Effects of Heat-Cooking with Edible Fats and Oils on the Levels of 3-Chloro-1, 2-Propanediol Fatty Acid Esters (3-MCPDEs), 2-Chloro-1, 3-Propanediol Fatty Acid Esters (2-MCPDEs) and Glycidyl Fatty Acid Esters (GEs) in Processed Foods.

This study investigated the effect of cooking on the levels of 3-chloro-1, 2-propanediol esters (3-MCPDEs), 2-chloro-1, 3-propanediol esters (2-MCPDEs) and glycidyl esters (GEs) in deep-fried rice cracker, fried potato, croquette, fish fillet, chicken fillet and cooking oils (rice bran oil and palm oil). The levels of 2-/3-MCPDE in rice cracker fried with rice bran oil and the used oil remained about the same, while the levels of GEs in them fell with frying time. The levels of 2-/3-MCPDEs in fried potato, croquette, fried fish and chicken cutlet fried with rice bran oil and palm oil respectively fell with frying time, while the level of GEs in them remained about the same. The levels of 2-/3-MCPDEs and GEs in fried rice cooked with rice bran oil were under the method limit of quantification. These results provide insights the cooking has no influence with the levels of 2-/3-MCPDEs and GEs in cooked foods.

[Evaluation of the immunochromatography kit for detection of emetic-toxin producing Bacillus cereus].

We evaluated the sensitivity and specificity of an immunochromatography kit, Single-path Emetic Tox Mrk (Merck), which targets a marker protein for the detection of Bacillus cereus that produces emetic toxin. Strains were isolated after outbreaks of food poisoning, and from retail prepared foods and food products. The strains were examined for the presence of the emetic toxin-synthetase gene by PCR. All 58 emetic strains isolated from the food poisoning cases showed a positive reaction in the immunochromatography kit. No emetic strains gave false negative result. Among 47 non-emetic strains, only two strains isolated from the food poisonings and one strain isolated from food products showed a false positive reaction in the test. We concluded that this method has high sensitivity and specificity. The test can be used for detection of emetic toxin-producing B. cereus not only from food poisoning cases, but also in food products.

[Quantitative determination of trans-fatty acids in oils and fats by capillary gas chromatography: results of a JOCS collaborative study].

Excessive intake of trans-fatty acids increases the risk of cardiovascular disease. Much attention is drawn to the consumption of trans-fatty acids worldwide, and regulations for trans-fatty acids are instituted in several countries. Precise and convenient methods for determination of trans-fatty acid level are required, but there is no standard method using capillary Gas Chromatography in Japan. Therefore, for the new standard method, collaborative studies were carried out. The results were as follows: 1) Heptadecanoate (C17:0 free fatty acid) was chosen for internal standard substance. 2) Two Gas Chromatography columns, SP2560 (100 m) column (100% cyanopropyl polysiloxane liquid phase) and TC-70 (60 m) column (70% cyanopropyl polysilphenylene-siloxane liquid phase), were examined in the collaborative studies. We measured the edible oil samples containing 2-45 g/100 g of trans-fatty acids, and trans-fatty acid contents were quantitatively the same with both columns. The range of reproducibility coefficient of variation were below 10%. 3) Fats and oils sampled were soybean, rapeseed, palm, palm kernel, beef tallow, pork fat and their hydrogenated forms, for which good peak resolution was achieved. From the above results, the technique evaluated in the present study was considered to be suitable for determination of the content of trans-fatty acids in fats and oils exclusive of fish oil and milk fat.