• 한국식품저장유통학회지
• /
• 제19권4호
• /
• pp.485-491
• /
• 2012

복숭아를 이용한 고부가가치 제품의 개발을 위하여 복숭아의 냉풍 및 적외선 건조 방법에 따른 품종별 건조 복숭아의 품질 특성을 조사하였다. 건조 방법에 따른 품종별('천홍', '유명') pH 및 가용성 고형분 함량은 전반적으로 적외선 건조에서 냉풍 건조 보다 높게 나타났으며, '천홍' 품종보다 '유명' 품종에서 pH 및 가용성 고형분 함량이 높은값을 나타내었다. 색도는 L과 ${\Delta}E$ value은 적외선 건조에서 높게 나타났고, 반면에 a, b value는 냉풍건조에서 높은 값을 보였다. 유리당 분석결과 조성은 sucrose > fructose > glucose 순이었고, 그 함량은 sucrose에서 50.71 mg/100 g으로 가장 높게 나타났으며, 적외선 건조가 냉풍 건조에 비해 전반적으로 높은 함량을 나타내었다. 유기산은 품종 및 건조 방법에 상관없이 oxailic acid, malic acid, citric acid가 동정되었으며, 그 중 citric acid 함량이 6.17 mg / 100 g으로 가장 높게 나타났다. 무기질은 모든 조건에 상관없이 K의 함량이 높게 나타났으며, 그 조성은 K > Mg > Ca > Na > Fe > Zn > Cu > Al의 순으로 나타났다. 전반적으로 적외선보다 냉풍 건조에서 높게 나타났고, '천홍'보다 '유명' 품종에서 함량이 높게 나타났다. 관능검사 결과 외관과 맛은 적외선 건조에서 높게 평가되었고, 색도와 조직감에서는 냉풍 건조에서 높게 평가되었다. 또한 NaCl로 전처리하였을 때 기호성이 높게 평가되어 건조와 함께 전처리를 병용하면 건조 과실의 기호성 향상에 기여할 것으로 생각된다. 이상의 결과에서 적외선 건조 방법으로 제조한 건조 복숭아의 품질이 전반적으로 우수하다고 판단되며, 건조 복숭아 제조 방법으로 적합할 것이라 사료된다.

• 한국식품저장유통학회지
• /
• 제21권6호
• /
• pp.838-843
• /
• 2014

본 연구에서는 근적외 분광법을 이용하여 양념용 채소로 많이 사용되는 파, 마늘, 양파의 건조 불균일성을 관찰하였다. 대류식 온풍건조기에서 건조 위치에 따른 양념채소류의 건조 상태 차이를 조사한 결과, 건조 트레이의 높이나 위치에 따라 바람의 온도와 습도에 차이가 발생하여 건조가 균일하게 되지 않았다. 건조 정도가 다른 양념채소류의 2차 미분 근적외 스펙트럼을 비교한 결과 1,390 nm에서 1,400 nm 부근의 수소결합이 약한 물이 먼저 증발되었고 1,420 nm 부근의 수소결합이 강한 물은 건조 후에도 잔존함을 관찰할 수 있었다. 초분광 NIR 이미징 기법으로 측정한 스펙트럼을 주성분분석함으로써 건조채소의 건조도를 가시적으로 판별할 수 있었다.

• 한국산업융합학회 논문집
• /
• 제8권1호
• /
• pp.47-55
• /
• 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 Wood Science and Technology
• /
• 제26권4호
• /
• pp.34-42
• /
• 1998

Three hardwood (ash, alder and black locust) and three softwood (Japanese red pine, radiata pine and Western hemlock) specimens were dried in microwave(MlW) oven and their drying rates were obtained. Their specific permeabilities were also measured by using a modified liquid permeability measuring device. The correlation between the M/W drying rates and permeabilities of six species were statistically analyzed. It was revealed that within a species there is a logarithmic relationship between the M/W drying rates and average moisture contents and that among species there is a linear relationship between the M/W maximum drying rates and the average specific permeabilities. A exception was Western hemlock, which was of low permeability and of high drying rate. A Me-time equation, which showed a good agreement with the actual data, was derived. Thus using this equation the moisture contents of wood and the drying end points of M/W drying could be predicted. Infrared images of the thermal distribution in wood were illustrated.

• Korean Chemical Engineering Research
• /
• 제50권6호
• /
• pp.1049-1055
• /
• 2012

화염 없이 연소가 일어나고 원적외선 복사열을 활용할 수 있는 매트 촉매버너를 제작하여 연소실험과 전열특성 분석을 수행하였다. 매트 촉매버너를 이용한 예혼합 연소실험에서 연소열의 9~17% 정도가 현열로 배출되었으며, 연소조건에 따라 차이를 보였다. 촉매버너와 시료 사이 거리증가에 따라 복사강도가 적어졌는데, 매트 촉매버너 아래에서 거리에 따라 변하는 복사에너지 흡수면적을 계산할 수 있는 수식을 유도하였다. 이 식을 멜라민 건조실험 결과와 비교하여 상관성이 있음을 보였다. 매트 촉매버너를 이용하여 멜라민, wood chip, 농산 pallet 등에 대한 건조실험을 수행하고, 이들의 건조속도로부터 에너지 이용효율을 계산하였다. 매트 촉매버너를 이용한 건조에서 최대 에너지 이용효율은 wood chip 건조에서 79% 정도까지 얻을 수 있었다.

• Journal of Biosystems Engineering
• /
• 제12권1호
• /
• pp.39-44
• /
• 1987

Measurement methods of moisture content were compared with 7 dried vegetables (red pepper, onion, green onion, garlic, ginger, carrot and radish). The moisture contents of dried vegetables having different moisture contents were determined by atmospheric oven drying, infrared balance, vacuum oven and Karl Fisher methods. Vacuum oven and Karl Fisher methods gave the relatively agreed results and considered to give the accurate moisture content. Atmospheric oven drying and infrared balance methods resulted in higher moisture content than methods mentioned above, because of the thermal decomposition of solid. Calibration of the moisture data of atmospheric oven drying method into the vacuum oven data was undertaken. The thermodecomposable solid fraction was high in onion, radish, green onion and carrot, and was in the range of 8.0-11.7% of the total solid in these products.

• 산업식품공학
• /
• 제21권1호
• /
• pp.42-48
• /
• 2017

본 연구에서는 원적외선을 이용하여 증자 호박고구마를 건조할 경우 건조두께, 건조온도와 송풍속도에 따른 건조특성과 건조제품의 색도변화 및 당도 등의 품질특성을 분석함으로써 증절간 호박고구마의 원적외선 건조를 위한 기초 자료를 제시하고자 하였다. 원적외선 건조의 경우 열풍건조와 비교하여 열효율이 높고, 건조속도가 빠르며, 피건조물의 품질이 우수하기 때문에 열풍건조의 단점을 보완할 수 있다(Ning, 2012). 그 결과를 요약하면 다음과 같다. 증자 호박고구마의 건조속도는 건조두께가 얇고, 건조온도가 높으며, 송풍속도가 빠를수록 증가하는 경향을 보였으며, 건조두께 8 mm, 건조온도 $80^{\circ}C$, 송풍속도 0.8 m/s 조건이 가장 빠른 것으로 나타났다. 본 연구에서 검증한 건조모델 중 Lewis 및 Modified Wang & Singh 모델의 경우 전체적인 건조시간대에서 비교적 잘 일치하는 것으로 나타나, 증자 고구마의 원적외선 건조 시 Lewis 및 Modified Wang & Singh 모델을 이용할 경우 높은 정밀도에서 건조시간 예측이 가능한 것으로 나타났다. 원적외선 건조 후 증절간 고구마의 색차(${\Delta}E$) 값은 건조온도가 낮고, 송풍속도가 느릴수록 낮은 경향을 보였으며, 건조두께 10 mm 조건이 8 mm 조건보다 색차가 적은 것으로 나타났다. 특히, 건조두께 10 mm, 건조온도 $60^{\circ}C$, 송풍속도 0.8 m/s 조건에서 색차값은 28.33으로 가장 낮은 것으로 나타났다. 당도는 건조두께가 얇고, 건조온도가 높으며, 송풍속도가 느릴수록 높은 경향을 보였다. 증자 호박고구마 건조 중 에너지 소비량은 건조온도가 높고, 송풍속도가 느리며, 건조두께가 얇을수록 감소하였으며, 건조두께 8 mm, 건조온도 $80^{\circ}C$, 송풍속도 0.6 m/s 조건에서 에너지 소비량은 12.06 kWh/kg-water로 가장 적은 값을 보였다. 따라서 증자 호박고구마의 건조시간, 색도변화, 당도 함량 및 에너지 소비량 등을 고려하면 증절간 호박고구마의 고품질화를 위해서는 건조두께 8 mm, 건조온도 $80^{\circ}C$, 송풍속도 0.6 m/s 조건이 적절한 것으로 판단된다.

• 한국의류산업학회지
• /
• 제17권2호
• /
• pp.295-304
• /
• 2015

This paper investigated wear comfort property of heat storage knitted fabrics for high emotional garment. For this purpose, ZrC imbedded PET knitted fabric was prepared and various physical properties such as thermal, wicking and drying characteristics were measured. In addition, far-infrared emission characteristics of ZrC imbedded PET was analysed and tactile hand property and dye affinity of ZrC imbedded knitted fabric were also studied in comparison with regular and other commercial heat storage PET knitted fabrics. It was observed that Zr imbedded amount in the yarn was 19.29% by ingredient analysis and far-infrared emission energy was $3.65{\times}10^2W/m^2$, emissivity was 0.906 at the range of wavelength $6{\sim}20{\mu}m$. It was found that maximum heat flow (Qmax) of ZrC imbedded PET knitted fabric was lower than that of regular PET one and warmth keepability rate was higher than that of regular PET one, which means ZrC imbedded PET have heat storage property. Drying property of ZrC imbedded knitted fabric was better than that of regular PET one due to heat by far-infrared emitted from ZrC in the core of filament. It revealed that wicking property of the ZrC imbedded fabric was not influenced by far-infrared emission, but affected by fibre physical properties. Tactile hand property of ZrC imbedded knitted fabric was not influenced by imbedding ZrC in the filament but affected preferably by structure of knitted fabric. Dye affinity of ZrC imbedded PET knitted fabric was less influenced by dyeing temperature and time than regular PET knitted one.

• Preventive Nutrition and Food Science
• /
• 제14권4호
• /
• pp.329-334
• /
• 2009

The effects of drying conditions on the antioxidant activities, luteolin, and volatile compounds of Chrysanthemi Flos flowers were evaluated. The flowers were dried with hot-air or far-infrared radiation at 40${^{\circ}C}$, 50${^{\circ}C}$ and 60${^{\circ}C}$, respectively, to reach 22$\pm$1% of moisture content. Each 10 g of the dried flowers were extracted with 100 mL of 95% ethanol. Increasing temperature in hot-air dried (HAD) conditions increased the antioxidant activities of the flower extracts. However, increasing temperature in far-infrared dried (FID) conditions decreased the antioxidant activities of the extracts. Luteolin, one of main flavonoids of Chrysanthemi Flos flowers, was present in the highest content at 60${^{\circ}C}$ FID flowers with a value of 139 $\mu$g/mL. Thirteen volatile compounds including camphor and β-caryophyllene were identified in chromatograms. Higher amount of the volatiles were found at 50${^{\circ}C}$ HAD and 40${^{\circ}C}$ FID. The results indicated that the antioxidant activities and volatile compounds of Chrysanthemi Flos flowers were significantly affected by drying conditions.

• 한국약용작물학회지
• /
• 제19권5호
• /
• pp.354-361
• /
• 2011

In order to product dry goods of Gastrodiae Rhizoma with high quality, tubers were treated with various dry methods such as cutting, drying methods and steaming. In cutting than no cutting, they were shown shorter drying hours and lower drying yield. Drying hours in freeze drying was shorter than those of hot air and far-infrared ray. Total polyphenol content was higher in cutting than no cutting. According to steaming, it was increased in freeze drying but decreased rapidly in the other dry methods. Among all treatments, hot air dry treatment with cutting and no steaming had the highest total polyphenol content. Gastrodin and 4-hydroxybenzyl alcohol contents generally were similar or higher in cutting than no cutting. By steaming, gastrodin content in freeze drying was decreased but 4-hydroxybenzyl alcohol content was increased. But hot-air and infrared ray dry, they were shown opposite results. Gastrodin and 4-hydroxybenzyl alcohol contents showed opposite reaction to each other and were shown various response by dry methods.