Drying Of Slices Research Articles

Sorption isotherms and drying kinetics modelling of convective and refractance window drying of feijoa slices (<i>Acca sellowiana</i> Berg)

The refractance window and convective drying modelling of feijoa is important to dryers design used for the fruit preservation. This work presents the sorption isotherms and the drying kinetics of the convective and refractance window drying of feijoa slices. Feijoa was dried by convective drying at 50, 60, and 70°C, air velocities of 0.5 and 1 ms−1 and by refractance window at 60, 70, 80°C, with thicknesses of 3 mm and 5 mm for both technologies. The sorption isotherms were determined at 25, 35 and 45°C. Twelve thin-layer models and the effects of the operative conditions were analysed. The most suitable models were the logistic and Midilli for both drying methods. The Peleg adsorption model adequately described the experimental data over the entire measured range of the water activity. Drying modelling and sorption isotherms can be used in process optimisation and dryers design.

Sorption isotherms and drying kinetics modelling of convective and refractance window drying of feijoa slices (<i>Acca sellowiana</i> Berg)

The refractance window and convective drying modelling of feijoa is important to dryers design used for the fruit preservation. This work presents the sorption isotherms and the drying kinetics of the convective and refractance window drying of feijoa slices. Feijoa was dried by convective drying at 50, 60, and 70°C, air velocities of 0.5 and 1 ms−1 and by refractance window at 60, 70, 80°C, with thicknesses of 3 mm and 5 mm for both technologies. The sorption isotherms were determined at 25, 35 and 45°C. Twelve thin-layer models and the effects of the operative conditions were analysed. The most suitable models were the logistic and Midilli for both drying methods. The Peleg adsorption model adequately described the experimental data over the entire measured range of the water activity. Drying modelling and sorption isotherms can be used in process optimisation and dryers design.

Modeling of Thin-layer Sun Drying of Slices of Meat in Kilishi Form

The sun-drying method is one of the methods used to dry kilishi in Niger and throughout Sub-Saharan Africa. It is a purely traditional process, which only requires the knowledge of the butcher. The objective of our work consists of, on the one hand, the evaluation study of the drying in the sun in a thin layer of slices of meat in the form of kilishi, in typically Sahelian climatic conditions and, on the other hand, the study of mathematical modeling of the physical process which takes place during this drying. The methodological approach consists in establishing a mathematical model, which predicts the thermal and mass balance of the product during the drying process and validates this model with an experimental test. The equations of the mathematical model governing the drying system are solved by the numerical method of Runge - Kutta in the 4th order. The results of the sun-drying evaluation study made it possible to determine the temperature evolution of the upper and lower side of the meat slices in kilish form, during the entire drying process. The monitoring of the loss of masses of the slices of meat allowed us to determine experimentally the water content as a function of time and the drying rate as a function of the water content. The comparison of the results of the numerical simulation of the mathematical model and those recorded experimentally are consistent. The relative errors between the simulation results and the experimental results are given by the statistical parameters R², MSE and RMSE. We have obtained for the set of values of R² close to one (1) and MSE, RMSE close to zero (0). This allowed us to conclude that the model is satisfactory.

Mathematical Modelling and Tray Drying Kinetics of Loquat Eriobotrya japonica

The present study was aimed to investigate drying of loquat slices in tray dryer at different temperatures Drying was conducted at 45°C, 55 °C, and 65°C at constant air velocity of 0.5 m/s in tray dryer;time taken for drying of slices was 12 h, 10 h and 9h respectively. The analysed moisture data was fitted in four different drying mathematical models, i.e. Henderson and Pabis, Page, Logarithmic and Newton (Lewis).Statistical analysis predicted that Page model was best-fitted model for describing drying characteristics of loquat slices. Best-fitted model was selected by obtaining maximum value of regression coefficient (R2 ) and minimum value of chi square (χ2) and root mean square error (RSME). It was observed that shrinkage percentage was less at higher temperature as compared to the lower temperature, i.e., 45°C.

Drying of ginger slices—Evaluation of quality attributes, energy consumption, and kinetics study

AbstractGinger slices were dried with Freeze drier (FD), relative humidity convective drier (RHCD), infrared drier (IR), and microwave drier (MD) at a temperature of 60°C. The influence of the drying techniques on total phenolic content (TPC), total flavonoid content (TFC), antioxidant activities, ABTS (2,2‐azino‐bis‐(3‐ethylbenzothiazoline‐6‐sulfonic acid), DPPH (1,1‐diphenyl‐2‐picrylhydrazyl), FRAP (Ferric reducing antioxidant power capacity), and CUPRAC (Cupric ion reducing capacity), rehydration ratio (RR), color, enzyme inactivation (polyphenol oxidase, PPO and peroxidase, POD), energy consumption rate (ECR), microstructure, volatile compounds (aroma profile), and drying kinetics were assessed. The results showed that FD‐ginger slices retained the highest antioxidant properties, ABTS (51.88 mgTE/g db), CUPRAC (95.51 mgTE/g db), DPPH (132.95 mgTE/g db), and FRAP (95.32 mgTE/g db), TPC (118.70 mg GAE/g db) and TFC (98.94 mg CE/g db), preserved microstructure and higher volatile compounds compared RHCD, IR, and MD. The RHCD‐ginger slices attained the highest RR (3.6), lowest ECR (7.88 kWh/kg), lowest PPO (17%), and POD (22%) residual activity with preserved color properties than FD, IR, and MD. RHCD also enhanced the drying kinetics and lessened the drying time compared to FD, IR, and MD. Page model best fitted the experimental results of drying kinetics (R2 > 0.99).Practical applicationOne of the world's most consumed and used spices is ginger and due to its high moisture content, drying is normally used for its preservation. Therefore, to attain dried ginger of better quality, an effective, safe, efficient drier that can preserve product quality and reduce processing time, as well as energy consumption, is required for commercial purposes as a poor selection can have an adverse effect on the product quality. The outcome of the current investigation will offer a better understanding of various drying techniques and also provide more information on the selection of the best drying technique for drying ginger.

Influence of coating pretreatment with carboxymethyl cellulose in an electrohydrodynamic system on convective drying of banana slices

AbstractFor the first time, a carboxymethyl cellulose (CMC) coating pretreatment was used in an electrohydrodynamic (EHD) system to produce convectively dried banana slices with improved quality and nutritional attributes. To this end, the impacts of the sample to CMC solution ratio (S:CSR) parameter at two levels of 1:1 and 1:2 and the EHD voltage parameter at four levels of 0, 16, 18, and 20 kV were investigated. The results showed that an increase in the EHD voltage from 0 to 20 kV significantly increased the water absorption capacity (WAC) (117.86%) and the total phenolic content (TPC) (20.83%) of the dried banana slices and significantly reduced their total energy consumption (SETotal) (30.03%), the drying time (27.9%), the shrinkage (74.52%), the shear stress (SS) (76.48%), and the total color difference (ΔE) (78.74%). Moreover, an increase in the S:CSR from 1:1 to 1:2 significantly reduced the shrinkage (20.62%), the SS (21.93%), and ΔE (33.02%) of the dried banana slices and significantly increased their WAC (24.40%) and TPC (16.88%).Practical applicationsAccording to the results obtained in this study, carboxymethyl cellulose coating pretreatment in an EHD system can be introduced as an innovative and practical pretreatment technique for production of convectively dried products. This approach improves both the quality indexes and nutritional attributes while increasing the performance of the convective drying process.

Comparing different processing methods in apple slice drying. Part 1. Performance of microwave, hot air and hybrid methods at constant temperatures

The drying curves, energy efficiency and colour variations of sliced apples dried at various temperatures and using different techniques were evaluated, i.e. microwave (35, 55 and 65 °C), hot air (35, 55, 65 and 75 °C) and combination of both (65 °C). The microwave (MW) tests also included comparison between air recirculation and continuous inlet of fresh air. Each drying method was evaluated at a fixed temperature level by means of a control system based on infrared thermography. The time required to complete the drying process at 65 °C varied from about 44 min for MW with fresh air ventilation (double with air recirculation), to 122 min for hybrid heating and 238 min for hot air. Drying kinetics was analysed by introducing a new semi-empirical model, capable of recovering the drying behaviour in terms of both mass loss and drying speed. The results showed that the hybrid drying mode, thanks to the reduced power of the microwaves, led to a lower drying rate than the microwave mode alone. Overall colour variations were minor in samples heated with MW to 65 °C (ΔE = 19.8). No significant differences were found between the drying methods with regard to energy consumption. As expected, the fastest drying occurs as the temperature increases, which requires more heat generation within the test samples.

Comparing different processing methods in apple slice drying. Part 2 solid-state Fast Field Cycling 1H-NMR relaxation properties, shrinkage and changes in volatile compounds

The objective of this paper was to study the effects of three different drying methods: microwave (MW), hot air (HA) and a combination of both (HY), on the 1H NMR relaxation properties, shrinkage and volatile compounds of Golden Delicious apple slices. Fast field cycling NMR relaxometry revealed that the HA samples dried at different temperatures (65 and 75 °C) appeared to contain less restrained water as compared to the sample obtained by MW heating at the same temperatures. In fact, the longitudinal relaxation times (T1) of the water molecules in the HA dried slices were shorter than those measured for the MW dried samples, thereby revealing that in the MW slices, water molecules behave more like as a pseudo-ice layer. For this reason, shrinkage was much more accentuated in apples dried by the HA and hybrid methods, compared to the MW procedure. Likewise, HA drying had a bigger effect than MW and HY on the aromatic profile of the apple slices, causing a significant decrease in esters while ketones increased.

PEMODELAN MATEMATIK KANDUNGAN AIR PADA PENGERINGAN APEL

Drying is one of the most significant method in food preservation. This study was conducted to investigate mathematical models of thin layer drying of apple slices. The kinetic of thin layer drying of apple slices was experimentally investigated in a hot air convective dryer. Crank solution for difusion in slab model and Lewis model for drying in thin layer were used to predict the drying profile. Drying characteristic of apple slices were determined using ambient air at 50 oC and 0,4167 m/s linier velocity. The result showed that Lewis model was more convenient for short-period drying, whereas the Crank solution model was more appropiate for long- periode drying.

Computational Fluid Dynamics Modelling of the Heat Pump Drying of Banana: Preliminary Studies

The distribution of local temperature, moisture and velocity gradients obtained in CFD calculations can be used to develop models for predicting the parameters in a drying process. This article reports a preliminary result on the efforts to characterizing the performance of a heat pump dryer using Computational Fluid Dynamics (CFD). A three dimensional, pressure based, transient, laminar, incompressible model of heat pump drying of banana slices using Ansys 14.5 (15), a CFD package- FLUENT was investigated. Turbulent cases were also examined. The geometry was considered as elemental volume with symmetrical walls while the banana slices were designed as solids with pores containing a mixture of water and air. Parameters/variable/geometry investigated include velocity, moisture and temperature distribution of the air within the dryer and of the banana slices. The result of the numerical simulation was validated with experimental results from a heat pump dryer and there were agreements. The model is successful in predicting the temperature profile and mass fraction of moisture. Keywords— Ansys, Banana, Computational Fluid Dynamics (CFD), Contour plots, Drying, Velocity and temperature distribution

Studying the operation of innovative equipment for thermomechanical treatment and dehydration of food raw materials

The paper reports results of investigating innovative equipment for the integrated processing of food raw materials, which would make it possible to implement the local energy influence directly on the particles of a dispersed material, the near-boundary layer, the moisture retained in the product's solution or capillaries. The analysis of food raw materials processing techniques has been performed, their benefits and shortcomings have been identified. It was found that product quality, energy consumption and cost are mainly determined at the stages of thermal processing, drying. We have examined innovative equipment based on rotary thermosiphons for evaporating food non-Newtonian liquids. An experimental bench has been designed, and the procedure for studying the hydrodynamics of condensate motion in condensers of rotary thermosyphons of various structures has been devised. The experimental bench represents a model of the device with a rotary thermosiphon made of glass. The result of our study is the established rotational frequency, at which a condensate is locked by the centrifugal force for a branched condenser. Results from visualization of vapor-condensate movement have been presented. The innovative equipment for the evaporation of food non-Newtonian liquids under SHF radiation conditions has been investigated. Experiments involved food products and model systems. We have determined the degree of an increase in the concentration of non-aquatic components. Evaporation rate under conditions of SHF radiation is almost constant. The innovative equipment for drying fruit- and vegetable-based slices under conditions of IR radiation has been examined. An experimental bench has been designed and the research procedure has been devised. We have proposed the structure of an equation for calculating the mass transfer coefficient. The database of experimental findings has been generalized in the equation by similarity numbers. The equation makes it possible to calculate a mass transfer coefficient with error within ±15 %. The influence of IR radiation power on the kinetics of the process of drying fruit and vegetable slices has been determined. We have compared experimental data on slice drying under conditions of SHF and IR radiation

Effects of ultrasound-assisted methods on the drying processes and quality of apple slices in microwave drying

The strong physical effects of ultrasound can change the state of water in food. In order to study the effect of ultrasound on the microwave drying of apple slices, an ultrasonic online-assisted microwave vacuum drying (UOAMVD) device was designed. The curves of moisture content versus drying time, the change in dielectric constant and dielectric loss factor, and the flow characteristics of water molecules were obtained during microwave vacuum drying (MVD), microwave vacuum drying with the apple slices pretreated by ultrasound (MVDPU), and UOAMVD, was measured by a vector network analyzer and a low-field nuclear magnetic resonance and imaging analyzer. The differences in color and microporous structure of the different dehydrated products were determined. Compared with MVD and MVDPU, apple slices that underwent UOAMVD had a higher drying rate and improved drying uniformity, and the dielectric constant was significantly reduced. In addition, the color of the UOAMVD dehydrated samples was the closest to that of fresh apple slices, whereas the microporous structure was not obvious and there was granular starch overflow. UOAMVD significantly improved the microwave drying efficiency and quality of apple slices. This work provides a reference for enhancing the application of ultrasonic microwave combination drying.

Air jet impingement and hot air-assisted radio frequency hybrid drying of apple slices

A hybrid drying method for high moisture foods (apple slices) was proposed in this study. Air jet impingement (AJI) was applied as the 1st stage drying method for fresh samples, and hot air-assisted radio frequency (HA-RF) was used for the 2nd drying stage to reduce the moisture content of semi-dried samples to the target level (<15 g/100 g w.b.). Quality of the final products (color, vitamin C and total phenolic content) after hybrid drying process were evaluated and compared with those dried by HA-RF alone or AJI combined hot air (HA). The developed hybrid drying protocol for apple slices was 100 min AJI drying (with air jet temperature 65 °C, HA velocity 2.3 m/s and sample thickness 6 mm) for the 1st stage, and 100 min HA-RF drying (electrode gap of 12 cm and HA temperature of 60 °C) for the 2nd stage, to obtain products with target moisture content. Among the three drying methods, apple slices treated by the AJI combined HA-RF drying had the shortest drying time and the best product quality, including color, total phenolic and Vc retention. This study suggests AJI and HA-RF hybrid drying could be a promising method for producing dehydrated apple slices with high efficacy.

Effect of contact ultrasonic power on moisture migration during far‐infrared radiation drying of kiwifruit

AbstractIn order to explore the effect of direct contact ultrasound (DCU) on moisture migration during far‐infrared radiation (FIR) drying of kiwifruit, the drying characteristics, microstructure, water status, and moisture change of kiwifruit slices during drying were investigated based on scanning electron microscopy (SEM), low‐field nuclear magnetic resonance (LF‐NMR), and magnetic resonance imaging (MRI). The results showed that the drying time at ultrasonic power of 54 W was 40% shorter than that without DCU application. SEM observation verified that higher ultrasonic power could produce more and larger microcapillaries in the microstructure of kiwifruit slices, which was beneficial for moisture migration. LF‐NMR detection indicated that water mobility and distribution in kiwifruits changed during drying. The relative proportion of free water in kiwifruits decreased from 70 to 0% with the prolongation drying time at different ultrasonic powers, the removal time for free water at ultrasonic power of 54 W was 57% shorter than that without DCU application during FIR drying, and higher ultrasonic power could accelerate the shifting of water in different states. MRI results illustrated that the DCU application at higher ultrasonic power could promote moisture migration and water removal during FIR drying, and then increase drying rate.Practical applicationsDrying is a commonly utilized process method in food and agricultural industry. Far‐infrared radiation (FIR) drying, as one of the modern drying methods, has desirable advantages including high‐energy efficiency and uniform heating. However, it has unsatisfied promoting effect on internal mass transfer. Ultrasound has significant positive effect on moisture diffusion and water removal. In this study, direct contact ultrasound (DCU) was applied in FIR drying of kiwifruit slices. The study verified that the DCU application in FIR drying could promote drying rate, produce loose microstructure, and shorten drying time significantly. The increase in ultrasonic power could accelerate moisture migration and mass transfer to facilitate water removal. Therefore, DCU application with higher ultrasonic power is beneficial to increasing drying rate and reducing drying time of FIR drying, and FIR drying technology combined with DCU is promising in food industry and can be developed for other food products.

Influence of drying techniques and temperatures on drying kinetics and quality characteristics of beef slices

Beef slices were vacuum-dried (at 60, 70 and 80 °C) and oven-dried (at 60 °C), respectively. The drying rate was significantly influenced by the drying technique and temperature. Six kinetic models were selected to evaluate the moisture ratio data, with regard to adjusted regression coefficient (R2), the reduced chi-square (χ2) and root mean square error (RMSE). Among the tested models, the Page model showed the best fit to the experimental drying data. The lipid oxidation, rehydration rate, color and shear force properties of vacuum-dried beef slices were considerably better compared to oven-dried beef slices. Furthermore, vacuum drying at >60 °C ensured suitable microbiological quality and safety of the dry beef slices during storage due to the low water activity (0.45) of the product. Consequently, these results can be used to simulate the vacuum drying of beef slices and improve the efficiency of the drying process and the product quality.

Optimization of energy consumption of a solar-electric dryer during hot air drying of tomato slices

High-energy demand of convective crop dryers has prompted study on optimization of dryer energy consumption for optimal and cost effective drying operation. This paper presents response surface optimization of energy consumption of a solar-electric dryer during hot air drying of tomato slices. Drying experiments were conducted with 1kg batch of tomato samples using a 33Central Composite Design (CCD) of Design Expert 7.0 Statistical Package. Three levels of air velocity (1.0, 1.5 and 2.0ms–1), slice thickness (10, 15 and 20mm) and air temperature (50, 60 and 70oC) were used to investigate their effects on energy consumption. A quadratic model was obtained with a high coefficient of determination (R2) of 0.9825. The model was validated using the statistical analysis of the experimental parameters and normal probability plot of the energy consumption residuals. Results obtained indicate that the process parameters had significant quadratic effects (p &lt; 0.05) on the energy consumption. The energy consumption varied between 5.42kWh and 99.78kWh; whereas the specific energy consumption varied between 5.53kWhkg–1and 150.61kWhkg–1. The desirability index method was applied in predicting the ideal energy consumption and drying conditions for tomato slices in a solar-electric dryer. At optimum drying conditions of 1.94ms–1air velocity, 10.36mm slice thickness and 68.4oC drying air temperature, the corresponding energy consumption was 5.68kWh for maximum desirability index of 0.989. Thermal utilization efficiency (TUE) of the sliced tomato samples ranged between 15 ≤ TUE ≤ 58%. The maximum TUE value was obtained at 70oC air temperature, 1.0ms–1air velocity and 10mm slice thickness treatment combination, whereas the minimum TUE was obtained at 50oC air temperature, 2.0ms–1air velocity and 20mm slice thickness. Recommendation and prospect for further improvement of the dryer system were stated.

Optimisation of energy consumption of a solar-electric dryer during hot air drying of tomato slices

High-energy demand of convective crop dryers has prompted study on optimisation of dryer energy consumption for optimal and cost effective drying operation. This paper presents response surface optimisation of energy consumption of a solar-electric dryer during hot air drying of tomato slices. Drying experiments were conducted with 1 kg batch of tomato samples using a 33 central composite design of Design Expert 7.0 Statistical Package. Three levels of air velocity (1.0, 1.5 and 2.0 ms–1), slice thickness (10, 15 and 20 mm) and air temperature (50, 60 and 70°C) were used to investigate their effects on energy consumption. A quadratic model was obtained with a high coefficient of determination (R2) of 0.9825. The model was validated using the statistical analysis of the experimental parameters and normal probability plot of the energy consumption residuals. Results obtained indicate that the process parameters had significant quadratic effects (P&lt;0.05) on the energy consumption. The energy consumption varied between 5.42 kWh and 99.78 kWh; whereas the specific energy consumption varied between 5.53 kWhkg–1 and 150.61 kWhkg–1. The desirability index method was applied in predicting the ideal energy consumption and drying conditions for tomato slices in a solar-electric dryer. At optimum drying conditions of 1.94 ms–1 air velocity, 10.36 mm slice thickness and 68.4°C drying air temperature, the corresponding energy consumption was 5.6 8kWh for maximum desirability index of 0.989. Thermal utilisation efficiency (TUE) of the sliced tomato samples ranged between 15 ≤TUE ≤58%. The maximum TUE value was obtained at 70°C air temperature, 1.0 ms–1 air velocity and 10 mm slice thickness treatment combination, whereas the minimum TUE was obtained at 50°C air temperature, 2.0 ms–1 air velocity and 20 mm slice thickness. Recommendation and prospect for further improvement of the dryer system were stated.

Multi-Objective Optimization and Quality Evaluation of Short- and Medium-Wave Infrared Radiation Dried Carrot Slices

Abstract Optimum technology and quality evaluation of short- and medium-wave infrared radiation (SMIR) dried carrot slices were studied. Effects of drying temperature, drying time and infrared power of SMIR drying on the moisture content, color parameter and β-carotene content of dehydrated carrot slices were investigated. The experimental data were well predicted by a modified second-order polynomial model. Drying temperature and drying time had significant effects on moisture content, color parameter and β-carotene content. However, infrared power only showed significant effect on the moisture content. Response surface method (RSM) was used for optimization of SMIR drying of carrot slices, and the optimum condition was found as drying time of 50 min, infrared power of 1125 W, and drying temperature of 70 °C. SMIR dried products were proved to be favorable by comparing with hot-air dried ones due to its higher rehydration ratio (6.89) and β-carotene content (462.48 μg/g).

DESIGN AND EVALUATION DIRECT SOLAR- DRYER TO DRY RED ONIONS SLICES

An direct solar–electrical dryer has been designed and constructed at a Zagazig City of , Sharkia governorate, Egypt. Solar dryer consists of solar flat plate air collector with V-corrugated absorption plate in conecation with drying tray uint. The red onions most popular to consumer no dayes in the Zagazig City so that it was chosen to experiment. The new dryer prototype was tested its efficiency for drying red onions slices 5 &10 mm to study the effect of drying air velocities (0.4,0.5 and 0.6 m/s) at air temperature (40.82,42.37 and 43.81)respectiviely.The qualitative analysis for drying of onions slices 5 mm showed that initial moisture content of about 88% (wet basis) was reduced to final moisture content of about (10%,12% and 16%) for velocities (0.4,0.5 and 0.6 m/s),while it were (16%,18% and 20.8%) for onions slices 10 mm respectiviely.The average percent of dryer efficiency was found to be 16.07, 12.83 and 12 % for air speed 0.4,0.5 and 0.6 m/s respectiviely. In order to estimate and select the suitable form of solar drying curves, five different mathematical models, were compared according to their coefficient of determination R2, MBE, RMSE, %E and chi square X2 to estimate experimental drying curves. The page and Modified page II model in this condition proved to be the best for predicting drying behavior of red onions slices 5 and 10 mm with (R2 = 0.9961 and 0.9899) and (X2 = 0.000121 and 0.000423).The effective moisture diffusivity (Deff) was obtained using Fick’s diffusion equation and its value varied from 1.46× 10-9 to 1.59× 10-9 m2/s and 5.25× 10-9 to 5.72× 10-9 m2/s. The temperature dependence of the diffusivity coefficients was described with the activation energy (Ea) value of 21.33 kJ/mol and 19.14 kJ/mol for red onions slices 5 and 10mm.Finally an economic evaluation was calculated using the criterion of payback period which is found very small 1.84 years compared to the life of the dryer 25 years.

Low humidity air drying of apple slices: Effect of EMR pretreatment on mass transfer parameters, energy efficiency and quality

Abstract The apple slices were treated with electromagnetic radiations (EMR) namely, infrared (IR) and microwave (MW) and dried using low humidity air (LHA) and normal hot air (HA) at 40 °C. The effect of EMR pretreatment on drying kinetics, mass transfer, shrinkage, porosity, energy efficiency and product quality was evaluated. The combination of EMR pretreatment with LHA drying reduced the drying time by 23.4 to 27.3%, and the dried product had lower shrinkage (60 to 65%) as well as higher porosity (0.38 to 0.45) compared to control. Among the EMR pretreatments, IR treated slices retained a higher amount of ascorbic acid (78.68%), phenolic content (74.42%), antioxidant activity (79.54%) and better color compared to MW treated. EMR pretreatment reduced the energy requirement for drying by 26.5 to 37.1%. The mass transfer parameters (moisture diffusivity and mass transfer coefficient) estimated using the analytical model proposed by Dincer and Dost showed higher values for EMR treated samples. Moisture content predicted for both the drying methods showed good agreement with experimental values. The present study demonstrated that for heat sensitive products like apple, a combination of IR pretreatment and LHA drying could be effective for reducing drying time as well as energy requirements and also to obtain better quality products.