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As a preliminary study about the reduction of the antigenicity of whey protein isolate(WPI) by treatment of chymotrypsin, trypsin, pancreatin, and protease from Aspergillus oryzae, the properties and antigenicities of whey protei:v hydrolysates(WPH) were investigated. When degrees of hydrolysis (DH) were measured by use of trinitrobenzensulfonic acid(TNBS), the DH of the WPH treated by pancreatin or protease from Aspergillus oryzae(5.05∼11.47) were much higher than those of the tryptic or chymotryptic WPH(15.67∼20.20). And the pretreatments of heat(75℃ , 20 min) and/or pepsin resulted in higher DH of WPH, generally. When the molecular distributions of the WPH were determined by high performance size exclusion chromatography(HPSEC), the ratios of polypeptides with molecular weight more than lOkDa ranged from 12% to 36%, and the average molecular weights and the average peptide lengths of the WPH were 4,252∼9,132 dalton and 38∼83 amino acids, respectively. And there was no bitter taste in all of the RPH. Results of SDS-PA(lE showed that most of intact native proteins were eliminated by the enzymatic hydrolysis but there were a few bands of peptides larger than 14.2 kDa in some WPH. When antigenicity was assayed by competitive inhibition enzyme-linked immunosorbent assay(cELISA), monovnlent antigenicity of WPH to rabbit anti-WPI antiserum were lowered to 10^(-1.7)-10^(-4.9) times and less by the enzymatic hydrolysis. And the pretreatments of heat and pepsin resulted in the lowest antigeniciy within a group of enzymatic hydrolysis, especially in case of the pancreatic hydrolysate(PDP) whose antigenicity was found almost to be removed.
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