Recently, it has been discovered that heat pump drying is an efficient method of drying for drying industries. Heat pumps deliver more heat during the drying process than the work input to the compressor. Heat pump drying is a more advanced method than the traditional South African industrial and agricultural drying methods, such as direct/indirect sunlight, wood burning, fossil fuel burning, e...

Experiments were undertaken to study the relationship between the drying constant and the shrinkage constant of food products during drying. Three particular geometrical shapes of parallelepiped, cylindrical and spheres were selected from potatoes (aspect ratio = 1:1, 2:1, 3:1), cut beans (length: diameter = 1:1, 2:1, 3:1) and peas, respectively. The volumetric shrinkage behaviour and drying be...

The drying kinetics of hawthorn in a pilot-scale experimental fluidized bed dryer with and without vibration was investigated. The effect of operating parameters, such as vibration intensity, drying air flow rate, and temperature, on the drying rate and shrinkage of hawthorn was studied. The hawthorn fruit was dried at various drying air temperatures ranging from 40-70oC and drying air volume f...

The objective of this work was to determine the effects of blanching and two drying methods, open-sun drying and natural convection solar drying, on the quality characteristics of red pepper. A 2 × 3 factorial design with experimental factors as 2 drying methods (open-sun drying and use of solar dryer) and 3 levels of pepper blanching (unblanched, blanched in plain water, and blanched in 2% NaC...

The quest for novel technologies in the area of food processing & preservation has led to the application of fluidization technique for enhancing the process capabilities, energy efficiencies and overall quality retention in the final products. However, this paper reviews the various fruits and vegetables dried in the fluidized bed dryer and their retention of sensory attributes in the dried pr...

Based on a review of 71 relevant publications all dealing with control aspects in drying, this paper aims to promote more works in common between drying and control communities. First, it is shown that the use of control tools really started to emerge in drying applications only since 1979. In a second phase started around 1998, new trends based on more advanced concepts have also appeared in d...

This study was done to determine the effects of different thermal drying methods (sun drying, microwave drying and hot air oven drying) on the total phenolic content (TPC), total anthocyanin content and the antioxidant properties of Vitex negundo (VN) tea. Significant decline (P < 0.05) in antioxidant properties of hot air oven drying shows that this method is not the best method to preserve an...

BACKGROUND Drying of nectarine slices was performed to determine the thermal and physical properties in order to reduce product deterioration due to chemical reactions, facilitate storage and lower transportation costs. Because nectarine slices are sensitive to heat with long drying period, the selection of a suitable drying approach is a challenging task. Infrared-vacuum drying can be used as ...

Drying of solid particles is generally divided into three periods: a short initial heating period, a constant drying rate period, and a falling drying rate period. Drying in a fixed under various drying conditions was experimentally studied. The main goals of the measurements were to calculate the heat transfer coefficient based on the measured values, and to evaluate the validity of the consta...