[Determination of antibiotic residues and other inhibitors in milk--quality assurance system]. / Oznaczanie zawartosci antybiotyków i innych substancji hamujacych w mleku--system zapewniania jakosci.

In the methods used widely for the determination of antibiotic residues in food product of animal origin the antibiotic-sensitivity of microorganisms is used. An advantage of microbiological methods is their high detection rate, but they are not specific. The test strains are not selectively sensitive and are inhibited by many antibiotics. False positive results of these tests may be due to the presence in tissues or milk of natural substance, e.g. enzymes or compounds of external origin--detergents or other drugs, e.g. sulphonamides. The microbiological tests--plate and tube STD and Polutest, as well as the enzymatic Penzym test, all recommended in the Polish Standards PN-91/A-86033 for milk control for the detection of antibiotic residues were compared. The authors describe the requirements to be met by the systems of quality ensuring during determination of antibiotics and other inhibitors in milk. The requirements to be met by the methods of this determination are discussed, together with the principles of intralaboratory and interlaboratory quality controls.

[Cold pressed oils]. / Oleje tloczone na zimno.

In recent years the interest in cold pressed oils has increased. In the Polish market, besides a wide assortment of imported products, Polish oils, mainly rapeseed oil, are also ever more frequently available. Cold pressed oils are used in food and pharmaceutical industry and also in the production of cosmetics. The production of cold pressed oils is simple and the investments for it are low. A limitation of the use of this method is low efficiency of the process (6-15% of oil remains in the pressed residues). For obtaining of proper oil it is indispensable to use ripe, clean, non-damaged and correctly stored seeds. Moreover, the conditions and parameters of the production and storage are important, especially the temperature and duration of pressing. The quality of oil is reduced at higher temperatures. At the temperatures below 40 degrees C the process yields oil of good quality permitted for consumption. The quality and the durability of the obtained oil depend on many factors, among them on the composition of fatty acids, the conditions of production and storage, on the presence of prooxidants and antioxidants. The analogue of the Polish cold pressed oil may be "cold pressed oil" and "virgin oil" the definitions and properties of which were proposed at the 21st Session of the Committees for Codex Alimentarius for Fats and Oils of the FAO/WHO (London, 1993).