Factors affecting β carotene destruction in moist preserved leaf protein

Leaves are, and will probably remain, an important dietary source of β carotene (provitamin A). There is enough of it in extracted leaf protein (LP) to make that a useful source. β carotene is rapidly destroyed when LP, especially from young leaves, is preserved with salt. Destruction can be partly prevented by avoiding contamination with iron during preparation, by coagulating LP by heating rather than acidification, and by treatment with chelating agents. The unsaturated fatty acids in leaf lipids seem not to be involved in the destruction.