Fennel seed is a more alkalizing food than many. In general green vegetables and seeds are alkalizing after digestion while animal and dairy products are more acid forming. The pH of the undigested food is not what is being measured. It is a measurement of the ash/chemicals that are produced during digestion that are measured. Lime and lemon juice are acidic but their affect in digestion turns alkalizing.
Lists of alkalizing foods and foods that have more of an acidic effect after digestion: http://www.alkalizingforlife.com/page/page/5128908.htm
A more acidic system may be associated with an increased risk for cancer as cancer cells prefer a more acid environment. During health our bodies are naturally slightly more alkaline than acidic.
Fennel seed is available as a powdered spice. And pomegranate extract of some sort is also available in a capsule form. A capsule would be a small amount compared to a half cup serving of a liquid product but the capsule is dehydrated so it is more concentrated than a liquid juice product.
Disclaimer: Opinions are my own and the information is provided for educational purposes within the guidelines of fair use. While I am a Registered Dietitian this information is not intended to provide individual health guidance. Please see a health professional for individual health care purposes.