Thanit Swasdisevi, Sakamon Devahastin, Rittigrai Ngamchum and Somchart Soponronnarit

pp. 809 - 816

Abstract

The application of far infrared radiation (FIR) to vacuum drying is interesting since FIR leads to higher drying rates and yields the dried product of better quality. In this work far infrared radiation drying of Cavendish banana slices under vacuum was investigated. Cavendish banana slices with an initial moisture content of 300%(d.b.) were dried at various vacuum pressures (5, 10 and 15 kPa), temperatures (50, 55 and 60°C) and thicknesses (2, 3 and 4 mm) until the final moisture content of 7% (d.b.) was reached. The results
revealed that the vacuum pressure, temperature and thickness had significant effects on the drying kinetics and various qualities of the dried banana viz. color, hardness and shrinkage. Combined FIR-vacuum drying shows good potential of producing a fat-free shuck-like product from banana. In addition, the optimum condition for infrared-vacuum drting is at temperature of 50°C, pressure of 5 kPa and thickness of 2 mm.

Keywords

• drying kinetics
• color
• hardness
• shrinkage
• temperature distribution