Watermelon production has become important in West Africa, but the transformation of this fruit rich in water and micronutrients is a weak link of the sector. The objective of this process is to develop new technologies of using watermelon. The process consists in parboiling paddy rice with watermelon juice. Paddy rice is spread on trays to solar dry and then the drying is finalized in the shade. This system reduced moisture content of paddy rice below 13% for its conservation and shelling. This new transformation process significantly increases the content of L-citrulline and L-arginine two amino acids that play an important role in human metabolism.