Kishk - a dried fermented milk / cereal mixture. 2 Assessment of a variety of protein analytical techniques for determining adulteration and proteolysis

A variety of protein assays were applied to the analysis of 25 commercial samples of Lebanese Kishk to detect the adulteration of goat's milk with cow's milk. Polyacrylamide gel elec- trophoretic (PAGE) methods could detect the degree of adulteration - 25 %. Using sodium dodecyl sulphate (SOS-PAGE), reverse phase high performance Iiquid chromatography (RP-HPLC) and anion-exchange fast protein liquid chromatography (FPLC) failed to detect the degree of adulteration in Kishk due to a very extensive proteolysis that made the distinction of the original caseins very dif- ficult. Moreover, the immunoassay technique (Cortecs method) had Iimited application for powder products and cou Id not be used effectively to calculate the degree of adulteration of goat's milk Kishk with cow's milk. © InralElsevier, Paris.