Data Views Exclude Ubiquitous Chemicals Activities: 592 Chemicals w/Activities: 81 CSV Excel PDF All Chemicals: 121 Previous12345 Show all rows. Paginate rows. Click on column headings to sort table by that column # Activity Chemical Part All Bark Flower Fruit Leaf Plant Resin, Exudate, Sap Seed Low PPM High PPM StdDev *Reference 23 23 CITRIC-ACID Fruit -- -- * *Unless otherwise noted all references are to Duke, James A. 1992. Handbook of phytochemical constituents of GRAS herbs and other economic plants. Boca Raton, FL. CRC Press.