Drying of organic blackberry in combined hot air-infrared dryer with ultrasound pretreatment

Abstract

In this study, prediction and analysis of energy and exergy in a combined hot air-infrared dryer with ultrasound pretreatment for organic blackberry was carried out. The effect on product color and greenhouse gas (GHG) emission was assessed. To predict energy and exergy parameters such as energy utilization ratio, energy utilization, exergy loss, and exergy efficiency, both the artificial neural network (ANN) and adaptive neuro fuzzy inference system (ANFIS) methods were employed. Drying experiments were undertaken at three temperature levels of 50, 60, and 70 C in air speed of 1 m/s and ultrasound pretreatment time 15, 30, and 45 min, as compared to controlled samples (without pretreatment). Results demonstrated that by raising the inlet air temperature and ultrasound pretreatment time, color change rate decreased, while energy utilization and exergy efficiency increased. Energy and exergy prediction results by means of ANN and ANFIS methods showed that ANFIS method achieved a higher R2 and lower RMS as compared to ANN. The highest level of GHG emission (NO x , CO 2 ) was obtained at 50 C temperature for samples without pretreatment.

Optimization and Prediction of the Drying and Quality of Turnip Slices by Convective-Infrared Dryer under Various Pretreatments by RSM and ANFIS Methods

“…D eff will decrease as a result of a decline in the drying time [ 33 ]. Similar results were reported by other researchers for cranberry snacks [ 17 ], blackberry [ 30 ], and okra [ 42 ]. They declared that the use of different pretreatments can increase the moisture diffusivity coefficient compared to the control samples.…”

“…Fick’s law, Equation (2), can describe the moisture transport in the descending stage of the drying process [ 30 ]: …”

Application of Infrared Heating for Roasting Nuts

“…e low penetration power of infrared radiation is one of the limitations of this method. Also, prolonged exposure may cause fracturing in biological materials, and insensitivity to the reflective properties of the coating is another limitation of this technology [15,16].…”

“…Reducing roasting time and increasing roasting efficiency are advantages of combining IR with another heating method. e combination of infrared and hot air method has been extensively used for drying and roasting agricultural products, including organic blackberry [16], potato chips [35], sponge gourd slices [36], whole longans [37], pineapple rings [38], and murta berries [39]. e combination of these thermal methods intensifies the transfer of mass and heat, thus reducing the roasting time and energy consumption and increasing production efficiency [40,41].…”

Comparison between airborne ultrasound and contact ultrasound to intensify air drying of blackberry: Heat and mass transfer simulation, energy consumption and quality evaluation

“…Thus, it is of interest to use ultrasound technology to accelerate air drying of blackberry and protect the bioactives. To date, ultrasound has been merely used as a pretreatment for air drying of blackberry [22] , [25] , whereas neither airborne ultrasound nor contact ultrasound has been applied for blackberry dehydration.…”