Effects of Osmotic Dehydration on the Hot Air Drying of Apricot Halves: Drying Kinetics, Mass Transfer, and Shrinkage

Abstract

This study aimed to determine the effects of osmotic dehydration on the kinetics of hot air drying of apricot halves under conditions that were similar to the industrial ones. The osmotic process was performed in a sucrose solution at 40 and 60 °C and concentrations of 50% and 65%. As expected increased temperatures and concentrations of the solution resulted in increased water loss, solid gain and shrinkage. The kinetics of osmotic dehydration were well described by the Peleg model. The effective diffusivity of water 5.50–7.387 × 10−9 m2/s and solute 8.315 × 10−10–1.113 × 10−9 m2/s was calculated for osmotic dehydration. Hot air drying was carried out at 40, 50, and 60 °C with air flow velocities of 1.0 m/s and 1.5 m/s. The drying time shortened with higher temperature and air velocity. The calculated effective diffusion of water was from 3.002 × 10−10 m2/s to 1.970 × 10−9 m2/s. The activation energy was sensitive to selected air temperatures, so greater air velocity resulted in greater activation energy: 46.379–51.514 kJ/mol, and with the osmotic pretreatment, it decreased to 35.216–46.469 kJ/mol. Osmotic dehydration reduced the effective diffusivity of water during the hot air drying process. It also resulted in smaller shrinkage of apricot halves in the hot air drying process.

Osmotic Dehydration, Drying Kinetics, and Quality Attributes of Osmotic Hot Air-Dried Mango as Affected by Initial Frozen Storage

“…The falling-rate period of drying indicates that the rate of water removal from the surface by the hot air is higher than the water migration rate from inside to the surface of the sample, and therefore, the overall drying rate continuously declines as the moisture content is decreased [35]. This drying behavior has been reported by other authors in several raw materials, e.g., beetroot [12] and apricot [36]. It should be noted that the effect of freezing on drying behavior usually depends on the type of food.…”

Effect of Argan oil, thyme, and rosemary on the drying process of Sardina Pilchardus fillets

“…Such low values of X eq had a negligible effect on X(t), which depended mainly on the values of X(t) and X(0) (Pavkov et al, 2021).…”

“…The X eq values were a bit lower than the final moisture content of dried sardine fillets samples. Such low values of X eq had a negligible effect on X(t) , which depended mainly on the values of X(t) and X (0) (Pavkov et al, 2021).…”

Effect of Osmotic Dehydration Pretreatment on the Drying Characteristics and Quality Properties of Semi-Dried (Intermediate) Kumquat (Citrus japonica) Slices by Vacuum Dryer

“…It is possible to use different osmotic solutes in the food industry such as; sucrose, glucose, fructose, maltodextrin, sorbitol, sodium chloride, and their mixtures [ 14 , 22 , 23 , 24 ]. OD has been applied as a pre-processing step in fruits like lemon [ 25 ], kiwi [ 26 ], pineapple [ 27 ], and apricot [ 28 ]. This pre-treatment is usually conducted at mild temperatures [ 29 ].…”