Gossypol recovery from the methanol phase in two-phase extraction of cottonseed kernel

Cottonseed oil and cottonseed meal with good quality could be obtained from cottonseed kernel by a two-phase extraction system which was composed of petroleum ether and methanol.Gossypol in cottonseed kernel was dissolved mostly in methanol phase during the extraction process.If the gossypol in methanol phase could be recovered and purified,there would be great economic benefit to the process.Reservation ability of gossypol in methanol phase at different conditions was investigated.Results indicated that the lower the reserving temperature,the dimmer the reserving space and the shorter the reserving time,the smaller the loss of gossypol in methanol phase.A water-dilution method was studied to recover gossypol from methanol phase and some technical parameters were obtained.The best recovery method was firstly to concentrate the methanol solution to 1.0 mL/g cottonseed kernel and then add to it orderly with double volume water,0.5 g NaCl per 50 g cottonseed kernel.Adjusting the solution pH to 5 and then filtrate gossypol crystal after 8 h deposition time.Under the conditions,gossypol recovery reached 68.25% yield and 96.9% purity,which showed that the water-dilution method to recover gossypol from methanol phase solution was a feasible method.