Selective separation properties of sintered TiO2 on stainless steel metallic membranes and formed-in-place (FIP) chitosan membranes were investigated with whey solutions at various pHs. Both fresh whey from Clemson University blue cheese processing and reconstituted whey solutions prepared from dried whole sweet whey powder were studied. Feed stock pH had a major effect on filtration tux and individual protein rejection rates. Minimum filtration fluxes were found at solution pH between 4 and 5, except at pH 8 for fresh whey filtered with FIP chitosan membranes. Protein rejection characteristics of reconstituted whey were different from those of fresh whey.; Sintered TiO2 on stainless steel metallic membranes were double coated with alginate on chitosan (A/C) or chitosan on alginate (C/A) and tested for selective separate of beta-Lactoglobulin (β-Lg) and alpha-Lactalbumin (α-Lc) from fresh whey at pH 4. The whey was fast filtered through a sintered TiO2 on stainless steel metallic membrane. The filtration tux of C/A composite membrane was about twice as that of A/C membrane. The rejection rate of β-Lg and α-Lc by C/A composite membrane was also higher than that of A/C composite membranes. Smaller amounts of the small molecular weight protein fraction (polypeptides) were retained by C/A membrane than by A/C membrane. These results indicated that C/A composite membrane had superior selective properties to concentrate β-Lg and α-Lc with a lower contamination of polypeptides.
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