Chemical evaluation of protein quality and phenolic compound levels of some Cucurbitaceae oilseeds from Cameroon

Abstract

This work studies the chemical evaluation of protein quality and phenolic compound contents of some Cucurbitaceae (egusi) oilseeds from different areas in Cameroon. These seeds are Cucumeropsis mannii, Cucurbita maxima, Cucurbita moschata, Lagenaria siceraria and Cucumis sativus. The seeds were cleaned, dried, ground and part of the powder was defatted. The defatted cakes were analysed for total and soluble nitrogen, true proteins and amino acids, while the undefatted seeds were analysed for phenolic compound contents. The defatted cakes had high total protein contents. The trichloroacetic acid soluble fraction of these proteins ranged from 25% (C. maxima from North West) to 94% of total proteins (C. sativus from Adamawa and South West), due to the post harvest treatment of the seeds. They were rich in most essential amino acids, giving protein digestibility, corrected amino acid scores of 0.67 for C. sativus and 0.48 for C. mannii which was for lysine, indicating that in the absence of tryptophan and methionine, lysine was the limiting amino acid in these seeds. These seeds had low levels of phenolic compounds (0.34 to 0.43%). Defatted C. mannii could be good for preparing infant formula, especially when mixed with soybean, in order to increase its lysine content.

Keywords: Cucurbitaceae (egusi) seeds, proteins, amino acids, phenolic compounds

African Journal of Biotechnology Vol. 12(7), pp. 735-743