The extractable β-carotene content of Guku (Bidens pilosa) leaves after cooking, drying and storage

The β-carotene content of young tender leaves of Guku (Bidens pilosa) was found to be 64 μg g-1 in fresh samples. The extractable β-carotene content of Guku leaves boiled for 20 min was 31% greater than that in leaves blanched for 1 min. Boiling for up to 60 min resulted in a 6% decrease of β-carotene compared with the concentration in blanched leaves. Drying in the sun and in the shade resulted in losses of β-carotene of 92% and 93% respectively. After 6 days of refrigeration of unblanched leaves, about 38% of the β-carotene was lost. There was no appreciable change in the levels of β-carotene after the blanched leaves had been kept frozen at -18d̀C for 5 weeks. Blanched mature leaves had 62% more β-carotene than young leaves.