Intermittent Microwave Drying Research Articles

Heating uniformity improvement of the intermittent microwave drying for carrot with simulations and experiments

AbstractHeating uniformity is always a concern in microwave drying for foodstuff, where unsatisfied product quality could be caused by over‐ or inadequate‐heating. To deal with this concern, multi‐physics field rotation simulation models and intermittent microwave drying modes were designed and evaluated in this study. Four drying modes with different intermittent time ratios (R1/2, R1/3, R1/4, and R1/5) were first applied in drying experiments. Their effects on temperature distribution, drying characteristics, and quality aspects (chromatic aberration, rehydration ratio, vitamin C content, and sensory evaluation) for carrot samples were compared and analyzed. The results revealed that the carrot quality in R1/4 mode drying was increased by up to 64% in comparison with the other three modes. The root‐mean‐square error of the moisture ratio was maintained at a lower value, and a better consistency was also achieved in R1/4 mode. To further improve the drying performance and efficiency, a novel stage intermittent‐time control strategy was attempted, that is, an appropriate strategy was used in each drying stage. With this method, the best drying effect could be obtained. The above work can promote a deeper understanding of the drying kinetic and provide novel operation strategies in the microwave drying of food products.Practical applicationsA multi‐physics field rotational simulation model (MFRSM) coupled with an intermittent microwave drying process, including electromagnetic heating, heat, and mass transfer, was developed to characterize the drying process of rotating samples in an intermittent microwave dryer. The MFRSM was helpful to analyze the continuous microwave drying process of the sample and deepen the understanding of the internal heat and mass transfer process of the sample. Four modes with different intermittent schedules were designed, and simulation models were also established. The drying characteristics in different modes were analyzed; a long intermittent time could affect the drying efficiency on account of the driving force, while a short intermittent time would reduce the product quality because of the continuous high temperature. R1/4 mode was founded in terms of drying efficiency and drying quality. An optimized stage intermittent‐time control strategy (R‐IO mode) was designed. The drying time in the three stages was shortened by 25% in total compared with R1/4 mode. Meanwhile, the vitamin C retention, the taste quality of the dried products were improved. These works are expected to provide benefits for the understanding of the intermittent microwave drying modes on drying kinetic using the MFRSM. It can also be useful in the development of an IMD for food materials.

Quality and energy efficiency evaluation of Rosmarinus officinalis L. by intermittent and continuous microwave drying: Polyphenol composition, bioactive compounds quantification, antioxidant properties, physical characteristics, and energy consumption

AbstractImproper drying is one of the major causes of beneficial bioactive compounds' degradation in bio‐crops together with high energy consumption. Preservation of the compounds is crucial in retaining the bioactivities of the herbs with diverse industrial applications. Continuous microwave drying (CMD), despite being effective and efficient, has not merged with the industry as process intensification due to the challenges of overheating. This study investigates the application of intermittent microwave drying (IMD) on rosemary and its compounds, to address the issues of overheating and the subsequent loss of bioactive compounds resulting from CMD. This technology is implemented through the application of microwaves in a periodic on/off manner. Although CMD had the shortest drying duration (>20 min) and the highest drying rate (0.431 kg H2O/kg DB min), IMD had the highest effective diffusivities (1.292 × 10−10 m2/s) indicating better moisture kinetics and evaporation. CMD exhibited favorable physical characteristics of shrinkage (83.40%), bulk density (669.23 kg/m3), and rehydration capacity (34%). However, both methods displayed high antioxidant activity (90.36%–93.78% inhibition). Higher compound concentrations of Carnosic acid (4.85 mg/g), Carnosol (6.86 mg/g), and Rosmarinic acid (14.36 mg/g) were achieved using IMD. Lastly, IMD had a higher energy efficiency (1.70%) than CMD due to drying by residual heat generation and redistribution.Practical applicationDrying is a crucial first post‐harvest process to preserve aromatic and medicinal herbs and plants for downstream processing. However, the sensitive and diverse nature of bioactive compounds makes it practically impossible to implement one drying technology to process all. Microwave technology is highly favored by researchers as well as industries to replace traditional convective hot air drying due to its effectiveness and higher efficiency. Nevertheless, the overheating issue from the continuous microwave is still a challenge while processing delicate herbs and their bioactive compounds. Especially, herbs like rosemary which possesses thermolabile compounds. The current study implements microwave technology periodically to benefit from sustainable drying via microwave without overheating and subsequent loss of bioactive compounds. The outcome of this study demonstrated the effectiveness of the intermittent microwave technology which proved to be more energy efficient than continuous microwave while retaining higher bioactive compound concentration in rosemary leaves.

Pore Evolution in Cell Walls of Food Tissue during Microwave-Assisted Drying: An In-Depth Investigation.

Microwave (MW) heating is a unique approach that, unlike conduction- and convection-based heating, can provide volumetric heating. Complex microstructural changes in food materials occur because of simultaneous heat and mass transfer during drying, significantly affecting food structure and quality. Food properties, drying methods, and other drying parameters all have an impact on the microstructure of food samples, which in turn affects drying kinetics and food quality. However, no study has been undertaken to investigate the development of nano-micro-pores (NM-pores) on the cell walls and their relationship with the moisture migration mechanism. This study presents a novel investigation of the microstructural changes in food during microwave drying, with a focus on the formation of nano-micro-pores (NM-pores) on cell walls and their impact on moisture transport kinetics. The utilized hot air was maintained at a temperature of 70 °C, whereas microwave (MW) power levels of 100 W, 200 W, 300 W, and 400 W were used in microwave drying. The findings of the study indicate that the development of NM-pores occurs only during intermittent microwave drying (IMCD), while the cell wall of the food samples tends to burn or collapse in continuous microwave drying (CMD) due to the high heat generated. Additionally, no NM-pores were observed in the cell wall during convective drying. During IMCD with microwave power ranging from 100 W to 400 W, a range of pore sizes from 0.1 μm to 8.5 μm were observed. Due to the formation of NM-pores and collapses, MW drying takes around 10-20 times less time than convective drying to remove the same quantity of moisture. The effective moisture diffusivity values were found to be the highest in CMD at 4.70 × 10-07 m2/s and the lowest in CD at 2.43 × 10-09 m2/s. IMCD showed a moderate diffusivity of 2.45 × 10-08 m2/s. This study investigates the formation of NM-pores on cell walls during microwave drying and their impact on moisture transport kinetics and establishes correlations between microstructure modifications and moisture migration pathways.

Intermittent Microwave Drying Characteristics and Quality Changes of Xilin Fire Ginger Slices

Intermittent Microwave Drying Characteristics and Quality Changes of Xilin Fire Ginger Slices

Study on the effect of intermittent microwave drying conditions on the bioactive compounds and antioxidant capacity of beetroots

The object of this research was the beetroots prepared by intermittent microwave drying at different conditions. The paper aimed to investigate the influence of intermittent microwave drying conditions (power density, microwave gap ratio and slice thickness) on the bioactive compounds and antioxidant capacity of beetroots. A microwave drying system SAM-255 (CEM Corporation, USA) was used to intermittent microwave drying of fresh beetroots. The effect of different power densities (1.0, 1.5, 2.0, and 2.5 W/g), microwave gap ratios (1, 2, 3, and 4) and slice thicknesses (2, 4, 6, and 8 mm) on the bioactive compounds and antioxidant capacity of beetroots were investigated. Colorimetric methods were used to determine contents of betalains, total phenolic and total flavonoid, and antioxidant capacity of dried beetroots. The ascorbic acid content was determined using 2,6-dichloroindophenol titration method. Results showed that power density, microwave gap ratio and slice thickness significantly affected the drying time, bioactive compounds and antioxidant capacity of beetroots. The drying time decreased with the increasing of power density, while increased significantly with the growth of slice thickness and microwave gap ratio. The shortest drying time (35.4±2.6 min) of beetroots was occurred at microwave gap ratio of 2. The content of betacyanins was found to be the highest in the dried beetroots with thickness of 2 mm. The beetroots with slice thickness of 2 and 4 mm showed the highest betacyanins content. Moreover, the highest content of ascorbic acid (240.00±2.32 mg/100 g) and total flavonoid (14.52±0.06 mg rutin equivalent (RE)/g) was appeared at power density of 2.0 W/g, while the content of total phenolic to be highest (12.54±0.13 mg gallic acid equivalent (GAE)/g) at slice thickness of 6 mm. For the antioxidant capacity of dried beetroots, the 1,1-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity reached to the highest value of 6.43±0.03 mg trolox equivalent (TE)/g at power density of 2.5 W/g. While the highest values of ferric-reducing antioxidant power (FRAP) (15.47±0.10 mg TE/g) and 2,2′-azino-bis-(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical scavenging activity (25.31±0.30 mg TE/g) at microwave gap ratio of 2. It was found that ABTS radical scavenging ability and FRAP were related to the presence of reductions including betalains, ascorbic acid, and total flavonoid in beetroots. The most effective condition for intermittent microwave drying of beetroots were microwave gap ratio of 2, power density of 2.0 W/g, and slice thickness of 4 mm, leads to a better preservation of bioactive compounds and high antioxidant capacity.

Effect of intermittent microwave drying on nutritional quality and drying characteristics of persimmon slices

The novelty of this paper was to evaluation the effect of intermittent microwave drying (IMD) on the nutritional quality and drying characteristics of persimmon slices. Persimmon slices were treated with IMD at the microwave power levels of 280, 350, 420, 490, and 560 W, and the drying characteristics, nutritional components, and sensory properties were determined and analyzed. The results showed that the drying process of persimmon slices could be divided into three stages; increasing speed, constant speed, and decreasing speed. Meanwhile, the higher the microwave power, the shorter the drying time and the higher the drying rate. With the increase of microwave power, the contents of soluble sugar, soluble tannin, vitamin C, and ash increased gradually, but had no obvious effect on the content of insoluble tannin, while the contents of soluble protein and vitamin E decreased gradually, and the overall acceptability score increased first and then decreased. In this study, the comprehensive scoring method was used for dried persimmon slices. The optimal microwave power for IMD persimmon slices was determined to be 490 W, which could effectively improve the drying rate and nutritional value, and has good sensory acceptability.

Study on the Effect of Intermittent Microwave Drying Conditions on the Bioactive Compounds and Antioxidant Capacity of Beetroots

Study on the Effect of Intermittent Microwave Drying Conditions on the Bioactive Compounds and Antioxidant Capacity of Beetroots

Intermittent microwave drying and heated air drying of fresh and isomaltulose (Palatinose) impregnated strawberry

Fresh and osmotically pretreated (using a 35% isomaltulose solution) strawberries are highly perishable. This work aimed to dry them by intermittent microwave drying (IMD) and heated air drying (HAD) and evaluate their qualitative parameters. The sample temperature was monitored during IMD, adopting a setpoint temperature of 60 °C and continuous airflow, at room temperature. The HAD was performed by exposing the samples to air at 60 °C. IMD stood out for being faster (up to 64.91%) and consuming less energy (up to 73.16%) than HAD. During IMD, the magnetron was off for most of the time (up to 74.13%). The isomaltulose impregnation reduced drying rates in both methods, increasing drying time. Dried samples showed water activity (aw) within the safe range (aw<0.6). The impregnation process was carried out to a reduced shrinkage product besides the enrichment with isomaltulose. Non-pretreated strawberries had lower aw, hardness, and total color difference, and higher levels of bioactive compounds and antioxidants, especially with the IMD method. Retentions of up to 47.46%, 70.26%, and 81.18% of anthocyanins, phenolic compounds, and antioxidant capacity were obtained by IMD, respectively, concerning fresh strawberries. Therefore, IMD was an interesting alternative for fresh and impregnated with isomaltulose strawberries drying.

Numerical analysis of heat and mass transfers during intermittent microwave drying of Chinese jujube (Zizyphus jujuba Miller)

A 3-D coupled electromagnetics, heat transfer, and mass transfer model for intermittent microwave drying of jujube fruit was developed to understand and optimize the effect of duty cycle (power level) and initial moisture on the temperature and moisture distributions and the rate of drying. The model was validated using measured temperature, pressure, and moisture content histories. A comprehensive understanding of the spatial and time evolutions of temperature, moisture, pressure, microwave power absorption, and evaporation rate were obtained. A uniformity index for temperature and moisture, that more closely relates to quality, was computed as drying progressed, providing unique insight into how the power level can affect quality in such a complex drying process. The effect of duty cycling was clearly seen, showing a sharp increase in temperatures, evaporation rate and pressure during the ON-phase, followed by decrease during the OFF-phase. Moisture profiles tracked the temperature cycling. Low moisture samples heated more spatially uniformly at relatively lower temperatures and with more uniform moisture profiles. Lower duty cycles (effectively lower power) reduced both the rate of temperature rise and the moisture loss, while improving the uniformity of temperature and moisture. The model provided a comprehensive mechanistic insight into the complex microwave drying process that would greatly reduce the time and resources in the design of product, process, and equipment.

Drying of foods under intermittent supply of microwave energy: proposal for a mathematical model

Intermittent microwave drying improves the quality of the dehydrated product, because reduces the effect of microwave hot spots. Mathematical modelling is essential to understand the physics of this drying process and to optimize the operation conditions. However, there are few modelling studies about intermittent microwave drying. This work proposed a mathematical model based on mass balances of liquid and vapor water in which a non-equilibrium formulation described the water phase change. The microwave heating, described by Lambert’s law, was accounting as source term on the thermal energy conservation equation. The numerical solution used the finite element method, and the experimental drying of potato samples validated the simulated drying. The values of moisture content and temperature obtained by numerical solution of the model showed good agreement with experimental data. From this, it was observed the presence of three periods in the drying kinetics: an initial heating phase almost without drying, follow by a phase with constant drying rate, and final a decrease of drying rate and temperature increasement. The model results showed that the interior temperature was higher than the surface temperature of sample, and there was water evaporation inside the potato. In additional, the gradients of temperature were reduced due to intermittency of the microwave power. This redistribution of temperature could contribute to the improvement of product quality during drying.

Effects of intermittent microwave drying conditions on characteristics and physical properties of beetroots

Effects of intermittent microwave drying conditions on characteristics and physical properties of beetroots

Comparative assessment of volatile and phenolic profiles of fresh black carrot (Daucus carota L.) and powders prepared by three drying methods

Drying is a common method in the post-harvest processing of fruits and vegetables and it can play a crucial role on the quality of the final product. This work examined the influence of three drying processes (freeze-drying: FD, intermittent microwave drying: IMWD and hot air convective drying: HACD) on the aroma and phenolic constituents of black carrot which is an essential vegetable in terms of its nutritive and health benefits. It was found that the drying process had substantial effects on the aroma and phenolic compositions of the black carrot powder samples. GC–MS analysis revealed a total of 32 volatiles in all samples. The FD samples had more numbers of aroma compounds after the fresh samples. Prevailing aroma groups were terpenes and alcohols. The highest amount of volatiles was found in the FD samples meaning that the FD played a crucial role in conserving the volatiles as compared to the HACD and IMWD. HPLC-DAD-ESI-MS/MS analysis yielded 34 constituents including 22 colorless phenolics and 12 anthocyanins. Regarding the phenolics, the highest amount was quantified in the HACD and IMWD samples. Chlorogenic acids were the major phenolic acids. The FD and IMWD caused a decline in the amount of anthocyanins while HACD resulted in an increase. Sensory analysis revealed that the FD method conserved the aroma to a greater extent and its overall acceptability was higher.

Power control in microwave drying of green turnip

In microwave (MW) drying, the adjustable incident MW power is preferred to improve the product quality and reduce energy consumption. However, the control of incident MW power during the drying process is still a challenging task. By comparing continuous and intermittent microwave drying with gradually reduced microwave power, a control strategy in microwave drying of the green turnip taproot was proposed, based on the experimentally determined dielectric properties and the variation of the electric field intensity with temporal moisture content. The experiments show that such a power control results in higher rehydration ratio of dried green turnip and reduction in energy consumption than these in the continuous and intermittent microwave drying. Moreover, such a power control strategy can maintain the material temperature within the set values with low fluctuations.

Impact of production and drying methods on the volatile and phenolic characteristics of fresh and powdered sweet red peppers

Aroma, phenolic compounds and sensory properties of fresh and powdered organic and conventional sweet red peppers dried by three methods (hot air, intermittent microwave and infrared) were studied. The number of aroma compounds was higher in both fresh and powdered organic pepper samples; however, the total amount was higher in conventional samples. In both organic and conventional samples, alcohols were the dominant aroma group. (E)-β-ionone and β-ocimene, which are important compounds in peppers, were determined only in organic peppers. Among the drying methods, intermittent microwave drying was more effective in creating new aroma compounds. The liquid chromatography, coupled with tandem mass spectrometry (LC–MS/MS) revealed that luteolin derivative compounds comprised an average of 70% of the phenolics. Higher amount of phenolic were determined in organic samples. Infrared drying was more effective in retaining of phenolics than the other two methods. Sensory analysis revealed that hot air-dried samples were least preferred.

Mathematical Modeling, Moisture Diffusion and Color Quality in Intermittent Microwave Drying of Organic and Conventional Sweet Red Peppers

The aims of this research were to evaluate the influence of intermittent microwave drying on the moisture diffusion and color qualities of organically and conventionally grown sweet red peppers and mathematically express drying kinetic data. Pepper samples of 150 g were dried at 150, 300 and 450 W using a microwave oven. Results showed that intermittent microwave drying at 450 W occurred mainly in the falling rate period, whereas drying at lower powers resulted in relatively longer constant rate periods for both peppers types. The Midilli model provided the best fit for all data. The moisture diffusivity (Deff) values of organic and conventional samples ranged from 59.69 × 10−10 to 182.01 × 10−10 m2s−1 and from 59.11 × 10−10 to 181.01 × 10−10 m2s−1, respectively, and the difference was insignificant. The pre-exponential factor for the Arrhenius equation (D0) and activation energy (Ea) values were almost identical for both product types. Overall, organic or conventional growing did not alter the structural features related to the heat transfer properties. Intermittent microwave drying at 150 and 300 W for organic peppers and 150 W for conventional peppers gave the highest ΔL*, Δa* and a*/b* values, producing the most bright and red pepper powders. Thus, these treatments can be used to produce higher color quality powders.

Intermittent Microwave Drying of Apple Slices: Drying Kinetics, Modeling, Rehydration Ratio and Effective Moisture Diffusivity

In this research, thin layer drying characteristics, rehydration ratio and effective moisture diffusivity of apple were investigated using microwave dryer which has intermittent and continuous modes. Drying time varied between 25 and 215 minutes and they declined with the rise in microwave power and reduction in pulsing ratio. In an attempt to pick the optimum thin layer models for the drying applications, 8 mathematical models suited to the experimental results. On the grounds of the statistical tests evaluation, Midilli et al model which represent drying characteristics are optimally suited than other models. The highest rehydration ratio was recorded for the samples dried at 100W continuous mode and the lowest ratio at 300W continuous application. Effective moisture diffusivity values were computed by the 2nd law of Fick and changing between 3.04x10-9 and 2.53x10-8 m2 s-1. Consequently, the intermittent microwave method could be used as a favorable drying method for obtaining high-quality fruit slices or processing valuable material and continuous microwave drying can be taken as another drying approach for apple samples.

Instant controlled pressure drop (DIC) coupled to intermittent microwave/airflow drying to produce shrimp snacks: Process performance and quality attributes

Effects of operating parameters of the instant controlled pressure drop (DIC) texturing process followed by intermittent microwave (MW) and airflow drying were studied for the manufacture of novel swell-dried shrimp snacks. The DIC processing parameters were the absolute pressure of saturated steam (P = 0.4, 0.55, and 0.7 MPa) and the treatment time (t = 70, 100, and 130 s). Intermittent MW drying with active time tON of 30 s and tempering time tOFF of 60 s followed DIC-texturing of blanched shrimp samples (30 g cubes of 1 cm3). The MW density power levels tested were 6, 12, and 24 W/g wb (wet basis). The airflow condition was fixed at 3.2 m/s, 20 °C, and 276 Pa water vapor pressure. Drying performance along with the organoleptic, structural, and functional quality parameters was measured for the dried product. The results showed that the highest DIC processing parameters of P = 0.7 MPa for 170 s were the best texturing conditions, while the MW power level of 24 W/g wb yielded the most effective drying performance when 90% of moisture was removed in 10 min, with organoleptic quality attributes and structural properties better than those of conventionally dried shrimp. Furthermore, the aroma was better preserved, and the exceptionally high absolute expansion ratio (Ɛabs = 13.84) and porosity (φ = 92.83%) allowed enhancement of the desired crispness of the snacks as well. The highly porous microstructure also results in improved rehydration performance.

Multi-stage continuous and intermittent microwave drying of quince fruit coupled with osmotic dehydration and low temperature hot air drying

Abstract In recent years, using intermittent microwave (IM) to dry foodstuffs has been taken into consideration as one of the new drying methods in food industry. The aim of this research was to dry cubic pieces of pre-treated “quince” fruit by sucrose osmotic solution using IM – hot air (HA) drying at a low temperature (40 °C) in order to investigate the effects of this process on improving the dried product quality. The variables of the process included sucrose osmotic solution in 5 concentration levels of 0 (control), 10, 30, 50, and 70% (w/w) and microwave at 4 powers of 0 (control), 360, 600, and 900 W, with 4 pulse ratios of 1, 2, 3, and 4. Findings indicated that compared to control samples, the samples pre-treated by osmotic solution had lower effective moisture diffusion coefficient (Deff). However, Deff increased through increase in power and pulse ratio of the microwave. Increasing the concentration of the osmotic solution, power, and pulse ratio led to significant decreases in shrinkage. Due to high shrinkage, the quince samples dried by continuous microwave – HA method showed higher bulk density in comparison to the samples dried by IM – HA. In addition, samples dried by IM with low power showed the highest rehydration followed by those dried by IM with high power; however, the control samples dried merely by HA had the lowest rehydration. Moreover, a significant decrease in specific energy consumption was noticed through increasing the microwave power. Drying by IM – HA at the power of 900 W and the pulse ratio of 4 had the lowest specific energy consumption, while drying with only HA had the highest specific energy consumption.

Effect of intermittent microwave drying on biophysical characteristics of rice

AbstractThe dehydration performance of intermittent microwave drying and its effect on the biophysical characteristics of rice (Oryza sativa L.) were quantified. Three pulse ratio levels (PR2, PR3, and PR5) were tested. Two dehydration performances (temperature and drying rate) and seven biophysical quality indices (moisture content, microstructure, glass transition temperature, color, hardness, crack percentage, and germination) of rice were measured. Different semi‐empirical moisture ratio models were optimized to fit the experimental data. The results showed that the temperature of rice treated by PR2, PR3, and PR5 were significantly different from each other during the process. The rice temperature dried by PR5 was the lowest and it tended to be constant at the late stage. The average drying rates of rice treated by PR2, PR3 and PR5 were 0.568, 0.437, 0.265% w.b. gg−1.min−1, respectively. With the increase of pulse ratio, the porosity of kernel glume cross section and the glass transition temperature of dried rice decreased. The moisture content changed significantly (p &lt; .05). However, the hardness and color of rice showed no significant differences (p &lt; .05). The crack quality and germination rate of dried rice treated by PR5 were significantly higher than those of the other treatments (p &lt; .05). Page model was found to be the most fitted model. By considering the drying performance and quality, PR5 was the most suitable microwave drying treatment for rice.Practical applicationsRice is one of the most important staple food sources of human being. Newly harvested rice are wet and easy to mildew, need to be dried for the sack of long‐term storage. Compared with conventional hot air drying, intermittent microwave drying greatly improved the drying rate of rice. High pulse ratio treatment can significantly reduce the temperature rise speed of rice, and comprehensively improve the bio‐physical quality of rice, for example, crack percentage, germination rate and so on. The application of the mathematical model of rice drying performance provided a reference for the design of drying process. The research results are helpful to the application of intermittent microwave drying technology in rice drying industry.

Effects of intermittent microwave drying on quality characteristics of pistachio nuts

ABSTRACTIn this research, the effect of intermittent microwave drying (IMD) on drying time and quality characteristics for three varieties of Iranian pistachio nuts was investigated and compared with the sun drying method. The quality parameters, such as chemical characteristics, physical parameters, and sensory evaluation were considered. Three varieties, Kal-Khandan, Kaleh-Bozi, and Ghermez, were dried in an 800-W, 2,450-MHz domestic microwave oven. Experiments were conducted in three material loads of 50, 100, and 150 g under intermittent method at 6 s of power-on and 70 s of power-off with three replications. The total drying time was in the range of 114.03–266.07 min, depending on material loads and varieties. The higher the material load, the longer the drying time. The results showed that the effect of drying method on the shell splitting size was very significant (p < 0.01). Texture analysis showed that the firmness and Meyer hardness of sun-dried pistachio nuts’ kernels are lower than those dried by the IMD method. In IMD by increasing the material loads, the Meyer hardness mean value is decreased. The analysis of chemical characteristics indicated that the IMD has no substantial consequence on sample fat and protein contents, while acidity and peroxide values were affected significantly (p < 0.05). Sensory evaluations revealed that the highest average score was gained at the material load of 150 g.