• Korean Journal of Food Science and Technology
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• v.47 no.4
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• pp.539-543
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• 2015

A hardy kiwifruit is a good source of phenolics and antioxidants. This study was aimed at investigating the effects of hot air drying at three different temperatures (35, 50, and $70^{\circ}C$) for 24 h on the total phenolic and flavonoid contents and the antioxidant capacity of hardy kiwifruits of Actinidia arguta ${\times}$ A. deliciosa cv. Mansoo. Dried kiwifruit extracts were produced using 80% (v/v) aqueous ethanol under homogenization. Hot air drying lowered the total phenolic and flavonoid contents and decreased the antioxidant capacity in the dried kiwifruits compared with their fresh counterparts. The results also revealed high positive linear correlations of antioxidant capacity with total phenolic and flavonoid contents, indicating that phenolics are the major contributors to antioxidant capacity. Our results suggested that an optimal drying process must be determined for industrial application in order to obtain dried kiwifruits with increased antioxidant capacity for consumers.

• Journal of Life Science
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• v.26 no.11
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• pp.1269-1274
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• 2016

The oyster is called "milk of sea" which is abundant in taurine, glycogen, cellenium. It could be used in making natural source. Recently, consumers have more interest in natural source because of their diverse preference and its special taste. The goal of this study is to optimize maillard reaction condition for manufacturing natural seasoning using oyster and oyster cooking drip hydrolysate. The result was judged by browning degree and pyrazine, which is flavor components when food heating. Hydrolysate and sugar react according primarily to type of sugar - glucose, xylose and fructose. Xylose was selected as best sugar of browning degree. In the case of sugar contents, all conditions over 1% of sugar contents are almost same. Therefore, the lowest 1% of sugar was selected as appropriate condition. According to the reaction with different temperature, browning degree and pyrazine contents had been increased over $60^{\circ}C$, but the product at $120^{\circ}C$had off-flavored. So, $100^{\circ}C$ is the best condition for the browning reaction. And in accordance with different reaction time, after 6 hours, there was no change in pyrazine and browning reaction. Therefore, to manufacture natural seasoning source, it is optimal to react xylose for maillard reaction at $100^{\circ}C$ for 6 hr with hydrolysate of oyster and oyster cooking drip.

• Applied Biological Chemistry
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• v.46 no.2
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• pp.101-106
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• 2003

Soybean curd was prepared using cuttlebone powder treated with acetic acid (ATC), and its characteristics were determined. Soybean protein was coagulated by adding calcium chloride, magnesium chloride, and ATC at 0.7, 1.2, and 0.9%, respectively, or higher. Yield, white index, texture, and sensory evaluations revealed the optimal concentration of ATC for preparation of soybean curd was 2.0% of total soybean weight. The proximate compositions of soybean curd prepared by adding 2.O% ATC were 75.9%, 12.6%, 1.9%, 5.3%, 6.60, and $1.0×10^4$ CFU/g in for moisture, crude protein, crude ash, crude lipid, pH, and viable cell count, respectively. Although white index and mineral content of both soybean curds were similar, texture of ATC-prepared soybean curd was superior to that of soybean curd prepared with 1.5% calcium chloride.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.8
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• pp.1009-1017
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• 2008

For the effective use of exopeptidase from squid viscera as food processing aids, the viscera of Argentina shortfin squid (Illex argentinus) were fractionated by various methods such as acetone treatment, ammonium sulfate treatment, anion exchange chromatography, and gel filtration. The positive exopeptidase fractions were obtained from the fraction II treated by cold acetone ($30{\sim}40%$, w/w), the fraction V by ammonium sulfate ($60{\sim}70%$ saturation), the fraction II (0.2 M NaCl) by anion exchange chromatography, and the fraction I ($30{\sim}50\;kDa$) by gel filtration. The specific activities of positive fractions from viscera of I llex argentinus against substrates were higher to LeuPNA than to ArgPNA. Total activity and recovery against LeuPNA of positive fraction by gel filtration were 1,867 U and 30.69%, respectively, which were the highest among those of positive fraction. The results suggested that the gel filtration chromatography method was the most efficient method for the fractionation of exopeptidase from viscera of Illex argentinus.

• Food Engineering Progress
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• v.13 no.4
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• pp.269-274
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• 2009

The main objective of this study was to establish optimum condition of wet grinding process for manufacturing microparticulated seaweed calcium. Process parameters such as concentration of forming agent, rotor speed, bead size, feed rate, and grinding time were adapted during wet-grinding of seaweed calcium. The particle size range of the raw seaweed calcium was 10-20 $\mu$m. The calcium particles were reduced to under 1 $\mu$m as nano scale after grinding. Gum arabic was suitable for forming agent and 5%(w/v) concentration was the most effective in grinding efficiency. A wet-grinding process operated at 4,000 rpm rotor speed, 0,4 mm bead size, and 0.4 L/hr feeding rate, respectively, produced less than 600 mm(>>90%)-sized particles. In batch systems, 8 cycles of grinding showed higher efficiency, but 20 min of grinding time in continuous processing was more efficient to reduce particle size than the batch processing. Based on the result, the optimum conditions of the wet grinding process were established: operation time of 20 minutes, rotor speed of 4,000 rpm, bead size of 0.4 mm, feed rate of 40 mL/min and 30% mixing ration with water. The size of the resulting ultra fine calcium particles ranged between 40 and 660 mm.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.10
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• pp.1326-1333
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• 2007

For preparing the basic ingredients of Gomtang-like products from the extracts of salmon frame, the extraction conditions of salmon frame were examined, and the characteristics of the extracts were compared with commercial Gomtang. Based on the crude protein, Ex-N and sensory attributes, the extractions were optimized by extracting pretreated-salmon frame in 12 times (v/w) of water for 12 hrs, before filtering with cheese cloth to yield 3 times the volume of the raw material. The concentrations of heavy metals in extracts from salmon frame were below the safety limits suggested by KFDA. The mai or amino acids were glutamic acid and aspartic acid as the free amino acids, and glycine, proline, and glutamic acid as the total amino acids. The calcium and phosphorus contents were 18.0 mg/100 mL and 33.1 mg/100 mL, respectively, and they accounted for 20% and 18% of the recommended daily allowance for mineral intake. The angiotensin I converting enzyme (ACE) inhibitory activity was improved by incubation with Flavourzyme for 4 hrs and its $IC_{50}$ was 2 mg/mL. The results above suggested that the enzymatic hydrolysates from extracts of salmon frame could be used as a basic ingredient for preparing Gomtang-like products.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.63 no.1
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• pp.35-40
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• 2018

${\gamma}$-Aminobutyric acid (GABA) has antihypertensive and anti-stress effects on humans. The present study aimed to investigate the effect of glutamate concentration, bran content, and barley cultivars on GABA production and determine the optimal reaction condition. Barley bran resulted in higher GABA productivity compared with that of rice bran. The higher the bran content, the higher was the GABA productivity. Furthermore, high glutamate concentration resulted in high GABA production. However, there was a decrease in the glutamate conversion rate. The production of GABA varied with temperature and barley cultivar. The optimal condition for GABA production using barley bran was 0.15 g/mL barley content, 10 mM glutamate concentration, and $20^{\circ}C$ reaction temperature. Under optimal condition, the GABA concentration was 10.34 mM, and glutamate conversion rate was 75.1%. Furthermore, the GABA productivity of the GABA production reaction using barley bran differed depending on the cultivar. Dasong and Yeongbaekchal showed higher GABA productivity than that by other cultivars.

• Proceedings of the KWS Conference
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• 2010.05a
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• pp.27-27
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• 2010

청정에너지원의 수요가 증가함에 따라 에너지원의 공급로의 역할을 하는 강관의 수요가 증가하고 있다. 소재가공 기술의 발전과 함께 경량의 고장력 강재의 적용은 공급로의 역할을 하는 강관의 비용절감 및 자원의 효율적 이용 측면에서 지속적으로 연구 개발을 이어왔다. 이러한 추세에 따라 구조용 또는 라인파이프용 강관에서도 고장력 강재의 적용과 함께 고인성 그리고 용접성의 향상을 위한 다양한 라인파이프용 강재의 개발과 이의 적용이 그간 활발히 진행되어왔다. 용도상 반드시 필요한 특성인 고장력, 고인성, 용접성 등 외에도 다양한 강재의 사용에 따른 제조공정상 즉 용접공정에서 발생될 수 있는 용접부의 기계적 특성 변화에 대한 특성 연구 및 기술 연구가 계속 되어왔다. 주로 강관을 생산하는데 쓰이는 ERW (Electric Resistance Welding) 공정에서도 이러한 문제점을 해결하기 위해 많은 연구가 진행되고 있다. ERW는 높은 생산성과 낮은 제조비용의 장점을 가지고 있으나 용접 후 용접부의 기계적 특성 감소로 인한 단점이 있다. 때문에 기계적 특성향상을 위해 최적의 용접조건에 대해 연구해야 할 필요가 있다. 본 연구에서는 4가지 합금강관의 ERW 용접시 용접 입열량의 변화와 용접부의 후열처리를 통한 미세조직의 변화와 기계적 특성에 대해서 고찰하였다. 4강종 시편의 미세조직을 OM, SEM을 통한 분석 이후 인장시험 및 경도시험 등을 통해 기계적 특성을 평가하였다. 대부분의 시편에서 입열량의 증가에 따라 Ferrite 분율이 증가하였고 용접중앙부의 Ferrite 양이 용접경계부 보다 많았다. Ferrite 집중부의 분포가 극명하게 관찰되었던 DP780 (적정) 강종과 미세하게나마 Ferrite 집중부가 존재하였던 K55 (과소, 과대) 강종에서 나란히 경도 하락 현상이 관찰되었다. 이는 강종마다 고유의 Ceq, 합금 중 Mn 농도, 입열량 등에 의한 복합적인 이유 때문으로 판단된다. 탄소가 0.3~0.4 wt% 함유된 중탄소강인 S45C, K55의 경우 용접중앙부와 용접경계부의 페라이트 분율 차이가 큰 것을 알 수 있었다. 이는 용접시 열에 의한 탈탄현상으로 인해 나타나는 현상으로 판단된다.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.6
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• pp.895-900
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• 1998

In order to the effective utility of marine by-product, crude lecithin was isolated from skipjack viscera oil and the lecithin was refined by bleaching and deodorization. Crude lecithin was separated from the skipjack viscera oil degummed with 0.4 ml of citric acid per 100 ml of the oil. Bleaching was effected by adding $5\%$ activated clay and treating for $40^{\circ}C$ for 90 min under vacuum, and deodorization was effectively conducted by steam distillation at $130^{\circ}C$ for 60 min under 4 ton of vacuum. The major fatty acids of the skipjack viscera oil. were 16:0. 18:1 (n-9), 22:6 (n-3), 18:0, and 16:1 (n-7). Crude and refined lecithins contained more aproximately $7\~18\%$ of 22:6 (n-3) than raw oil, the skipjack viscera oil.

• Food Science and Preservation
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• v.19 no.5
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• pp.703-711
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• 2012

This study was conducted to investigate the quality and organoleptic properties of dehydrated onions with steaming and heating. Sliced onions were treated as follows: steaming time ($X_1$, 5~25 min); drying temperature ($X_2$, $55{\sim}70^{\circ}C$) and drying time ($X_3$, 4~20 hr). All the variables were modelled and analyzed using a central composite design and response surface methodology (RSM). The coefficients ($R^2$) of the water content and water activity model induced from RSM were 0.9514 (p<0.01) and 0.9455 (p<0.01), respectively. The water content and water activity were affected by the drying temperature and time. The $R^2$ on the models of Hunter's L, a, b values were 0.9419 (p<0.05), 0.8818 (p<0.01) and 0.9360 (p<0.01), respectively. Hunter's L, a, b values were affected by the drying temperature and time, but Hunter's b value was not affected by the steaming time. In addition, the $R^2$ on the models of overall palatability was 0.8867 (p<0.05). The maximum palatability response was 5.92 when the steaming time was 13.14 min, the drying temperature was $63.11^{\circ}C$ and the drying time was 14.49 hr.