No abstract

The effect of pretreatment and infrared power on drying characteristics of apricot was investigated. The apricots were dried at 62, 74, 88 and 104 W infrared powers. It is observed that drying characteristics of apricot were greatly influenced by pre‐treatment and infrared power. To select the most appropriate thin‐layer drying model for drying process, ten mathematical drying models were fitted to the experimental data. Midilli et al. model satisfactorily described the drying kinetics of apricot. Effective moisture diffusivity (Deff) ranged from 2.37 × 10−9 to 6.23 × 10−9 m2/s and calculated using the Fick's second law. The values of Deff increased with the increase of infrared power. Activation energy was estimated by a modified Arrhenius type equation and found to be 1.63 and 1.67 kW/kg for control and SMB samples, respectively. Practical Applications Apricot is good source of health‐promoting compounds such as vitamins, polyphenols, carotenoids and natural salicylic acids. Due to both their seasonal and perishable nature, apricots should be subjected to some form of preservation in order to make them available for later consumption. Drying is one of the most common methods used for apricot processing. Infrared drying has gained popularity as an alternative drying method for a variety of agricultural products. Compared with hot air drying, infrared radiation heating offers many advantages such as greater energy efficiency, heat transfer rate and heat flux, which results in reduced drying time and higher drying rate. The main objectives of this study were to investigate the effect of pretreatment and infrared power on the drying time, fit the experimental data to ten thin‐layer drying models and compute effective moisture diffusivity of apricot halves.

The effect of temperature and pre-treatment on drying kinetics and color parameters of apricot was investigated. The apricots were dried at 50, 60, 70, and 80°C and constant air velocity of 2.0 m/s in cabinet dryer. Sodium metabisulfite solution (8%, w/w) was applied to 10 min prior to drying process. It was observed that both the drying temperature and the pretreatment affected the drying and color parameters. The drying times of pretreated samples were 6.49-20% shorter than those of control samples. To select the most appropriate thin-layer drying model for drying treatments, 10 mathematical drying models were fitted to the experimental data. Midilli & Kucuk model satisfactorily described the drying kinetics of SMB and control apricots. Effective moisture diffusivity ranged from 6.85 × 10 −10 to 2.10 × 10 −9 m 2 /s for control, between 7.83 × 10 −10 and 2.49 × 10 −9 m 2 /s for SMB samples calculated using the Fick's second law. Activation energy was estimated by using an Arrhenius type equation and found to be 34.25 kJ/mol and 35.39 kJ/ mol control and SMB samples, respectively.

Effect of infrared powers (62, 74, 88, 104 and 125 W) on drying kinetics of apricot pomace was investigated. It is observed that drying characteristics of apricot pomace were greatly influenced by infrared power. Henderson and Pabis model was investigated for describing thin-layer drying of apricot pomace. The model because of the high coefficient of determination (R2) as well as the lowest reduced chi-square (c2) and root mean square error (RMSE) values adequately described the experimental data of apple pomace drying. Effective moisture diffusivity (Deff) values were increased by increasing infrared power and changed between 1.67×10-9 and 6.03×10-9 m2/s. Activation energy was estimated by a modified Arrhenius type equation and found to be 2.32 kW/kg. The colour results were affected by drying conditions.