• Food Science and Preservation
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• v.22 no.2
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• pp.256-260
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• 2015

This study investigated the optimum pH condition for the efficient extraction of protein from Gastrodia elata Blume. Five extraction pH values (8, 9, 10, 11, and 12) and three precipitation pH values (2, 4, and 6) were used. The protein content, browning degree, and recovery yield of the protein obtained under each pH condition were determined. Most of the G. elata Blume was made up of carbohydrates, and its protein content was also high. The amount of the extracted protein increased according to the increase in the extraction pH, but did not significantly differ between pH 8 and pH 9. The browning degree of the protein significantly increased as the extraction pH increased. The greatest amount of protein was precipitated at pH 4, the recovery yield of which was also the highest. As a result, it was found that the combination of extraction pH 9 and precipitation pH 4, which resulted in a 38.7% recovery yield and a low browning degree, is the optimum condition for the efficient extraction of protein from G. elata Blume.

• Korean journal of food and cookery science
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• v.27 no.6
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• pp.793-801
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• 2011

We examined the quality characteristics of obtaining the optimal curing conditions for black garlic extract (BGE) added mackerel by using response surface methodology (RSM). The condition of RSM was included in 13 experimental points using two dependent variables: concentration of BGE (2.6~12.5 brix, X1) and curing time of BGE (17.58~102.42 min, X2). An assessment was conducted with four replicates on three independent variables: volatile basic amine (VBN, Y1), thiobarbituric acid (TBA, Y2), and shear force (Y3). The minimum content of VBN was 1.625 mg% at 3.17 brix, for 80.5 min. This was obtained when the BGE concentration was lower and the curing time was longer. The content of the TBA was 3.13~12.24 MA mg/kg at experiment range and the stationary point was at saddle point. Therefore, by using ridge analysis, the minimum point of TBA was 2.414 MA mg/kg at 3.5 brix for 84.4 min. The truth coefficient of the BGE concentration and curing time were 2.9 brix and 75.1 min, respectively, with a shear force ($120.764cm/kg^2$) shown at maximum point. The optimum Hunter color range was estimated from the lowest TBA value. The optimum range of the L color was 39.16~40.26, a and b color were 4.40~4.88 and 12.35~13.20, respectively.

• Current Photovoltaic Research
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• v.7 no.4
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• pp.103-110
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• 2019

Cu(In,Ga)₃Se₅ (β-CIGS) has a band gap of 1.35 eV, which is an optimum value for high solar-energy conversion efficiency. The effects of Cu and Ga content on the cell performance were investigated previously. However, the effect of Se content on the cell performance is not well understood yet. In this work, β-CIGS films were fabricated by three-stage co-evaporation of elemental sources with various Se fluxes at the third stage instead of at all stages. The average composition of five samples was Cu_1.05(In_0.59,Ga_0.41)3Se_y, where the stoichiometric y value is 5.03 and the stoichiometric Se/metal (Se/M) ratio is 1.24. We varied the Se/metal ratio in a range from 1.18 to 1.28. We found that the best efficiency was achieved when the Se/M ratio was 1.24, which is exactly the stoichiometric value where the CIGS grains on the CIGS surface were tightly connected and faceted. With the optimum Se/M ratio, we were able to enhance the cell efficiency of a β-CIGS solar cell from 9.6% to 12.0% by employing a Na₂S post deposition treatment. Our results indicate that Na₂S post deposition treatment is very effective to enhance the cell efficiency to a level on par with that in α-CIGS cell.

• Journal of Mushroom
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• v.16 no.2
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• pp.96-102
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• 2018

Sparassis latifolia is one of the most expensive mushrooms in Korean market owing to its high ${\beta}$-glucan content and immunoactivity. However, because of the long cultivation period and high contamination rates, it has low production efficiency. Therefore, we first need to establish the optimum conditions for liquid spawn production to increase its production efficiency. As a result of experiments, molasses culture medium was selected for mycelial growth. Also, the optimum sugar content for molasses and amount of aeration used were approximately 8 Brix% and 0.3~0.6 vvm, respectively. Mycelial dry weight increases, while the medium decreases, as the incubation period increases. Therefore, to achieve maximum production efficiency, the incubation period of 9 to 11 days is appropriate.

• Textile Coloration and Finishing
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• v.20 no.2
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• pp.75-82
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• 2008

The optimum extraction conditions of green tea used for a bath were investigated for application to textiles. The stability of the extracts and content of active ingredients were analyzed as well. The extraction was more effective in water and methanol than in ethanol. The optimum extraction temperature was determined as $80^{\circ}C$ in water and $60^{\circ}C$ in methanol. The solid extracts were obtained about 7% in water and 9% in methanol on the weight of dry green tea. The extracts were more stable in acid and neutral conditions than in alkaline region. From the analysis of contents of active ingredients, about 20% of effective catechins was appeared to be contained in the extract solid, which was thought to be available for application to textiles.

• Journal of The Korean Society of Grassland and Forage Science
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• v.17 no.2
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• pp.110-116
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• 1997

The objective of this experiment was to suggest the optimum nitrogen fertilization level for orchardgrass(0G)- red clover(RC) mixtures. The field trials were conducted from 1993 to 1994 in order to evaluate the dry matter yield, botanical composition, chemical composition, dry matter digestibility(DMD), crude protein dry matter (CPDM) and digestible dry matter(DDM) yields on the nitrogen levels( 0, 50, 100, 150 and 300kgha). The results obtained were summarized as follows : 1. With increasing nitrogen levels, the DM yield of OG-RC mixttures significantly increased(P<0.05). The maximum total DM yield (7,964kgha) was obtained at N 300kgha level, However, there was no significant difference between N 150 and 300kgha. 2. With increasing the nitrogen levels, the botanical composition of OG in OG-RC mixttures was significantly increased(P< 0.05), whereas that of RC was remarkably decreased(P< 0.05). 3. The CP content was decreased by increasing nitrogen level(P

• Korean Journal of Community Nutrition
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• v.18 no.4
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• pp.333-343
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• 2013

It is important to prepare and execute the menu plan for proper and balanced intake of nutrients in the adolescence. This study investigated the new approach for planning menu by ordinary meal pattern based on cooked foods groups. The amounts of cooked foods in the menu plan assumed to be single serving size. The middle school second graders participated for the study. A total of 313 questionnaires were analyzed using CAN-pro 3.0 and SPSS WIN 12.0 program. The average content of energy in the menu plan was 2,453 kcal, the average ratios of energy contribution by carbohydrate, protein and fat were 54.3%, 17.9%, 27.8%, respectively. A total of 56.9% menu plans (94.9% of male and 8.7% of female students') were below the lowest limit of optimum carbohydrate energy ratio of 55%. A total of 29.1% menu plans (33.1% of male and 23.9% of female students') were exceed the highest limit of optimum fat energy ratio of 30%. The NAR of minerals and vitamins were all 1.0 except for calcium (0.92) and folate (0.88). When INQ of the individual cooked food groups were calculated, kimch was the highest in all minerals and vitamins examined, suggesting that kimch may be the best source for all minerals and vitamins, including calcium and folate with the minimum change in energy content. In conclusion, the menu plan by ordinary meal pattern in this study was low in carbohydrate, high in fat, and contained enough minerals and vitamins except for calcium and folate for middle school students.

• Journal of Microbiology and Biotechnology
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• v.20 no.1
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• pp.117-126
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• 2010

A chitinase (CHT) and a protease (PRO) were purified from the culture supernatant of Serratia sp. TKU017, with shrimp shell as the sole carbon/nitrogen source. The molecular masses of CHT and PRO determined by SDS-PAGE were approximately 65 kDa and 53 kDa, respectively. CHT was inhibited by $Mn^{2+}$ and $Cu^{2+}$, and PRO was inhibited by most tested divalent metals and EDTA. The optimum pH, optimum temperature, pH stability, and thermal stability of CHT and PRO were pH 5, $50^{\circ}C$, pH 5-7, and <$50^{\circ}C$, and pH 9, $40^{\circ}C$, pH 5-11, and <$40^{\circ}C$, respectively. PRO retained 95% of its protease activity in the presence of 0.5 mM SDS. The result demonstrates that PRO is an SDS-resistant protease and probably has a rigid structure. The $4^{th}$-day supernatant showed the strongest antioxidant activity (70%, DPPH scavenging ability) and the highest total phenolic content ($196{\pm}6.2\;{\mu}g$ of gallic acid equiv./ml). Significant associations between the antioxidant potency and the total phenolic content, as well as between the antioxidant potency and free amino groups, were found for the supernatant. With this method, we have shown that shrimp shell wastes can be utilized and it is effective in the production of enzymes and antioxidants, facilitating its potential use in industrial applications and functional foods.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.1
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• pp.82-88
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• 2007

The objective of this study is to examine the effect of the waste oyster shell powder as the addition agent in bulking sludge thickening of paper manufacturing plant using DAF(Dissolved Air Flotation) and gravitational sedimentation. The effect of parameters such as dosage and size distribution of oyster shell were examined. The results showed that the optimum dosage of mixed oyster shell(size range : $\sim250{\mu}m$) was 0.8 g/L. The oyster shell addition of 5.0 g/L in sedimentation process was increased thickening concentration of 3.25 times. When 5.0 g/L of oyster shell was added in DAF process, water content of sludge was decreased from 95.5% to 82.7% in dewatering process using Buchner funnel test device. When size of oyster shell was divided four ranges($\sim53{\mu}m$, $53\sim106{\mu}m$, $106\sim150{\mu}m$, $150\sim250{\mu}m$), optimum size range for the flotation and dewatering was $53\sim106{\mu}m$.

• Journal of the Korean Society of Hazard Mitigation
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• v.2 no.3 s.6
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• pp.79-88
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• 2002

The main purpose of this paper is to evaluate the possibility of improvement in fatigue resistance of asphalt concrete mixture using the industrial waste material of K fiber. In this research, as an experimental equipment, the MTS with Closed-Loop Servohydraulic System was used and it was designed according to the U.S. standard testing procedure of ASTM D 4123. According to the test results, the optimum content of fiber with the length of 8mm was about 0.2 percent of total mixture weight. The optimum asphalt content for the fiber-reinforced asphalt concrete was about 5.5 percent of total mixture weight. Fatigue resistance of fiber-reinforced asphalt concrete was noticeable compared to the conventional dense-graded 20 asphalt concrete. In addition, the resilient moduli of fiber-reinforced asphalt mixture were $1.15{\sim}1.18$ times higher than those of conventional asphalt concrete.