Disclosed herein is a process for inhibiting browning of plant material comprising adding a chelating agent to a disrupted plant material and adjusting the pH to a value of 2.0 to 4.5. Processes for manufacture of soluble and insoluble products from a plant material are also disclosed. Soluble products are represented by proteins and soluble fibres, and insoluble products by insoluble fibres. The processes are particularly suited for processing of potatoes.