콘크리트 포장의 평탄성과 내구성은 환경 조건에 크게 영향을 받으며, 슬래브 상하부 간의 온습도 차이는 부등건조수축 및 와핑 (Warping) 현상을 유발하여 포장의 장기 성능 저하를 초래할 수 있다. 이는 주행성 저하, 균열 발생, 유지보수 비용 증가의 원인이 되 며, 특히 터널과 같은 특수 환경에서는 상하부 간의 습도 차이가 더욱 크게 나타나 부등건조수축이 심화될 가능성이 높다. 터널 내부 는 직사광선의 영향을 받지 않지만, 통풍이 잘 이루어져 건조한 환경이 조성되며, 이러한 조건에서는 슬래브 상부에서 수분 손실이 가 속화되고 하부는 습윤 상태를 유지하여 상하부 간의 큰 습도 차이를 발생시킨다. 이는 슬래브의 비균일한 수분 이동을 유발하여 부등 건조수축을 더욱 크게 발생하게 한다. 국내에서는 터널 길이가 500m 이상인 장대 터널에서 콘크리트 포장 적용이 증가하고 있으며, 아스팔트 포장 대비 화재 시 유독가스 발생 위험이 낮다는 이유로 국토교통부에서 콘크리트 포장을 권장하고 있다. 이로 인해 터널 내 콘크리트 포장의 사용이 증가하고 있 으나, 기상환경 변화 및 습도 관리 미흡으로 인해 콘크리트 포장 줄눈부에서의 평탄성 불량 문제가 빈번하게 발생하고 있다. 이러한 문제는 주행성 저하, 도로 이용자의 민원 증가 및 유지보수 비용 상승을 초래하고 있어, 구체적인 원인 분석과 대책 마련이 필요한 실 정이다. 따라서 본 연구는 터널과 같은 특수 환경에서 습도 조건이 콘크리트 슬래브의 부등건조수축에 미치는 영향을 실험적으로 분석하고, 슬래브의 수평 변형률 및 수직 변위를 측정하여 건조 수축에 따른 변형 거동을 정량적으로 평가하고자 하였다. 다양한 습도 조건에서 슬래브의 변형 양상을 비교 분석함으로써, 터널 환경에 적합한 콘크리트 포장 설계 및 유지관리 기준을 제시하고, 콘크리트 포장의 장 기 성능을 개선하기 위한 대책을 마련하고자 한다.
This study explored a method to enhance the drying process usability of local mangoes by producing foam-mat dried powder under varying drying temperatures (50, 60, 70°C) and foam thicknesses (3, 6, 9 mm). The drying process period ranged from 60 to 390 minutes based on the set conditions, with higher temperatures and thinner foams accelerating drying. Powder chromaticity (L*, a*, and b*) demonstrated a declining trend with increasing drying temperature and foam thickness, exhibiting notable variance in chroma values. The water absorption index varied significantly, between 3.08 to 4.24, under different drying conditions, although the water solubility index remained consistent across foam-dried samples. Powder moisture content ranged from 2.53% to 3.83%, with hygroscopicity escalating with temperature and foam thickness. Vitamin C structure was compromised during the hot air drying process, especially at temperatures above 60°C. Electronic nose analysis distinguished foam-dried powder from freeze-dried powder; however, a thicker foam yielded a scent profile closer to that of freeze-dried powder. The findings provide fundamental data on mango foam drying, which is expected to improve processing and storage tech for local mangoes.
Mushrooms have a unique taste and aroma, so in the processing of mushroom products with other ingredients, a separate pre-processing step is often taken to eliminate the mushroom aroma. In this study, we analyzed the changes in the concentration of volatile compounds according to drying conditions to promote the activation of processing using the fruiting bodies of yellow oyster mushrooms(Pleurotus citrinopileatus) and pink oyster mushrooms(P. djamor). The caps and stipes of yellow oyster and pink oyster mushrooms were separated and freeze-dried at -70oC for 120 hours. Subsequently, they were hot air-dried at temperatures of 40, 50, 60, and 70oC for 24, 24, 16, and 12 hours, respectively. The dried samples were pulverized and quantitatively analyzed by SPME-GC-MS. In the case of yellow oyster mushrooms, the concentration of t-2-nonenal in caps and stipes during freeze-drying was 164.43 g/g d.w. and 174.80 g/g d.w., respectively, whereas during hot air-drying, it significantly decreased to 0.35~3.41 g/g d.w. and 0.98~59.88 g/g d.w. In a similar manner, for pink oyster mushrooms, the concentration of 1-octen-3-ol during freeze-drying in caps and stipes was 31.05 g/g d.w. and 176.17 g/g d.w., respectively, whereas during hot air-drying, it significantly decreased to 1.59~9.66 g/g d.w. and 1.96~15.77 g/g d.w. Furthermore, most volatile compounds showed a tendency to decrease in concentration as the temperature during hot air-drying increased.
Isoflavones found in soybeans are present as glycosides and aglycones, which differ according to their chemical structure. The absorption rate and bioavailability of aglycones are greater than those of glycosides. It is known that aglycone isoflavones in soybean was converted from glycoside isoflavones by activating of endogenous β-glucosidase under drying (40~60℃) conditions after soaking. In this study, we compared and analyzed the proximate composition and isoflavone contents of soybean powders prepared under dried after soaking were analyzed. In the comparison of the proximate compositions, the moisture contents of white soybean powder dried after soaking (WSPDS) and black soybean powder dried after soaking (BSPDS) were decreased as compared with those of the control white soybean powder (CWSP) and control black soybean powder (CBSP). Whereas the contents of other proximate compositions were increased. The aglycone isoflavone contents were higher in WSPDS than in CWSP. Whereas the aglycone isoflavone contents of BSPDS had a similar content those of CBSP because of the component characteristics of black soybean. In conclusion, we believe that it is appropriate to identify and utilize the component characteristics of soybean varieties in order to induce an increase in the functional component content of soybeans under drying conditions after soaking.
This study aims to investigate the effect of drying temperatures on the quality characteristics and physicochemical properties of vegetables. Lettuce and napa cabbage were dried at 40, 50, and 60oC and analyzed for various quality indexes. Higher drying temperature induced the lower L* and higher a* and b* values of samples. Also, it resulted in lowering the rehydration ratio, pH, and total free amino acid content of dried vegetables. The outcome might be due to the damage to the internal structure of vegetables and the decomposition of free amino acids during thermal treatment. Higher drying temperatures led to higher soluble solid and total polyphenol contents due to the conversion of phenolic compounds from combined to free form during the drying process, which changed phenolic compounds from combined to free form. Consequently, samples dried at higher temperatures had higher DPPH radical scavenging ability. The final moisture content and drying time decreased as the drying temperature increased; moreover, the antioxidant activity increased. A lower drying temperature is beneficial to maintaining the chemical characteristics of crops.
본 연구에서는 지방 산화를 억제하고 품질이 우수한 부세 굴비의 가공법을 개발하기 위해 대두와 멸치의 복합 발효소재를 첨가한 염지제 처리 및 건조 시간에 따른 부세 굴비를 제조하여 품질 특성을 비교하였다. 발효소재 첨가에 따른 염지제와 부세 굴비의 DPPH 및 ABTS 라디칼 소거능은 발효소재의 함량에 따라 증가하였으나, 발효소재 1% 이상에서 부세 굴비의 라디칼 소거능은 유의적인 차이를 보이지 않았다. 발효소재의 함량이 증가할수록 부세 굴비의 아미노태질소 함량은 증가하고 VBN, TBARS, 산가는 감소하는 결과를 나타내나, 발효소재 1% 이상에서 품질의 유의적인 차이가 크지 않으므로 염지제의 발효소재 함량은 1%로 선정하였다. 염지제의 염도에 따른 부세 굴비의 품질을 분석한 결과 염도가 증가할수록 아미노태질소 함량은 증가하고 히스타민, VBN, TBARS, 산가는 감소하는 결과는 나타내며, 염지제의 염도는 품질 개선 효과가 가장 우수한 7% 조건을 선정하였다. 염지 처리 후 건조 시간에 따른 부세 굴비의 품질을 분석한 결 과 건조 시간이 증가할수록 수분은 감소하고 염도, pH, 아미노태질소, 히스타민, VBN, TBARS, 산가는 증가하였다. 그러나 건조 48시간 이하는 수분이 많아 저장성이 낮으며, 건조 96시간에서 히스타민과 산패도의 증가율이 높아지므로 부세 굴비의 건조 시간은 72시간이 적합한 것으 로 판단되었다.
Mulberry fruits were semi-dried using hot air (60-100℃) or cool air (20-40℃), and the effects of the dryingtemperature and processing time on the quality of the final driedmulberry fruits were investigated. Response surface methodologywas employed to establish a statistical model and predict theconditions resulting in minimal loss of the total phenolic content(TPC) and ascorbic acid. Thus, using overlapped contour plots,the optimal conditions for producing semi-dried mulberry fruits,which reduced the moisture residue to 45% and minimized thenutrient losses of TPC and ascorbic acid, were determined for thehot-air process (60.7℃ for 5.4h) and cool-air process (34.8℃ for23.3h). Plus, a higher drying temperature was found to lead to afaster loss of moisture and ascorbic acid, while the TPC wassignificantly decreased in the cool-air dried mulberry fruits due tothe higher activity of polyphenol oxidase between 30 and 40℃.
This study was conducted to examine the effects of additives and drying methods in Yukwa's manufacture. Additives had significant effects on hardness, and bean water and bean powder added group rated better than the baking powder and boiled bean added group. Sensory evaluation test showed that bean water and bean powder added group produced higher desirability. Drying methods had significant effects on all attribute of sensory evaluation, natural drying and incubative plate drying produced higher uniformity, denseness and overall desirability.
Background : The purpose to improved the quality of oriental medicinal herbs, contribute to the enlargement of farm’s income. The study is investigated the effect of high-quality stabilized production and reasonable drying methods, different storage conditions and package mediums for established GAP guide book in Angelica acutiloba Siebold & Zucc.
Methods and Results : Loss rate of drying method checked into 2 treatment, natural drying (218 hr. by sunshine) and heating dryer for 24 - 53 hr with Angelica acutiloba root of two years. After cleaning, first drying days by temperature, After cutting, second drying days by temperature under 40℃, 50℃ and 60℃. Changes hunter color values and quality by different storage conditions 2 treatment were normal temperature by indoor 20℃ and low temperature under refrigerating, 4℃. Storage period for 60 days, 120 days and 180 days with package 3 mediums under PE (polyethylene package), PP (polypropylene gunny sack) and WP (woven net package).
Conclusion : After first cleaning, reasonable hot air drying method in Angelica acutiloba root. Secondary drying oven after cutting, the temperature regulated in 40℃ and 50℃, the lowest loss rates. Packing material storage conditions are dry roots in the colorimetry that maintained at room temperature storage than PP packaging, cold storage for long-term stability to PE treatment.
본 연구는 홍시라떼 분말화의 최적조건 설정을 위하여 반응표면분석법(RSM)을 이용하였으며, 독립변수는 inlet temperature(X1), air flow rate(X2), 시료의 공급속도인 feed flow rate(X3)로 설정하고 종속변수로는 회수량(Y1), 수분흡 수지수(Y2), total phenolic compounds(Y3)로 설정하였다. 각 종속변수에 따른 회귀식은 모두 p<0.001 수준에서 유의성이 인정되었다. 홍시라떼의 경우 과당이 풍부하여 분말의 부착성이 높기 때문에 유리전이 온도와 입자의 표면 온도 차이가 낮을수록 회수량은 높아졌으며, 분말의 결정성과 응집성은 증가하여 수분흡수지수는 낮아졌다. 또한 낮은 inlet temperature(X1)와 높은 feed flow rate(X3)는 입자의 표면 온도와 열의 접촉 시간을 모두 낮추어 total phenolic compounds의 손실을 최소화 하였다. 각 독립변수와 종속변수의 영향을 나타내는 반응표면그래프를 이용하여 최적 분말화 조건을 예측한 결과 inlet temperature(X1) 90℃, air flow rate(X2) 53 mL/min, feed flow rate(X3) 17.00 mL/min로 결정되었다.
Background:The purpose of improving the quality of oriental medicinal herbs is to contribute to the improvement of the income of farm. The present study investigated the effect of reasonable drying methods, different storage conditions and packageing materials on quality and stability of Scutellaria baicalensis Georgi and for developing GAP (good agricultural practice) guide book.Methods and Results:Three methods of drying Scutellaria baicalensis roots produced over two years were used to estimate loss rate owing to drying, storage, and packaging. The methods of drying were categorized into natural drying (36 - 60 h by sunshine), drying with heat dryer (2 - 10 h), or drying with gas bulk dryer (2 - 10 h). After cleaning, and initial drying for a few days under controlled temperature conditions, the second phase of drying was carried out at 35, 45 and 55°C. Changes in hunter color values and quality under the two studied storage treatments (at 20°C indoors and at 4°C in a refigerator) were evaluated. Storage period for 60, 120, and 180 days in three packaging materials, PE (polyethylene package), PP (polypropylene gunnysack), and WP (watertight packing paper) were studied.Conclusions:Initial cleaning, reasonable gas drying and hot air drying, and drying in an oven at 35 and 45°C after cutting the roots resulted in the lowest loss rates in S. Baicalensis root. Hunter color valuse indicated that stroage of dry roots at room temperature was better than PP packaging, and that cold stroage was better than PE packaging for long-term stability.
꾸지뽕 열매는 미생물에 의한 오염과 물러짐으로 저장기간이 짧고 유통이 어렵다는 단점이 있다. 농산물에 적용할 수 있는 선도 유지 및 가공법은 여러 방법이 있지만 본 연구에서는 실질적으로 농민들이 적용할 수 있는 블랜칭 처리방법과 열풍 건조법에 대해 연구하였다. 먼저 블랜칭 처리 시간별로 꾸지뽕의 생균수를 측정하여 블랜칭 처리 시간이 증가할수록 미생물이 점차적으로 감소하는 것을 확인할 수 있었다. 그리고 블랜칭 처리 시간 및 건조 조건에 따른 건조 추세를 비교한 결과, 40℃에서 건조 시 무처리구 보다 블랜칭 처리구가 더 빠른 수분 감소 효과를 나타내었다. 하지만 건조 온도가 증가할수록 무처리구와 블랜칭 처리구 간의 건조 추세 차이는 점점 줄어드는 것을 확인하였다. 최종적으로 블랜칭 및 열풍건조의 최적 조건을 도출하기 위해 반응표면 분석법을 이용하였다. 조건에 따른 total polyphenol content, total flavonoid content, DPPH radical scavenging activity, 색차(ΔE)의 예측값은 각각 8.62 mg GAE/g, 56.65 mg RE/g, 40.26%, 11.69의 수치를 나타냈다. 최적 범위 내 임의의 조건 즉, 240 sec 블랜칭 처리 시간, 60℃ 건조 온도, 24 h 건조 시간에서 실험값은 10.06 mg GAE/g, 49 mg RE/g. 44.99%, 10.53을 나타냈으며 예측값과 실험값은 유사한 값을 보였다.
We compared the germination rate of dehisced ginseng (Panax ginseng) seeds that were dried under two different conditions, slowly at 15℃ [relative humidity (RH) 10-12%] and rapidly under a laminar airflow cabinet at 25℃ (RH 22-25%). The measurements showed that drying rate and seed moisture content (SMC) play important roles in storage ability and vigor. The seeds that were dried rapidly at 25℃ showed high GR compared with the seeds that were dried at 15℃ after 6 and 12 months of storage at -80℃ irrespective of MC. Seeds dried slowly at 15℃ with MC higher than 7.0% showed high GR maintenance after storage at -18℃ and at 4℃ in comparison with rapidly dried seeds. However, the GR of the slowly desiccated seeds decreased as mean SMC was reduced to less than 5.0%, whereas the rapidly dried seeds were distinguished by significantly high GR irrespective of the storage conditions. The ginseng seeds desiccated under different conditions showed differences in storage performance. Seeds with 7-9% MC that were dried slowly at 15℃ for 5-7 days showed high GR after 4℃ and -18℃ storage; however, longer periods of desiccation decreased the germination level remarkably compared with that of rapidly dried seeds.
This study was performed to evaluate the drying characteristics of food waste in oil vacuum evaporation system withdrying conditions and composition of food waste. The food waste was collected and separated into 4 categories such asvegetables, fruits, grain (rice), meats and others. which composition were 41.9%, 26.7%, 2.8%, 25.5% and 0.4%,respectively. Each food waste separated was dried and compared its characteristics in the same condition of vacuumpressure (−450mmHg), temperature (110oC) and mixing ratio (oil:food waste=1:1) for 90min of drying period. Theexperimental results showed that the moisture contents of dried vegetables, fruits and meats were less than 10%. Howeverthe grain was hard to be dried which moisture content was much high as 24.5%. This high value of the grain was thoughtdue to the viscosity of grain which prohibit oil penetration and water vaporization during drying process. In order tocompare drying characteristics with operating parameters, vacuum pressure, temperature and mixing oil type were changed.The operating temperature and vacuum pressure were major sensitive parameters. As the temperature increase and thepressure lower, the drying rate of food waste was increased and its efficiency was also improved. Especially, the moisturecontent of dried food waste was lower than 5% which was satisfied SRF standard 10% at the temperature over 110oC.Compared the effect of mixing oil type, waste cooking oil was more effective than refined oil in viewpoint of dryingefficiency. However, there is no difference of drying efficiency between fresh and waste cooking oil.