PubMed Health⌕ Search

Biomedical subjects

A S El-Nockrashy

Publications and source records attributed to A S El-Nockrashy.

4 recordsLinked to original sources

Cottonseed colour fixed pigments. Part I. Selectivity of hexane isomers.

The selectivity of hexane isomers towards cottonseed pigments and colour fixed pigments was illustrated by using spectrophotometric analysis of crude, refined and bleached oils, and by refinability and bleachability criteria. Crude cottonseed oil contains besides the alkali-refinable gossypol and gossypurpurin, several colour fixed pigments. Anhydrogossypol, gossyfulvin, anthocyanins and carotenoids seem to be responsible for the colour-fixation of the oil. Only carotenoids are eliminated by bleaching. Selectivities of hexane isomers towards colour fixed pigments are in the following order: isohexane less than n-hexane less than cyclohexane less than benzene less than methylcyclopentane.

Alkanes↗

Biochemical changes in cottonseed during development and maturity.

The changes in cottonseed constituents at different boll ages ranging from 5 to 60 days after flowering are reported. A gradual depletion of sugars coincided with gradual formation of oil has been found. Proteins are accumulated at a more or less even rate. Gossypol starts its appearance in 10 days old boll, and continuously increases. The iodine value of the oils shows gradual increase, while the acid value continuously decreases. Continuous decrease in total saturated fatty acids during development and maturity was observed while linoleic acid continuously increases. The total phospholipid content of the oil continuously decreases. The total saturated fatty acid contents of the phospholipids are generally higher than that of their corresponding oils.

Carbohydrates↗