• Food Science and Biotechnology
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• 제18권6호
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• pp.1511-1514
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• 2009

Liquid whole egg (LWE) was subjected to high hydrostatic pressure (HHP), a consecutive combination of nisin and HHP (nisin-HHP), or a consecutive combination of ultrasound and HHP (ultrasound-HHP), and functional properties of processed LWE were compared to those of raw LWE. Little changes in foaming and emulsifying properties were observed by the application of HHP alone and the combined process of nisin and HHP. In contrast, ultrasound-HHP combination resulted in significant changes in color, foaming, and emulsifying properties. The maintenance of functional properties after HHP treatment agreed with expectation, because the HHP processing condition had been selected where minimal rheological changes had occurred.

• Food Science and Biotechnology
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• 제16권5호
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• pp.848-853
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• 2007

The effects of high-hydrostatic pressure (HHP) on the ginsenoside concentration in Korean red ginseng were investigated. HHP-pretreated Korean red ginseng samples were compared to samples produced by a conventional method. Six-year-old Korean fresh ginseng (Panax ginseng C.A. Meyer) samples were vacuum-packaged in polyethylene film and treated at room temperature for 1 min with HHP (200-600 MPa) and steamed at $98^{\circ}C$ for 3 hr. Major ginsenosides of red ginseng were analyzed by HPLC. HHP-pretreated red ginseng showed a 45% higher level of total major ginsenosides than conventionally prepared red ginseng. The levels of 4 protopanaxadiol-type ginsenosides increased 34-43% and the levels of 5 protopanaxatriol-type ginsenosides increased 45-66%. Scanning electron microscopy and electrical conductivity spectrum analysis showed that HHP pretreatment damaged ginseng plant cells and increased extraction efficiencies of ginsenosides from red ginseng products.

• 한국식품영양학회지
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• 제27권5호
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• pp.805-816
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• 2014

We investigated the quality characteristics and resulting sensory evaluation of semi-dried silver pomfret treated with high hydrostatic pressure (HHP) processing and brining for 14 days at 4 and $10^{\circ}C$ to evaluate the effects of treatment with HHP processing. HHP treatment and brining could cause compaction of fibers and the space between muscle. The G' values of all samples were higher than the G" values and the tan ${\delta}$ values of the tissue ranged from 0.222 to 0.251 with no further changes observed during storage. HHP treatment and brining significantly increased the total color difference, and the HHP and brine-treated group scored significantly higher than the others in terms of sensory evaluation. HHP treatment combined with brining could have a significant effect on the quality characteristics of the semi-dried products and their storage stability, and it is suggested from the results that they may have the potential to satisfy the requirements to produce commercially marketable food grade products.

• Journal of Microbiology and Biotechnology
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• 제29권8호
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• pp.1240-1247
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• 2019

This study was conducted to examine the inactivation effect of the combined treatment of high hydrostatic pressure (HHP; 400 MPa for 1, 3, and 5 min) and cationic surfactant washing (0.05% benzethonium chloride, BEC) against Listeria monocytogenes inoculated on fresh-cut broccoli (FCB). Washing with BEC at concentrations exceeding 0.05% resulted in 2.3 log-reduction of L. monocytogenes counts on FCB, whereas HHP treatment had approximately 5.5-5.6 log-reductions regardless of the treatment time. Scanning electron microscopy corroborated microbial enumeration, revealing that the combined treatment was more effective in removing L. monocytogenes from FCB than individual treatment with HHP or BEC. Color and total glucosinolate content were maintained after the combined treatment, although the hardness of the FCB slightly decreased. The results clearly suggest that the combined treatment of HHP and BEC washing has potential value as a new sanitization method to improve the microbial safety of FCB.

• Nuclear Engineering and Technology
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• 제53권8호
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• pp.2616-2628
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• 2021

The results of effective irradiation swelling in a wide range of burnup levels are numerically obtained for an inert matrix fuel, which are verified with DART model. The fission gas swelling of fuel particles is calculated with a mechanistic model, which depends on the external hydrostatic pressure. Additionally, irradiation and thermal creep effects are included in the inert matrix. The effects of matrix creep strains, external hydrostatic pressure and temperature on the effective irradiation swelling are investigated. The research results indicate that (1) the above effects are coupled with each other; (2) the matrix creep effects at high temperatures should be involved; and (3) ranged from 0 to 300 MPa, a remarkable dependence of external hydrostatic pressure can be found. Furthermore, an explicit multi-variable mathematic model is established for the effective irradiation swelling, as a function of particle volume fraction, temperature, external hydrostatic pressure and fuel particle fission density, which can well reproduce the finite element results. The mathematic model for the current volume fraction of fuel particles can help establish other effective performance models.

• 한국식품과학회지
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• 제42권5호
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• pp.533-540
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• 2010

마늘의 사용 확대와 고부가가치의 새로운 기능성 소재 및 제품을 개발하고자 마늘의 독특한 향을 제거하기 위하여 침지액의 pH와 초고압처리시간을 달리하여 실험하였으며, 마늘향의 변화를 GC와 전자코를 이용하여 측정하였다. 시료를 90분간 완충용액(pH 1.8-10.2)에 침지 시킨 뒤 500 MPa의 압력으로 56초-15분4초 초고압처리를 하였다. GC 분석 결과 19개의 함황화합물이 분리 동정되었고 알데하이드, 알콜, 퓨란, 탄화수소, 케톤류 역시 검출되었다. 전자코 분석으로 얻은 데이터로 주성분 분석을 실시한 결과 초고압처리한 시료 모두 대조구에 비하여 이취가 많이 감소하였고, 초고압처리시간이 증가할수록 마늘의 향이 급격히 감소하였다. 강산성 및 강알카리 조건에서도 마늘의 향은 감소하였다. pH는 마늘 향의 형성에 영향을 주었으며 특히 강산의 경우 마늘향의 저감화에 더 효과적이었다. 초고압처리시간이 증가함에 따라 총 sulfide 화합물의 양이 감소하였고 pH 6의 용액에 침지 후 15분 4초간 초고압처리한 시료의 경우 생마늘에 비하여 향이 약 70% 감소하였다. 전자코와 GC-MS 결과의 상관성 분석 결과 $R^2$ 값이 0.9620로 나타나 두 실험결과가 유사함을 입증해 주었다. 이상의 결과를 토대로 침지액의 pH와 초고압처리시간의 조절로 마늘 이취의 저감화가 가능함을 확인할 수 있었다.

• 한국정밀공학회지
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• 제12권7호
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• pp.148-157
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• 1995

This study deals with controlling the speed of Hydrostatic Transmission (HST) system throuth the control of pumping stroke of positive displacement pump using high-speed solenoid valve controlled by digital closed loop PWM method. The method which was done in this study is as follows: First, we modified original positive displacement pump and designed pumping stroke control system of HST by using the high-speed solenoid valve. Second, after experimenting static and dynamic characteristics on each signal flow, we identified system parameter of approximated model. Finally, to control the speed of HST, we controlled the angle of the swash plate of positive displacement pump by controlling the pressure in the control cylinder chamber. Test which was carried out in the laboratory shows that transient and steady state response could be improved by PID controller.

• 한국식품과학회지
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• 제32권2호
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• pp.349-355
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• 2000

열처리에 의한 식품의 성분변화를 줄이기 위한 비열처리 공법 중 하나로 새롭게 주목받고 있는 초고압처리를 적용하여 새우젓의 저장성을 증진시키고자 하였다. 염농도를 달리하여 $20^{\circ}C$에서 6주간 발효시켜 제조한 새우젓의 미생물 수는 염농도 18%에서 가장 높은 미생물 수를 보였으며 일반세균 수는 $3.4{\times}10^5\;CFU/g$, 호염성 세균 수는 $6.4{\times}10^4\;CFU/g$, 효모 수는 $4.2{\times}10^5\;CFU/g$, 호염성 효모 수는 $3.0{\times}10^4\;CFU/g$이었다. 새우젓을 초고압 살균시 압력과 처리시간이 증가할수록 살균효과가 증가되었으며 사멸패턴은 1차반응으로 확인되었다. 염농도 8%와 18% 새우젓에서 $k_p$값은 호염성 세균이 일반세균에 비하여 낮은 값을 보였다. 또한 처리압력에 따라 $log(k_p)$는 직선적으로 증가하였으며 회귀직선의 기울기는 일반세균보다 호염성 세균이 큰 기울기 값을 보여 호염성 세균의 압력에 의한 사멸속도상수의 변화가 일반세균에 비하여 큰 것으로 나타났다. 초고압 공정은 저염발효 새우젓의 살균에 응용될 수 있었으며 최적 처리조건은 6,500기압에서 10분간 처리하는 것이었다.

• 현장농수산연구지
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• 제22권2호
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• pp.5-15
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• 2020

생막걸리의 유통기간은 연장하고자 UV조사와 초고압처리를 하였다. UV조사는 막걸리내 미생물을 감소시키지 못하였으나 초고압처리는 급격하게 감소시켰다. 막걸리의 생균수는 2.2-5.8 × 10⁷ CFU/mL이었으나 300MPa로 1분간 처리하였을 때 1.4-10 × 10³ CFU/mL로 감소하였고 400MPa 처리에 의해서는 4-68 CFU/mL, 500MPa 처리에 의해서는 40CFU/mL이하로 감소하였다. 효모는 400MPa 압력에서 사멸하였고 Bacillus amyloliquefaciens와 Rummeliibacillus stabekisii 500MPa 압력에서도 생존하였다. 400과 500MPa의 압력으로 처리한 막걸리는 상온(25℃)에서 30일간 저장하여도 균체수가 증가하지 않았고 알코올, 산도, 아미노산도의 변화도 억제되었다. 그러나 30일 이상 상온에서 저장하면 막걸리의 산도와 아미노산도가 증가하면서 음용이 어려웠다. 저온(4℃)저장에서는 저장 70일까지 막걸리의 품질변화를 억제시켜 신선한 막걸리와 유사한 맛을 가지고 있었다.

• Journal of Plant Biotechnology
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• 제46권1호
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• pp.56-60
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• 2019

Ginsenosides are active constituents of ginseng (Panax ginseng) that have possible anti-aging, physiological and pharmacological activities, such as anti-cancer and anti-inflammatory effects. Although the ginseng root is generally used more often than the aerial parts for medicinal purposes, the flowers also contain numerous ginsenosides, including Rb2, Rc, Rd, Re and Rg1. Therefore, an extract from the flowers of the P. ginseng could have the pharmacological efficacy of bioactive compounds including ginsenosides. The high hydrostatic pressure extraction (HHPE) is a method that is used for the efficient extraction of bioactive compounds from plant materials. In this study, we compared the yield of ginsenosides from ginseng flowers under different conditions of extraction pressure and time of HHPE. The results indicate that the total yield of the ginsenosides improved as the pressure increased from 0.1 to 80 MPa and treatment duration increased to 24 hours. In addition, the ginsenoside extracts from HHPE at 80 MPa, which possessed a higher total ginsenoside concentration, decreased the viability of the primary human epidermal keratinocytes (HEKs) significantly than the ginsenoside extracts from HHPE at 0.1 MPa. Collectively, we found that the method of HHPE that was performed for 24 hours at 80 MPa showed the highest yield of ginsenosides from the flowers of P. ginseng. In addition, our study provides a foundation for the efficient extraction of ginsenosides, which had a potent bioactivity, from flowers of P. ginseng through HHPE.