use of modern data analysis to determine initial correlations between properties of the surrogate milk products and the MS spectra.

Clear documentation of the results in written form and presentation in a seminar lecture.