• Korean Journal of Food Science and Technology
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• v.54 no.3
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• pp.306-312
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• 2022

To test bee pollen as an ingredient for heat-processed foods, bee pollen was puffed under heat at various pressures and examined for its physicochemical properties and antioxidant activities. As the puffing intensity increased, the browning index, total reducing capacity, and DPPH radical scavenging activity of the bee pollen increased significantly (p<0.001). This was attributed to the formation of Maillard reaction products during the puffing process. The wheat flour-puff yeot-gangjeong added with puffed bee pollen showed significantly (p<0.01) higher antioxidant activities than its counterpart with raw bee pollen. In addition, the gangjeong retained the physicochemical characteristics of the puffed bee pollen such as color, soluble solids, titratable acidity, and pH. The results showed that the puffed bee pollen could potentially be used as an ingredient in thermally processed foods and retain its superior antioxidant properties.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.115.2-115.2
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• 2010

최근 유가 상승 및 에너지 확보, 경질 원유 생산량 및 부존량 감소로 인하여 대체 석유자원의 개발에 대한 연구 및 관심이 급증하고 있다. 기존의 연소 방식이 아닌 연료를 청정 가스로 전환하여 이용하는 가스화 기술 개발이 진행되고 있다. 석탄은 매장량이 세계적으로 풍부 할뿐만 아니라, 지역적으로도 편재되어 있지 않은 에너지원인 석탄을 활용하는 새로운 발전기술로 환경보전성이 우수하며, 효율이 기존의 발전 시스템보다 뛰어난 에너지 이용기술로 각광받는 분야이다. 석탄 슬러리는 분쇄한 석탄을 믹서를 사용하여 소량의 계면활성제를 첨가하여 제조한다. CWM 제조용 석탄은 대체로 고유수분 5%이하, 회분 10%이하의 석탄이 추천되고 있으며, 수분이나 회분량, 산소함량, 입자의 세공율이 증가할수록 고농도화에 불리한 것으로 나타나고 있다. 연료적 가치를 향상시키기 위해서는 물의 함량을 적게, 즉 석탄의 농도를 증가시키는 것이 중요하다. 일반적인 CWM 규격으로는 석탄농도 65% 이상이 바람직한 것으로 보고되고 있다. 석탄가스화에 연료로 사용되는 CWM의 연료성상 및 미립화 정도, 제조 조건 등에 따라 많은 차이가 발생한다. 본 실험에서는 1.0T/D급 습식 분류층가스화기에서 이용할 CWM의 제조를 위하여 소형 믹서를 이용하여 석탄의 농도에 따른 점도 변화와 석탄의 분쇄입자 크기에 따른 점도 변화, 계면활성제와 첨가제의 농도에 따른 점도 특성을 실험하였다.

• Korean Journal of Food Science and Technology
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• v.17 no.6
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• pp.421-425
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• 1985

The changes of pectic substances during baking at $175{\sim}180^{\circ}C$ for 30 minutes and polygalacturonase activities of three sweet potato cultivars on textural properties were investigated. The three different types of sweet potato cultivars were the dry type (Wonki), the intermediate type (Shinmi), and the moist type (Chunmi). The moisture content, alcohol insoluble solid content, composition of pectic substances and hardness were determined before and after baking. It was found that HCl-soluble pectin was significantly changed into water soluble and sodium hexametaphosphate soluble pectin by baking. The dry type, Wonki showed the lowest moisture content, but the highest alcohol insoluble solid content and hardness. Wonki, whose polygalacturonase activity was the highest, had the highest HCl-soluble pectin content after backing.

• Korean Journal of Food Science and Technology
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• v.31 no.1
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• pp.164-170
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• 1999

Cracking of rice caused by moisture migration during storage under different relative humidity conditions was investigated for the establishment of safe storage condition of rice. Rice was cracked when a large difference in equilibrium relative humidity $({\Delta}ERH)$ between the rice and the environment was present. External and internal cracks were generated as the results of moisture desorption and adsorption, respectively. The external cracks by moisture desorption generated in all directions and shaped irregularly, while the internal cracks by moisture adsorption did in radial direction and showed a typical shape. The cracking trend could be analyzed by the Weibull function, and the cracking constant increased with ${\Delta}ERH$. The frequency of cracked rice increased linearly with In $({\Delta}ERH)$. The critical crack-inducing ${\Delta}ERH$ was $11.3{\sim}16.4%$ during desorption and $10.8{\sim}17.1%$ during adsorption. A diagram for the safe storage of rice was developed with respect to the initial moisture content and the water activity of rice.

• Korean Journal of Food Science and Technology
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• v.18 no.2
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• pp.82-87
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• 1986

The water sorption isotherms of binary mixtures, prepared by corn starch and isolated soybean protein (ISP) or casein, were measured and analyzed. Simple equations to predict moisture content from knowledge of composition and water activity of the mixture were derived by applying Response Surface Analysis. Comparison between predicted and experimental moisture content for 13 combinations of corn starch-lSP mixture at the range of $a_w$ 0.25-0.87 resulted in a maximum error of only 6.06% and an absolute mean error of 2.60%, and for the mixture of corn starch-casein the error was -4.39% and 2.12%, respectively. The agreement between experimental and predicted water sorption isotherms was shown to be 'highly acceptable' for the binary mixtures of 50% corn starch-50% ISP and 50% corn starch -50% casein.

• Korean Journal of Food Science and Technology
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• v.18 no.3
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• pp.234-240
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• 1986

Soybean hydrolysate (SHT) was prepared from defatted soybean by hydrolysing with papain and ${\alpha}-amylase$ and water sorption isotherms were determined as a function of proteolysis degree. The moisture content and B.E.T. value of SHT at a certain water activity $(A_w=0.80)$ increased lineraly with increasing degree of proteolysis. However, they changed drastically above 70% proteolysis. The water holding capacity of 78% SHT was similar to that of sorbito. The results indicate the increase of water sorption capacity is due to the release of polar groups through hydrolysis. Mizrahi equation generally gave the best fit for isotherms of SHT. Storage stability of intermediate moisture foods containing $5{\sim}10%$ SHT increased considerably, although some favorable characteristics decreased.

• Korean Journal of Food Science and Technology
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• v.49 no.4
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• pp.401-407
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• 2017

This study investigated the effect of roasted rice bran (RRB) on bread quality. Bread containing RRB showed small and specific loaf volumes. Baking and cooling loss rates of bread with RRB were lower than bread without RRB. The pH of bread decreased and total titratable acidity increased with increase in the amount of RRB. Water activity (Aw) and moisture contents of bread increased with RRB levels in bread. Bread containing RRB presented lower L value and higher redness (a) and yellowness (b) values. Crumb hardness, springiness, and gumminess increased, whereas cohesiveness decreased upon addition of RRB. Addition of 5% RRB resulted in higher scores in sensory evaluation than the control, however, bread with 15% RRB had the lowest score. Therefore, 5% RRB can be used in bread production.

• Korean Journal of Food Science and Technology
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• v.29 no.2
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• pp.314-319
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• 1997

The objectives of this study were to examine the effect of storage time, temperature, pH, and NaCl concentration on hydroperoxide lyase and lipoxygenase activities, and to establish important informations to the production of typical cucumber flavor. Conditions affecting lipoxygenase and hydroperoxide lyase would be important for cucumber flavor production. Maximum activity was observed at pH 5.0 for hydroperoxide lyase and pH 5.5 for lipoxygenase. Both enzymes were relatively stable at $40\;to\;50^{\circ}C$ for 6days storage time. Maximum activity of both enzymes was observed with 0.2 M NaCl at pH 5.0. Activities were stimulated with concentrations of NaCl from 0.05 to 0.2 M. Hydroperoxide lyase and lipoxygenase activities were decreased at concentration of NaCl greater than 0.2 M.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.119.1-119.1
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• 2016

크라이오 워터펌프(CWP)는 크라이오 펌프(CP)와 달리 10 K 활성탄 어레이는 장착하지 않고 100 K 정도로 냉각시킨 배플만을 사용하여 물의 배기속도를 최적화 하는 데 초점을 맞춘 진공펌프다. 용기 압력이 10-9 mbar 대가 될 때까지는 잔류기체의 90% 이상이 수분이므로 다른 기체들의 배기 보다는 물을 잘 배기하는 것이 배기시간을 단축하고 도달 진공도를 낮추는 첩경이라는 아이디어에 근거를 두고 있다. CWP는 물 흡착확률을 거의 1에 가깝게 만들어서 오리피스 컨덕턴스에 육박하는 이상적인 펌프를 제작할 수 있지만 용도상 직부형(close type), 통과형(in-line type) 및 내장형(in-vessel type) 등 세 가지 다른 형태에 따라 성능도 약간씩 다르다. CWP는 모든 기체에 반응하는 정통적인 CP에 비해 훨씬 간단하고 저렴하게 만들 수 있으면서도 진공 시스템에 큰 영향을 미칠 수 있지만 물 이외의 기체들을 배기할 펌프가 필요하다는 측면에서 활용에 제약이 있다. 만일 TMP를 이미 사용하고 있거나 작은 TMP를 추가로 달아서 충분히 작동이 가능한 시스템이면서 수분 발생이 많은 곳이나, 또 활성탄의 오염이나 산소 분위기 등 CP 투입이 꺼려지는 환경이라면 CWP 사용이 좋은 선택이 될 수 있다. CWP의 물 배기용량은 CP의 알곤이나 질소 배기용량에 준하는 크기로 0.5g/cm2 이상임이 실험적으로 입증되었다. 따라서 일반적인 상황에서 정상 작동시 대부분의 기체는 TMP로 배출하고 잔류 수분만 포집하므로 CP처럼 주기적인 재생이 필요 없다. 필요하다면 CWP는 금속 표면에 응축된 물을 드라이펌프 작동만으로 쉽게 제거할 수 있고 혹시 오염 물질이 붙어도 세척이 용이하다. 이런 사용상 융통성과 여러 가지 장점에도 불구하고 그동안 물배기에 대한 인식이 미흡하고, 또 부수적이고 추가적인 비용이 드는 것으로 생각되어 주목을 받지 못했지만 디스플레이와 반도체 산업을 필두로 물 분압을 낮추고 생산수율을 높이는 것에 점점 더 관심이 높아지면서 CWP에 대한 수요도 높아지고 있다. 본 보고에서는 20인치 통과형 CWP를 만들고 14인치 TMP에 얹어 복합 진공배기시스템을 구성한 후 물 배기속도와 알곤, 질소 및 수소 배기속도를 측정하고 예측치와 비교했다. 아울러 물 배기용량 측정 및 CWP의 온도제어와 펌프재생 특성 평가 결과도 정리했다.

• Korean Journal of Food Science and Technology
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• v.23 no.4
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• pp.478-484
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• 1991

As a work on the preparation of spread type product using chungkook-jang, proximate composition and enzyme activity of chungkook-jang were analyzed and extrusion capillary viscometer was made. The effects of moisture content, oil type and content and temperature on the rheological properties of chungkook-jang spread were investigated. As the moisture content of chungkook-jang spread increased from 55% to 65%, apparent viscosity $({\eta}a)$ decreased and spreadibility and L value in Hunter color system increased. On the contrary, as the added oil content of chungkook-jang spread increased from 10% to 30%, rla increased and spreadibility and L value decreased. Specially, in case of palm olefin addition, the rla of chungkook-jang spread was more high than that of soybean oil addition. As the temperature of chungkook-jang spread increased, rla decreased and spreadibility increased. In the same conditions, the ${\eta}a$ of chungkook-jang spread increased in order of B. natto, B. natto and B. subtilis mixture and B. subtilis fermentation.