the effect of humidity and compactional pressure on the wheat germ lipase activity

the use of proteins and peptides as human therapeutics has been increased in recent years. lipase is a relatively homogeneous proteinaceous enzyme indicated in maldigestion. the purpose of the present study was to evaluate the effect of humidity along with compactional pressure on the enzymatic activity of wheat germ lipase. samples of lipase powder were kept at different relative humidity (rh) conditions (24, 40, 63 and 75 %) before compaction under various pressures (74-372 mega pascal or mpa). the relative enzymatic activity of the compacts was then determined by titration method using triacetin as substrate. density measurements were also conducted in order to describe the possible mechanism of the enzymatic activity. the results indicated densities of the compacts prepared under various compactional pressures increase as humidity rises. based on the results, activity loss of the compacts following relative humidity increase can be related to steric hindrance caused by higher pressures. however, there was no significant difference between densities at different compactional pressures at a given humidity condition.