D-Mannitol is one of the most abundant sugar alcohols in nature. It can be produced in the biosphere by a range of organisms such as bacteria, yeast, fungi and almost all plants. Mannitol functions as a carbohydrate storage depot, as a scavenger for reactive oxygen species and as an osmoprotectant. Recent studies have shown that increased mannitol content in plants protects them against fungal infections and improves resistance to drought and high salinity. The mannitol pathway reversibly converts fructose to mannitol and serves as the main carbohydrate cycle for fungi survival. Measurement of mannitol level is important for evaluating mannitol metabolic pathways and commercially, in developing fungi and drought resistant plants. In BioVisi