The juicy pulp of Jamun/ Jambo fruit contains resin, gallic acid and tannin, and the taste can vary from acidic to fairly sweet. The Jamun seed is known to contain a bio-chemical called jambolin and glycoside, which is believed to check the conversion of starch into sugar. It is also a rich source of vitamins A & C. Popular name(s): Jambul, Jamun, Black Plum, Faux Pistachier, Indian Blackberry, Jambol, Doowet and Jambolan.