McNeal T P, Hollifield H C
U.S. Food and Drug Administration, Division of Food and Chemical Technology, Washington, DC 20204.
J AOAC Int. 1993 Nov-Dec;76(6):1268-75.
Microwave heat susceptors that convert electromagnetic energy to heat attain high temperatures that make it possible to cook some foods to golden crispness in a microwave oven. Susceptors are typically packaged with foods intended for microwave use, e.g., waffles, pizzas, and french fries. The high temperatures > 302 degrees F used to cook some foods release trace levels of volatile chemicals from metalized polyester film, adhesive, and paper packaging materials; these volatile chemicals may be absorbed by the food. We simulated microwave susceptor cooking conditions and developed protocols by using headspace concentration capillary gas chromatography and mass spectrometry to identify volatile chemicals released from heated susceptors. We purchased a limited, cross-sectional sample of local retail microwave food products packaged with susceptors and used our protocol to analyze 10 different susceptor products. Although more than 140 unique chromatographic peaks were tabulated, only 44 volatile chemicals were identified, including 1,1,1-trichloroethane, benzene, and 2-(2-butoxyethoxy)ethanol, which were derived primarily from the paper and adhesive susceptor components. No one susceptor contained all the identified substances. The standard additions technique was the preferred method for quantitation. Trichloroethane and 2-(2-butoxyethoxy)ethanol were present in several products at 75-122 micrograms/in.2 of susceptor surface area. Benzene was found in 3 susceptors at < or = 0.22 microgram/in.2 levels. Examination indicates that adhesives used in more recent susceptor products were reformulated to remove even this trace level of benzene.
将电磁能转化为热量的微波热感受器能达到高温，从而有可能在微波炉中将一些食物烹饪至金黄酥脆。热感受器通常与供微波炉使用的食品包装在一起，例如华夫饼、披萨和薯条。用于烹饪某些食物的高于302华氏度的高温会使金属化聚酯薄膜、粘合剂和纸质包装材料释放微量挥发性化学物质；这些挥发性化学物质可能会被食物吸收。我们模拟了微波感受器烹饪条件，并通过顶空浓缩毛细管气相色谱法和质谱法制定了方案，以识别加热感受器释放的挥发性化学物质。我们购买了一小部分用感受器包装的当地零售微波食品的横截面样本，并使用我们的方案分析了10种不同的感受器产品。尽管列出了140多个独特的色谱峰，但仅鉴定出44种挥发性化学物质，包括1,1,1 - 三氯乙烷、苯和2 - (2 - 丁氧基乙氧基)乙醇，这些主要源自纸质和粘合剂感受器成分。没有一个感受器包含所有已鉴定的物质。标准加入法是首选的定量方法。三氯乙烷和2 - (2 - 丁氧基乙氧基)乙醇在几种产品中的含量为75 - 122微克/平方英寸感受器表面积。在3个感受器中发现苯的含量≤0.22微克/平方英寸。检查表明，最近的感受器产品中使用的粘合剂经过重新配方，以去除甚至这种痕量水平的苯。
