• 한국식품과학회지
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• 제30권6호
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• pp.1327-1332
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• 1998

The optimum thermal condition of retort Biji product was determined by heat penetration curve, aerobic bacteria count and sensory test. Retort Biji showed a simple logarithmic heating curve regardless of solid content. Heating time was a $26{\sim}27$ min until Fo value reached 9 min and the amount of microorganism in the Biji product sterilized for 26 min at $121^{\circ}C$ were decreased to $10^{-4}\;CFU/g$, indicating the safe range for retort product. The rate of heat penetration was reduced as solid content and size of product were increased, whereas sterilization temperature and initial temperature of product influenced the heat penetration curve. Sensory scare indicated that there was no significant difference in color, flavor, and appearance among different thermal processes. However, Biji product sterilized at $121^{\circ}C$ showed the highest score in overall preference value.

• 한국구조물진단유지관리공학회 논문집
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• 제5권3호
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• pp.153-162
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• 2001

This paper presents the fundamental study on rational manufacture of Ultra High Strength(VHS) concrete using industrial by-products as like silica fume, slag and fly ash. In this study, we had tested various mixing cases to manufacture the UHS concrete(target compressive strength : over $1,000kgf/cm^2$) which is easily workable (target slump flow : $60{\pm}10cm$). The main variables are studied: 1) to find the optimum replacement ratio of mineral admixture. 2) to find a rational water-binder ratio and a proper binder content. 3) to find the method for reduction of slump loss. From the test results, it is concluded that the rational mix design can be made by using 40% slag, 10% silica fume. We found that compressive strength of UHS concrete increases according to decreasing W/B ratio but in W/B ratio 18~20%, the difference is vague and the compressive strength does not necessarily increase according to increasing binder content over 700kg.

• 한국식품조리과학회지
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• 제5권1호
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• pp.31-41
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• 1989

The effects of salting degree of cabbage on the chemical, microbiological, textural changes and taste of Korean whole cabbage Kimchi fermented at $21^{\circ}C$ was studied. Low salted Kimchi (1.8% NaCl, soaking for 2 hr. in 20% brine) was showed higher total acdity than high salted Kimchi II(3.1% NaCl, Soaking For 8 hr in 20% brine) and III(2.9% NaCl, no soaking in 20% brine). The changes in growth of lactic acid bacteria was relevant to the salt content of whole cabbage Kimchi. Kimchi I was showed higher growth rate of Lactic acid bacteria and slower death rate constant of Lactic acid bacteria than that of Kimchi II and III. In palatability test, salty taste of Kimchi II, III was more salty than that of Kimchi I ($p{\leqq}0.01$) and total evaluation of Kimchi I, II was more palatable than Kimchi III ($p{\leqq}0.05$) at 3rd's day (optimum taste). Cutting force by Rheometer was well correlated with the salt content of Kimchi.

• 한국식품영양학회지
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• 제24권1호
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• pp.111-116
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• 2011

The purpose of this study was to evaluate the optimum ratio of coffee waste to chocolate for the preparation and investigation of the sensory characteristics of coffee chocolates. Color values(L-value, redness, and yellowness), total flavonoids, radical scavenging activity, and sensory characteristics of coffee chocolates made with various concentrations of additives were measured. The coffee waste powders were added at weight percentages of 0, 1, 2, 3, and 4%. As the ratio of coffee powder to chocolate increased, total flavonoid content and radical scavenging activity increased. In sensory evaluation, significant differences(p<0.05) were shown in taste, bitterness, texture, and overall acceptability depending on the amount of coffee waste powder added. The optimal ratio for sensory acceptability of coffee chocolate was 2% added coffee waste powder.

• Advances in concrete construction
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• 제7권4호
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• pp.231-239
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• 2019

The present study deals with the development of metakaolin-based geopolymer concrete (GPC) and thereafter studying the effects of adding ultra-fine slag on its mechanical and permeability characteristics. The mechanical characteristics including compressive, split tensile, flexural strengths and elastic modulus were studied. In addition, permeability characteristics including water absorption, porosity, sorptivity and chloride permeability were studied up to 90 days. The results showed the effective utilization of metakaolin for the development of elevated temperature cured geopolymer concrete having high 3-day compressive strength of 42.6 MPa. The addition of ultra-fine slag up to 15%, as partial replacement of metakaolin resulted in an increase in strength characteristics. Similar improvement in durability properties was also observed with the inclusion of ultra-fine slag up to 15%. Beyond this optimum content of 15%, further increase in ultra-fine slag content affected the mechanical as well as permeability parameters in a negative way. In addition, the relationship between various properties of GPC was also derived.

• 한국식품과학회지
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• 제53권1호
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• pp.92-98
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• 2021

The effects of heat-moisture treatment (HMT) on rice flour (RF) have been investigated for possibility of texture modifier in protein-based foods matrix, tofu. The optimum condition for preparation of tofu with maximum textural parameters was investigated by using response surface methodology (RSM). Rice flour was subjected to moisture content (10-30%) and heating temperature (100-140℃). Based on the response surface and superimposed plots, the optimized conditions of hydrothermally treated rice flour was as followed: moisture content, 22%; temperature, 130℃, which showed lower swelling power as compared to native RF and became more stable during continuous heating and agitation than native one. Tofu, prepared with HMT-RF, showed a denser network structure than that with RF, thereby inducing an increase in textural parameters. From the above results, the addition of HMT-RF could preserve the quality of tofu and be useful for developing an acceptable protein-based food product.

• 한국환경보건학회지
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• 제23권2호
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• pp.44-56
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• 1997

When sewage sludge is treated by cornposting, higher moisture content and lower C/N ratio on sewage sludge is problems. This paper project to alesolve two problems. The almost trends in run 3 of MC 70% are similar to these in run 1 and 4 of MC 65%. A retention time of the highest temperature (>50$\circ$C) and increase rate of temperature in run 3 are an affinity to these in run 4. Particularly, decrease rate of temperature in run 3 is slower than others and this data shows the more activity of thermal microbial in run 3 than that in others. C/N ratio trends in run 3 shows slow reaction in initial stage but, after 9 days, is similar to that in run 1 and 4. Carbon trends in each run are a similarity to C/N ratio trends. Temperature, MC, carbon and C/N ratio trends in run 5, whose C/N ratio is 15, show less microbial activity than that in run 6, whose C/N ratio is 20. But temperature increase of the beginning stage and pH of the final stage in run 5 are greater than that in run 6. Final MC and carbon content in run 5 and 6 have a similar values. That is, final MC in run 5 and 6 is 49.39% and 48.97% and final carbon content in each run is 25.15% and 22.20%. Expecially, a temperature increase and C/N ratio decrease rate of the beginning stage in run 5 are greater than these in run 6. This shows the shorter lag time in run 5 than lag time in run 6.

• 한국약용작물학회지
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• 제25권2호
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• pp.102-107
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• 2017

Background: The present study was conducted to investigate the fatty acid content and habitat conditions of Glehnia littoralis in the Korean midwest region. Methods and Results: The emergence area of G. littoralis was 36.1 m from the coastline at an elevation of 4.2 m and slope of 4.3%. The soil of the habitat was sandy, the pH was 8.4, organic matter content was 0.4%, $P_2O_5$ content was 9.1 mg/kg and the content of K, Ca, Mg and Na were 0.09, 9.31, 0.43 and $0.23cmol^+/kg$, respectively. Other plants growing in this area with G. littoralis included 16 taxa. Plant with high coverage and frequency were Carex kobomugi, Elymus mollis, Imperata cylindrica var. koenigii, Lathyrus japonicus, Calystegia soldanella and Carex pumila. In the seeds of G. littoralis, the maximum fatty acid content was 65.5% oleic acid, 28.7% linoleic acid, 4.3% palmitic acid, 1.5% stearic acid, and 0.2% linolenic acid. Conclusions: In G. littoralis of Korean midwest, the scope of collection and cultivation for medicinal purposes was broad, because differences in associated vegetation, soil composition, and fatty acid content owing to habitat conditions was low.

• Current Research on Agriculture and Life Sciences
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• 제6권
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• pp.129-135
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• 1988

성숙 중 자두 과실의 당함량 및 invertase활성 변화와 효소학적 성질에 대하여 조사한 결과는 다음과 같다. 자두과실에 함유되어 있는 soluble sugar의 대부분은 sucrose, glucose 및 fructose이었다. 성숙 중 sucrose의 함량은 초기에는 서서히 증가하다가 그 이후 약간 감소하며 성숙말기에는 급격히 증가하였다. Glucose와 fructose는 성숙초기에는 완만히 증가하였으나, 그 이후 glucose는 감소, fructose는 증가하는 경향이었다. Invertase의 활성은 성숙함에 따라 증가하여 색깔의 변화가 일어나는 시기에 최고의 활성을 나타냈으며, 그 이후 급격히 감소하였다. 효소의 최적 pH와 온도는 각각 5.0과 $65^{\circ}C$였다. pH와 열안정성은 pH 5.0부근에서 안정하였으며, $70^{\circ}C$, 15분간에서 약 75% 잔존활성을 가졌다. 효소 활성은$Ca^{{+}{+}}$, $Cu^{{+}{+}}$에 의해 증가되었으나 $Hg^{{+}{+}}$에 크게 저해되었다.

• 한국가스학회지
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• 제2권1호
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• pp.1-6
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• 1998

전력을 적재 소모하는 (300 mW 이하) 촉매가스센서가 개발되었고, 천연가스에 열용량을 측정하기 위해 컴퓨터로 작동되는 샘플링 시스템에 사용되었다. 가스의 열용량은 촉매자스센서가 감지되는 연소가스에 노출되었을 때 발생된 에너지에 비례된다. 36.30 - 39.88 $MJ/m^3$ 범위의 정격 열용량을 갖는 천연가스의 열용량은 약 $1\%$ 에러 내에서 측정되었다. 각 가스들은 센서의 온도에 대하여 약간씩 다른 감응곡선을 갖고 있다. 따라서 한 온도에서 모든 감응이 같을 수는 없다. 작동 온도는 측정장치의 전 성능에 영향을 미치기 때문에 교정과정에서 최적의 작동 온도를 찾는 것은 중요하다.