Some preliminary observations on treatments which increase and decrease the stability of β-carotene in preserved, moist leaf protein

Abstract

β-carotene in leaf protein extracted from some species is destroyed in a few days when incubated with salt as a preservative. Its shelf-life can be greatly extended by pretreatment with oxalate, ascorbate mercaptans, phenolic substances, extracts made from leaves in which β carotene is more stable, and by tight compaction. Treatment with alum reverses the protective effect of these chemical pretreatments, it also increases the lability of β carotene in leaf protein extracted from species which usually give a relatively stable product. In these preparations of leaf protein, which were heated to 90 °C during preparation, β carotene is only partially extractable into some solvents which are miscible with water. It seems therefore to be present in more than one state, but differences in extractability could not be correlated with differences in lability.