• Culinary science and hospitality research
• /
• v.18 no.5
• /
• pp.293-304
• /
• 2012

This study was conducted to improve the sensory acceptability of modified Kochujang added with Tofu powder(25%, 50%, 75%, 100%) instead of Meju powder. These Kochujang samples were fermented for 45 days and examined in physicochemical properties and sensory characteristics. The result was as follows. Moisture content of the control was higher than that of the other Tofu powder Kochujang samples, which lasted for 30 days of storage. Moisture contents of all samples were increased by storage time. The pH of Kochujang added with Tofu powder was higher than that of the control. In general, pH values were decreased by storage time. Acidity decreased with Tofu powder increased while it generally increased with more storage time. In the lightness(L value), redness(a value) and yellowness(b value), control Kochujang was the lowest. There were no significant differences in the reducing sugar contents except 45 days. In sensory evaluation, color of Kochujang was evaluated light and off-flavor got weaker with Tofu powder increased. In the sensory attributes of odor, taste, overall acceptability, Tofu powder added Kochujang had high scores than the control, and especially 100% TP Kochujang had the best score.

• Food Science and Preservation
• /
• v.23 no.5
• /
• pp.666-672
• /
• 2016

The objective of this study was to evaluate the effects of low temperature-adapted Saccharomyces cerevisiae Y297 and fermentation temperatures on the quality of Yakju brewed. Physicochemical properties of Yakju brewed were compared pH, total acidity, ethanol, free amino acid, organic acid contents, and volatile flavor compounds in S. cerevisiae Y297 with control treatment. Cooked non-glutinous rice and saccharogenic amylase in koji were mixed with ethanol-producing yeasts and then fermented at $15^{\circ}C$, $20^{\circ}C$, and $25^{\circ}C$ for 20 days. Yakju brewed using the Y297 treatment showed the highest ethanol yield (17.9%) at $20^{\circ}C$. Expression of heat shock protein (HSP) 104 was evaluated by immunoblotting as an indication of adaptation to low temperatures ($15^{\circ}C$); levels of the HSP104 protein were higher in the Y297 treatment than in the control. Organic acid analysis showed that the lactic acid content of Yakju brewed using the control was the highest at $25^{\circ}C$. Finally, free amino acid analysis showed that the Y297 treatment had a higher proportion of essential amino acids than the control. Overall, these results indicate that S. cerevisiae Y297 could be used as a suitable yeast for Yakju brewed under low temperature ($15^{\circ}C$) condition.

• Food Science and Preservation
• /
• v.15 no.5
• /
• pp.706-710
• /
• 2008

This study evaluated the chemical components of five watermelon cultivars. Soluble solids and pH value in the Uoriggul cultivar were higher than those in other cultivars. The mineral components of watermelon were K (106.25-161.22 mg/100 g), P (11.29-20.98 mg/100 g), Mg (5.29-11.10 mg/100 g), Ca (4.10-5.63 mg/100 g), Na (0.92-1.28 mg/100 g), and Fe (0.25-0.46 mg/100 g). The contents of P, K, Na, Fe, Cu, and Zn in the Dalgona cultivar were higher than in other cultivars. The major free sugars of watermelon were fructose (3019.40-4311.11 mg/100 g), glucose (1070.02-1526.41 mg/100 g), and sucrose (4583.68-5341.07 mg/100 g). The total free sugar content was highest in the Uoriggul cultivar. Sensory evaluation revealed that the color, flavor, taste, texture and overall acceptability of Uoriggul were the highest among the cultivars.

• Clean Technology
• /
• v.25 no.1
• /
• pp.1-6
• /
• 2019

Effects of the Cu and K addition and the reduction condition of Fe-based catalysts for Fischer-Tropsch reaction are studied in a continuous flow reactor in this research. The catalysts for the reaction were prepared by homogeneous precipitation followed by incipient wetness impregnation. Physicochemical properties of the $Al_2O_3$ supported Fe-based catalysts are characterized by various methods including X-ray diffraction (XRD), temperature programmed reduction (TPR), and scanning electron microscopy (SEM). Catalytic activities and stabilities of the Fe/Cu/K catalyst are investigated in time-on-stream for an extended reaction time over 216 h. It is found that a reduction of the catalysts using a mixture of CO and $H_2$ can promote their catalytic activities, attributed to the iron carbides formed on the catalysts surface by X-ray diffraction analysis. The addition of Cu induces a fast stabilization of the reaction reducing the time to reach at the steady state by enhancement of catalytic reduction. The addition of K to the catalysts increases the CO conversion, while the physical stability of catalyst decreases with potassium loading up to 5%. The Fe/Cu (5%)/K (1%) catalyst shows an enhanced long term stability for the Fischer-Tropsch reaction under the practical reaction condition, displaying about 15% decrease in the CO conversion after 120 h of the operation.

• Journal of the Korea Convergence Society
• /
• v.12 no.6
• /
• pp.197-203
• /
• 2021

In this study, to develop a higher value-added makgeolli, the Korean traditional rice wine were made of four kinds of raw material cereals (wheat flour, puffed rice, non-glutinous rice, and glutinous rice). To investigate the development potential of makgeolli as functional materials, their physicochemical characteristics, phenol, flavonoid, and vitamin contents, and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)(ABTS) radical scavenging activity were evaluated. Puffed rice makgeolli and non-glutinous rice makgeolli among four types of makgeolli were higher contents of alcohol (16-16.5%). Of four types of makgeolli, puffed rice makgeolli showed 5.2±0.06 mg GAE/mL, the highest level content of total phenol, and flavonoid contents of them were similarly high, with a level of 470-490 ㎍ QE/mL. Puffed rice makgeolli containing the highest level content of total phenol resulted in 81.5%, the highest activity of ABTS radical scavenging. These results suggest that puffed rice may be an effective raw material for makgeolli to be developed the antioxidant functional materials.

• Journal of the Korean Recycled Construction Resources Institute
• /
• v.11 no.3
• /
• pp.260-266
• /
• 2023

In recent years, excessive emissions of carbon dioxide(CO₂) have become the cause of global climate change. Consequently, there has been significant research activity aimed at both removing and utilizing CO₂. This study assesses the potential utilization of railway tie concrete waste, generated from railway infrastructure, as a CO₂ absorption material and investigates the physicochemical properties before and after CO₂ absorption to understand the CO₂ removal mechanisms. Railway tie concrete waste primarily consists of Si(26.60 %) and contains 9.82 % of Ca. Compared to samples of Cement and Normal concrete waste, it demonstrated superior potential for use as a CO₂ absorption material, with approximately 98 % of the Ca content participating in CO₂ absorption reactions. Through Thermogravimetric Analysis(TGA) and X-ray Diffraction(XRD) analysis, it was confirmed that the carbonate reaction, where the Ca in railway tie concrete waste converts into CaCO₃ through reaction with CO₂ gas, is the primary mechanism for CO₂ removal. Furthermore, Scanning Electron Microscopy(SEM) analysis revealed the formation of numerous CaCO₃ particles with sizes less than 0.1 ㎛ after the CO₂ absorption reaction. This transformation of large internal voids in the CO₂ absorption material into mesopores resulted in an increase in the specific surface area of the material.

• Journal of the Korean Wood Science and Technology
• /
• v.40 no.3
• /
• pp.204-211
• /
• 2012

In this study, fast pyrolysis of pitch pine (Pinus rigida) was performed in a fluidized bed reactor under the temperature ranges between 400 and $550^{\circ}C$ at the residence time of 1.9 sec. Essential pyrolytic products (bio-oil, biochar, and gas) were produced and their yield was clearly influenced by temperature. The maximum yield of bio-oil was observed to 64.9 wt% (wet basis) at the temperature of $500^{\circ}C$. As pyrolysis temperature increased, the yield of biochar decreased from 36.8 to 11.1 wt%, while gas amount continuously increased from 16.1 to 33.0 wt%. Water content as well as heating value of bio-oils were obviously sensitive to the pyrolysis temperature. The water contents in the bio-oil clearly decreased from 26.1 ($400^{\circ}C$) to 11.9 wt% ($550^{\circ}C$), with increasing the fast pyrolysis temperature, while their higher heating values were increased from 16.6 MJ/kg to 19.3 MJ/kg. According to GC/MS analysis, 22 degradation compounds were identified from the bio-oils and 10 compounds were derived from carbohydrate, 12 compounds were derived from lignin.

• Clean Technology
• /
• v.21 no.2
• /
• pp.117-123
• /
• 2015

This inquiry was conducted to develop DeNOx catalyst for LNT. In order to develop appropriate catalysts, four catalysts, which do not use PGM (Platinum Group Metal), were carefully selected : Al/Co/Mn, Al/Co/Ni/Mn, Al/Co/Mn/Ca, Al/Co/Ni mixed metal oxides during preliminary experiments. Also, XRD, EDS, SEM, BET and TPD tests were carried as well to evaluate both physicochemical properties of such four catalysts. As a result of the experiment, four catalysts were composed of spinel-shaped crystals and had more than enough pore volume and size to have oxidation-reduction reaction of NOx gases. Additionally, through TPD test, all four types of catalysts were proved to possibly have an oxidation-reduction acid site and NO oxidation activities similar to commercial catalysts. Based on the results above, if we have further change in the composition components and active ingredients according to the catalysts that were chosen in this investigation, then we are more welcomed to expect to have an enhanced DeNox catalyst for LNT.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.57 no.4
• /
• pp.359-364
• /
• 2012

We conducted this study to identify the optimal milling degree for improving sensory quality of cooked rice and minimizing yield loss. The samples were analyzed for their physicochemical properties and sensory qualities using five different degree of milling(5.5~13.5%, based on brown rice). With increasing of milling degree, amylose content, breakdown, adhesiveness of cooked rice increased, whereas protein content, Mg/K equivalence ratio, fat content, setback and hardness of cooked rice decreased. In sensory quality test, the preference was significantly higher in the 9.5% and 11.5% milling degree. However, considering the yield of milled rice, the optimal milling degree for improving sensory quality of cooked rice was 9.5%.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.65 no.4
• /
• pp.294-302
• /
• 2020

Studies on the occurrence of rice preharvest sprouting (PHS) have primarily focused on temperature and rainfall duration at the time of PHS induction, but average temperature during grain filling can have a great influence on PHS. This study analyzed the effect of average temperature during grain filling on PHS occurrence and subsequent changes in grain quality after PHS. For two consecutive years, average temperature differences during grain filling were produced by varying the transplanting date. Artificial rainfall was treated under identical accumulated temperatures of 1200℃ after heading. It was confirmed that the occurrence of PHS was higher under high average temperature conditions during grain filling. In addition, the degree of grain quality reduction caused by PHS occurred more severely under high temperature conditions during grain filling. In order to reduce the risk of PHS occurrence and subsequent quality damage, it is important to control the planting date to avoid high-temperature conditions during grain filling.