PROBLEM TO BE SOLVED: To provide a technique for extracting a component in food using a reducing agent which is inexpensive and has mild reduction action.SOLUTION: Food and an extract which contains a sulfite are mixed with each other to extract a component in the food. The acquired food extraction liquid is brought into contact with an antibody for specifically recognizing a substance contained in a specific raw material to be inspected, and the presence and/or amount of the specific raw material in the food is inspected using an immunological measuring method. Further, a food inspection kit for inspecting the presence and/or amount of the specific raw material in the food contains (1) the extract and the sulfite to be added to the extract, or the extract to which the sulfite is added, and (2) the antibody for specifically recognizing the substance contained in the specific raw material to be inspected.