GreenProteins - Isolation of hydrophobic proteins from green plant materials

The objective of this project is to gain understanding on the status of green proteins in the leafy material and to develop a protein extraction process that enable the application of this protein fraction for human food.


Green leaves constitute an abundant source of food proteins such as rubisco (ribulose -1, 5- biphosphate carboxylase oxygenase). This protein has been extensively studied in terms of isolation method, nutritional profile and techno-functionality. Side streams of rubisco production are usually neglected for food applications, although these side streams are still rich in proteins. The proteins present in the side streams are regarded as hydrophopic or green proteins.

This project uses the leaves of sugar beet plants to study processing options for green protein extraction. Sugar beet leaves are one of the largest readily available sources of plant proteins in The Netherlands. The isolation of hydrophobic proteins together with rubisco from this source would in principle be sufficient to replace 30 % of the total meat consumption in The Netherlands. However, green proteins cannot be isolated in their native state because they are not soluble in water, and tend to denature during the currently used precipitation methods. Therefore, avoiding denaturation is crucial to achieve novel food applications.

Ethanol extraction - resulting product