Optimisation of drying of French marigold (Tagetes patula Linn.) flowers.

摘要

Drying experiments were carried out to optimise the drying conditions for French marigold (Tagetes patula Linn.) flowers (var. Jafri). The effects of temperature (45-65 degrees C), potassium metabisulphite (KMS) soaking (0.1-0.9%) and air velocity (2-3 m/s) on shrinkage ratio, colour change and organoleptic score were evaluated using response surface methodology. Air velocity in the selected range had no effect on the drying process. Application of graphical optimization technique revealed that drying of flowers in thin layers at 58-63 degrees C with pre-treatment of 0.85-0.90% KMS solution for 15 minutes at an air velocity of 2 m/s resulted in flowers with shrinkage ratio, SR>0.4; colour difference, Delta E<15; and organoleptic score, OS>8.0..