Patent ID: 7371418

Claim:
A method for adjusting the yield and purity of potato proteinase inhibitor II extracted from raw potato tubers, comprising the steps of: (a) extracting the potato proteinase inhibitor II and other protein products from the potato tubers by preparing a mixture of an organic acid selected from the group consisting of acetic, ascorbic, citric and formic acid, and comminuted potato tubers to form a solid fraction and a liquid fraction comprising the potato proteinase inhibitor II and other protein products, wherein said extraction is carried out in the absence of alcohol; (b) heating the liquid fraction of part (b) to a temperature between about 60° C. to about 90° C. for a time period between about 30 to about 180 minutes to selectively affect the purity and yield of the potato proteinase inhibitor II; and (c) removing denatured protein products to prepare a clarified extract solution.