• Food Science and Preservation
• /
• v.24 no.1
• /
• pp.74-83
• /
• 2017

This study was conducted to obtain the optimal conditions of hot air drying for Cudrania tricuspidata by response surface methodology (RSM). The independent variables were blanching time (60, 120, 240 sec), drying temperature (40, 60, $80^{\circ}C$) and drying time (12, 24, 36 h). The dependant variables were total polyphenol content (TPC), total flavonoid content (TFC), DPPH radical scavenging activity (DPPH), and color difference (${\Delta}E$). Viable cell colony was counted according to changes of blanching time. It was confirmed that microorganisms gradually decreased with increasing blanching time. From RSM results, the predicted values of TPC, TFC, DPPH, and ${\Delta}E$ were 8.62 mg GAE/g, 56.65 mg RE/g, 40.26% and 11.69, respectively. Experimental values within the optimal range (240 sec, blanching time; $60^{\circ}C$, drying temperature; 24 h, drying time) were 10.06 mg GAE/g, 49 mg RE/g, 44.99% and 10.53, respectively. The predicted values were similar to the experimental values. Comparing drying tendency according to changes of blanching time, moisture reduction was bigger in the blanched sample than that in control at $40^{\circ}C$. However, the differences between blanched and control decreased with increase of drying temperature. Viable cell gradually decreased as increasing blanching time.

• Korean Journal of Food Science and Technology
• /
• v.37 no.2
• /
• pp.154-163
• /
• 2005

Chemical and flavor components of Bulro Kugi (Lycium chinense Mill) fruit leaf, and root were compared. Fructose and glucose were detected in fruit and leaf, and sucrose in root, respectively. Citrate was the highest among organic acids in fruits, and malate in leaf and root Capsaicin was detected in leaf and root. Volatile flavor compounds were extracted by simultaneous distillation and extraction method using Likens and Nickerson's extraction apparatus. Concentrated flavor extract was analysed, and 128 compounds, including 22 acids 15 alcohols, 12 aldehydes, 8 esters, 10 furans, 26 hydrocarbons, 4 phenols, 2 pyrroles, 1 pyrazine, and 28 miscellaneous components. were identified by GC and GC-MS. Main volatile compounds were hexadecanoic acid and 2-furancarboxaldehyde in hot-air dried fruit, hexadecanoic acid and 1-hexadecene in fresh fruit, 3, 7, 11, 15-tetranethyl-2-hexadecan-1-ol and hexadecanoir acid in leaf, and hexadecanoic acid in root.

• Korean Journal of Food Science and Technology
• /
• v.31 no.6
• /
• pp.1549-1556
• /
• 1999

This study was conducted to investigate the effects of pre-treated sub-ingredients and deodorization materials on the smell intensity of Kimchi during fermentation.Among the various sub-ingredients of Kimchi, garlic, ginger and green onion have comparatively strong smell. The smell intensities of the sub-ingredients, which were pre-treated with various patented methods were examined using the sensory evaluation method and AromaScan. The results showed that the good methods to reduce the smell of sub-ingredients were hot air drying and soaking with heating treatment. The pH, titratable acidity and the number of microorganism of Kimchi prepared with pre-treated sub-ingredients were not different among samples during fermentation. The smell intensity of the Kimchi with pre-treated sub-ingredients was weaker than that of control until ten fermentation days, but the smell intensity after 10 days of fermentation was not different among samples. The addition of ${\alpha}-cyclodextrin\;and\;{\beta}-cyclodextrin$, which are known to have deodorization effect, at a level of 0.1% respectively, to Kimchi resulted in no difference in the pH, titratable acidity and smell intensity during fermentation at $10^{\circ}C$ compared to those of control Kimchi. However, the addition of deodorizer reduced sulfide classes such as methyl allyl sulfide, dimethyl disulfide, allyl sulfide, methyl propyl disulfide up to 50%.

• Korean Journal of Food Science and Technology
• /
• v.7 no.4
• /
• pp.187-193
• /
• 1975

A supplemental effect of Undaria Pinnatifida extract on the composite flour prepared from a blend of wheat, barley, sweet potato, potato, and defatted soybean flours was studied in terms of binding properties, cooking test, and sensory analysis. Dry noodle of the composite flour was made by the conventional method and air dried. Instant noodle was prepared in a hot vegetable oil bath after the noodle was made. The standard was made of wheat flour only. 1. The noodle prepared with composite flour (wheat flour : barley flour, 5 : 5) and Undaria Pinnatifida extract (1 or 2%) showed same results of cooking and sensory tests as well as properties of texture as the standard. 2. The mixture of wheat, barley and defatted soybean flour (10%) had a less efficient binding capacity with Undaria Pinnatifida extract. The binding effect was, however, significantly improved with the wheat and barley flour mixture with either sweet potato or potato flour. 3. The instant noodle prepared with the composite flour (either barley, or sweet potato, or potato was mixed with wheat flour up to 70% separately) and hydroxypropyl methyl cellulose (1% as final) showed the higher oil absorption and the sensory results were the same as the standard. Nevertheless, the binding properties and cooking quality were less efficient.

• Journal of Life Science
• /
• v.22 no.12
• /
• pp.1665-1671
• /
• 2012

This study was conducted to assess the removal of residual pesticides and to obtain high amounts of quercetin in onion peel extracts (OPEs) by 4 washing treatments. Washing is one of the standard processing steps in obtaining functional food ingredients from onion peel. After a first detergent wash (0.2% w/v) (DW) and hot air drying ($80^{\circ}C$, 24 hr) (B), 4 washing treatments were tested, including a second DW (C), ultrasonication ($50^{\circ}C$, 10 min) plus DW (D), 0.3% $H_2O_2$ (v/v) plus DW (E), and blanching ($95-97^{\circ}C$, 2 min) plus DW (F). This was followed by 60% (v/v) ethanol extraction and vacuum freeze drying of the OPE. The E treatment yielded 89.04% OPE and a quercetin content of 96.84% in the OPE compared with the B treatment, and had the highest efficiency of all treatments tested. The OPE was tested for the presence of 177 residual pesticides and three compounds were detected in all treatments: cyhalothirn, fluquinconazole and procymidone. Cyhalothirn and fluquinconazole levels were below the permitted levels for fresh onion, while procymidone was present in the high level range of 128.01~133.46 mg/kg in all samples. The E treatment was a better washing method than the others for removal of residual pesticides. It could reduce the level of residual pesticides without changing the functional properties of the OPE.

• Korean Journal of Construction Engineering and Management
• /
• v.9 no.4
• /
• pp.193-205
• /
• 2008

Quality is an important keyword representing the corporate competitiveness and image in today' s construction industry. Especially in concrete construction, any problems or defects in fresh concrete can significantly degrade the entire quality and performance of the facility built. Thus, adequate quality inspection and testing must be exercised over the fresh concrete, if concrete with the required strength, durability and appearance is to be obtained. The testing of concrete delivered to the construction job site involves testing of fresh concrete and performing strength tests on hardened concrete. The principal tests conducted on fresh concrete include the slump test and tests for air and salt content. The temperature of fresh concrete should be checked out hot or cold weather concreting. The 7-day and 28-day strength of hardened concrete are also determined by compression tests on usually cylinder samples. However, it is very complex and time-consuming process requiring a lot of efforts to document those on-site concrete testing results and to accumulate their historical data. The primary objective of this study is to suggest a unique PDA and web-based system which enables an on-site quality manager to effectively conduct the concrete inspection and testing, automatically document and accumulate the collected historical data, and promptly obtain the approval from supervisors. Finally, it is anticipated that the effective use of the proposed PDA and web-based system would be able to improve reliability of the concrete quality inspection and testing data as well as significantly reduce the approval process.

• Proceedings of the Korean Society for Agricultural Machinery Conference
• /
• 2002.02a
• /
• pp.558-563
• /
• 2002

시설원예에서 난방장치를 사용하는 겨울철 재배 농산물의 생산비 중 난방 연료비가 30%~37% 정도를 차지하여 비중이 가장 높다. 따라서 시설원예 농가에서는 난방비를 절감하는 것이 농가소득과 직결되므로, 난방장치의 선정이 대단히 중요하다. 본 연구에서는 겨울철 재배 농산물의 생산비 중 30%-37% 정도를 차지하는 연료비를 절감하기 위해 기존의 온풍난방기와 다른 새로운 방식의 열교환기와 원심식 송풍블로워를 사용하는 블로워 송풍방식의 온풍난방기를 개발하고 개발된 온풍난방기의 가동으로 인한 난방 연료비 절감효과와 온실내의 균일한 온도분포를 획득하기 위해 8연동 비닐온실에서의 시험을 실시하였으며 얻어진 결과를 요약하면 다음과 같다. 가. 저 정압용의 전동기 축직결식 송풍팬을 대신하여 고 정압용의 블로워 송풍팬을 장착하고 열교환 면적을 크게 한 지그재그식 환류의 열교환실을 채용한 온풍난방기를 개발하였다. 나. 공시한 온실에서 기존 온풍난방기의 2일 가동시 DH당 연료 사용량이 평균 1.082$\ell$/$^{\circ}C$.hr 이며, 블로워 송풍방식 온풍난방기의 3일 가동시 DH당 연료 사용량은 평균 0.854$\ell$/$^{\circ}C$.hr로써 21%의 난방 연료비 절감효과가 나타났다. 다. 블로워 송풍방식 온풍난방기는 동일시간대 3$^{\circ}C$의 경시적 온도변화가 발생하였고, 기존의 은풍난방기의 동일시간대 온도변화는 최대 6.1$^{\circ}C$로 나타나 개발된 블로워 송풍방식 온풍난방기가 동일시간대 온실내의 온도변화를 크게 줄일 수 있었고 온도분포를 비교적 균일하게 하는 효과가 있음을 확인하였다.도 33$^{\circ}C$를 기준으로 한 열 회수 시간은 유입공기 온도가 52$^{\circ}C$ 및 64$^{\circ}C$ 일 각각 120분 및 140분으로 나타났다. (3) 제 3종 자갈: 축열조로 공급되는 공기의 온도가 52$^{\circ}C$와 64$^{\circ}C$ 일 때, 축열조 출구의 공기온도가 33$^{\circ}C$에 도달될 때까지 가열되는데 소요된 시간은 가열공기의 온도가 52$^{\circ}C$와 64$^{\circ}C$ 일 때 각각 180분과 150분이었고, 방열에 소요된 시간은 각각 240분 및 270분으로 나타났다. 방열과정 동안 축열조 출구의 최고 공기온도는 가열 공급공기의 온도가 52$^{\circ}C$ 와 $65^{\circ}C$일 때 각각 35.5$^{\circ}C$ 및 39.5$^{\circ}C$였다. 출구 공기온도 33$^{\circ}C$이상을 기준으로 한 에너지 회수시간은 유입공기 온도가 52$^{\circ}C$ 및 64$^{\circ}C$일 때 각각 140분 및 160분으로 나타났다. 이와 같이 자갈이 작을수록 축열조 출구의 공기온도가 기준온도 33$^{\circ}C$에 도달되는 시간이 길었으며, 이것은 축열조내의 공극이 작고 비중량이 커 자갈층을 가열시키는 축열시간이 길어지기 때문인 것으로 사료된다. 또한 작은 자갈일수록 방열시간도 다소 길어져 회수 가능 열에너지가 큰 것으로 나타났다

• Journal of the Korean Wood Science and Technology
• /
• v.9 no.3
• /
• pp.16-23
• /
• 1981

This study has been carried out to make a comparative study for the adhesive control methods specifically developed for application to formaldehyde. The method for formaldehyde determination used in this report is the improved chromo tropic acid determination. The results are summarized as follows: 1. The soaking treatment in aqueous solution of urea wok the most scavenging effect on the formaldehyde release from a plywood sample glued with a urea formaldehyde adhesive, and other removal treatment such as resorcinol, albumine-, and hardener-treatment gave significant reduction too. 2. In glue shear strength of dry test, 2% of resorcinol treatment and soaking treatment showed the highest strength and all the other treatment met the standard, but in hot water soaking test, 2% of resorcinol treatment gave the best results, on the other hand, adding the hardener showed the lowest strength and failed in meeting the standard. 3. Air dried moisture content of all treated plywood met the standard which calls for 13% or bellow. 4. In this comparative study, we can make a strong combination each other or go into the details of one treatment for the best result through the more study.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.11 no.3
• /
• pp.241-248
• /
• 2001

The main factors of breakthrough are known to sampling time, flow rate, concentration of the sample, temperature, humidity, and the physical characteristics of the solid sorbent tube. However, no study has been reported the effect of temperature and sampling volume on the breakthrough of acharcoal tube during vinyl chloride monomer (VCM) sampling. The objective of this study is to suggest the optimal sampling condition during VCM sampling based on National Institute for Occupational Safety and Health (NIOSH) method. To evaluate adequate sampling volume for VCM without breakthrough, volume of 1, 2, 3, 4, and 5 L each from VCM of 1, 5, 10, 15, and 20ppm at flow rate of 0.05 L/min were sampled in $22^{\circ}C$ and $40^{\circ}C$. At $22^{\circ}C$, in the case of 1, 5, 10, and 15ppm, VCM was adsorbed completely in first section of charcoal tube regardless of sampling volume. But in 20ppm, detection rates are 99.56% in first section and 0.44% in second section. At $40^{\circ}C$ of 1ppm, VCM was adsorbed completely in first section. In 10, 15, and 20ppm, detection rates of second, third, and forth sections were decreased significantly by reduction of sampling volume. In determination of breakthrough based on NIOSH method, no breakthrough was occurred in 20ppm at $22^{\circ}C$. At $40^{\circ}C$, breakthrough was occurred in 10, 15, and 20ppm when sampling volume was 5L. Although no breakthrough was occurred when sampling volume was 3L. Finally, in environment of temperature around $22^{\circ}C$, breakthrough may not occurred up to 20ppm during sampling for VCM. During sampling for VCM in environment of temperature around $40^{\circ}C$, no breakthrough occurred in 1-5ppm and 10-20ppm when sampling volume is 5L and 3L respectively. This result suggests that the sampling volume should be considered when VCM sampling under hot conditions (> $22^{\circ}C$) by the NIOSH method No. 1007.

• Journal of Animal Environmental Science
• /
• v.11 no.1
• /
• pp.1-10
• /
• 2005

This study was carried out to measure the environmental related parameters from two types of swine houses. Indoor temperature, relative humidity, carbon dioxide level, ammonia concentration and emission were measures every 2 minutes from each house with portable monitoring units. Carbon dioxide concentration balance was used to estimate the ventilation rates of the different houses. Daily ammonia concentrations in the growing-finishing and farrowing houses ranged from 2 to 17 ppm and 6 to 15 ppm respectively. The daily ammonia emission rate from the manure averaged 4.37 g/h$\cdot$500 kg from growing-finishing house and 4.82 g/h$\cdot$500 kg from the farrowing house. The above findings proved that summer season was associated with higher ammonia emission rates due to higher ventilation rate and ambient air temperature.