Shukra is in no way related to Sugar( Sweet), Shukra in a real sense means the reproductive fluids, these fluids or Shukra emerge out of all the other six Dhatus of Ayurved. The other meaning of Shukra is Venus the planet and as per Six tastes thus assigned in Vedic astrology Shukra or Venus represents the sour taste, and the sweet taste is assigned to Jupiter.