scholarly journals İncirin Sıcak Hava ve Mikrodalga Destekli Köpük Kurutma Yöntemi ile Kurutulması

2019 ◽  
Vol 7 (2) ◽  
pp. 291
Author(s):  
Mehmet Koç ◽  
Feyza Elmas ◽  
Emine Varhan
Keyword(s):  
Diffusion Coefficient ◽  
Effective Diffusion ◽  
Microwave Drying ◽  
Drying Rate ◽  
Drying Process ◽  
Hot Air Drying ◽  
Air Drying ◽  
Hot Air ◽  
Rate Period ◽  
Foam Thickness

In this study, the drying process of fig foam was carried out with hot air (60, 70, 80°C) and microwave (100, 300, 600 W) and the effect of drying process parameters and foam thickness on drying kinetics was investigated. The drying process was carried out only falling drying rate period and no constant drying rate period was observed. The drying times of the microwave drying were lower than the drying times of hot air drying due to the volumetric heating in addition to the large evaporation area on the foam surfaces. Drying times were shortened by increasing the temperature and microwave power whereas drying time increased with increasing foam thickness. Experimental drying data were placed in semi-empirical models of the 2. Fick's diffusion equation to determine kinetic parameters. Among them, it was found that Wang and Singh and Logarithmic models were better fitted for microwave and hot air drying respectively. The effective diffusion coefficient values for microwave and hot air drying varied between 9.94×10-10-405.69×10-10, 13.26×10-10-26.65×10-10 m2·s-1, respectively. Effective diffusion coefficient values increased with increasing temperature, microwave power and foam thickness. High thickness supported the diffusion process by convection of heat due to the increase in gaps in the structure. Activation energy which calculated with Arrhenius equation was varied from 2.195-2.379 W·g-1 for microwave drying and 12.952-21.426 kJ·mol-1 for hot air drying.

scholarly journals Hot air drying characteristics and nutrients of apricot armeniaca vulgaris lam pretreated with Radio Frequency(RF)

2018 ◽  
Author(s):  
X.L. Huang ◽  
M.C. Peng ◽  
J.X. Liu ◽  
Y. Lei ◽  
X.J. Yang ◽  
...  
Keyword(s):  
Radio Frequency ◽  
Drying Rate ◽  
Hot Air Drying ◽  
Air Drying ◽  
Drying Characteristics ◽  
Hot Air ◽  
Rate Period ◽  
Pretreatment Time

Apricot pretreated with RF and then dried with convective hot air at 65℃, 3.0m/s in this research. RF pretreatment time of 20, 30, 40 and 50min were chosen. Results showed that, there is only falling rate period during apricot hot air drying, and the drying rate of apricot is improved significantly; Herdenson and Pabis model is suitable for apricot hot air drying; retentions of flavonoids, polyphenols and Vc in dried apricot were higher than those of fresh apricot; when RF treating time was chosen 30mins, nutrients retentions of Vc, flavonoid and polyphenols were 0.9543mg/100g, 5.4089mg/100g and 7.3382mg/100g, separately.   Keywords: apricot fruit, hot air drying, drying rate, nutrients, radio frequency 

scholarly journals Effect of Temperature and Microwave Power Levels on Microwave Drying Kinetics of Zhaotong Lignite

Processes ◽  
2019 ◽  
Vol 7 (2) ◽  
pp. 74 ◽  
Author(s):  
Pengfei Zhao ◽  
Chenhui Liu ◽  
Wenwen Qu ◽  
Zhixiu He ◽  
Jiyun Gao ◽  
...  
Keyword(s):  
Activation Energy ◽  
Thin Layer ◽  
Apparent Activation Energy ◽  
Microwave Power ◽  
Microwave Drying ◽  
Hot Air Drying ◽  
Air Drying ◽  
Hot Air ◽  
Thin Layer Drying ◽  
Rate Period

Microwave drying is a promising and effective way to drying and upgrading lignite. The influence of temperature (100–140 °C) and microwave power levels (500–800 W) on thin-layer drying characteristics of Zhaotong lignite under microwave irradiation were investigated. Fourteen thin-layer drying models were used to analyze the microwave drying process while six thin-layer drying models were used to analyze the hot-air drying process. The microwave drying processes at all temperature (100–140 °C) or low microwave power levels (500–700 W) exhibited four periods: a warm-up period, a short constant period, the first and second falling rate period, while one falling rate period was found during hot-air drying. The effective diffusion coefficient of lignite were calculated and it increases with increasing temperature and microwave power levels. During microwave drying, the two-term exponential model is the most suitable model for all applied conditions, while the Modified Page model is the most suitable model to describe the hot-air drying experiments. The apparent activation energy were determined from Arrhenius equation and the values for the first and second falling rate period are 3.349 and 20.808 kJ·mol−1 at different temperatures, while they are 13.455 and 19.580 W·g−1 at different microwave power levels. This implies the apparent activation energy is higher during the second falling rate period, which suggest that the dewatering of absorbed water is more difficult than capillary water. The value of apparent activation energy in hot-air drying is between the first and second falling rate period of microwave drying. Results indicate that microwave drying is more suitable to dewatering free water and capillary water of lignite.

Hot Air Drying and Vacuum Drying Characteristics of Scarlet Runner Beans

2012 ◽  
Vol 8 (3) ◽  
Author(s):  
Yoshiki Muramatsu ◽  
Eiichiro Sakaguchi ◽  
Takahiro Orikasa ◽  
Akio Tagawa
Keyword(s):  
Diffusion Coefficient ◽  
Moisture Content ◽  
Initial Moisture Content ◽  
Vacuum Drying ◽  
Drying Method ◽  
Drying Process ◽  
Hot Air Drying ◽  
Air Drying ◽  
Drying Characteristics ◽  
Hot Air

Abstract The drying characteristics and volume changes of scarlet runner beans were measured under various conditions to obtain useful basic information for the optimum drying method and conditions. The sample was dried using two drying methods: hot air drying and vacuum drying. The measured changes in moisture content of the sample with the hot air drying process were in good agreement with the exact solution of the infinite plane sheet model. The estimated diffusion coefficients were 3.8×10 -7 -7.4×10 -7 (m 2 h -1) for hot air drying and were related to absolute temperature by an Arrhenius-type equation. The hull of the scarlet runner bean is hard and thick, and the drying rate of the sample was much slower than that of other beans. To establish an efficient drying method without the quality loss, the vacuum drying characteristics of the sample were measured at several levels for temperature and initial moisture content. For the vacuum drying process, an exponential model could be used to estimate the changes in moisture content of the sample. The values of diffusion coefficient for vacuum drying were approximately twice as much as the values of diffusion coefficient for hot air drying at the same temperature. The effects of drying method, temperature, and initial moisture content on the sample quality were investigated, and the optimum drying method and conditions for scarlet runner beans were proposed. Volumetric changes in the sample were determined by measuring particle density. The specific volume of the sample was represented as a linear function of moisture content.

The influence of inhibit avoid water defect responses by heat pretreatment on hot air drying rate of spinach

2016 ◽  
Vol 168 ◽  
pp. 113-118 ◽  
Author(s):  
Takashi Watanabe ◽  
Takahiro Orikasa ◽  
Hiroshi Shono ◽  
Shoji Koide ◽  
Yasumasa Ando ◽  
...  
Keyword(s):  
Drying Rate ◽  
Hot Air Drying ◽  
Air Drying ◽  
Heat Pretreatment ◽  
Hot Air

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

Experimental Study on Hot-air Drying Process Parameters Optimization of Chinese Jujubes

2013 ◽  
Vol 12 (21) ◽  
pp. 6154-6158
Author(s):  
Xiao Kang-Yi ◽  
Chuan Feng-Li ◽  
Shu Gang-Li ◽  
He Lei Cui ◽  
Wen Fu-Wu
Keyword(s):  
Experimental Study ◽  
Process Parameters ◽  
Parameters Optimization ◽  
Drying Process ◽  
Hot Air Drying ◽  
Air Drying ◽  
Process Parameters Optimization ◽  
Hot Air

Influence of Drying Rate on Hot Air Drying Processing of Fresh Foods Using Pulsed Electric Field

2020 ◽  
Vol 15 (7) ◽  
pp. 1123-1125 ◽  
Author(s):  
Takahiro Yamada ◽  
Kouya Yamakage ◽  
Katsuyuki Takahashi ◽  
Koichi Takaki ◽  
Takahiro Orikasa ◽  
...  
Keyword(s):  
Electric Field ◽  
Pulsed Electric Field ◽  
Drying Rate ◽  
Hot Air Drying ◽  
Air Drying ◽  
Hot Air ◽  
Fresh Foods

scholarly journals Changes in Aroma Profile of Shiitake Mushroom (Lentinus edodes) during Different Stages of Hot Air Drying

Foods ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 444 ◽  
Author(s):  
Lei Qin ◽  
Jing-Xuan Gao ◽  
Jia Xue ◽  
Dong Chen ◽  
Song-Yi Lin ◽  
...  
Keyword(s):  
Volatile Compounds ◽  
Sensory Evaluation ◽  
Early Stage ◽  
Organosulfur Compounds ◽  
Lentinus Edodes ◽  
Drying Process ◽  
Shiitake Mushroom ◽  
Hot Air Drying ◽  
Air Drying ◽  
Hot Air

To clarify the changes in the aroma characteristics of shiitake mushrooms (Lentinus edodes) during hot-air drying, volatile compounds of L. edodes were analyzed using sensory evaluation, electronic nose, and purge and trap combined with gas chromatography-mass spectrometry (PT-GC-MS) at different timepoints of the drying process. Results showed that the sensory and volatile profile changed significantly during the drying process at 60 °C for up to 12 h and the drying process could be divided into three stages: early stage (<2 h), middle stage (2–3.5 h) and late stage (>3.5 h). Volatile compounds in fresh L. edodes consisted mainly of ketones and alcohols. The early stage of drying decreased the concentration of ketone and alcohol compounds and promoted the generation of cyclic organosulfur compounds through a series of enzymatic and non-enzymatic reactions, which mainly contribute to the characteristic odor of shiitake mushroom. Partial least squares-discriminant analysis (PLS-DA) showed that the volatile compounds released after different drying times could be divided into four groups, which have been confirmed by sensory evaluation results. The results suggested that the unique flavor of dried mushrooms is mainly due to the activation of enzymes during the drying process, which act on lentinic acid to produce sulfur-containing heterocyclic compounds. We believe that our study makes a potential contribution to the mushroom cultivation and processing industry to achieve an improvement in sensory quality.

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