• Preventive Nutrition and Food Science
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• v.17 no.2
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• pp.122-128
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• 2012

Gelidium (G.) elegans is a red alga inhabiting intertidal areas of North East Asia. We examined anti-oxidative and anti-inflammatory effects of G. elegans, depending on drying and extraction conditions, by determining reactive oxygen species (ROS) and nitric oxide (NO) in 3T3-L1 and RAW 264.7 cells. Extraction yields of samples using hot air drying (HD) and far-infrared ray drying (FID) were significantly higher than those using natural air drying (ND). The 70% ethanol extracts showed the highest total phenol and flavonoid contents compared to other extracts (0, 30, and 50% ethanol) under tested drying conditions. The scavenging activity on 2,2-diphenyl- 1-picrylhydrazyl (DPPH) and nitrite correlated with total phenol or flavonoid content in the extracts. The greatest DPPH scavenging effect was observed in 70% ethanol extract from FID and HD conditions. The production of ROS and NO in 3T3-L1 and macrophage cells greatly decreased with the 70% ethanol extraction derived from FID. This study suggests that 70% ethanol extraction of G. elegans dried by FID is the most optimal condition to obtain efficiently antioxidant compounds of G. elegans.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.9
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• pp.1320-1325
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• 2012

This study investigated the bulk properties of red pepper powders according to drying method and variety. Bulk density, compressive characteristics, irrecoverable work, dynamic angle, and stress relaxation were investigated. Loose bulk density ranged between 0.420 $g/cm^3$ for Cheongyang cultivar and 0.427 $g/cm^3$ for Hanbando cultivar by hot-air drying. The highest tapped bulk density was 0.586 $g/cm^3$ for Hanbando cultivar by far-infrared drying and the lowest value was 0.523 $g/cm^3$ for Hanbando cultivar by sun drying. Hausner ratio reached a maximum value of 1.370 for Hanbando cultivar by far-infrared drying. Compressibility ranged between 0.0016 for Cheongyang cultivar by sun drying and 0.0023 for Hanbando cultivar by far-infrared drying. Compression ratio reached a maximum value of 1.032 for Hanbando cultivar by hot-air drying. Dynamic angle of repose ranged between 37.47 and $42.97^{\circ}$. Irrecoverable work ranged between 76.0 and 81.7%. Relaxation reached a maximum value of 24.31% for Cheongyang cultivar by far-infrared drying.

• Journal of The Korean Society of Grassland and Forage Science
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• v.42 no.2
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• pp.73-78
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• 2022

This experiment was conducted to establish the technology for artificial hay preparation in Korea. Using far-infrared heater, a device that can control temperature, airflow, and far-infrared radiation was produced and conducted on the fourth harvested alfalfa. The drying conditions were carried out by selecting a total of four conditions. For each condition, the radiation rate was set to around 40% (33-42%), and the temperature was set at 58~65℃, and the speed of the airflow was fixed at 60m/s. The overall drying time was set to 30 min in the single and 60 min (30-30 min) and 90 min (30-30-30 min) in the complex condition, and the radiation rate and temperature were changed by time period. In the case of drying condition 1, the final dry matter (DM) content was 46.26%, which did not reach a DM suitable for hay. However, all of the alfalfa corresponding to the remaining drying conditions 2 to 7 showed a DM content of 80% or more, resulting in optimal alfalfa hay production. In power consumption according to the drying conditions, the second drying condition showed the lowest at 4.7 KW, and the remaining drying conditions were as high as 6.5 to 7.1 KW. The crude protein content was found to be high at an average of 25.91% and it showed the highest content in the 5th drying condition (26.93%) and the lowest value in the 6th drying condition (25.16%). The digestibility showed a high value with an average of 84.90%, and there was no significant difference among treatments (p>0.05). Considering the above results, it was judged that drying condition 2 was the most advantageous.

• Food Science and Preservation
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• v.11 no.2
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• pp.189-194
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• 2004

This experiment was carried out to compare the quality of semi-dried persimmon according to various drying methods and ripeness degree of persimmons. Most of persimmons were dried naturally there were much opportunities of contamination by impurities, microorganism and discoloration. There were need for developing various drying methods and knowing proper mature degree of persimmons in order to enhance the quality of semi-dried persimmons. Drying time of semi-dried persimmons by hot-air, far infrared ray and dehumid drying could be shorten approximately 11∼12 days, comparing with natural drying. And the loss ratio of natural drying and artifical drying were 7.0% and 0.0%. The moisture content of natural drying and dehumid drying were simillar and the hardness were very low in comparing other drying methods. Average pannel scores in semi-dried persimmons after drying showed that dehumid drying and natural drying were excellent in total prefernce ; 3.9 and 3.4, respectively. Unriped persimmons showed lower moisture content, color values and higher hardness than riped and overriped persimmons. The total preference of riped and overriped fruit were superior than unriped fruit.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• v.10 no.1
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• pp.253-256
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• 2005

• Journal of the Korean Society of Industry Convergence
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• v.8 no.1
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• pp.47-55
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• 2005

Infrared heating has been traditionally used in industrial applications for processes such as dehydration of food industrial. This heating method involves the application of radiation in the wavelength range of 2 to 50 micrometers. In this work, simultaneous heat balance equations were developed to simulate the infrared radiation heating of agricultural products. The equations assume that moisture diffuses to the outer boundaries of the material in liquid form and evaporation occurs at the surface of the agricultural products. Energy for moisture evaporation is supplied by the infrared radiant energy. The optimum temperature and drying time for the best drying conditions of changing the red peppers with the moisture content of 18% and the restore rate of 80~85% are $80^{\circ}C$ and 44 hours. The performance of radiation tubes coating with the radiation paint developed in this research has the energy of $2.27{\times}103W/m^2{\mu}m$, $150^{\circ}C$ within the scope of radiation wave length of $2{\sim}30{\mu}m$ and has the radiation 0.92~0.93, which is superior to the general radiation tubes. The extinction coefficient according to the band pass filter using the 4 flux theory ha higher dependability on wave length, accounting for $2{\sim}17{\mu}m$ and $5{\times}105{\sim}106m-1$. A comparison between the theoretical energy transfer whose figures are interpreted according to 4 flux theory and the experimental energy transfer of far infrared dryer leads to the findings of the agreement less than 5%.

• Journal of the Korean Society of Food Culture
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• v.29 no.1
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• pp.91-100
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• 2014

This study investigated the antioxidative activities and quality characteristics of gruel as a home meal replacement with Angelica keiskei powder pre-treated by far-infrared radiation or freeze-drying methods. Far-infrared treated Angelica keiskei powder (F-IAP) showed significantly lighter, weaker green, and stronger yellow color values than powder subjected to freezedrying (FAP) (p<0.001). F-IAP showed higher total phenolic compound contents than that of the FAP. ABTS radical scavenging activity of F-IAP was 50.31%, which was significantly higher than that of FAP, at 43.51% (p<0.05). Color values of gruel significantly decreased with increased addition of Angelica keiskei powder (p<0.05). Gruels containing far-infrared treated Angelica keiskei powder (F-IAG) showed higher total phenolic compound contents as well as ABTS radical scavenging activities compared to the gruels containing freeze-dried Angelica keiskei powder (FAG). Gruels containing 5 g of Angelica keiskei powder showed 2.0 to 2.5 times higher antioxidant activities than those containing powder alone due to the presence of other ingredients with antioxidant activities such as black soybean or sweet pumpkin. In the results of sensory evaluation, F-IAG containing more than 5 g of Angelica keiskei powder had higher sweetness and roasted grain flavor, as well as lower bitterness and astringency compared to FAG. Sensory acceptance tests of all samples showed higher scores than 5.0 representing possibilities of successful development of gruels as a home meal replacement containing Angelica keiskei powder.

• Korean Journal of Materials Research
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• v.9 no.12
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• pp.1205-1210
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• 1999

Far infrared ceramic/aluminum composite powders for thermal spray were fabricated by spray drying method and investigated the characteristics of the plasma sprayed coating layers, I.e. microstructure, phases, thermal shock resistance and spectral emissivity. The shape of the spray dried composite powder was spherical and the particle size distribution was 34~105${\mu}m $. Aluminum was distributed homogeneously in the spray dried composite powder. Spectral emissivity of the plasma sprayed coating layer ranges from 3 to 14${\mu}m $ whereas spectral emissivity of the raw ceramic powder ranges from 8 to 14${\mu}m $. And then spectral emissivity of the coatings was better than that of the raw powder but spectral emissivity was decreased with increasing aluminum content. It was found that aluminum content ranging from 20 to 30wt% was suitable for fabricating far-infrared radiator by plasma spraying method.

• Food Science and Biotechnology
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• v.16 no.2
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• pp.187-192
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• 2007

The objectives of this study were to examine changes in the color and antioxidant compounds of paprika powder under various conditions, as well as to establish the suitable conditions for drying and storage. Paprika was dried using the following methods: freeze-drying, vacuum drying, far infrared-ray drying, and hot-air drying. Measurements of the moisture content, color pigments, and antioxidant compounds (total carotenoids, capsanthin, ascorbic acid, and total polyphenols) were completed during 120 days of storage at 4 and $30^{\circ}C$. We found that drying methods, storage temperatures, and packaging materials affected the American Spice Trade Association (ASTA) and Hunter color values, as well as the antioxidant content of paprika powder. There was a high correlation (r=0.87, p<0.01) between the ASTA color and the $a^*/b^*$ value. The loss of red color was closely related to the reduction of moisture content (r=0.81, p<0.01) during storage. Drying paprika with a low temperature in the absence of air resulted in better retention of the carotenoids and ascorbic acid. Also, as the retention of the carotenoids and ascorbic acid increased, the stability of the red pigment increased. Freeze-drying was found to be the most suitable drying method for the stability of the antioxidant compounds and red pigment.

• The Korean Journal of Food And Nutrition
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• v.25 no.3
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• pp.538-545
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• 2012

The objective of this work was to study the effect of far infrared ray-vacuum drying having reflection and dispersion functions(RD-FRVD) and hot air drying(HAD) on the quality changes of dried vegetable flakes. HAD was regarded as a control. Browning degrees, color value, titratable acidity and pH value were measured as chemical evaluations. Rehydration and electron micrographs were investigated as physical evaluation. Microbial cells were counted. The color value and browning degrees were increased in both RD-FRVE and HAD. In case of degree of those changes, RD-FRVD made less changes than HAD. Especially, green bean sprout had no differences in color value and browning degrees between raw material and dried-rehydrated material. There were no significance differences in titratable acidity and pH value between raw material and dried-rehydrated material. The total microbial counts were gradually reduced in RD-FRVD. The rehydration rates of dried vegetable flakes were typically increased in RD-FRVD. Also, these results were investigated electron micrographs evaluation. Therefore, these results showed that the quality of dried-rehydrated vegetable flakes was typically enhanced by using RD-FRVD.