Effects of cadmium and zinc on the quality of quail's eggs.

We report the effects of cadmium (Cd) and zinc (Zn) on the quality of Japanese quail's eggs. For this study, 60 birds were divided into 3 groups of 20 subjects each. The animals in group 1 received 4 mg Zn/d, whereas those in group 2 were given a combination of 4 mg Zn/d and 0.12 mg Cd/d. The quails in group 3 were not given any supplements, acting as controls. The distribution of Cd and Zn in the eggs, the eggs' mass, and the strength and thickness of the shells were determined after 35 and 58 d of supplementation. Zinc showed a positive effect on the mass of eggs and accumulated mainly in the egg white. The content of Cd was significantly lower in the egg yolk of birds in group 1 (p<0.001), whereas those in group 2 had decreased eggshell thickness and strength in comparison to groups 1 and 3 (p<0.001). These results suggest that the adverse effects of Cd on the quality parameters of eggs from commercially important bird species can be, at least in part, counteracted by Zn supplementation.

The fate of added nitrate used in the manufacture of Emmental cheese.

The aim of this study was to observe the dynamics of nitrates and nitrites during the six stages of manufacture of Emmental cheeses. Samples were taken of untreated milk, of pasteurized milk, of milk with nitrates added, of pressed cheese curd, of whey, of maturing cheese and of the final product. The samples were drawn from a commercial operation in a cheese factory in the eastern part of Slovakia. The mean NaNO2 content in untreated and in pasteurised milk was 0.2 and 0.1 mg kg-1, respectively and the mean NaNO3 content was 0.9 and 0.9 mg kg-1 respectively. Nitrates were added to the milk to prevent 'blowing' of hard cheese by micro organisms. In milk with nitrate added the mean content was 81.2 mg kg-1 NaNO3; the maximum value being 90.0 mg kg1 NaNO3. After pressing, the mean value of nitrate was found to be 20.6 mg kg-1 NaNO3. A considerable quantity of nitrates passed into the whey, where the mean nitrate content was 67.0 mg kg-1 NaNO3. The final product had a markedly decreased content of nitrates (3.3 mg kg-1 NaNO3) and nitrites (0.2 mg kg-1 NaNO2) when compared with the values in cheese during maturation (11.3 mg kg-1 NaNO3; 0.4 mg kg-1 NaNO2).