• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.1
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• pp.89-97
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• 2009

Jujube wine was treated with hydrostatic pressure (500 MPa, 5 min) or freezing ($-20^{\circ}C$, 3 days and thawed $20^{\circ}C$, 4 hr) and their microbial counts, physicochemical properties, and sensory characteristics were investigated during storage at $35^{\circ}C$ for 60 days. Microorganisms in pressure-treated jujube wine were not detected during the whole period and chemical compositions as well as color were slightly changed. Sensory quality was significantly preserved until 20 days without increasing sweet aroma and taste. In freezing-treated wine, bacterial counts were decreased after 10 days and remained below 10 CFU/mL while lactic acid bacteria and yeast were not detected. Changes of chemical composition were smaller than those of the untreated wine but bigger than those of the pressure-treated or heat-treated wine. Instrumental color was changed after $10{\sim}20$ days resulting from the increase of L value and the reduction of a value. Sensory quality was significantly similar with the fresh wine for 10 days, suggesting that pressure treatment would be the most effective sterilization method to improve the shelf life of jujube wine whereas freezing treatment would be insufficient.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.8
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• pp.1136-1140
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• 2011

This study was designed to evaluate the potential of using high pressure processing (HPP) for extending shelf life of seasoned squid during refrigerated storage. The vacuum-packed seasoned squid samples were subjected to 400 MPa for 20 min using a custom-made high pressure processor. Microbial counts, dimethylamine (DMA), trimethylamine (TMA), total biogenic amine, autolytic activity were determined on days 0, 7, 14, and 21 of refrigerated storage. The numbers of indigenous bacteria were effectively reduced by 2.77 log CFU/g after HPP treatment. The amounts of DMA and TMA produced in the control samples increased up to 15.99 and 42.82 mg/g after 7 days of refrigerated storage when compared to 5.27 and 10.21 mg/g the HPP-treated samples, respectively. The autolytic activity of the HPP-treated sample (4.32 nkat/g) significantly lower than that of the control (7.13 nkat/g) after 7 days of refrigerated storage. Therefore, HPP can be applied as a potential squid processing method microbiological safety and shelf life.

• Food Science and Preservation
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• v.22 no.1
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• pp.70-77
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• 2015

The physiological properties of water extracts from Hizikia fusiformis extracted using different extraction methods (water extraction, WE; autoclave extraction, AE; high pressure extraction, HPE) were investigated. The freeze-dried powder yields from HPE, AE and WE were 29.33, 27.84 and 23.63%, respectively. The $L^*$ and $b^*$ color values were higher in WE, while the $a^*$ color values were higher in WE and AE. The total sugar content of AE (60.14%) was higher than those of WE (47.10%), HPE (40.97%). The reducing sugar content (7.88%) and protein content (42.83%) of AE was higher than those of WE, and HPE. The uronic acid (5.04%), total free amino acid (785.19 mg/g), taurine (19.16 mg/g), aspartic acid (66.63 mg/g), asparagine (204.84 mg/g), alanine (188.87 mg/g) and ammonium chloride (243.91 mg/g) contents, however, were the highest in HPE. Additionally, the crude polysaccharide yield was higher in HPE (4.75%) than in AE and WE, and the crude saccharide (fucose, galactose, glucose, xylose and fucose) yields were higher in AE. It can be concluded that optimum conditions for the efficient extraction of Hizikia fusiformis depending on components are high pressure and a lower temperature than in the typical process.

• Korean Journal of Food Science and Technology
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• v.48 no.1
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• pp.92-95
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• 2016

Ultra-high pressure (UHP) was applied to glutinous rice (Dongjin) and brown rice (Shindongjin) to determine its effects on the textural characteristics of cooked rice and bacterial reduction in uncooked rice. Hardness and stickiness of the cooked glutinous and brown rice pretreated with 500 MPa for 5 min were significantly attenuated compared to that of the control rice (p<0.05). After the UHP treatment, particles of the glutinous and brown rice were observed to be finer when cross sections of the rice were analyzed using field emission scanning electron microscope. The total bacterial count in the brown rice treated with 600 MPa for 5 min was reduced from $10^7CFU/g$ to $10^4CFU/g$, while the number of thermoduric bacteria in the brown rice was not significantly different after the UHP treatment. These results suggest that UHP may be an effective method for improving texture of dried rice and to reduce bacterial count in raw rice.

• Food Science of Animal Resources
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• v.28 no.4
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• pp.499-504
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• 2008

Even though pork have frequently induecd allergic reactions in Korea, few papers have been published on pork allergy. This study was carried out to investigate the changes in allergenicity of porcine serum albumin (PSA) by microwave, sonication, and high hydrostatic pressure (HHP). The binding ability of p-IgG to PSA treated with microwave (1,5, or 10 min) directly decreased with increasing treatment time. Particularly, the binding ability of PSA treated 10 min was about 30%. Immunoblotting assay with p-IgG showed that band of PSA treated microwave directly disappeared at 5 and 10 min. However, the binding ability of PSA was not changed by the microwave treatment without heat. Also the reduction of allergenicity by sonication or HHP treatment was not found. In conclusion. allergenicity of PSA treated with microwave directly decreased with increasing time, therefore these results may be used for development of hypoallergenic pork.

• Food Science of Animal Resources
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• v.20 no.1
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• pp.44-55
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• 2000

신선한 품질의 식품에 대한 수요가 증가함에 따라 열처리의 대체수단으로 이용하기 위한 고압기술의 전망이 밝다. 압력을 이용하여 가공된 과일 쥬스와 잼이 이미 일본시장에 출시되고 있다. 전세계적으로 다른 식품의 안전을 위해서도 이 기술에 대한 개발노력이 진행중이다. 압력과 열, 시간의 복합효과에 대한 이해는 식품의 안정성에 대한 이 기술의 이용 가능성을 더해준다. 효소의 비활성화와 미생물의 사멸을 위한 압력과 시간의 의존도에 대한 상세한 연구는 식품저장에 초고압기술을 활용하는데 있어 매우 중요하다. 에너지 비용을 절감하기 위한 설계의 개선과 여러 식품성분의 변화에 대한 이해는 이 기술의 응용에 큰 도움이 될 것이다. 안전성과 저장성이 높은 신선한 식품을 생산할 수 있는 초고압 기술은 곧 광범위하게 이용될 전망이다.

• Proceedings of the KIEE Conference
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• 2008.11a
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• pp.400-402
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• 2008

제주도의 지속적인 전력수요 증가에 능동적으로 대처하고자 육지-제주간 초고압 직류연계(HVDC) 추가 건설사업이 추진 중에 있다. 초고압 직류 송전계통을 신뢰성 있게 운전하기 위해 양측 변환소에 설치될 제어 및 감시계통간 정보전송로의 화보는 매우 중요하다. 본 논문에서는 고품질, 대용량화 되어가는 전력데이터를 안정적으로 전송하고 해저케이블 고장감시 및 향후 정보 통신 분야의 부가가치 창출을 위한 최적의 해저광통신케이블을 소개하고자 한다.

• Proceedings of the KIPE Conference
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• 2013.11a
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• pp.241-242
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• 2013

본 논문에서는 메모리 데이터 베이스를 사용하여 초고압 송전 설비의 제어 및 보호 장치의 데이터 이중화 기법에 대해 고찰 하고자 한다. 초고압 송전 설비는 항시 전력을 공급해야 하므로 제어 및 보호 장치의 이중화는 선택이 아닌 필수라 할 수 있겠다. 이중화 기법중에서 메모리 데이터 베이스를 이용한 고속 데이터 이중화 기법에 관해 고찰 하고자 한다. 메모리 데이터 베이스를 이용하는 방법 이외에도 여러 이중화 방법이 있으나 메모리 데이터 베이스를 이용하면 여러가지 장점을 지니고 있어 편리한 데이터 이중화 구현이 가능 하다.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.846_846
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• 2009

노즐의 용삭은 초고압 가스 차단기의 압력 상승에 중요한 역할을 한다. 기존의 연구는 총 아크 에너지와 용삭량과의 관계에 집중되어 왔으며 아크 에너지 대신 전류의 제곱등을 사용하기도 했다. 본 논문에서는 반복 시험을 통해 노즐 용삭 특성을 구하였으며, 이를 통해 아크의 전류, 전압과 용삭량과의 상관관계를 구하였다. 또한 계단형 노즐을 사용하여 노즐 반지름과 용삭량과의 관계에 대해서도 살펴보았다.

• Proceedings of the KIPE Conference
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• 2014.11a
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• pp.125-126
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• 2014

본 논문에서는 실시간 자바를 사용하여 초고압 송전 설비의 제어 및 보호 장치의 구현에 대해 고찰 하고자 한다. 초고압 송전 설비는 대단위 시스템이라서 객체 지향 프로그래밍이 유리하지만, 실시간 운영체제 상에서 고속으로 실시간 동작을 해야 하므로 객체지향 프로그래밍이 모순 된다 할 수 있다. 실시간 자바를 통해서 대형 HVDC 시스템에서 객체 지향 설계의 유연함과 고속 실시간 시스템을 구현 할 수 있는 장점을 동시에 가질 수 있는 방법에 대해 고찰 해 보자.