scholarly journals Evaluation of the Changes in Thermal, Qualitative, and Antioxidant Properties of Terebinth (Pistacia atlantica) Fruit under Different Drying Methods

Agronomy ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1378
Author(s):  
Yousef Abbaspour-Gilandeh ◽  
Mohammad Kaveh ◽  
Hamideh Fatemi ◽  
José Luis Hernández-Hernández ◽  
Alejandro Fuentes-Penna ◽  
...  
Keyword(s):  
Specific Energy Consumption ◽  
Antioxidant Properties ◽  
Microwave Drying ◽  
Total Phenol Content ◽  
Drying Methods ◽  
Drying Method ◽  
Flavonoid Content ◽  
Rehydration Ratio ◽  
Drying Time ◽  
Hot Air

This study aims to investigate the effect of different drying methods on the thermal, qualitative, and antioxidant properties and pH of terebinth. To perform the experiments in this study, the hot air (HA), infrared (IR), microwave (MW), hot air–infrared (IR–HA), and hot air–microwave drying (MW–HA) methods were considered. The results showed that the minimum drying time was obtained by the hot air–microwave (MW–HA) method. However, the lowest specific energy consumption (SEC) and the highest energy efficiency (ηe) were obtained by the MW method. Considering the color criteria, the best method was obtained by the MW–HA method. The highest amount of rehydration ratio (RR) and the lowest shrinkage (Sb) of the dried terebinth samples were obtained using the MW dryer compared with other drying methods. The MW and MW–HA methods resulted in higher contents of total phenol content (TPC), total flavonoid content (TFC), and antioxidant capacity (AntiOX) than other methods. According to the results of this study, the most effective drying method for terebinth was determined to be the MW and MW-HA methods.

scholarly journals Comparative Study of Hot Air Drying and Microwave Drying for Dewatered Sludge

2021 ◽  
Author(s):  
Wittawat Wulyapash ◽  
Awassada Phongphiphat ◽  
Sirintornthep Towprayoon
Keyword(s):  
Microwave Power ◽  
Specific Energy Consumption ◽  
Microwave Drying ◽  
Drying Methods ◽  
Drying Time ◽  
Hot Air ◽  
Air Temperatures ◽  
Dewatered Sludge ◽  
Dried Sludge ◽  
Seafood Processing

Abstract Large amounts of sludge are generated from wastewater treatment in seafood processing industries. Most of the dewatered sludge in Thailand is not utilized and disposed by landfilling. The dried sludge utilization as refuse-derived fuel (RDF) is an alternative solution due to the gross calorific value (GCV), which is greater than 21.9 MJ/kg. However, the key obstacle is its high moisture content of 87.4% (wet basis). Therefore, drying methods using hot air and microwave techniques were investigated for preparing dried sludge. The effects of hot air temperatures (100-150 °C) and microwave power levels (100-800 W) were compared on drying kinetics, specific energy consumption (SEC), and characteristics of the dried products. The results showed that drying times were decreased by increasing the hot air temperatures. In the same way, the increase in microwave power levels decreased the drying time. The application of microwaves contributed to reducing the drying time by more than 46% compared to the hot air. The reduction of drying times resulted in the saving SEC. The GCV of the dried sludge decreased with the decrease in the volatile matter (VM) due to the high component of VM as 79.5-80.3% (dry ash-free basis). The sludge dried by the microwaves showed a lower GCV than the hot air products. However, dried sludges still had high GCV (≥ 20.8 MJ/kg). Furthermore, the minimal variation of the product characteristics demonstrated that the microwave technique could be applied as an alternative drying method with a rapid process compared to the conventional hot air technique.

Effect of microwave, infrared, and convection hot-air on drying kinetics and quality properties of okra pods

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Hany S. EL-Mesery ◽  
Mona A. Elabd
Keyword(s):  
Energy Consumption ◽  
Air Temperature ◽  
Specific Energy ◽  
Specific Energy Consumption ◽  
Drying Methods ◽  
Air Velocity ◽  
Rehydration Ratio ◽  
Drying Time ◽  
Shrinkage Ratio ◽  
Hot Air

Abstract Okra pods were dried using the following drying regimes; microwave (MWD), infrared (IRD) and convective hot-air drying (CHD). The objective of this investigate was to report the influences of drying methods on okra quality under different drying conditions. Data analysis showed that rehydration ratio and colour change increased with increase in drying air temperature and air velocity while specific energy consumption and shrinkage ratio decreased with increase in drying air temperature under (CHD). The rehydration ratio and colour of dried okra increased with increase in both infrared intensity but it also increased with a decrease in air velocity under (IRD). In the MWD method, drying time, specific energy consumption and shrinkage ratio decreased with increases in microwave power while the rehydration ratio and colour increased. Optimum drying period, specific energy consumption, colour, shrinkage and rehydration ratio were obtained for microwave drying. The model of Midilli et al. is the greatest for describing the drying curves of okra under all the drying processing conditions.

scholarly journals Determination of Drying Patterns of Radish Slabs under Different Drying Methods Using Hyperspectral Imaging Coupled with Multivariate Analysis

Foods ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 484 ◽  
Author(s):  
Dongyoung Lee ◽  
Santosh Lohumi ◽  
Byoung-Kwan Cho ◽  
Seung Hyun Lee ◽  
Hyunmo Jung
Keyword(s):  
Moisture Content ◽  
Hyperspectral Image ◽  
Partial Least Square ◽  
Least Square ◽  
Moisture Distribution ◽  
Microwave Drying ◽  
Drying Methods ◽  
Drying Method ◽  
Drying Time ◽  
Hot Air

Drying kinetics and the moisture distribution map of radish slabs under different drying methods (hot-air drying (HAD), microwave drying (MD), and hot-air and microwave combination drying (HMCD)) were determined and visualized by hyperspectral image (HSI) processing coupled with a partial least square regression (PLSR)-variable importance in projection (VIP) model, respectively. Page model was the most suitable in describing the experimental moisture loss data of radish slabs regardless of the drying method. Dielectric properties (DP, ε ) of radish slices decreased with the decrease in moisture content (MC) during MD, and the penetration depth of microwaves in radish was between 0.81 and 1.15 cm. The PLSR-VIP model developed with 38 optimal variables could result in the high prediction accuracies for both the calibration ( R c a l 2 = 0.967 and RMSEC = 4.32 % ) and validation ( R v a l 2 = 0.962 and RMSEC = 4.45 % ). In visualized drying patterns, the radish slabs dried by HAD had a higher moisture content at the center than at the edges; however, the samples dried by MD contained higher moisture content at the edges. The nearly uniform drying pattern of radish slabs under HMCD was observed in hyperspectral images. Drying uniformity of radish slabs could be improved by the combination drying method, which significantly reduces drying time.

Effect of drying methods on the nutritional content and In- vitro Antioxidant capacity of Chenopodium album L. and Spinacia oleracea L.

2021 ◽  
pp. 4361-4366
Author(s):  
Sonia Singh ◽  
Neetu Agrawal
Keyword(s):  
Spinacia Oleracea ◽  
Chenopodium Album ◽  
Microwave Drying ◽  
Total Phenolic ◽  
Drying Methods ◽  
Drying Method ◽  
Nutrient Quality ◽  
Oven Drying ◽  
Sun Drying ◽  
Hot Air

The herbs, Chenopodium album Linn. and Spinacia oleracea Linn. belongs to Chenopodiaceae family, are the two nutritious and edible green leafy food crops, abundantly found especially in the northern-west region of India. These plants have gained renown popularity, because of their high nutritional content including protein, amino acids, carbohydrate, and even the presence of phenolic components, which ultimately may get affected with drying and storage techniques. Impact of different drying methods (microwave drying at 4 minutes, hot air oven drying at 5 hours and sun drying at 8-10 hours) on nutrient quality and antioxidant property of Chenopodium album Linn. and Spinacia oleracea Linn. leaves were evaluated by using UV spectrophotometritc assay, total phenolic content and DPPH free radical scavenger method. Drying treatments were significantly decreased the moisture, carbohydrate and protein content present in C.album and S. oleracea. Hot air oven drying method produced dried samples of C.album and S. oleracea had significantly similar antioxidant activity when compared with the samples obtained from sun drying method. The dried samples obtained from hot air oven drying technique showed significant presence of total phenolic content in C. album and S. oleracea (6.44±0.12 mg/g, 6.69±0.40 mg/g) whilst the traditional sun drying method produced 8.00±0.02 mg/g and 7.89±0.37 mg/g). It is concluded that microwave drying and hot air oven drying were the methods to preserve appreciable percentage of nutrient components compared to the fresh samples. On other hand, the traditional method produced substantial reduction of nutrient quality. From statistical analysis, hot air oven drying technique was considered as optimum method which showed satisfactory % retention of protein (65.86%) and carbohydrate (85.95%) at 5 hours (shorter time than sun drying time period) along with significant antioxidant activity (34.89 μg/mL and 35.60 μg/mL) similar as obtained from the traditional technique (32.00 μg/mL).

Effects of drying methods on color retention and chlorophyll of celery (ApiumgraveolensL.), spinach (Spinacia oleraceaL.), Malabar spinach (Basella albaL.)

2020 ◽  
pp. 53-61
Author(s):  
Dat Q Tran
Keyword(s):  
Microwave Drying ◽  
Drying Methods ◽  
Hot Air Drying ◽  
Drying Time ◽  
Air Drying ◽  
Color Retention ◽  
Hot Air ◽  
Drying Techniques ◽  
Dried Vegetables

Dried vegetables are considered convenient for storage, transportation and preservation. The different drying techniques could influence the quality of resulting products. This study aimed to evaluate the effects of three distinguish drying methods as hot-air drying, foam-mat drying and microwave drying on the color retention and chlorophyll of green vegetables powder. Fresh spinach(Spinacia oleraceaL.), celery (Apium graveolensL.), Malabar spinach (Basella albaL.) were dried by different methods: hot air at 60oC, foam-mat at 60oC and microwave at 270 W until the samples reached approximately 9% of moisture content (wb). The drying time of the dried samples by microwave, foam-mat and hot-air method were 60, 210 and 240 min, respectively. Foam-mat dried vegetables were found to have the best quality in terms of color and the residual chlorophyll content. The findings suggest that foam-mat drying is promising in dried vegetable processing

Effect of Pre-Treatments and Drying Air Temperature on the Quality of Dehydrated Oyster Mushroom (Pleurotus Florida)

2019 ◽  
Vol 56 (1) ◽  
pp. 34
Author(s):  
Parul Bora ◽  
Asha Kawatra
Keyword(s):  
Citric Acid ◽  
Oyster Mushroom ◽  
Drying Methods ◽  
Rehydration Ratio ◽  
Drying Time ◽  
Drying Characteristics ◽  
Drying Temperature ◽  
Hot Air ◽  
Adverse Influence

<em>Experiments were conducted on pre treated dehydrated oyster mushroom with steeping in citric acid and sodium chloride and blanching to investigate the effect of pre treatments and drying methods on drying characteristics of mushroom and quality of dried oyster mushroom. Drying was accomplished in a cabinet dryer using hot air at 40<sup>O </sup>C, 60<sup>O</sup>C and by sun drying. The drying characteristics of mushroom were not affected by the pre-treatments significantly. However, the rate of drying increased with the increase in drying temperature. Increase in drying temperature significantly reduced the total drying time. Pre treatments and drying temperature had adverse influence on the rehydration ratio, hardness and colour of the dehydrated mushrooms. Blanching improves the colour of the dehydrated mushroom but increased hardness also. A loss of protein was observed during blanching</em>

Assessment of Quality Attributes of Banana Slices Dried by Different Drying Methods

2014 ◽  
Vol 10 (2) ◽  
pp. 251-260 ◽  
Author(s):  
Kianoosh Pirnazari ◽  
Ali Esehaghbeygi ◽  
Morteza Sadeghi
Keyword(s):  
Moisture Transfer ◽  
Color Change ◽  
Drying Methods ◽  
Drying Method ◽  
Hot Air Drying ◽  
Drying Time ◽  
Moisture Movement ◽  
Air Drying ◽  
Hot Air ◽  
Significant Difference

Abstract In the present study, banana slices were dried and compared using electrohydrodynamic (EHD) drying method at 4.5, 6.5, and 8.5 kV/cm; oven at 50, 60, and 70°C; and hot-air drying at 50, 60, and 70°C at a constant air velocity of 1.5 m/s. ANOVA showed that drying method had a significant effect on drying time, rehydration capacity, shrinkage, color features (L*, a*, b*, and ∆E), and consumed energy. The values of consuming energy for EHD at 8.5 kV/cm, oven, and hot-air drying at 70°C were 2.99, 20.9, and 81.7 kJ/g run on full capacity of each dryer, respectively. Oven drying led to a greater color change than did hot-air. No significant difference was observed between the color change feature ∆E for EHD and hot-air dried samples in the orthogonal contrast analysis. The falling rate period for EHD moisture movement showed that diffusion was describing the moisture gradients and the internal moisture transfer was dominant. EHD is not fast; however, its advantages like less energy needed, lower shrinkage, and great rehydration capacity make it a good choice for combining with other convection drying methods.

scholarly journals Comparative Evaluation of Drying Kinetics of Carrot Slices in Hot air and Microwave Drying

2021 ◽  
Vol 10 (4) ◽  
pp. 242-248
Author(s):  
Gitanjali Behera ◽  
◽  
Mitali Madhumita ◽  
J. Aishwarya Aishwarya ◽  
V. Gayathri ◽  
...  
Keyword(s):  
Microwave Drying ◽  
Quality Analysis ◽  
Rehydration Ratio ◽  
Hot Air Drying ◽  
Drying Time ◽  
Air Drying ◽  
Hot Air ◽  
Sensory Score ◽  
Kinetics Of ◽  
Different Thickness

Carrot is most the important vegetable grown throughout the World. It is also a very good source of βcarotene, α-carotene and zeaxanthin. The post-harvest losses because of having high moisture content limit the utilization of carrot. In the present investigation, the comparative analysis was done between hot air drying and microwave drying for different thickness of carrot slices. The quality analysis for both the dried products was performed and compared. The drying time was varied between 3.5 h to 10 h for try drying whereas for microwave drying it was 240 sec to 681.6 sec. The drying time reduces drastically in case of microwave drying in comparison to hot air drying. The moisture ratio for both dried techniques was found to decreasing with an increase in drying time. The microwave dried samples showed a better rehydration ratio than the hot air dried sample. Also, the dehydration ratio of dried carrot sample using microwave drying was found to be lowest compared to the hot air dried sample. The microwave dried carrot slices showed a better sensory score in terms of colour and shape than hot air dried sample. Therefore, microwave drying may be recommended to dry carrot slices to have better energy efficiencies

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

Foods ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 86 ◽  
Author(s):  
Ebrahim Taghinezhad ◽  
Antoni Szumny ◽  
Mohammad Kaveh ◽  
Vali Rasooli Sharabiani ◽  
Anil Kumar ◽  
...  
Keyword(s):  
Specific Energy Consumption ◽  
Moisture Diffusivity ◽  
Microwave Drying ◽  
Drying Methods ◽  
Diffusivity Coefficient ◽  
Drying Time ◽  
Quality Properties ◽  
Color Value ◽  
Artificial Neural Network Ann ◽  
Drying Conditions

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

scholarly journals Kurutma Yöntemlerinin Deveci Armudunun Kurutma Kinetiği ve Renk Parametreleri Üzerine Etkisi

2021 ◽  
Vol 9 (5) ◽  
pp. 897-908
Author(s):  
Ilknur Alibas ◽  
Aslıhan Yılmaz ◽  
Seda Günaydın ◽  
Begüm Arkain
Keyword(s):  
Energy Consumption ◽  
Specific Energy Consumption ◽  
Initial Moisture Content ◽  
Quality Parameters ◽  
Drying Method ◽  
Hot Air Drying ◽  
Drying Time ◽  
Air Drying ◽  
Hot Air ◽  
Thin Layer Drying

Deveci pear (Pyrus communis L. cv. Deveci) slices, whose initial moisture content is 5.24 ± 0.003 kgsu kgKM-1 (%83.95 ± 0.01 w.b), were dried by shade drying and hot-air drying at 60, 80 and 100°C until the final moisture reached 0.13 ± 0.001 kgsu kgKM-1 (%11.40 ± 0.06 w.b), and the drying processes of these methods were completed in 11150, 437, 252, and 148 minutes, respectively. In the study, experimentally obtained time-dependent moisture ratios were modeled using twenty different thin-layer drying equations. Accordingly, the model that gives the closest results to experimental data for 60°C and 100°C was the Modified Henderson & Pabis's equation. On the other hand, Alibas equation and Jena & Das equation were found to be the best models in shade drying and hot-air drying at 80°C, respectively. Despite no energy consumption in the shade drying method, some reasons such as this method being quite long and causing negative effects on the quality parameters of the product revealed that the shade drying method was not suitable for drying of Deveci pear. It was observed that total energy consumption increased with the increase of the drying temperature. Also, it was determined that the increase in temperature negatively affected the quality parameters. It was found to be a suitable method for drying the Deveci pear of the hot-air drying at 60°C due to the operating parameters such as drying time and specific energy consumption, as well as quality parameters such as brightness, redness, yellowness, chroma, hue angle, total color change and browning index were very close to the fresh product.

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