Low Temperature Seaweed Drying Using Dehumidified Air

The seaweeds are the important commodities as raw material for food or additives. One of the popular seaweeds, Eucheuma cottonii, contains carrageenan for starch or fiber sources that can be applied for beverages or gelatin. Currently, the seaweed has been widely provided as dry product in order to minimize the cost for transportation as well as prolong storage life. However, current drying process still deals with energy in-efficiency and product quality degradation. The dehumidified air can be an option to retain the seaweed quality. With lower humidity, the driving force for drying can be improved in which shortened drying time. This research aimed to study the effect of air temperature, humidity, and velocity on seaweed drying. For supporting the study, the several drying kinetic models were developed to predict drying rate. Furthermore, the seaweed quality was evaluated based on rehydration ratio. Results showed that for all cases, drying at 70oC or below can provide reasonable drying time. The higher air temperature and air flow, the faster drying time. Meanwhile, the dehumidified air also affected drying time positively. In addition, the model based on Page is the best option to estimate the drying rate. For all drying condition, the rehydration ratio of dry seaweed was close to the initial wet condition. This implied that the dry seaweed was very suitable for food.