Interest in alternative plant-based protein sources is
continuously
growing. Sugar beet leaves have the potential to satisfy that demand
due to their high protein content. They are considered as agricultural
waste and utilizing them as protein sources can bring them back to
the food chain. In this study, isoelectric-point-precipitation, heat-coagulation,
ammonium-sulfate precipitation, high-pressure-assisted isoelectric-point
precipitation, and high-pressure-assisted heat coagulation methods
were used to extract proteins from sugar beet leaves. A mass spectrometry-based
proteomic approach was used for comprehensive protein characterization.
The analyses yielded 817 proteins, the most comprehensive protein
profile on sugar beet leaves to date. Although the total protein contents
were comparable, there was a significant difference between the methods
for low-abundance proteins. High-pressure-assisted methods showed
elevated levels of proteins predominantly located in the chloroplast.
Here we showed for the first time that the extraction/precipitation
methods may result in different protein profiles that potentially
affect the physical and nutritional properties of functional products.