• 한국식품영양학회지
• /
• 제35권5호
• /
• pp.302-312
• /
• 2022

The purpose of this study was to investigate the Maillard reaction-related physicochemical properties of three maize varieties (Kwangpyeongok, Sinhwangok2ho and Gangdaok) after roasting them for different times (0, 15, 25, 40, and 55 minutes). The Maillard reaction is a non-enzymatic browning reaction involving reducing sugars and amino compounds. The content of reducing sugar, the causative agent of the Maillard reaction, decreased as roasting time increased. Gangdaok showed the lowest reducing sugar content of 1.04 mg/g after 55 minutes of roasting. In the elapsed roasting time, chromaticity 'L' and 'b' values decreased. At 55 minutes of roasting, wherein the Maillard reaction occurred most actively, Gangdaok showed the lowest 'L' value of 56.37 and the highest 'a' value of 7.60. Gangdaok had superior conditions for inducing the Maillard reaction compared to other varieties, and it is consider that 'flint-type', an endosperm characteristic, may have been the influencing agent. This study detected a total of 52 types of volatile aroma compounds (VACs), of which 28 were produced after roasting. Of the total VACs detected, 2-Formyl-5-methylfuran and 2-Furancarboxaldehyde accounted for 43.8~45.5% and have been confirmed to be the major VACs present in roasted maize. Most of the correlations between the Maillard reaction-related characteristics showed high correlation coefficients.

• 지질공학
• /
• 제33권1호
• /
• pp.61-68
• /
• 2023

본 연구는 화성암 지역의 생태·자연도 1등급 토양의 표토와 심토를 채취하여 물리화학적 특성에 대해 분석하고 비교하는 것이 목적으로, 채취한 토양시료를 대상으로 함수율과 pH를 측정하고 X-선 형광분석 및 X-선 회절분석을 실시하였다. 연구결과, 함수율은 표토가 심토보다 높게 측정되었고 pH는 표토가 심토보다 더 산성으로 측정되었다. X-선 형광분석 결과, I9 시료가 카올리나이트와 가장 가까운 위치에 도시되었고 I7 시료가 카올리나이트와 가장 먼 위치에 도시되었으며, 그 외 시료들은 모두 I7 시료와 I9 시료의 사이에 위치한다. X-선 회절분석 결과, 점토광물의 평균 함량은 표토가 심토보다 높게 나타났으며 대표적으로 산출되는 점토광물로는 일라이트, 버미큘라이트, 카올리나이트, 녹니석, 깁사이트 등이 있다. 본 연구에서 얻은 결과는 향후 심토의 표토화를 위한 표토 복원 시 기초자료로 활용될 것으로 기대된다.

• 상하수도학회지
• /
• 제36권5호
• /
• pp.261-273
• /
• 2022

In this study, we collect water control valves that have had accidents due to existing cracks, etc. are collected, and propose investigation items for strengthening the valve structural safety evaluation through a series of analyzes from valve specifications to physicochemical properties are proposed. The results of this study are as follows. First, there was a large variation in the thickness of the body or flange of the valves to be investigated, which is considered to be very important factor, because it may affect the safety of the valve body against internal pressure and the flange connected with the bolt nut. Second, 60% of the valves under investigation had many voids in the valve body and flange, etc. and the decrease in thickness due to corrosion was relatively large on the inner surface in contact with water rather than the outer surface. It is judged that the investigation of depth included voids is very important factor. Third, all valves to be investigated are made of gray cast iron foam, and therefore it is judged that there is no major problem in chemical composition. It is judged that the chemical composition should be investigated. Fourth, as a physical investigation item, the analysis of metal morphology structure seems to be a very important factor for nodular cast iron from rather than a gray cast iron foam water valve with a flake structure. As it was found to be 46.7~68.8% of the standard recommended by KS, it could have a direct effect on damage such as cracks, and therefore it is judged that the evaluation of tensile strength is very important in evaluating the safety of the valve.

• 한국정보전자통신기술학회논문지
• /
• 제16권2호
• /
• pp.109-115
• /
• 2023

본 논문은 UV(ultraviolet) 처리된 자기 조립 단분자막(fluorinated self-assembled monolayers; FSAM)을 배향막으로 사용한 액정의 배향 특성을 분석하였다. 물리화학적 분석을 사용하여 UV 처리 전후의 ITO(indium-tin-oxide) 유리 기판의 FSAM 특성을 확인하였다. FSAM 표면은 UV 처리에 의해 소수성에서 친수성으로 변화하였다. LC(liquid crystal) 분자는 UV 처리된 FSAM 표면에서 수평방향으로 정렬되었고 선경사각도 90°에서 0°로 변화하였다. UV 처리된 FSAM을 배향막으로 사용하여 제작된 TN(twist nematic) 셀의 전기광학(electro optics; EO) 특성은 기존의 PI(polyimide) 배향막에 비해 응답 시간이 빠른 것을 확인하였다. 이는 UV 처리된 FSAM 이 LCD(liquid crystal display)의 기존 폴리이미드 배향막을 대체할 잠재적인 가능성을 가진다.

• 한국환경보건학회지
• /
• 제27권1호
• /
• pp.36-43
• /
• 2001

Chitosans were prepared from red crab chitin under various alkali treatment conditions(different alkali concentrations, reaction times and temperatures) and theirphysicochemical properties were investigated. The nitrogen content and deacetylation degree of red crab chitin were 6.15% and 22.17A%, respectively. By the IR spectra, red crab and reference chitin showed the sharp bands at 1650 $cm^{-1}$ / and 1550 $cm^{-1}$ /, which are characteristic of chitin. The nitrogen contents of prepared chitosans ranged from 6.19~7.48%. Thedeacetylation degree was increased from 63~76% and 48~78% with increasing reaction time and temperature, whereas viscosity was decreased. The nitrogen content and yield of red crab chitosan perpared from chitin with 50% NaOH, 1:25(w/v) for 3.0 hr at 120$cm^{-1}$ / were 7.26% and 85.0%, respectively. and viscosity, deacetylation degree and molecular weight, 67.0 mPa.s, 75.0% and 6.5$\times$10$^{5}$ Dalton, respectively. From the IR spectra, the amide absorption bands of red crab and reference chitosan became very weak, similarly. And at solid state $^{13}$ C-NMR spectra, C=O(carbonyl carbon) signals absent, whereas $CH_3$(methyl carbon) was residues. Chemical shift of $^{13}$ C-NMR spectra of red crab and reference chitosans were in good agreement with slight experimental deviation.

• 한국조리학회지
• /
• 제15권2호
• /
• pp.309-321
• /
• 2009

연구는 당귀분말을 첨가한 쿠키의 품질특성과 관능특성을 평가한 것으로써, 당귀분말 첨가 쿠키 반죽의 pH는 6.13~6.26의 범위였으며, 반죽의 밀도는 0.99~1.15의 범위였다. 당귀분말 첨가의 증가에 따라 쿠키의 퍼짐성은 작아졌으며, 명도와 황색도의 감소, 적색도의 증가로 인해 전반적으로 쿠키가 어두워지고 진해지는 경향을 나타내었다. 기계적 조직감의 특성은 강도와 경도가 당귀분말의 첨가비율에 따라 높아지는 경향을 나타내어 쿠키 제조에 있어 당귀분말의 첨가는 쿠키를 단단하게 하는 역할을 하였다. 관능 선호도에서는 색, 냄새, 조직감, 맛, 전반적인 선호도의 항목에서 당귀분말 무첨가 쿠키보다 일정 범위의 당귀분말을 첨가한 쿠키의 선호도가 높아졌으며, 그 중에서도 쿠키의 전체 재료 배합량 대비 1.5%의 당귀분말을 첨가하는 것이 가장 이상적인 것으로 평가되었다.

• International Journal of Industrial Entomology and Biomaterials
• /
• 제6권2호
• /
• pp.151-155
• /
• 2003

Using gel filtration chromatography, high molecular silk fibroin with high purity was obtained and silk flbroin microsphere particles (SFMP) could be simply made by spray dryer method. Also, some of the physicochemical properties of SFMP and morphology were investigated. The average molecular weight of pure silk fibroin protein dissolved in calcium chloride is about 61,500g/㏖ as measured by gel permeation chromatography. SFMP was spherical in shape, and particles, sized average of 2 ${\pm}$ 10 ${\mu}$, were observed by SEM and particle analyzer, respectively. Obtaining microspheres particles by spray dryer method accelerated the transition from the random coil to the $\beta$-sheet structure during spray dryer treatment. It was identified by the basic fourier transform infrared spectroscopy of SFMP. The swelling ratio of SFMP is majorly dependent on the pH of the solution, not on the occurred gelation. The characteristic structure, which might be applicable to immobilization of drugs is superior to other matrix materials for the use of biomaterials with skin affinity.

• 한국식품영양학회지
• /
• 제20권4호
• /
• pp.369-377
• /
• 2007

An investigation evaluating the preparation and physicochemical properties of sauce with various herbs(sancho, sage, and rosemary) derived from soy sauce was performed. The effects of the different kinds of herbs added to sauce for roasted mackerel were assessed using physiochemical, sensory, flavor, and texture analysis properties. This fish was then compared to, fish with salt. The moisture, crude protein, crude fat, and crude ash content of the roasted mackerel were significantly higher than the control(p<0.05, p<0.001). The salinity content of the herb sauce added samples were significantly higher than the control(p<0.05). Conversely, the pH and peroxide value of the herb sauce added samples were significantly lower than the control(p<0.001). A positive trend was observed for color value with sancho added sauce(p<0.001). The another positive effects on the texture of fish was observed for texture analysis, adhesiveness, springiness, gumminess, and chewiness with herb sauce added samples(p<0.05). In the flavor profile, the fishy smell was disappeared and antifungal flavor was improved with herb added sauce. Flavor, taste, texture, and overall preference of herb sauce were significantly highest in sancho added sauce(p<0.05, p<0.001). Results suggest that the best herb sauce for roasted mackerel was sancho added sauce.

• 한국응용과학기술학회지
• /
• 제32권4호
• /
• pp.748-757
• /
• 2015

품종별 수확시기에 따른 떫은 감의 품질변화를 분석하고 이를 이용한 곶감제조를 통해 고품질의 곶감 생산을 위한 곶감의 식품학적 특성을 분석 하였다. 고품질의 곶감 생산을 위해서는 품종별 떫은 감의 적절한 선택과 적정숙도를 갖춘 과육을 선별하는 것이 매우 중요하다. 미숙과의 경우 수분함량, 색도값이 적숙과 및 완숙과에 비해 낮은 값을 보인 반면 경도는 높게 나타났다. 고품질의 곶감의 생산하기 위해서는 최소한 적황색 혹은 녹황색인 적숙과 이상의 떫은 감을 사용해야 한다.

• 한국식생활문화학회지
• /
• 제33권1호
• /
• pp.55-61
• /
• 2018

This study examined the quality of bread made from a wheat flour, oat powder, and wild carrot powder mixture. The lightness and redness values decreased with increasing amount of wild carrot powder addition, while the yellowness was increased significantly. In a sample of wild carrot powder addition, the total volume was lower than the control. The texture profile analysis of oat bread, such as hardness, gumminess and cohesiveness decreased significantly with increasing amount of wild carrot powder addition. In the case of springiness, the value was not significant. The sensory evaluation of oat bread was significantly different in all analyses. Oat bread (BCB2.0) containing 2.0% (w/w) wild carrot powder showed the highest value in the four sensory evaluation items. Therefore, the 2.0% (w/w) addition of wild carrot powder addition was appropriate. An analysis of the physicochemical active component and DPPH scavenging activity of oat bread revealed a higher total flavonoid and total polyphenol content than normal bread. The DPPH scavenging activity was also 20.3% compared to the wild carrot powder. The availability of wild carrot powder in oat bread could be identified.