Depressants comprising a moderately oxidized polysaccharide having about 0.05 to about 4.5 mmol of anionic charge per gram at a pH of about 6 to about 7, or about 0.2 to about 5 mmol of anionic charge per gram at a pH of about 10 to about 11.2, are provided. Also disclosed are processes for enriching a desired mineral from an ore comprising the desired mineral and gangue, wherein the process comprises carrying out a flotation process in the presence of one or more of the depressants.