Dehydrated jasmine flowers obtained through natural convective solar drying retain scent volatiles and phenolics – A prospective for added-value utility

Although season-specific, Jasminum spp. are cultivated commercially for their sweet-scented flowers and their postharvest utility in various value-added products. However, to ensure year-round availability of quality floral biomass, jasmines are to be dehydrated and stored. In the present study, we attempted to dehydrate fresh jasmine flowers using a custom-made natural convective solar drying and compared the outcome with four widely used drying methods namely, sun drying, shade drying, oven drying and freeze drying. Subsequently, the retention capacities of scent volatiles and phenolics in dehydrated flowers of Jasminum auriculatum and J. sambac were compared. Total phenolic contents (TPC) were found to be high in both freeze dried and natural convective dried samples whereas the antioxidant capacity was high in natural convective dried samples. Phenolic acids viz. protocatechuic acid, vanillic acid, and caffeic acid were detected; these phenolic acids were shown to retain in higher amount in natural convective dried samples. Further, freeze and convective-dried flowers were also shown to retain maximum contents of scent volatiles. These observations suggest that custom-made low-cost natural convective solar dryer could be explored at large scale to obtain good quality dried flowers of Jasminum spp. for added-value utility.