Evaluation of short cut pasta air dehydration assisted by microwaves as compared to the conventional drying process

2005 ◽  
Vol 68 (2) ◽  
pp. 175-183 ◽  
Author(s):  
M.N. Berteli ◽  
A. Marsaioli
Author(s):  
S. Spilimbergo ◽  
A. Zambon ◽  
T. M. Vizzotto ◽  
G. Morbiato ◽  
M. Toffoletto ◽  
...  

This work explore the use of supercritical CO2 drying as alternative technique for the obtainment of pasteurized and high quality dried product. Several tests were conducted on animal, vegetable and fruit matrixes in order to investigate the effectiveness of SC-CO2 drying process at different process conditions. Design of experiment was performed to find the optimal process conditions for vegetable and fruit matrices, using the final water activity of the products as key indicator for the drying efficiency. The inactivation of naturally present microorganisms and inoculated pathogens demonstrated the capability of SC-CO2 drying process to assure a safe product. Moreover, retention of nutrients was compared with conventional drying methods. Results suggest that supercritical drying is a promising alternative technology for food drying. Keywords: supercritical drying; carbon dioxide; food drying; microbial inactivation


2021 ◽  
Vol 42 (3Supl1) ◽  
pp. 1487-1498
Author(s):  
Naiara Nobre dos Reis ◽  
◽  
Joyce Yumi Taira ◽  
Leda Battestin Quast ◽  
Ernesto Quast ◽  
...  

Microwave drying has shorter processing times compared with convection drying, which results in high-quality products and reduced energy consumption. The objective of this study is to evaluate the drying process of Araucaria angustifolia seeds using hot air at atmospheric pressure by applying microwaves (300 W and 500 W), and comparing them with the conventional drying process using hot air (80 °C). The drying time using hot air with microwaves at 500 W and 300 W was reduced by 83.33% and 73.89%, respectively, compared with conventional drying. The drying process occurred in the transient regime, with the predominance of a period of decreasing drying rate. The internal temperature of Araucaria seeds increased with the exposure time to the drying process, whereas the moisture content decreased. This tendency was greater for seeds subjected to electromagnetic fields, especially those exposed to higher power. The total phenolic compounds (TPCs) were lower by microwave drying when compared with conventional drying. The TPC loss was influenced by the internal temperature of the seed. Alternative methods to promote the increased retention of phenolic compounds during the drying process include decreasing the microwave power before the end of drying, combining traditional microwave-associated drying methods, and controlling the applied microwave power.


2018 ◽  
pp. 157-172
Author(s):  
Marko Veizovic ◽  
Zdravko Popovic ◽  
Nebojsa Todorovic ◽  
Goran Milic

The subject of this paper is the analysis of the quality of natural and conventional drying of subfossil oak wood. In addition to the drying quality, the colour of this material, as well as the effect of the drying process on colour change have been tested. The subfossil oak logs that were used in this experiment originate from the Morava River in Central Serbia. After sawing, timber was air-dried to about 20% moisture content (MC) followed by kiln-drying to 9.5% MC. By examining the quality of air-drying of the subfossil oak wood, a high presence of cracks was found, as well as the inaccuracy of humidity measurement using electric moisture meters. The stack for kiln-drying consisted of 24 boards, of which 4 were used for the monitoring of MC and MC distribution across the thickness of plank during drying. Drying quality was evaluated after the kiln-drying process. Although mild drying conditions during kiln-drying were applied, the gap as a measure of case-hardening had a value greater than usual for oak of same thickness. It was found that the drying process has no significant effect on the change in the colour of subfossil wood. The colour of the subfossil oak wood was significantly darker than the usual oak wood, and the colour difference between the central and the outer parts of the trunk of the subfossil oak was determined.


2021 ◽  
Vol 67 (1) ◽  
Author(s):  
Xiang Weng ◽  
Yongdong Zhou ◽  
Zongying Fu ◽  
Xin Gao ◽  
Fan Zhou ◽  
...  

AbstractLow permeability of wood causes problems during drying of timber. This study evaluated the effects of microwave (MW) pretreatment on the conventional drying behavior and mechanical damages of Chinese fir lumber. MW pretreatment of lumber was performed at applied MW energy of 43 kWh/m3, and then, the samples were dried in a laboratory drying kiln. The results showed that the drying rate was effectively increased after MW pretreatment. The moisture content (MC) deviation in thickness and residual stress indexes of MW-pretreated samples were significantly decreased in comparison with the control samples, and the appearance quality of wood samples was not clearly affected by the MW pretreatment. Scanning electron microscope (SEM) micrographs demonstrated that pit membranes were damaged after MW pretreatment, and the micro-cracks in radial section as well as detachments between ray parenchyma cells and tracheids were also observed. Consequently, new pathways for moisture migration during drying process were formed after MW pretreatment, which contributed to the improved permeability of Chinese fir lumber and decreased drying time.


2021 ◽  
Vol 14 (1) ◽  
pp. 26-34
Author(s):  
Della Yusfita Sari ◽  
Mustain Zamhari ◽  
Robert Junaidi

The drying process on kemplang crackers is one of the factors that determine the quality of the resulting product. Conventional drying has many disadvantages, namely fluctuating heat and poor hygiene that will affect product quality. So that kemplang crackers can be stored for a long time, it is necessary to reduce the water content of kemplang crackers. Drying kemplang crackers can use a drying rack with a biomass energy source from coconut shells. This study aims to design a tray dryer with biomass energy to obtain dryer performance based on the drying rate and to obtain a product that meets SNI No. 8272-2016. The treatments that were varied were set point temperatures of 55oC, 60oC, 65oC, and 70oC with mass variations of 50 gr, 100 gr, and 150 gr. The results showed that the optimum drying conditions at 70oC for 4 hours with an air velocity of 5.2 m/s2 obtained 9,84% moisture content in 50 gr kemplang crackers, 15.39% in 100 gr crackers and 19,2 in kemplang crackers 150 gr and a drying rate of 0,035028 kg/hour m2. The drying process requires 5,24 kg of dried coconut shell to produce heat energy of 95.358,81024 KJ with a by-product in the form of liquid smoke.


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