We extracted and studied nobiletin and synephrine from the waste peels of Shiikuwasha (Citrus depressa Hayata) by using vinegar. Following examination of extraction using several kinds of solvents, nobiletin quantities were seen to be higher for 5% acetic acid than those for other solvents were. Quantities of synephrine were similar following extraction using all types of solvents. Extracted quantities of synephrine were lower when solvent concentration was low, whereas nobiletin quantities were higher when solvent concentration was high. Moreover, addition of sucrose, at a concentration of 4.8～16.7% in a solvent showed no change in the extracted amount of synephrine, while nobiletin quantities increased after addition of 4.8% sucrose.
