Determination of drying kinetics and physicochemical characterization of apricot pomace in hot-air dryer

et al. 2020

Foods

The effect of hybrid infrared-convective (IRC), microwave (MIC) and infrared-convective-microwave (IRCM) drying methods on thermodynamic (drying kinetics, effective moisture diffusivity coefficient (Deff), specific energy consumption (SEC)) and quality (head rice yield (HRY), color value and lightness) characteristics of parboiled rice samples were investigated in this study. Experimental data were fitted into empirical drying models to explain moisture ratio (MR) variations during drying. The Artificial Neural Network (ANN) method was applied to predict MR. The IRCM method provided shorter drying time (reduce percentage = 71%) than IRC (41%) and microwave (69%) methods. The Deff of MIC drying (6.85 × 10−11–4.32 × 10−10 m2/s) was found to be more than the observed in IRC (1.32 × 10−10–1.87 × 10−10 m2/s) and IRCM methods (1.58 × 10−11–2.31 × 10−11 m2/s). SEC decreased during drying. Microwave drying had the lowest SEC (0.457 MJ/kg) compared to other drying methods (with mean 28 MJ/kg). Aghbashlo’s model was found to be the best for MR prediction. According to the ANN results, the highest determination coefficient (R2) values for MR prediction in IRC, IRCM and MIC drying methods were 0.9993, 0.9995 and 0.9990, respectively. The HRY (from 60.2 to 74.07%) and the color value (from 18.08 to 19.63) increased with the drying process severity, thereby decreasing the lightness (from 57.74 to 62.17). The results of this research can be recommended for the selection of the best dryer for parboiled paddy. Best drying conditions in the study is related to the lowest dryer SEC and sample color value and the highest HRY and sample lightness.

Section: Mathematical Modelingsupporting

confidence: 94%

Parboiled Paddy Drying with Different Dryers: Thermodynamic and Quality Properties, Mathematical Modeling Using ANNs Assessment

Taghinezhad

Szumny

et al. 2020

Foods

“…Higher decrease in moisture at the product's surface causes the product's center and surface moisture gradient to increase and the moisture to move faster inside the product and thus increases the D eff . The D eff value for drying eggplants in a US‐CON dryer was between 3.31 × 10 –9 and 11.16 × 10 –9 m 2 /s (Garcia‐Perez, Ozuna, Ortuño, Cárcel, & Mulet, ), it was between 2.45 × 10 –9 and 2.94 × 10 –9 m 2 /s for grapes in a US‐CON dryer (Garcia‐Perez, Carcel, Simal, Alvarado, & Mulet, ) it varied within the range of 1.01 × 10 –9 and 1.85 × 10 –9 m 2 /s for apricots in a convective dryer (Kayran & Doymaz, ) and its ranges for the leaves of olive trees were from 1.48 × 10 –9 to 6.59 × 10 –9 m 2 /s in a microwave dryer, from 0.053 × 10 –9 to 0.44 × 10 –9 m 2 /s in a hot air convective dryer and from 0.11 × 10 –9 to 0.62 × 10 –9 m 2 /s in a vacuum dryer (Elhussein & Şahin, ).…”

Section: Resultsmentioning

confidence: 99%

The effect of microwave and convective dryer with ultrasound pre‐treatment on drying and quality properties of walnut kernel

Abbaspour‐Gilandeh

Jahanbakhshi

2019

J Food Process Preserv

In this study, the drying kinetics of walnuts was investigated including specific energy consumption (SEC), shrinkage, and walnut kernels' color in two dryers, namely ultrasonic‐convection (US‐CON) and ultrasonic‐microwave (US‐MIC). To carry out this study, walnut samples were dried at three MIC powers (270, 450, and 630 W), three input air temperatures (40, 55, and 70°C) and four duration of ultrasonic pre‐treatment (0 min (control sample), 10, 20, and 40 min). Fifteen mathematical models were used to describe the walnuts' moisture ratio. The results showed that the Midilli et al. model was the best model for describing the process of drying walnuts in US‐CON and US‐MIC dryers. Effective moisture diffusivity (Deff) values were calculated to be between 2.77 × 10–9 and 5.56 × 10–9 m2/s for the US‐CON dryer and 3.12 × 10–9 to 8.99 × 10–9 m2/s for the US‐MIC dryer. The lowest rates of color change were observed in the US‐MIC dryer at the lowest microwave power and the lowest duration of ultrasonic pre‐treatment. The lowest SEC for the US‐CON dryer was 19.52 kWh/kg, and it was 15.90 kWh/kg for the US‐MIC dryer. The highest rate of shrinkage was 14.21%, which was seen in the US‐CON dryer at the air temperature of 70°C and the duration of ultrasonic pre‐treatment of 40 min. According to the results, the best quality of walnut with the lowest changes of color and shrinkage in the microwave dryer was calculated at microwave power 270 W and control sample. Practical applications Drying foods and agricultural products using microwave dryers is a relatively cheap method and has attracted the attention of many researchers today. Also, numerous studies have been conducted on drying agricultural products through microwave and convection dryers with ultrasound pre‐treatment. The result of this study could be applied for gathering comprehensive information regarding the drying process (kinetic, Deff, Ea, and SEC) as well as the qualitative properties (color and shrinkage) of walnut kernels dried using the microwave and convective hot air dryers accompanied by ultrasound pre‐treatment.

“…Diffusion is a principal mechanism during moisture movement to the surface which is vaporized (Salehi, Kashaninejad, & Jafarianlari, ). The second law of Fick's diffusion described the drying process during the decreasing rate period for more foodstuffs (Amiri Chayjan et al, ; Kaveh & Amiri Chayjan, ; Kayran & Doymaz, ). The second Fick's law for effective moisture diffusivity in thin layer drying was proposed as (Crank, ):

MR = \frac{(M - M_{normale})}{(M_{normali} - M_{normale})} = \frac{8}{{normalπ}^{2}} \sum_{n = 1}^{\infty} \frac{1}{{((), 2 n - 1)}^{2}} \exp ((), - {(2 n - 1)}^{2} π^{2} t \frac{D_{eff}}{4 L^{2}})

where, L is the half thin layer thickness (m) and t is the drying time (s).…”

Section: Methodsmentioning

confidence: 99%

“…Drying modeling of agricultural products is used for improving available drying systems, anticipation the air flow over the product, developing new designs and improving the control process (Aghbashlo, Kianmehr, & Samimi-Akhljahani, 2008;Mirzaee et al, 2010). Some published article are about mathematical modeling of different dried products such as Amiri Chayjan, Kaveh, and Khayati (2017), Kaveh, Amiri Chayjan, and Nikbakht (2017), Kayran and Doymaz (2017), Sarimeseli, Coskun, and Yuceer (2014) and Sahin and Doymaz (2017). But, such models are very complex and time consuming.…”

Section: Introductionmentioning

confidence: 99%

Using PSO and GWO techniques for prediction some drying properties of tarragon (Artemisia dracunculus L.)

Karami

J Food Process Engineering

Mirzaee‐Ghaleh

et al. 2018

In this article, the effects of air temperature and velocity on drying characteristics of tarragon (Artemisia dracunculus L.) were investigated. The experiments were done at four temperatures of 40, 50, 60, and 70 °C and three air velocities of 1, 1.5, and 2 m/s. According to the results, the drying term of tarragon reduced significantly with increasing drying air temperature. The values of effective moisture diffusivity (Deff) were ranged between 1.34 × 10−10 and 2.74 × 10−10 m2/s. Also, by increasing drying air temperature the values of specific energy consumption (SEC) were decreased. The values of SEC were between 20.50 and 66.90 MJ/kg. Also Deff and SEC values were modeled by particle swarm optimizer (PSO) and gray wolf optimizer (GWO) algorithms. Drying air velocity and air temperature were considered as input parameters for the models. Based on three statistical parameters includes R2, MSE, and MAE for predicting Deff and SEC, GWO performance was better than the PSO. Practical applications The purpose of drying crops is decreasing of moisture content for providing secure storage and significant influence on the quality of dried crops. In this research, the effective moisture diffusivity (Deff) and specific energy consumption (SEC) values were modeled by PSO and GWO algorithms. The procedure can be applied in postharvest processing of medicinal plants.