Effect of baffle on drying rate of peppercorns in a fluidized bed dryer

Abstract

Peppercorn is an important crop in Thailand which gives an export income 50-70 million baht per year.  The average capacity of peppercorn production is 3.5 million tons per year. Moreover, the product price tends to consistently increase. Peppercorn can be used not only as herbal ingredient in a variety of foods but also used as food flavor.  It contains essential volatile oils that help to preserve the food and extend shelf life. This paper studied the characteristics of drying peppers using a fluidized bed dryer fitted with baffle turbulators at various pitch ratios (PR = 0.5, 0.55, and 0.6) on drying rate (DR). During each test, the mass of pepper was measured every 15 minutes to determine moisture removal. It can be found that moisture content considerably decreased in the first 20 minutes and then gradually decreased before moisture became constant at 3 hr of drying.  In addition, the fluidized bed dryer fitted with baffle turbulators gave higher drying rate than a typical fluidized bed dryer (without baffle) by 20% at similar operating conditions.