جستجوی مقالات مرتبط با کلیدواژه « مادون قرمز » در نشریات گروه « کشاورزی »

Vegetables are perishable and cultivated seasonally. The aim of this study was to employ a combined thawing through hot air-infrared system, while investigating the effects of temperature, airflow velocity, and infrared radiation power on thawing time and the quality attributes of thawed carrots. In this research, carrot samples, having been washed and shaped using a cylindrical mold measuring 22.5 mm in diameter and 12 mm in height, were subjected to freezing at -18°C for 48 hours. Thawing parameters were air temperature (30°C and 40°C), airflow velocity (0.5  and 5 m/s), and infrared power (100 and 300 watts). The sample thawed at 25°C was control sample. Data analysis showed that reciprocal effect of increasing temperature, power of the radiation source and air flow speed had a significant effect on the thawing time, vitamin C, β-carotene, the thawing loss, and pH (P≤0.05). This system was able to significantly reduce the thawing time this time for the control sample was 47.66 minutes and for the shortest thawing time, the treatment 8 (F5P300T40) was 6.23 minutes. The lowest pH value was related to treatment 7 (F0.5P300T40) 5.81 and the highest value was related to treatment 1(F0.5P100T30) 6.15. The highest amount of β -carotene was related to treatment number 8 (F5P300T40) 48.12 mg/100g and  the lowest amount was related to treatment 5 (F0.5P100T40) 14.03 mg/100g. The highest amount of vitamin C was related to treatment 4(F5P300T30) 12.36 mg/100g and the lowest amount was related to treatment 1(F0.5P100T30) 3.68 mg/100g. . In the thawing loss, the highest amount was related to treatment 1 (F0.5P100T30) 19.7% and the lowest amount was related to the control sample7.44%. . Due to the low start-up cost, shorter process time and favorable quality, hybrid defrosting is widely used in the food industry.

The present study was conducted to investigate the influence of drying methods on the amount of some effective compounds in fruit Ecballium elaterium M. Bieb extract based on a completely randomized statistical design with 15 treatments and 3 replications. The treatments included different drying methods (1- Shade drying at room temperature (25±3°C) with suitable ventilation, 2- Sun drying, 3- Oven drying at 35°C, 4- Oven drying at 45°C, 5- Oven drying at 55°C, 6- Vacuum oven drying at 35°C, 7- Vacuum oven drying at 45°C, 8- Vacuum oven drying at 55°C, 9- Infrared drying at 0.2w, 10- Infrared drying at 0.3w, 11- Infrared drying at 0.4w, 12- Microwave drying at 200w, 13- Microwave drying at 500w, 14- Microwave drying at 800w) which were compared with the fresh fruit of the plant (as a control). The studied traits were total phenols content, total flavonoids content, radical scavenging activity assay, soluble tannin, total amino acids, total soluble protein, total alkaloids, and total cucurbitacin. The results showed that different drying methods had a significant effect on soluble tannin and cucurbitacin content (P≤0.05) and also on other traits (P≤0.01). The highest amount of total phenol and flavonoids was related to fresh plants and then vacuum oven drying at 45 °C, and the highest amount of antioxidant activity and soluble tannin was found in fresh plants and then the vacuum oven drying at 55°C. The highest amount of amino acids was related to fresh plant and then 200 watt microwave treatment and the highest amount of total protein, alkaloids and cucurbitacin was related to fresh plant and then shade treatment.

Among the various hot air drying methods, fluidized bed drying has significant advantages such as high heat and mass transfer, uniform moisture reduction of products with short time and high drying rate and uniform process at entire surface of the product due to efficient mixing with the drying air and high efficiency of process. In recent years, usage of infrared drying to dry food products has increased over conventional drying methods due to higher product quality, uniform heat distribution, high energy efficiency, high heat transfer rate and less processing time, facilitating the control of raw material temperature, reduced necessity for air flow across and the high ability to control process parameters in infrared heating. In this study, kinetics of carrot cubes drying by infrared-fluidized bed dryer were investigated.

Fresh carrot were washed with tap water and peeled manually then diced by dicer. To drying carrot cubes by combined infrared- fluidized bed method a laboratory scale dryer was designed and performed. In this study, drying of carrot cubes (0.5 and 1 cm3) was performed in factorial design experiments using air temperatures of 50, 60 and 70 °C and three levels of infrared power (200, 400 and 600 W) in three replications. To describing the infrared-fluidized bed drying behavior of carrot cubes, five mathematical models (Page, Modified Page, Henderson & Pabis, Midilli and Logarithmic) were evaluated.

The results demonstrated that the change in inlet air temperature, size of carrot cubes and infrared power had a significant effect (P <0.05) on water withdrawal from the sample and drying time decreased with increasing air temperature and infrared power and decreasing carrot cubes size. Therefore, the energy consumption was also reduced considerably, decreasing from 12.63 Kwh/kg in bed fluidized method (without infrared power) to 2.28 Kwh/kg using infrared -fluidized bed drying. The Page model was identified as the suitable model to describe the drying kinetics of carrot cubes by infrared-fluidized bed dryer that showed a good agreement with experimental data.

The statistical analysis of variance showed that air temperature, sample size and infrared power had a significant effect on water withdrawal rate of samples and therefore drying time. According to the results, using infrared-fluidized bed drying as a combined method in comparison with conventional hot air drying methods can reduce drying time and energy consumption and costs considerably.

Dehydration of fruits and vegetables is a widely used unit operation (Funebo et al., 2000). Intermittent infrared radiation, in which the product surface maintained at constant temperature, is a novel drying method to produce high quality dehydrated fruits and vegetables (Zhu & Pan, 2009; Zhu et al., 2010). One of the most important physical changes in the quality of food during drying is the decrease in external volume. This change in volume is called shrinkage and is an unavoidable phenomenon during the dehydration process. Shrinkage is usually expressed by the ratio between the volume of the sample after and before drying (Yan et al., 2008). Shrinkage also affects the porosity of dried materials and it is the parameter determining about the mass transfer properties, mechanical properties, and the texture of food product (Witrowa-Rajchert & Rząca, 2009). The three qualitative parameters such as the degree of shrinkage, density and firmness of the product are related to each other (Funebo et al., 2000). Maximal shrinkage and structural collapse were shown to decrease until kept quality characteristics (Barzaghi et al., 2008). The factors affecting shrinkage include volume of water extracted from the product, mechanical mobility of the solid matrix, drying rate, and process conditions such as temperature, air flow rate, and relative air humidity (Moreira et al., 2000). The important consequences of shrinkage occurring during drying result in a loss of rehydration ability. Dehydrated products are usually rehydrated prior to their use (Krokida, M, & Marinos-Kouris, 2003). The rehydration behavior is studied as an indicator of texture damage (Giraldo et al., 2006). Rehydration is a complex process that is intended to restore the properties of the fresh product by contacting dehydrated products with a liquid phase. This process to be composed of three simultaneous steps: (1) absorption of water into the dry material, (2) swelling of the rehydrated product, and (3) loss or diffusion of soluble components. Rehydration ability or capacity measures the ability of a dehydrated product to rehydrate (Maldonado et al., 2010). Mathematical models of rehydration will be useful in designing and optimizing this operation that have been applied as exponential models or capillary absorption theory or Fick’s diffusion laws (Lee et al., 2006). In this research, the effect of this heating method on the physical-qualitative characteristics of dried apple slices, including volume, density, shrinkage and behavior of rehydration were studied. Apples (Golden Delicious variety) were purchased from a local market and according to Acevedo et al., 2008 kept in 0°C±1°C and relative humidity ranging from 90% to 95%. The samples were skinned manually and then cut into slices with different thicknesses of 5mm, 9mm and 13mm and all with 20mm in diameter. The average moisture content of apple was measured using oven (Binder FD53) at 103 °C for 24 hours and it was equal to 84.11% based on wet weight (AOAC, 2000). Operation of infrared radiation with intermittent heating method was performed at three constant temperatures of 70, 75 and 80 °C using the infrared dryer similar to Liu et al., 2014. Shrinkage coefficient of product was estimated with both theoretical (βtheo) and practical (β) methods according to Talla et al., 2004. Also, the mathematical models as Peleg (Reyes et al., 2011) and Exponential (Krokida et al., 2003) equation were compared to describe the rehydration process in dried product using adjusted R-squared (Adj.R2) and root mean squared error (RMSE). Statistical analysis of the effect of thickness and temperature on the shrinkage coefficients (βtheo, β) was performed in SPSS software in version of 19. To achieve this aim, a completely randomized design (CRD) with factorial arrangement with two factors as thickness (at three levels) and temperature (at three levels) was used. Also, two methods of computing the shrinkage coefficients (theoretical and practical) were compared together with one-way F test. Mean comparison was performed by Duncan test with 95% confidence level (P<0.05). All experiments were performed in three replications. The results showed that increasing of the temperature caused greater volume and density changes during rapid dehydration of the product. The density changes were more intense for the thin product (reducing the final density to about 0.6 g/cm3). Also for thicker products, the density changes were slower during the process (reducing the final density to about 0.7 g/cm3). During process, the variation of product shrinkage indicated an exponential rising trend which was influenced by the amount of evaporated water. Shrinkage coefficient is significantly increased at higher processing temperature and thickness of product (β equal to 0.164), representing that the product is heavily affected by the structural collapse phenomenon. The observations were similar to those reported by many researchers (Mayor & Sereno, 2004; Nowak & Lewicki, 2004; Katekawa & Silva, 2006). The temperature of 80 °C showed significantly higher theoretical and practical shrinkage coefficient than the other two tested temperatures (70, 75 °C). The difference between the two methods of calculation in shrinkage coefficient (theoretical and practical) was also significant and the difference increased with the increase of temperature (more than 6%). Jannot et al., 2002 reported that the error in the practical method can be due to the noisy data (deviation from the actual value). Limitation of rehydration capacity (RC) in slices with high shrinkage stress confirms the damage of the texture of the product (reduction in predicted equilibrium moisture content: Xe from 6.523 to 4.148 kg/kg, db). Rehydration process in different product thicknesses is described better using Peleg model (higher Adj.R2 and lower RMSE) compared with the exponential one. The observations were similar to those reported by many researchers (Krokida, M, & Marinos-Kouris, 2003; Nathakaranakule et al., 2010). The physical properties including shrinkage and density in the dried product are affected by process and product conditions. The low occurred shrinkage that reflects the preservation of the internal structure of the product and will be effective in rehydration behavior. In fact, reabsorption cannot be simply defined as the returned process of dehydration. Because of moisture reabsorption is completely affected by the texture, structure and properties of the dried product. Therefore, mild thermal conditions prevent the structural breakdown of apple slices and, at low thicknesses, due to the reduced volume of water evaporated from the slices, the shrinkage coefficient is reduced, thus preserving the internal physical structure of the infrared dried product.

Rosemary is an evergreen and aromatic plant of the mint family, which has many antioxidant and medicinal properties. Nowadays, to increase the quantity of extraction and improve the quality of essence, the plant is dried and then the extraction process is performed. Thus, new and combined methods for drying of plants containing essence have been studied. Different drying methods such as hot air, microwave, microwave- vacuum, sun and freeze drying have been studied by many researcher to dry rosemary and the quality of the extracted essence and the kinetics of mass transfer have been investigated. Drying by means of infrared is considered for many agricultural products but this method has not been applied to rosemary until now. Therefore, the purpose of this study was to investigate the kinetics of drying and the effect of infrared drying on the volume, color and quality of essence of rosemary leaves. Our specific target was modeling of the infrared drying process and compare it with other drying methods.

In this study, the geometric properties of rosemary leaves were measured by Mitutoyo Micrometer. Then, by using electromagnetic radiation in the range of infrared spectrum (100, 200 and 300watts) freshly prepared leaves of rosemary were dried. After essence extraction by clevenger method, the volume of extraction and components were determined by GC/MS and according to the power of infrared wavelength were evaluated by completely randomized design. The quality of dried rosemary and essences were also studied by ImageJ software, and color parameters a*, b*, L*, chroma (C*), browning index, total color difference and Hue angle, were calculated by completely randomized design. In addition, drying curves, effective diffusivities and activation energy determined by using moisture measurement data.

According to the results of analysis of variance and Duncan's Multiple Range test at 5% level, it was observed that with increasing the power of the infrared lamp in the drying process, color parameters like L, b, Chroma and BI in dried rosemary decreased and ΔE, A and Hue angel increased. Analysis of variance and comparison of Duncan's mean at 5% level showed that increasing the infrared power has a significant effect on reducing the volume of essence. In the case of essence color, it was perceived that with increasing the power of the infrared lamp, the color parameters like A, L and Hue angel decreased and b, BI and Chroma increased. Furthermore, increasing the infrared power in the drying process of rosemary has a significant effect on reducing the volatile compounds of rosemary essence. Effective diffusivities varied from 33.3×9.10-9 to 1.0907×10-8. The activation energy was also determined as 30.243 kW/kg. To predict the rosemary drying trend by using eight models, regression modeling was performed through MATLAB software (version 2016). Results showed that, Midilli model for the power of 200 and 300 watts and Verma model for the power of 100 watts, due to high correlation coefficient index and low standard error, were two suitable models for evaluation of Drying kinetic and prediction of drying process.

Increasing infrared power during drying process of rosemary leaves decreases the efficiency of essence extraction. Moreover, increasing the infrared power has a significant effect on reducing the active ingredients like cineol and Beta-Pinene in essence. The color of dried rosemary and extracted essence are affected by infrared radiation power and varies with increasing the power. Rising the infrared radiation power results in an increase in the effective diffusivity coefficients. Also, it can be concluded that, midilli and verma are two best models for prediction of drying trend of rosemary.

Button mushroom (Agaricus bisporus) is a high nutritional valuefood that is allocated about 40% of the mushroom market share and contains 32.5 % protein, 1.6 % fat, 9.2 % fibre, 7.5 % ash, 6.8 % moisture and 42.4% carbohydrate according to dry basis. Button mushroom is highly perishable product that shelf-life at 4 °C is up to 8 days. In this research, to increase the shelf life of button mushroom and producing high quality product, infrared (IR) dryer was used and mass transfer kinetics of the samples was measured.

In this study, drying of button mushroom in an infrared dryer at irradiation power of 150, 250 and 375 W and distance of 5, 10, 15 and 20 cm was investigated. The effect of lamp power and distance of sample from radiator on time and drying rate, and moisture diffusion coefficients were evaluated in a factorial experiment based on completely randomized design. For drying kinetics modeling, the 9 mathematical models including, Fick's Diffusion, Approximation of diffusion, Page, Modified Page –II, Newton, Midilli, Logarithmic, Verma and Two term were evaluated and the best model with the highest correlation coefficient and the lowest standard error was selected.

The results showed that the effect of lamp power and distance on the drying process of button mushroom is significant. Increase in infrared lamp power from 150 to 375 W, and decrease in the distance of lamp from sample from 20 to 5 cm reduced drying time button mushrooms 56.6 and 55.3 %, respectively. The maximum drying time was related to the power of 150 watts and the 20 cm lamp distance, which took 190 minutes to complete the process. Also, the lowest drying time is related to 375 W power and 5 cm lamp distance, which recorded time for this treatment was 30 minutes. By increasing the lamp power and reducing the irradiation lamp distance in the drying process of button mushroom, the effective moisture diffusivity coefficient had an increasing trend. By increasing the lamp power from 150 to 375 W, the effective moisture diffusivity coefficient increased from 3.8×10-9 m2s-1 to 11.0×10-9 m2s-1 (at a distance of 5 cm from the lamp). By increasing the sample distance from 250 W lamp, from 5 to 20 cm, the effective moisture diffusivity coefficient for a button mushroom decreased from 7.0×10-9 m2s-1 to 2.2×10-9 m2s-1.

Effective diffusivity coefficient of button mushroom moisture was between 1.2×10-9 to 11.0×10-9 m2/s. In modeling of mushroom drying process, Page model has better match with the experimental results compared with other models.

One of the main goals of drying agricultural crop is reduction of the moisture content and obtain optimum moisture in order to get maximum storage time and reduction of crop losses in the processing stage. Regarding to new science application and different methods of drying, use of new methods such as drying with infrared ray is necessary to be studied. In this study in order to determine effect of air temperature at three levels of 40, 50 and 60 ° C and ultimate paddy moisture at levels of %7-8, % 9-10 and %11-12 (based on dry weight) on drying time and paddy husk percent of Tarom Hashemi was used rotary cylindrical drier of infrared in three replications. Besides, effect in three levels of temperature and moisture and two type crop of paddy and brown rice on some mechanical properties of the dried paddy were determined by instron apparatus in five replications. The results indicated that the studied factors temperature and moisture had a significant effect on drying time. However, temperature and moisture factors hadn’t significant effect on the husk present. Measurement of Mechanical properties of rice paddy after drying indicated that among three factors: type crop (paddy and brown rice), moisture and temperature; two factors of type crop and moisture were more effective on mechanical properties. The obtained results of the research showed that optimum temperature of drying and optimum ultimate moisture (based on dry weight) are 57/68 ° C degree and %7/5 and under such conditions optimum time of drying was 84/76 minutes so that husk percent, break time and force were %21/54, 4/24 sec and 33/92 N respectively, besides size of displacement up to break point was 0/34 mm.

In this research, stepwise cooking and temperature fuzzy controller were designed during the infrared irradiation of apple with intermittent heating method. For this purpose, the dry blanching process and dehydration of apple slices were examined at three temperatures of 70, 75 and 80 °C based on the blanching speed and vitamin C preservation. The fuzzy controller of the temperature with the feedback loop was designed, simulated, and implemented by comparing two first and second order transfer functions in MATLAB software. Simulation efficiency was examined using the indices of integral squared error (ISE), integral absolute error (IAE), integral time-weighted absolute error (ITAE) and steady state error (ess). The results revealed that the temperature of 80 °C and time of 15 minutes were appropriate for blanching operation and temperature of 70 °C was appropriate for dehydration. The simulation results confirmed that the higher order of the transfer function led into a faster response, but increase in oscillations and reduction in the stability were not appropriate.  For the first-order transfer function, the values of efficiency indices, including (ISE), (IAE) and (ITAE) were calculated to be 0.760, 0.821 and 0.589, respectively, of second-order transfer function. The simulation indicated the reliability of the fuzzy control model and showed an acceptable computational efficiency, since the fuzzy rule test during simulation showed a high sensitivity to maintain steady state error (ess) close to zero.

In the present study, an infrared-assisted solar dryer was used to determine the drying kinetics, energy consumption and quality parameters evaluation of Echium amoenum. Experiments were conducted with two levels of drying air flow rate (0.0025 and 0.005 m3s-1) and three levels of IR lamp power (100, 150 and 213 W). Drying time, energy consumption and evaluation of quality properties in different air flow rates and lamp powers were compared to the conventional method (shade drying). Five empirical models were fitted on the experimental data and the goodness of regression models were evaluated using coefficient of determination (R2), root mean square error (RMSE), and Chi square (χ2). Results of drying time in the different experiments showed highly significant differences respect to the conventional method (p-value<0.01). Also results showed that increasing the air flow rate and IR power caused a reduction of 37% and 17% in drying time, respectively. Best empirical model to describe the drying behavior was the Page model. The lowest specific energy consumptions (SEC) was 4.63 MJ kg-1, which was occurred at the air flow rate and IR power of 0.005 m3s-1 and 150 W and the highest SEC was 5.26 MJ kg-1 and occurred at 0.0025 m3s-1 of air flow rate and 213 W of IR lamp, respectively. Finally, the air flow rate of 0.005 m3s-1 and the IR power of 150 W was recommended for Echium amoenum drying in the IR-ASD because of the fair energy consumption and the suitable product color.

Infrared thermometer is one of the proper irrigation scheduling tools that can be used in fields or gardens with different soil texture. In order to schedule irrigation of maize (SC704) in Urmia climate conditions, using a difference in temperature of canopy cover of plant and air in 2017, a research was conducted at research farm of Urmia University college of agriculture under drip irrigation. In this research, the effects of various irrigation water treatments were investigated. The experimental design was carried out in a randomized complete block design with three levels of irrigation I1, I2 and I3 of 50, 75 and 100 percent of water requirement in three replications, respectively. Based on the results, the average values of CWSI for maize during the growth period for treatments of I1, I2 and I3 were calculated to be 0.53, 0.44 and 0.28, respectively. The results showed that the CWSI index increased with decreasing water requirement. The threshold of water stress index (0.28) of I3 treatment (no stress treatment) was the basis for irrigation scheduling. Then, some relationships were presented to determine the irrigation time of maize, using the CWSI index in Urmia climate for July, August and September as ,and  respectively.

Roasting is an important step in nuts processing and one of the ways to improve the color, flavor and unique aroma and taste, which can, in addition to positive changes, reduce the amount of nutrients in the nuts. So, It is very important to select the appropriate conditions for roasting. In this study, the effect of infrared (IR) power (400-600 W) and roasting time (4-10 min) on energy consumption, color parameters (L*, a*, b* value, ΔE, BI, SI, WI, hº), texture, moisture content and sensory properties of sunflower kernel were investigated. In addition, the regression models for the responses were obtained and the proper roasting conditions were determined using response surface methodology (RSM). Quadratic model was proposed for color change (L*، a* ،ΔE، hº، WI) and linear relation for texture, BI and moisture content and 2FI for energy consumption. Roasting at 492.5 W IR power for 9.1 min were found to be convenient or proper roasting conditions. Also, roasted kernels had acceptable quality in terms of sensory properties compared to the conventional method (hot air).

Although the soil salinity as an effective factor on soil and water management is typically assessed by measuring the soil electrical conductivity (ECe), this conventional laboratory method is time-consuming and costly. Therefore, near-infrared spectroscopy (NIR) as a fast, cheap and non-destructive method to assess soil salinity level can be considered as a valuable alternative method. Reviews of literature on the application of NIR spectroscopy for soil salinity prediction have shown that there is no sufficient information about the effect of soil texture on results accuracy; therefore, in this study the soil salinity was predicted under different soil salinity levels and various soil textures. The effect of different pre-processing methods was also investigated to improve the predicted soil salinity. Twenty three surface soil samples were collected from different places in Fars province, then; some soil properties such as percentage of particles size and ECe were measured. These samples were artificially salted by adding the water in different salinity levels to the soil samples. The ECe of these soils were between 2.1 to 307.5 dS/m and then all samples dried to reach the field capacity level. Soil reflectance spectra were obtained in 350-2500 nm wavelength range. The absorbance and derivative of reflectance spectra were calculated based on the reflectance spectra. In order to determine the effect of smoothing technique, as a pre-processing method, 4 various methods (moving average, Gaussian, median and Savitzky-Golay filters) in 12 different segment sizes (3,5,7,9,11,13,15,17,19,21,23 and 25) were applied and the processed spectra introduced to Partial Least Square Regression (PLSR) model to predict soil salinity in two calibration and validation steps. At the first step, the soil salinity was predicted for all samples using of reflectance, absorbance and derivative of reflectance spectra under 4 pre-processing methods and 12 segment sizes. According to the R2 and RMSE indices, the best type of spectra, the effect of various pre-processing methods and the best segment size in prediction of soil salinity were determined as absorbance spectra, moving average and Savitzky-Golay filters for segment size of 25 and 15, respectively. In the second step, the effect of soil texture on prediction accuracy was investigated. For this purpose, soil samples were divided into the coarse and fine textures and soil salinity was predicted for each of these groups using different pre-processing methods and different segment sizes. In prediction of soil salinity by absorbance, reflectance and derivative of reflectance spectra, the R2 values in validation step were 0.742, 0.706 and 0.670; and RMSE values were 29.92, 31.96 and 33.9 (dS.m-1), respectively. The absorbance spectra were the best spectra type in prediction of soil salinity. Therefore, in next step, absorbance spectra were used only for predicting the salinity in fine and coarse soil textures. Results showed that the prediction in coarse texture was better than that of the fine texture (R2= 0.836 and R2=0.756, respectively). It was also revealed that the highest R2 occurred in coarse texture and the accuracy of prediction was reduced in fine textures. The results showed that the performance of different pre-processing methods is related to the spectrum type. Although the pre-processing methods had no positive effect in using of reflectance spectra, but it improved the predicted values which were obtained using of absorbance and derivative of reflectance spectra. The best results were occurred when the absorbance spectra were used. Moving average method increased the accuracy of prediction more than the other pre-processing methods, and according to the results this method, for the segment size of 25, was the best technique in soil salinity prediction. According to the R2 and RMSE indices, the prediction of soil salinity by absorbance spectra was more accurate than the prediction using reflectance and derivative of reflectance spectra (R2= 0.742, 0.706 and 0.670, respectively). Although the predicted soil salinity in coarse soils were more accurate than that in fine soils. Using of absorbance spectra to predict the soil salinity in all soil textures was efficient. The results showed that using of pre-processing methods improved the soil salinity prediction by absorbance and derivative of reflectance spectra, and the moving average and Savitzky-Golay filter were the best pre-processing methods.

Roasting is an essential process that improves the taste, color, texture and appearance of the product. The shelf-life is also extended as a result of roasting. The temperature and the duration of roasting are the most important factors that influence favorable traits. IR is a novel technique for roasting that, compared to conventional heating, has positive advantages such as shorten heating time, significant energy saving and uniform heating. This study aimed to investigate the effect of IR, compared to conventional, roasting on some physicochemical and quality properties of soybeans. Moreover, the conditions of roasting soybeans via the two mentioned methods were optimized using Response Surface Methodology (RSM). Soybean seeds were collected from a commercial farm in Gorgan (North of Iran) and were dried in an oven at 40 °C for 48 hours until the moisture content became lower than 5 % w/w. For each treatment, 25 g of raw soybeans were spread in glass petri dishes and were then roasted under the conditions selected for each experiment. In conventional roasting an electrical oven with the temperature range of 180 to 260 °C and time duration of 5 to15 min was used. IR roasting was performed using an IR-warm air apparatus with a constant power of 1300 W at the air temperature of 180-240 °C for 5-15 min. After the temperature equilibrium was reached, the samples were packed in polyethylene bags and were kept at 4 °C until further analysis. For each roasting method, a central composite design consisted of two variables of time and temperature (each in three levels) and a total of 13 experiments were applied. Response surface analysis was performed using Design-Expert software. The moisture content of samples was determined by drying the samples in a drying oven at 105 °C until a constant weight was reached. The total phenol content was measured quantitatively by the Folin-Ciocalteu colorimetric method based on the reaction of reagents with the active hydroxyl groups of phenolic compounds. The radical scavenging activity of the samples was determined by the DPPH radical. The force needed to break the roasted seeds was evaluated using a texture analyzer equipped with a load cell of 25 Kg. The color of samples was evaluated in a special box under controlled conditions (in terms of light intensity and camera position) using a digital camera and the color parameters (L*, a* and b*) and the color change (ΔE) were determined. According to the results, the second- and first-order models were suggested for the study of time and temperature effects on moisture reduction that were both significant (p<0.05). In two methods, total phenolic content and antioxidant activity models were significantly (p<0.05) second-order. With increasing time and temperature, these above values increased. Hardness and color differences of oven roasting were both first-order but only color differences were first-order for infrared roasting. Effects of two parameters were significant in all models. Optimum conditions for soybeans roasting sing oven and infrared were 223°C – 13 min and 231°C – 11 min, respectively. In optimum condition, experimental data for the moisture content, total phenolic content, antioxidant activity, hardness and color differences were: (1.10, 4.53, 42.75, 9.03, and 4.93) , (1.58, 4.93, 47.85, 6.20, and 4.79) respectively. Based on above results, infrared can be introduced as a replacement of conventional oven method for the roasting of soybeans.

In food industry, the use of quality monitoring and evaluating systems which increase the production efficiency and desirability of product is increasing. Fuzzy logic has provided an appropriate tool in the design of the decision maker systems based on human experience. In this study, a fuzzy system was designed for sensory evaluation of apple slices during drying using infrared radiation. For this purpose, the slices of apple were prepared in three thicknesses of 5 (Thin), 9 (Moderate) and 13 mm (Thick). Intermittent radiation operation was performed at three constant temperatures of 70 (Low), 75 (Moderate) and 80 °C (High) to achieve a moisture level of 15 (Low), 20 (Moderate) and 25 % kg/kg, wb (High). Evaluating the sensory attributes including color, aroma, flavor, texture and overall acceptability was performed by ten trained panelists using linguistic and hedonic method. Similarity analysis between sensory properties in terms of importance and statistical analysis for considering the impact of process conditions on the desirability were also performed. Finally, the fuzzy model has been set. The results showed that, color and texture are of the same importance with Pearson correlation coefficient (PCC) equal to 0.981 in the sensory evaluation. Sensory qualities of apple slices were better in thin slices, low temperature and moderate humidity. Fuzzy model with mean absolute percentage error (MAPE) equal to 14.54 %, had a good prediction about average evaluated scores.

Chicken nugget is one of the popular ready to eat food in the world. Due to high fat content in nuggets cooked using conventional method and obesity and corresponding disease, different methods such as partial frying and other final cooking method have been considered recently. In this study, chicken nuggets were cooked using several cooking methods including deep-fat frying, IR cooking, Pre frying - IR cooking (PF-IR) and IR cooking-post frying (IR-PF) using various IR power and process times. The effect of each treatment on moisture and fat contents and moisture loss kinetic (DeffandEa) of the chicken nuggets was investigated. The results revealed that fat content of samples reduced from 11.78% (control) to 2.18-11.62% in infrared, pre frying-infrared and infrared-post frying methods. The moisture and fat contents of the nuggets decreased when the higher IR power and longer process time were applied. The minimum moisture content was observed during PF-IR method (620 W-7 min). Moisture diffusivity value enhanced by increasing power of IR and the highest amount (2.69×10-8)was obtained in the sample prepared using pre frying-infrared process in 620 W and 7 min cooking time. Finally, cooking process modeling was conducted using Khazaei and Logarithmic models and the best model for describing each process was chosen. Logarithmic model was better for infrared cooking and Khazaei model was selected for describing pre frying-IR and IR-post frying mass transfer kinetics.

L-Ascorbic acid (vitamin C) is the most important vitamin in terms of nutrition. Ascorbic acid is a thermolabile (heat-sensitive) compound that can be degenerated aerobically or anaerobically. The degradation rates of ascorbic acid differ with the changes in environmental conditions such as temperature and water activity. It is ascertained that the other nutrients residing in a food can be preserved in case the Vitamin C content is preserved. Thus, the compound is considered as the nutritional quality index during the food processing. The simultaneous infrared dry-blanching and dehydration (SIRDBD) with intermittent heating method is a novel process in which the temperature is kept constant. Over-blanching causes product quality decline and nutrients, especially vitamins, deterioration. Therefore, the precise process conditions (time and temperature) are specified with the objective of preventing over-processing. To do so, such factors as access to the specific center temperature, access to a certain level of enzymatic inactivation and preservation of a given ratio of Vitamin C should be taken into account. This is subject to the biophysical properties of fruits and slices size and shape. The aim of this study was to determine the appropriate operating conditions for blanching step. For this purpose, the effect of irradiation temperature and thickness of the product on the destruction of polyphenol oxidase (enzymatic browning agent) and vitamin C were investigated. Apple slices (Golden Delicious variety) were prepared with thickness of 5, 9 and 13 mm and 20 mm in diameter. Irradiation was carried out at three constant temperatures of 70, 75, and 80 ° C. The central temperature of the product was recorded during processing. To evaluate the enzymatic activity of polyphenol oxidase (PPO) and its effect on the product color, apple slices were removed from the device in 2- minute intervals and the process was continued till the time no sign of color change stemming from catechol reagent addition was observable. Vitamin C content measurement was carried out with 30- minute intervals during drying till apple slice reaches constant weight. It was performed based on titration by the use of 2, 6-Dichlorophenol-Indophenol (DCPIP). To calculate the browning index (BI) due to PPO activity, image acquisition was made with the use of a flatbed scanner. The treated samples were placed on the scanner and then a black box was utilized so as to prevent the interferences of the peripheral lights and light reflections. The images featured a 300 dpi quality and were saved in TIFF-24 bit format. Color analysis of the obtained images was carried out in color spaces L*a*b* by the use of “color space convertor” pelagin in ImageJ software, version 1.6.0. Statistical analyses were carried out in SPSS software, version 19. To do so and in order to assess the time required time for the blanching, there was made use of completely randomized design (CRD) in factorial format (32) considering two factors, namely thickness (in three levels) and temperature (in three levels). The statistical analyses of the vitamin degradation kinetic constant (k), as well, were conducted based on randomized complete block design (RCBD) in the course of which the temperature and thickness were considered as the block and the treatment, respectively. Mean comparisons were undertaken based on Duncan test in a 95% confidence level (P

A practical model including a parameter as a function of drying condition were introduced to predict the effect of far-infrared radiation (FIR) in a combined rough rice drying process. Tests were conducted in three replication for four levels of FIR (0, 0.1, 0.2 and 0.3 Wcm-2) and three levels of inlet air temperature (30, 40 and 500C). The results obtained from the simulation of the proposed model demonstrated that the models were capable satisfactorily express the characteristics of drying rough rice in combined dryer. Also due to the effects of combination of hot air and FIR drying technique on drying rates, cracking enhancement ratio (CER), required breaking energy for grain, specific energy consumption (SEC) and optimal method was presented. Combination of hot air at temperature of 40 0C and FIR at intensity of 1000 W.m-2 is the best way to have lowest SEC and highest grain quality point of view.