Abstract
Lactose in different types of cheese were measured by the Draft Standard Method of International Dairy Federation (1966), the results being compared with those by colorimetric phenolsulfuric acid method and osazone method.
1) Because the most of the natural and process cheeses contained insufficient amount of lactose (less than 0.24%) for the IDF method, the preliminary test by the simple and sensitive colorimetric method is recommended before the adoption of IDF method. For this purpose the phenol-sulfuric acid colorimetric method is suitable.
2) Considerable amount of glucose (about 0.2%) was detected in some process cheese samples. The IDF method should not be applied for such cheeses. Paperchromatography and glucose-oxidase colorimetric method are convenient for the detection of reducing sugars other than lactose and the determination of glucose in cheese, respectively.
