| abstract |
The present invention provides an ultrafiltration method for isolation and purification of a proteinase inhibitor extract from plant tissue, preferably potato tubers. The extraction and isolation of the proteinase inhibitor from potatoes begins with the addition of an organic acid, preferably formic acid, and a salt, preferably sodium chloride, to raw potatoes. The mixture is subjected to process steps to extract soluble proteins. Undesired proteins are denatured and removed, resulting in an extract solution suitable for ultrafiltration. The ultrafiltration process comprises two parts, concentration and diafiltration. The concentration part is primarily for dewatering, and as such, acids, salts, and other small molecules are removed concurrent to concentration. An ideal ultrafiltration membrane composition comprises regenerated cellulose with a nominal molecular weight cut-off of 10,000 Dalton. A concentration factor of 10 times volume of the clarified extract volume is achieved using a 100 mM ammonium bicarbonate solution. |