• Food Science and Biotechnology
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• v.18 no.6
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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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• v.16 no.5
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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.

• The Korean Journal of Food And Nutrition
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• v.27 no.5
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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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• v.29 no.8
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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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• v.53 no.8
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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.

• Korean Journal of Food Science and Technology
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• v.42 no.5
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• pp.533-540
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• 2010

Effects of pH (1.8-10.2) and time (56 sec-15 min 4 sec) at high hydrostatic pressure (500 MPa) on the reduction of volatile compounds in garlic were studied. Volatile components of garlic were obtained from the headspace, analyzed, and identified by gas chromatography (GC)-mass spectrometry and an electronic nose. Nineteen sulfur compounds were identified as major compounds in garlic, and furan, aldehydes, alcohols, and ketones were also detected. Off-flavor compounds were more effectively reduced under strong acidic conditions. As the residence time at 500 MPa increased from 56 sec to 15 min 4 sec, the total amount of volatile compounds decreased significantly. The total amount of sulfur compounds decreased about 70% compared to those of raw garlic when the garlic was soaked in buffer (pH 6.0) and treated at 500 MPa for 15 min 4 sec. A principal component analysis showed that the off-flavors of garlic were reduced by the operating time of high hydrostatic pressure as well as pH treatment. The correlation coefficient of the results between GC and the electronic nose analysis was 0.9620. Therefore, pH and high hydrostatic pressure treatment could be used as an efficient method for reducing of garlic off-flavor.

• Journal of the Korean Society for Precision Engineering
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• v.12 no.7
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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.

• Korean Journal of Food Science and Technology
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• v.32 no.2
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• pp.349-355
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• 2000

This study was conducted to enhance the storage stability of fermented shrimp with different salt contents using a high hydrostatic pressure. The effects of the magnitude of pressure and treatment time on the microorganisms of the fermented shrimp were investigated. The highest microbial counts with respect to the salt levels were observed at 18% salt, showing $3.4{\times}10^5\;CFU/g$ for general bacteria, $6.4{\times}10^4\;CFU/g$ for halophilic bacteria, $4.2{\times}10^5\;CFU/g$ for yeast and $3.0{\times}10^4\;CFU/g$ for halophilic yeast. The degree of sterilization increased with the magnitude of pressure and treatment time, and the sterilization could be analyzed by the first order reaction kinetics. The sterilization rate constants $(k_p)$ of the halophilic bacteria was lower than that of general bacteria. The $log(k_p)$ increased linearly with pressure and the slope of the regression line of the halophilic bacteria was greater than that of general bacteria, indicating that the sterilization of the halophilic bacteria was more dependent on the pressure. High hydrostatic pressure treatment was an effective non-thermal sterilization method for the salted and fermented shrimp, and the optimum treatment condition was for 10 min at 6,500 atm.

• Journal of Practical Agriculture & Fisheries Research
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• v.22 no.2
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• pp.5-15
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• 2020

To extend the shelf life of draft makgeolli, UV irradiation and high hydrostatic pressure were conducted. UV irradiation did not reduce the total cell number in makgeolli, but high hydrostatic pressure treated drastically decreased. The number of viable cells in makgeolli was 2.2-5.8 × 10⁷ CFU/mL, but when treated with 300 MPa pressure for 1 minute, it decreased to 1.4-10 × 10³ CFU/mL, with 400 MPa to 4-68 CFU/mL, and with 500 MPa to under 40 CFU/mL. Yeast died at 400 MPa pressure, but Bacillus amyloliquefaciens and Rummeliibacillus stabekisii survived at 500 MPa pressure. The makgeolli treated with 400 and 500 MPa pressure did not increase the number of cells even when stored at room temperature (25℃) for 30 days, and changes in alcohol, acidity, and amino acid vlaue were also suppressed. However, when stored for more than 30 days at room temperature, the acidity and amino acid levels of makgeolli increased, making it difficult to drink. At low temperature (4℃) storage, the quality change of makgeolli was suppressed until 70 days of storage, so it had a taste similar to that of fresh makgeolli.

• Journal of Plant Biotechnology
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• v.46 no.1
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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.