Preparation of cottonseed protein concentrate by sieving and density fractionation with K_2CO_3 solution

The distribution of particle size of the cottonseed meal and protein content was obtained. The content of protein is only 15% for those particles of the diameter in the range of 450～1 000 μm. It is valueless to processing them. They can be not processed for those particles of the diameter less than 105 μm because they contain much protein. After being sieved, the cottonseed meal was processed by density fractionation with K 2CO 3 solution for those ones the diameter in 105～220,220～355,355～450 μm and bigger than 1 000 μm,and the suitable K 2CO 3 concentrations for each particle size were 42%,40%,37%and 35% respectively.By using this method,66% the cottonseed protein with the content of protein concentrate can be got and the protein yield is 75.2%.