Pengeringan rosel dengan menggunakan mesin pengering

Abstract

The size of roselle calyxes was reduced by more than 60% after drying. Dried calyxes can be stored at room temperature and easily handled prior to processing into powder, candy and cordial. Drying can be carried out at 60–80 °C with no significant in quality differences. Drying at 80 °C shortened the drying time to about half as compared to drying at 60 °C. Commercial drying of roselle using large dryer with the capacity of about 200 kg at 70 °C took 9 hours. The drying cost was estimated at about RM53 per batch with the dried product recovery of about 11%. The colour of calyxes powder measured after drying (L* and a* value) was 33 and 23, i.e. an increase of 100% of initial colour measured on fresh calyxes. However, roselle powder that dissolved in water produced red solution with pH around 2.7. Abstrak