Abstract
Whey cheese is produced from cheese whey, a by-product of cheese manufacture. It is classified into two groups, one is produced through concentration of whole whey being called “Mysost” while the other is produced by use of whey proteins (albumin cheese). Almost all of whey cheese imported to Japan belongs to the former.
Determination of total solids, fat and chlorides of whey cheese was carried out in this report. It is prescribed in the international standard that the total solids content of whey cheese should be determined by the drying process at 88±2°C, using aluminum dishes containing sea sand. From our experiment it became clear that it was impossible to obtain constant weight by this procedure. It was not adequate to apply the standard method for the determination of dry matter in cheese and processed cheese on whey cheese since the content was charred at the temperature of 105°C. Finally, the drying temperature was settled to 102°C. Three lots of whey cheese imported in the fiscal year 1975 were found to contain 74-77% of total solids when determined by this procedure.
So far as the determination of fat was concerned, Schmid-Bondzynski-Ratzlaff methad was proved to be inadequate for the analysis of fat in whey cheese because the content was charred during digestion with hydrochloric acid, the charred product being extracted with ether and light petroleum. Contrary to this, satisfactory results were obtained by the adoption of the Roese-Gottlieb method usually applied for the determination of fat in liquid milk. The fat contents of imported whey cheeses, measured by the above-mentioned procedure, were found to be within the range of 2.8-4.1% of the total solids, being classified as “skimmed whey cheese”.
Chloride content, estimated by the modified Vothard's method (with filtration), was found to be 0.6-0.7% expressed as chlorine on whole basis (0.9-1.2% as NaCl), giving appropriate saltiness on the product.
