Introduction of alkali soaking and microwave drying processes to improve agar quality of Gracilaria verrucosa

2017 ◽  
Vol 34 (12) ◽  
pp. 3163-3169 ◽  
Author(s):  
Yong-Woon Kim ◽  
Hyun-Jae Shin
Keyword(s):  
Gracilaria Verrucosa ◽  
Microwave Drying ◽  
Agar Quality

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

scholarly journals Determination of Various Drying Methods’ Impact on Odour Quality of True Lavender (Lavandula angustifolia Mill.) Flowers

Molecules ◽  
2019 ◽  
Vol 24 (16) ◽  
pp. 2900 ◽  
Author(s):  
Łyczko ◽  
Jałoszyński ◽  
Surma ◽  
García-Garví ◽  
Carbonell-Barrachina ◽  
...  
Keyword(s):  
Solid Phase ◽  
Microwave Drying ◽  
Convective Drying ◽  
Drying Methods ◽  
Drying Method ◽  
Sensory Panel ◽  
Lavandula Angustifolia ◽  
Preservation Method ◽  
Vacuum Microwave

True lavender flowers (Lavandula angustifolia Mill.) is a critical source of essential oils and a flavouring agent used in numerous industries like foods, cosmetics and pharmaceuticals. Its main volatile constituents are linalool and linalyl acetate, which are commonly considered as main odour-active constituents (OACs). Nevertheless, the quality of true lavender flowers is highly dependent on its post-harvest treatment, mainly the preservation method. Recognising that drying is the most frequently used preservation method, the influence of various drying methods, including convective drying (CD) at 50, 60 and 70 °C, vacuum-microwave drying (VMD) with powers 240, 360 and 480 W and combined convective pre-drying at 60 °C followed by vacuum-microwave finish-drying with power 480 W (CPD-VMFD), on the quality of true lavender flowers was verified. The evaluation of influence was carried out by HS-SPME(HS, solid-phase microextraction), GC-MS, GC-MS-O (gas chromatography–mass spectrometry–olfactometry) techniques. Moreover, the sensory panel has assessed the sample odour quality. As a result, the optimal drying methods regarding the requirements for products were established. Overall, for total essential oil recovery, CD at 50 °C is the optimal drying method, while for odour quality concerning the sensory panel evaluation, VMD with power 360 W combined CPD-VMFD and CD at 50 °C is the optimal drying method.

Intermittent Microwave Drying of Litchi: Drying Kinetics and Quality Formation in Color Difference

2012 ◽  
Vol 482-484 ◽  
pp. 2090-2095 ◽  
Author(s):  
Feng Ying Xu ◽  
Zhen Chen ◽  
Chang You Li ◽  
Jian Yuan Liao ◽  
Han Zhang ◽  
...  
Keyword(s):  
Multilayer Structure ◽  
Small Amplitude ◽  
Color Difference ◽  
The Other ◽  
Microwave Drying ◽  
Drying Process ◽  
Biochemical Effect ◽  
Thermal Transmission ◽  
Better Than

In order to reveal the characteristics of thermal transmission and drying quality on the litchi’s multilayer structure, the peel and flesh that separated from fresh fruit were dried with the whole fruit by microwave radiation in three kinds of tempering intermittent HT0101, HT0505 and HT1010. Their characteristics of dehydration and the changes of color difference in drying process were compared. The results showed that microwave drying had influences on the capability of dehydration and the quality of color difference in different interval. The influence of HT0505 was more significant, while the other two conditions, in which there were only a small amplitude of cross and fluctuation, were approximate. In the same conditions of microwave drying, the capability of dehydration of peel and flesh separated was better than that of whole fruit, and the dehydration speed of peel was the fastest. As to color difference, the changes of peel and whole fruit were smaller and much easily to tend to stable. The change of the color difference on the flesh was obvious and finally tended to stable. The further research still needed the further study on biochemical effect during the transformation of quality.

scholarly journals Coupling of microwave radiations to convective drying for improving fruit quality

2018 ◽  
Author(s):  
Neila Bahloul ◽  
M. A. Balti ◽  
M. S. Guellouze ◽  
Nabil Kechaou
Keyword(s):  
Microwave Radiation ◽  
Power Level ◽  
Bound Water ◽  
Microwave Oven ◽  
Microwave Drying ◽  
Convective Drying ◽  
Heat Temperature ◽  
Red Color ◽  
Variable Condition

The present study aims to find the best drying method to minimize the duration of the operation while respecting the nutritional value of the product. Experiments of convective drying and microwave radiation were respectively carried out with a convective dryer (heat temperature: 65 °C and air velocity: 1.3 m/s) and a microwave oven (power level: 100 W and frequency: 2450 MHz). Six coupling tests between the convective drying and microwave radiation were conducted. The only variable condition is the time output of tomatoes from the convective dryer or the microwave oven corresponding to an intermediate mass ratio (IMR) 0.5, 0.4 and 0.3. The microwave drying removes the bound water faster than convective drying. This explains the observed time savings due to convection-microwave and microwave-convection combined drying. The combination of convection drying and microwave drying to an IMR 0.5 preserved better the red color and the antioxidants of the tomato. Thus, the convection–microwave combined drying (IMR 0.5) proved most suitable for preserving the quality of tomatoes. Keywords: convective drying; microwave; coupled drying; color. 

scholarly journals The Influence of Different Drying Methods on Constituents and Antioxidant Activity of Saffron from China

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Yingpeng Tong ◽  
Xingyi Zhu ◽  
Yongqiu Yan ◽  
Ruoxi Liu ◽  
Feng Gong ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Microwave Drying ◽  
Drying Methods ◽  
Drying Method ◽  
Vacuum Oven ◽  
Oven Drying ◽  
Electric Oven ◽  
Long Time ◽  
Spectrum Effect

More and more saffron has been cultivated in China because of the increasing saffron demand, but no paper has studied the influence of drying methods on the quality of Chinese saffron. In this paper, three different dehydration treatments applied in actual production were evaluated: dehydration with electric oven, vacuum oven, and microwave. We determined that the highest quality of saffron will be obtained when fresh saffron is treated at higher temperatures (no more than 70°C) for a long time by electric oven drying and vacuum oven drying. In microwave drying, treatments at lower microwave power and longer time benefit the quality of saffron. In addition, the influence of the drying method on antioxidants in saffron is discussed. The correlation between individual saffron profiles and the antioxidant value was estimated by spectrum-effect relationships analysis.

The Design and Test for the Intermittent Work-Style Drying System

2012 ◽  
Vol 490-495 ◽  
pp. 1728-1732
Author(s):  
Lin Chen ◽  
Xue Song Tai
Keyword(s):  
Control System ◽  
Temperature Control ◽  
Microwave Drying ◽  
Temperature Control System ◽  
Electronic Components ◽  
Work Style ◽  
Drying System ◽  
Drying Chamber ◽  
Better Than

In order to improve the quality of microwave drying, we propose the microwave drying temperature control system which consists of microcontroller (AT89S52), temperature sensors (DS18b20) and other electronic components. The system can monitor the real-time temperature of the drying chamber and can control the drying process automatically , let the temperature cannot out of the permitted range(control the extent permitted automatically), these processes ensure the quality of the dried crop. The results shows that crops using the system are better than those that not used（using）. These tests proved (prove) that the microwave temperature control system can achieve its designed function.

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