Drying kinetics of soy protein isolate-corn starch film during preparation and its moisture adsorption characteristics during storage

To better understand the mass transfer process of moisture in the soy protein isolate-corn starch(SPI-CS)films during preparation and storage process,the drying kinetics model of SPI-CS films with different formation conditions during the drying process and the moisture adsorption characteristics of the SPI-CS films under different humidity conditions were investigated.Within the range of experimental conditions,the moisture migration rule in the SPI-CS films during the drying preparation was combined with the Page model which was expressed as MR=exp(-kt^(n)).It was found that the adsorption equilibrium needed shorter time(about 3 h)when the SPI-CS films existed in the environment with lower humidity(RH<54%).Additionally,the secondorder adsorption kinetic equation was successful to describe the moisture adsorption characteristic of the SPICS films during storage under different humidity conditions.

Performance Analysis and Drying Kinetics of Maize in an AflaSTOP Dryer

The performance of an AflaSTOP dryer which utilises biomass energy for drying maize was investigated. The drying behaviour of maize grains in the dryer was also investigated using ten (10) thin-layer mathematical models. The models were compared based on coefficient of determination (R2) and Root Mean Square Error (RMSE) values between experimental and predicted moisture ratios. At an average drying air temperature of 50°C and drying air velocity of 2.5 m/s, maize at average moisture content (MC) of 17.5% (wb) was dried to an average MC of 11.5% (wb) in three (3) hours. The drying and thermal efficiency were calculated as 81.1% and 29.6% respectively. Overall, drying took place in the falling rate period. The Logistics model was best to describe the thin-layer drying kinetics of maize in the dryer with R2 value of 0.9902 and RMSE value of 0.04908.

Influence of Osmotic Dehydration with High Electric Field on the Drying Kinetics and Mass Transfer of Green Apples

Traditional thermal methods of drying food have often led to loss of flavours, nutrients, vitamins, etc., which encourages non-thermal pretreatments such as osmotic dehydration （OD） and/or high electric field （HEF） application to improve the overall product quality. The aim of this study was to evaluate the effect of osmotic dehydration （50% sucrose） with high electric field strengths of 0.5 and 1.0 kV/cm as pretreatments on the drying kinetics and mass transfer of green apples during convective drying at 65 ~C and microwave drying at 1 W/g. The added value of the OD and HEF on the drying kinetics, and the effective mass transfer coefficients of the subsequent drying methods were investigated through this research. The efficacy of these pre-treatments was assessed and compared using cell disintegration index, product texture and thus bring forth new correlations between these pre-treatments and the cell disintegration index using dielectric spectroscopy and its effect on the product texture.

The Application of a Mathematical Modelling of Drying Kinetics in the Natural Solar Drying of Banana

In this work, a new mathematical modelling of drying kinetics is described. At first, the modelling of the transfer speed （St） of water was performed. Then St was used as basis to state the drying rate model. The drying rate depends not only on drying time, but also on some modelling parameters which are themselves time-dependent. All the modelling parameters are calculated directly from the experimental drying data. Then the theoretical model of the moisture content was stated. Subsequently, the drying kinetics of natural solar drying of plantain banana was studied as illustration. The drying rate was investigated. The comparison with other models encountered in literatures proved that the current theoretical model was decidedly more accurate. Then the modelling of moisture content of banana was performed and the results were compared with the Henderson and Pabis model. The current theoretical modelling provided by far the best fit.

Determination of the Drying Kinetics Modeling and Activation Energy of Medium-Grain and Long-Grain Rough Rice under Isothermal Conditions

The available literature revealed a gap in reporting the rough rice drying kinetics parameters under isothermal conditions, particularly for Arkansas medium- and long-grain varieties. Therefore, medium-grain (RO170112 and Titan) and the long-grain (Diamond and Wells) rough rice varieties were dried under isothermal conditions. The drying process occurred under 40°C, 50°C, 60°C, 70°C, 80°C, 90°C, and 100°C in a system emulating the thermogravimetric analyzer. Drying kinetics models were studied for four well-known models: Page, Newton, Logarithmic, and Henderson & Pabis. The drying kinetics constants were determined for the four studied models. The initial moisture content of rough rice was 28.2% db. Profound moisture reduction was observed during the first three hours of drying, followed by less moisture content reduction. The results showed that at the drying temperature of 100°C and after 6 hours of the drying process, the lowest moisture content reached 13.9% (db) for Titan rough rice. The drying rate of rough rice ranged between 7.41 and 2.01%/h during the first hour of drying under the studied temperature range of 40°C to 100°C. The drying rate was higher with the higher temperature levels during the first three hours. Among all the studied models, the Page, Newton, and Logarithmic models best fit 25%, 25%, and 50% of the twenty-eight studied cases. The challenge that arose from these results led to evolving a mathematical solution by joining the three models in one equation. The combined model showed the best fit for all the studied cases, with R2 ranging between 0.9999 and 0.9954 for the medium- and long-grain rice varieties. Increasing the drying temperature increased the effective moisture diffusivity values. The highest effective moisture diffusivity of 18.104 × 10-9 m2/s was obtained at the drying temperature of 100°C for medium-grain rice, Titan. The activation energy values ranged between 17.77 and 24.48 kJ/mol for the four rough rice varieties.

Effects of drying methods on the drying kinetics and quality of maize

At present, maize is mostly dried by hot air, and the quality of maize after drying in this way is poor. So it is particularly important to explore the influence of new drying methods on the drying characteristics and quality of maize. Five drying methods, including hot air drying (HAD), vacuum drying (VD), infrared drying (IRD), variable temperature drying (VTD), and vacuum IR drying (VID), were used to analyze the drying rate (DR), moisture ratio (MR), effective moisture diffusion coefficient (Deff), hardness, nutrient composition, color, and microstructure of maize to investigate the effects of different drying methods on the drying kinetics and quality of maize kernels. The results showed that among the five drying methods, the Modified Page drying model could most reflect moisture changes. VTD was better than the other methods in terms of DR, cracking rate, hardness, and crude fat. The highest lysine content in maize was obtained using HAD. The protein content was higher in IRD (p<0.05). The dough characteristics were better in VID and VTD than in IRD. The IRD, VTD, and VID-treated maize had a better color appearance. Microstructure analysis showed that the starch granules of VID, IRD, and VD-treated maize were oval, but large gaps could be found between the granules. The granules were also densely stacked, with most of them relatively intact. Correlation and clustering analysis showed different degrees of correlation between the physicochemical indicators. The overall quality in VTD was the best, followed by VID, whereas HAD and VD showed poorer quality. In terms of economic value and product quality, VTD was the most suitable drying method for maize. This study can provide a theoretical basis for the application of maize drying in the processing industry.

Optimization of chanterelle mushroom drying kinetics under heat pump dryer using Taguchi design method

The optimum drying conditions with regard to minimum color changes, high rehydration ratio and drying rate for chanterelle mushrooms is inadequately known. To address this problem, drying kinetics for chanterelle mushroom samples with sizes of 20 mm×20 mm×20 mm cube, 20 mm×20 mm×30 mm cuboid, and Ø40 mm×20 mm cylindrical shape were experimented. Drying air temperatures of 40℃, 48℃, and 56℃ at superfluous humidity and velocity of 2.2 m/s were used. Initial color pixels for each sample were determined using Note 8 Pro Xiaomi smartphone camera and image processing tool in Matlab R2019a. Triplicate experimentation was done based on L9 Taguchi orthogonal arrays with drying rate, specific moisture extraction rate, color change, and rehydration ratio being the response parameters. The drying rate increased from 1.1174 g/g∙min to 1.3478 g/g.min as the temperature rose from 40℃ to 56℃. The mushroom cube had the highest drying rate of 1.2860 g/g∙min while the cylindrical shape had the lowest rate of 1.1764 g/g∙min. Similarly, SMER increased from 0.006 326to 0.013 27 g/kWh with the temperature rise. Contrary, SMER decreased from 0.006 92 to 0.013 63 g/kWh in cylinder to cube respectively. Color change was highest at 40℃ (13.49) and lowest at 56℃ (11.94). The mushroom cube had the lowest color change of 9.28 on average when compared to other shapes. Rehydration ratio was highest at 56℃ (3.824) as compared to 48℃ and 40℃. Additionally, the mushroom cube had the highest rehydration ratio of 4.55 on average as compared to other shapes. Temperature variation significantly influenced the drying rate and SMER. However, temperature variation had insignificant differences in color change and rehydration ratio. Mushroom shape variation had a significant difference in all the response variables tested. Conclusively, mushroom cubes at the drying temperature of 56℃ gave optimized drying conditions for chanterelle mushrooms with minimal quality deviations. Thus, chanterelle mushrooms can be sliced into cubes to allow quick drying rate, better SMER, rehydration ratio, and have minimal color change.

Solvent transport dynamics and its effect on evolution of mechanical properties of nitrocellulose(NC)-based propellants under hot-air drying process

Appropriate drying process with optimized controlling of drying parameters plays a vital role in the improvement of the quality and performance of propellant products.However,few research on solvent transport dynamics within NC-based propellants was reported,and its effect on the evolution of mechanical properties was not interpreted yet.This study is conducted to gain a comprehensive understanding of hot-air drying for NC-based propellants and clarify the effect of temperature on solvent transport behavior and further the change of mechanical properties during drying.The drying kinetic curves show the drying time required is decreased but the steady solvent content is increased and the drying rate is obviously increased with the increase of hot-air temperatures,indicating hot-air temperatures have a significant effect on drying kinetics.A modified drying model was established,and results show it is more appropriate to describe solvent transport behavior within NC-based propellants.Moreover,two linear equations were established to exhibit the relationship between solvent content and its effect on the change of tensile properties,and the decrease of residual solvent content causes an obvious increase of tensile strength and tensile modulus of propellant products,indicating its mechanical properties can be partly improved by adjustment of residual solvent content.The outcomes can be used to clarify solvent transport mechanisms and optimize drying process parameters of double-based gun propellants.

Effects of different drying methods on drying kinetics and physicochemical properties of Chrysanthemum morifolium Ramat

The effects of infrared-assisted hot-air drying(IR-HAD),temperature,humidity controlled hot-air drying(THC-HAD),and hot-air drying(HAD)on the drying kinetics,physicochemical properties,chlorogenic acid content and microstructure of chrysanthemum were experimentally examined.The results showed that the drying time reduced with increasing air drying temperature,with IR-HAD needing the shortest drying time,followed by THC-HAD and HAD.The effective moisture diffusivities(Deff)of chrysanthemum under IR-HAD,THC-HAD,and HAD at 60℃ were 3.22×10^(-9) m^(2)/s,2.19×10^(-9) m^(2)/s,and 2.89×10^(-9) m^(2)/s,respectively.IR-HAD preserved chrysanthemum surface color better than THC-HAD and HAD,whereas the THC-HAD samples obtained higher water holding capacity(WHC),water binding capacity(WBC),and chlorogenic acid content.Additionally,peroxidase(POD)residual activity of the samples decreased with increasing blanching time.The current work provides a theoretical basis for the drying of chrysanthemum.

Modeling microwave drying kinetics and moisture diffusivity of Mabonde banana variety

This study investigates the microwave drying kinetics of thin layer Mabonde banana variety(MBV)at power levels between 100 and 300 W.Six mathematical drying models:Wang and Singh,Verma,Two-term,Page,Two term exponential,and Logarithmic models were fitted to experimental drying data obtained from the study.The statistical consistency of the models was determined using statistical parameters including coefficient of determination,mean bias error,root mean square error,and reduced Chi square.Moisture migration from banana slices was described using the Fick’s diffusion model.The effective diffusivity was calculated.The results indicated that drying took place largely in the falling rate period.The time required to reduce the moisture of banana to a certain level was dependent on the microwave output,being the longest at 100 W and shortest at 300 W.The effective moisture diffusivity increased with increasing microwave power with values at 4.89×10^(-10),1.09×10^(-9) and 1.69×10^(-9) m^(2)/s at 100,200,and 300 W,respectively.The Wang and Singh model gave the best results for the description of thin layer drying of MBV.

Infrared drying kinetics and moisture diffusivity modeling of pork

This study investigated the drying kinetics of pork slice in infrared drying condition.Drying temperature,slice thickness and initial moisture content were selected as influencing factors on the drying characteristics and drying rate of pork slice.Drying curves obtained from the experimental data were fitted to semi theoretical and/or empirical thin layer drying models.The effects of drying temperature and slice thickness on the model constants were evaluated by the multiple regression method.All the models were compared according to three statistical indexes,i.e.,root mean square error,chi-square and modeling efficiency.The slice thickness,drying temperature and initial moisture content have significant influences on the effective diffusivity coefficient of pork.The results showed that the drying rate of pork slices increased with the increases of drying temperature and initial moisture content.The decreases of slice thickness also led to an increase of drying rate.The Henderson and Pabis model can best describe the drying curves of pork.

Color changes and drying kinetics modeling of basil seed mucilage during infrared drying process

The physicochemical properties and color of dried seed mucilage (gums) depend on thecondition and method of drying. So, in this study, the effects of infrared (IR) dryer systemparameters such as IR power (150, 250, and 375 W), distance of mucilage from lamp surface(4, 8, and 12 cm), mucilage thickness (0.5, 1.0, and 1.5 cm) on drying kinetics and colorindexes (L*a*b*) of basil seed mucilage (BSM) were examined in an IR dryer system. IR dry-ing kinetic of BSM was modeled using mathematical approach. Thus, experimental mois-ture ratio data were fitted to 8 various empirical models. It was found that Page model hasthe best fit to show the kinetic behavior and acceptably described the IR drying behavior ofBSM with the highest correlation coefficient values and the lowest standard error values.The average effective moisture diffusivity (Deff) increased from 1.69×10^(-9)to 9.21×10^(-9)m^(2)/s with increasing lamp power from 150 W to 375 W, while it was decreased from7.93×10^(-9)to 2.65×10^(-9)m^(2)/s and 7.81×10^(-9)to 1.82×10^(-9)m^(2)/s with increasing the dis-tance of mucilage from 4 to 12 cm and the reduction of mucilage thickness from 1.5 to0.5 cm, respectively. The increasing in IR radiation power has a positive influence on thelightness (increasing L* index) of dried BSM and it reduced color changes index (DE) from13.04 to 11.51. The results showed that IR drying method has great industrial potential insaving processing time as well as energy with better maintenance of color and quality ofdried BSM.

Generalized single-layer model for drying kinetics of unpeeled-longan

Dried longan fruit has become an important export product of Thailand.Knowledge about drying kinetics is essential to optimize the drying process.In this study,drying kinetics of unpeeled longan fruits was investigated by varying the parameters as follows:air temperature 50~90℃,relative humidity 4%~20%,air velocity 0.2~0.5 m/s,and size of the fruits.The drying curves of longan fruit,dried in a single layer,were strongly affected by the temperature of the drying air and fruit size but less dependent on relative humidity and velocity of the drying air.Eight single-layer drying models were selected from literature to identify suitable ones for fitting moisture ratio curves to data obtained from the drying experiments.Both,the proportional and exponential coefficient of drying time in the‘Page’model could be given in a generalized function for each of the investigated drying parameters.Moreover,the two coefficients could be correlated to all drying parameters simultaneously.This allowed establishing a generalized‘Page’model for estimating drying curves for any value of temperature,fruit size,relative humidity and air velocity within the range of performed experiments.The analysis also revealed an inner correlation between the two‘Page’coefficients,which opens new doors for further research on the application of the‘Page’model for describing drying processes.

Experimental study on drying kinetics of anchovy using centrifugal fluidized bed technique

The present study investigated the drying kinetics of anchovy experimentally using centrifugal fluidized bed technique.The main purpose was to experimentally investigate the effect of the inlet air temperature on the drying kinetics of anchovy in a centrifugal fluidized bed dryer,to fit the experimental data to the widely used mathematical models of drying.Further,the effective moisture diffusivity and activation energy in anchovy drying were investigated in the current work.The drying experiment was conducted at drying air temperatures ranging over 70-120°C.The air velocity and rotating speed of the air-distributor were fixed at 1.5 m/s and 150 r/min,respectively.Pressure drop across bed was approximately 390 Pa,while the layer height was fixed at approximately 2 cm.The anchovies were dried starting from 412%db down to 16%db;drying time ranged from 64 min to 172 min.It was found that the drying temperature was a significant factor in decreasing the moisture content,moisture diffusivity and drying time.The moisture diffusivity and activation energy were investigated at 0.11×10-9-0.25×10-9 m2/s and 20.32 kJ/mol,respectively.When compared to existing models,the Midilli model proved to be in good agreement with change in moisture ratio.

Effects of different pulsed vacuum drying strategies on drying kinetics,phenolic composition,and antioxidant capacity of chrysanthemum(Imperial chrysanthemum)

This work aimed to discuss effects of pulsed vacuum drying(PVD)at different temperatures(45°C,50°C,55°C and 60°C),vacuum durations(5 min,10 min and 15 min)and multi-stage heating on drying kinetics,colour attributes,phenolic compounds and antioxidant capacity of chrysanthemum(Imperial chrysanthemum).Results indicated that successive temperature increase reduced the drying time and enhanced the drying rate and moisture diffusivity.Lower temperature(45°C)and the multi-stage(35°C-55°C-60°C)drying presented the superiority in the protection of color,preservation of phytochemical composition(chlorogenic acid,luteolin,total phenolic and total flavonoid content)and improvement of antioxidant capacity(DPPH and FRAP)of chrysanthemum,which was attributed to the low-oxygen drying environment and reduction of thermal degradation losses.Based on the results of drying efficiency and drying quality,the multi-stage heating(35°C-55°C-60°C)has the excellent potential to produce high-quality dried chrysanthemum on a commercial scale.

Kinetic model research on drying characteristics of artificial magnetite green pellet

In this study,the effects of drying temperature,hot airflow speed and diameter of green pellet on drying rate of artificial magnetite pellet were deeply investigated to clarify the drying characteristics of artificial magnetite green pellet.The results show that the drying process of artificial magnetite green pellet has three stages,accelerated drying stage,constant drying stage and decelerated drying stage.And drying temperature and hot airflow speed both have significant reciprocal effects on moisture ratio and drying rate of green pellet during the drying process.However,the diameter of green pellet has little effect on drying process of green pellet.Then the drying fitting models of Correction Henderson and Pabis,Lewis,Correction Page(III),Wang and Singh are used to describe the drying kinetics of artificial magnetite green pellet.The fitting results indicate that the drying process of artificial magnetite pellet can be described by Correction Page(III)model accurately.Finally,the contrast experiments demonstrate that the fitting model can well describe the actual drying process.

Predicting Drying Performance of Osmotically Treated Heat Sensitive Products Using Artificial Intelligence

The main goal of this research is to develop and apply a robust Artificial Neural Networks(ANNs)model for predicting the characteristics of the osmotically drying treated potato and apple samples as a model heat-sensitive product in vacuum contact dryer.Concentrated salt and sugar solutions were used as the osmotic solutions at 27◦C.Series of experiments were performed at various temperatures of 35◦C,40◦C,and 55◦C for conduction heat input under vacuum(−760 mm Hg)condition.Some experiments were also performed in a pure vacuum without heat addition.Dimensionless moisture content(DMC),effective moisture diffusivity,and mass flux were considered as the performance parameters in this study.Results revealed that the osmotic dehydration using a concentrated sugar solution shows a higher reduction in the initial moisture loss of 19.87%compared to 5.3%in the salt solution.Furthermore,a significant enhancement of drying performance of about 27%in DMC was observed for both samples at vacuum and 40◦C compared to pure vacuum drying conditions.Using the experimental data,a robust artificial neural network(ANN)was proposed to describe the osmotic dehydration’s behavior on the drying process.The ANN model outputs are the dimensionless moisture contents(DMC),the diffusivity,and the mass flux.Whereas the ANN inputs were the drying time,the percent of sugar solution,and the percent of salt solution.For the ANN apple’s model,the minimum root mean square error(RMSE)values were 0.0261,0.0349 and 0.0406,for DMC,diffusivity,and mass flux,respectively.Whereas the best correlation coefficients of the above three parameters’determination values were 0.9909,0.9867 and 0.9744,respectively.For the ANN potato’s model,the minimum RMSE values were 0.0124,0.0140 and 0.0333,for DMC,diffusivity,and mass flux,respectively.And the best correlation coefficients of the parameters’values were found 0.9969,0.9968 and 0.9736,respectively.Accordingly,the ANN model’s prediction has a perfect agreement with the experimental dataset,which confirmed the ANN model’s accuracy.

Optimization of the Design and Drying Process Adapted to Pineapple Slices

The present work is a study on the influence of temperature and the velocity of air on the drying kinetics of pineapple slices. The main objective is to define from this drying kinetics rules to help a designer choose an adequate principle or drying configuration and optimize the design of dryers adapted to the use of it. The experiments were made in an electric dryer using a parallel flow system. The air was used at three different temperatures （40, 50 and 60 ~C） and at four different velocities （0.27, 0.5, 1 and 1.8 m/s） during the experiment. The results show that an increase of 10 ℃ of the drying temperature reduced the drying time by 45% and increased the drying velocity by 30%. On the set of air velocities tested, it was noticed that the influence of air velocity on drying was more striking at the beginning than at the end of the drying process （variation of less than 20%）. Whatever the variation of parameters during the drying process, the best performance was observed when the products water content during the drying process was between 50% and 80%.

Comprehensive comparison of cellulose nanocrystal (CNC) drying using multi-frequency ultrasonic technology with selected conventional drying technologies

Cellulose nanocrystals(CNCs)have garnered increased attention due to their renewable nature,abundant feedstock availbility,and good mechanical properties.However,one of the bottlenecks for its commercial production is the drying process.Because of the low CNC concentrations in suspension after isolation,CNC drying requires the removal of a large amount of water to obtain dry products for the following utilization and saving shipping costs.A novel multi-frequency,multimode,modulated ultrasonic drying technology was developed for CNC drying to improve product quality,reduce energy consumption,and increase production rate.CNCs dried with dif-ferent drying technologies were characterized by Fourier transform infrared(FT-IR)spectra anal-ysis,X-ray diffraction(XRD)analysis,thermogravimetric analysis(TGA),differential scanning calorimetry(DSC),and redispersibility to measure the quality and property changes.Under the same temperature and airflow rate,ultrasonic drying enhanced drying rates,resulting in at least a 50%reduction in drying time compared to hot air drying.The mean particle sizes of CNC from ultrasonic drying changed little with settling time,indicating good redispersibility.In addition,ultrasonic dried CNCs exhibited good stability in aqueous solutions,with the zeta potentials rang-ing from-35 to-65 mV.Specific energy consumption and CO_(2) emissions of various CNC drying technologies were evaluated.Energy consumption of ultrasonic drying is significantly reduced compared to other drying technologies.Moreover,the potential CO_(2) emissions of the fully elec-trified ultrasonic drying could be net zero if renewable electricity is used.

Effect of Molecular Structure on Diffusion of Alcohols through Type-A Zeolite Pores(0.5 nm)

Drying kinetics for alcohol-soaked type-A zeolite(pore size 0.5 nm)was determined at 50°C for 12 small-molecule alcohols(from C1 to C10).The second-phase of drying of wet porous materials reports on the mass-transfer characteristics within the solid matrices.This stage follows pseudo first-order kinetics(k1),and the second-order rate constant k2=k1/(fluxional area)was found to correlate with the surface tension of the liquids imbibing the solid matrix(p<0.002).k2 values decrease along the homologous linear alcohols,and branched-chain alcohols diffuse faster than their linear analogues due to their lower surface tensions.No independent contribution was found from the molecular size of the alcohols in the experiment reported here.Characteristic velocity and enthalpy of vaporisation of the liquids were not found to be significant independent variables,either.The find agrees with the notion that liquid movement in pores is governed during the drying processes by the liquid chemical potential gradient between the pore space and gas phase above the porous particle surfaces,this gradient being a function of the molecular cohesion of the moving liquid front(surface tension,g).The results can be expressed by the linear Gibbs-energy relation log(k2/s^(-1)·m^(-2))=(2.5±0.5)-(1.6±0.2)×10^(2)(g/J·m^(-2)).