The present disclosure describes methods of obtaining and/or deriving proteins from plants of the Nicotiana species and methods for incorporation of such proteins into various products. For example, a method for obtaining a protein-enriched material from a plant of the Nicotiana species or portion thereof is provided, comprising: extracting one or more proteins from the plant material into a solvent to form a liquid protein-containing extract; separating a solid extracted plant material from the liquid protein-containing extract; clarifying the liquid protein-containing extract to form a clarified protein-containing extract and a solids fraction; and treating the clarified protein-containing extract so as to provide a protein-enriched material comprising at least about 60% protein by weight.