PROBLEM TO BE SOLVED: To easily observe an existence state of an oil drop in food containing the oil drop and a solid particle other than the oil drop, such as gratin and stew using white sauce, and deep-fried tofu and dough of deep-fried bean curd containing vegetable using soybean protein. SOLUTION: A food composition comprising the food is diluted with an aqueous solution containing a low-molecular surfactant such as a sodium lauryl sulfate and a sugar ester to prepare a stable diluted emulsion, and the diluted emulsion is observed by an optical microscope to measure easily an emulsified state with satisfactory reproducibility. COPYRIGHT: (C)2007,JPO&INPIT
