Optimization of drying protocols for Dendrobium cv. Emma white for quality dry flower production

An investigation was carried out at the ICAR-Indian Institute of Horticultural Research, Bengaluru to study the influence of drying methods and desiccants on the quality of dried florets of Dendrobium orchid cv. Emma White. The experiment comprised 8 treatment combinations involving two drying methods viz., microwave oven and hot air oven in combination with four different desiccants viz., silica gel, borax powder, sand and silica gel+ borax powder + sand (1:1:1 v/v). The study was designed as a completely randomized factorial experiment (FCRD) with three replications. Hot air oven drying using silica gel as the desiccant resulted in the highest weight loss (86.37%), moisture loss (84.96%) and the lowest moisture content (13.63%) along with the minimum reduction in floret diameter (0.56 cm). Sensory evaluation of the dried florets based on colour, shape, petal texture and mechanical damage during drying revealed that the hot air oven drying using silica gel as a desiccant recorded the highest scores for colour, shape and petal texture with minimal mechanical damage. In contrast, microwave oven drying with sand as the desiccant had the lowest scores for colour, shape, petal texture and the recorded highest level of mechanical damage. During storage, florets embedded in silica gel and dried in a hot air oven retained the best scores for colour, shape and recorded the least mechanical damage.