Effect of different drying time on physicochemical properties of black carp ( Mylopharyngodon piceus ) by hot air

Author(s):  
Yixin Wang ◽  
Haiyuan Huang ◽  
Wenzheng Shi
2021 ◽  
Vol 15 (3) ◽  
Author(s):  
L. Avdieieva ◽  
E Zhukotskyi ◽  
H. Dekusha ◽  
S. Ivanov

The paper reviews and analyses the advantages and disadvantages of the existing technologies of drying shiitake mushrooms, which are a valuable source of bioactive polysaccharides, vitamins, antioxidants, etc. The findings presented in the paper show how various drying methods and their thermotechnological operating parameters affect the mechanostructural properties, chemical composition, content of aromatic substances and other compounds of mushrooms. It has been demonstrated that the traditional convection drying of shiitake in the temperature range 50–60°C allows maximum preservation of phenolic compounds, organic acids, nucleotides, sulphuric aromatic substances, and enhances the unique aroma of the mushroom. Radiation drying has such advantages as lower shrinkage of dried shiitake mushrooms, a higher coefficient of rehydration and higher hardness, and the drying time reduced by 66% compared with freeze-drying. Vacuum drying makes it possible to obtain high quality products, but significantly increases the duration of the process and reduces the content of aromatics. Radiation drying combined with hot air allows obtaining a dry form of shiitake rich in protein and bioactive polysaccharides and having high physicochemical properties, and reduces the duration of the process by 37.5% compared with convection drying. Spray drying of shiitake mushrooms is highly practical economically and allows organising industrial manufacture of high-quality dry mushroom powder in large volumes. It is characteristic of this drying method that its temperature effect on the product is slight, which makes it possible to preserve thermolabile bioactive substances. When using spray drying, it is advisable to add dextrin additives. This improves the structuring and moisture-conducting properties of the suspensions and their thermal stability, and helps preserve the unique aroma of shiitake mushrooms due to encapsulation of aromatic compounds. Studying the effect of various drying methods on the physicochemical properties of shiitake will lead to improving the existing technological processes and will make it possible to obtain products with desired properties.


2021 ◽  
Author(s):  
Wittawat Wulyapash ◽  
Awassada Phongphiphat ◽  
Sirintornthep Towprayoon

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.


2014 ◽  
pp. 5-12
Author(s):  
Tamás Antal

In this study, the effects of freeze drying (FD), hot-air drying (HAD) and combined drying (HAD-FD) on drying characteristics, energy uptake, texture, rehydration and color of carrot were investigated. Results showed that HAD-FD significantly improved the drying time compared with FD under the same operating conditions, and the HAD-FD can reduce the total cost of dehydration. The drying kinetics was described by the Henderson-Pabis and the third degree polynomial models in the case of HAD, FD and HAD-FD. The HAD carrot samples were exhibited shrinkage, case hardening, poor rehydration and brown surface. The FD carrot cubes appeared porous structure, excellent rehydration, soft texture and loose color. The HAD-FD samples were superior to HAD products and was nearer in quality to FD products with respect to appearance, rehydration and surface resistance (texture). Finally, it is concluded that HAD-FD is effective in improving the FD drying rate. However, the combined drying has a small-scale adverse effect on product quality.


2021 ◽  
Vol 12 (1S) ◽  
pp. 62-73
Author(s):  
Nor Anis Shafira Rosidi ◽  
Asmaliza Abdul Ghani @ Yaacob ◽  
Nurhayati Yusof ◽  
Norzaida Yusof

Large production of red dragon fruit by-products, which are frequently discarded from food industry has become a major waste problem. Converting this waste into useful products with good physicochemical properties could solve the pollution issues. Thus, a study was carried out to investigate the effect of blanching and drying temperatures on physicochemical properties of red dragon fruit peel powder. Dragon fruit peel was pre-treated with hot water at 90 °C for 2 minutes before being dried in hot air oven dryer at 50 °C, 60 °C and 70 °C. Results showed that the powdered sample of blanched and dried at 50 °C had significantly higher fiber, water activity and moisture content than those of unblanched/blanched and dried at 60 °C and 70 °C. Result also showed that the colour of this powder was similar to the fresh dragon fruit peel. When dried at 50 °C, the unblanched and blanched powders exhibited a slightly higher water solubility index compared to those dried at 60 °C and 70 °C. Based on the evaluation of bulk and tapped densities, all powders having the Carr Index in the range of values between 20 and 28 thus can be categorised as slightly poor flowing. For all conditions studied, powder that was blanched and dried at 50 °C was the best condition as it contained the highest amount of fiber with good physicochemical properties.


2012 ◽  
Vol 1 (2) ◽  
Author(s):  
Nihar Ranjan Sahoo ◽  
Uma Sankar Pal ◽  
Sanjaya Kumar Dash ◽  
M.D. K. Khan

A prototype heat pump dryer has been developed for drying of fruits and vegetables at low temperature and relative humidity to maintain the quality of dried product. Onions, of Nasik red variety were peeled, trimmed and sliced to 2 mm thickness. The onion slices were dried in the heat pump dryer at 35ºC (32 % R.H.), 40ºC (26 % R.H.), 45ºC (19 % R.H.) and 50ºC (15 % R.H.). Samples were also dried in a hot air dryer at 50ºC (52 % R.H.) for comparison. The drying rate increased with increase in drying air temperature, associated with reduced R.H., in the heat pump dryer. Drying took place mainly under the falling rate period. The Page equation, resulting in a higher coefficient of determination and lower root mean square error, better described the thin-layer drying of onion slices than the Henderson and Pabis equation. Heat pump drying took less drying time of 360 min and yielded better quality dried product, with higher retention of ascorbic acid and pyruvic acid and lower colour change, as compared to a hot air dryer at the same drying air temperature of 50ºC.


2018 ◽  
Vol 83 ◽  
pp. 330-340 ◽  
Author(s):  
Xueshu Zhang ◽  
Yubang Shen ◽  
Xiaoyan Xu ◽  
Meng Zhang ◽  
Yulin Bai ◽  
...  

Author(s):  
Dat Q Tran

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


2018 ◽  
Vol 26 (4) ◽  
pp. 202-208
Author(s):  
Sang Im Oh ◽  
Seo Young Kim ◽  
Ja Hee Lee ◽  
Ae Kyung Lee

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