• Food Science and Preservation
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• v.21 no.4
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• pp.544-548
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• 2014

This study was conducted to investigate the effects of various heat treatments on the microbial reduction and germination of red radish seeds for the development of effective and economical sterilization methods of improving microbial safety without reducting the germination rate. Hydrothermal treatment was conducted at 60, 65, 70, 75, 80, and $90^{\circ}C$ for 30 and 60 seconds, and dry heat treatment was performed at 70, 80, 90, and $100^{\circ}C$ for 5 minutes. In the seeds that underwent the hydrothermal treatment, time had little effect on the microbial reduction. There was no significant microbial reduction over time. However, there was significant microbial reduction as temperatures increased (p<0.001). The total plate count (TPC) was reduced by more than 3 logs, and Listeria monocytogenes was not detected at temperatures above $70^{\circ}C$. In the seeds that were subjected to the dry heat treatment, the TPC and the population of the L. monocytogenes were significantly reduced as the temperatures increased (p<0.001). After treatment at $100^{\circ}C$ for 5 minutes, the TPC and the L. monocytogenes were reduced by 3 logs. As with the microbial reduction, time had little effect on the germination. There were no significant changes in the germination after the hydrothermal treatment over time; but at the temperatures above $75^{\circ}C$, the germination rate significantly decreased as the temperature increased (p<0.001). When the seeds were soaked after the hydrothermal treatment, their germination was stimulated. The dry heat treatment at temperatures of $80^{\circ}C$ and higher significantly decreased the germination rate as the temperature increased (p<0.001). Dry heat treatment before the germination of the seeds soaked in distilled water for three hours significantly decreased the germination at temperatures greater than $90^{\circ}C$ (p<0.05). This study showed that appropriate heat treatments can increase the microbiological safety and germination of red radish seeds.

• Korean Journal of Food Science and Technology
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• v.24 no.4
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• pp.393-395
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• 1992

The ${\alpha}-lactalbumin({\alpha}-la)$ concentration in raw and laboratory-heated milks by HPLC was 1.20 mg/ml (unheated), 1.17 mg/ml ($63^{\circ}C$, 30min), 1.13 mg/ml ($72^{\circ}C$, 15sec) and 0 mg/ml ($100^{\circ}C$, 10min), respectively. Whereas, ${\alpha}-lactalbumin$ concentration ranges of commercial milks were $1.00{\sim}1.02\;mg/ml$ (pasteurized), $0.23{\sim}0.68\;mg/ml$ (UHT-pasteurized) and $0.77{\sim}0.89\;mg/ml$ (UHT-sterilized), respectively. It was supposed that the ${\alpha}-lactalbumin$ content of sterilized milk will be lower than that of UHT milk, but the opposite occurred. This discrepancy would be caused by the different heating system in the milk plants, where indirect UHT-treatment had more heat intensity than direct UHT-processing. The HPLC determination of ${\alpha}-lactalbumin$ may be an indicator to evaluate correctly and rapidly heated milks.

• Journal of Food Hygiene and Safety
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• v.18 no.1
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• pp.6-13
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• 2003

Various kinds of genetically modified organisms (GMO) and processed foods have been developed during recent years. Genetically modified organisms can be classified into several groups as their development methods. Generally, GMO has three foreign DNA regions such as gene expression adjustment region(Promoter), termination region (terminator) and structure gene. Detection of these regions can be done particularly by polymerase chain reaction (PCR). PCR-based detection can virtually be performed for any GMO within short of time. The most important prerequisite for the application of PCR-based detection is to decide abstraction method of efficient nucleic acids. Specially, in the case of processed food, because nucleic acids of foodstuffs are damaged by heat treatment (sterilization), pressure and fermentation, DNA must be extracted ken the samples prior to PCR analysis. Although many DNA extraction protocols are available, they have rarely been compared in a comprehensive method. In this study low widely used commercial and non-commercial DNA extraction methods-DNeasy$^{TM}$, Wizard$^{TM}$, CTAB, phenol/chloroform system-were compared with respect to the quality and yield of nucleic acids and insertion genes.nes.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.498-498
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• 2013

Atmospheric Pressure Plasmas have pioneered a new field of plasma for biomedical application bridging plasma physics and biology. Biological and medical applications of plasmas have attracted considerable attention due to promising applications in medicine such as electro-surgery, dentistry, skin care and sterilization of heat-sensitive medical instruments [1]. Traditional approaches using electronic devices have limits in heating, high voltage shock, and high current shock for patients. It is a great demand for plasma medical industrial acceptance that the plasma generation device should be compact, inexpensive, and safe for patients. Microwave-excited micro-plasma has the highest feasibility compared with other types of plasma sources since it has the advantages of low power, low voltage, safety from high-voltage shock, electromagnetic compatibility, and long lifetime due to the low energy of striking ions [2]. Recent experiment [2] shows three-log reduction within 180-s treatment of S. mutans with a low-power palm-size microwave power module for biomedical application. Experiments using microwave plasma are discussed. This low-power palm-size microwave power module board includes a power amplifier (PA) chip, a phase locked loop (PLL) chip, and an impedance matching network. As it has been a success, more compact-size module is needed for the portability of microwave devices and for the various medical applications of microwave plasma source. For the plasma generator, a 1.35-GHz coaxial transmission line resonator (CTLR) [3] is used. The way of reducing the size and enhancing the performances of the module is examined.

• The Korean Journal of Food And Nutrition
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• v.16 no.3
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• pp.180-186
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• 2003

In order to prediction of lethal effects on target microorganisms, this study was developed the program in the basis of Excel that was systemized with Visual Basic. This program was automatically calculated the lethal effects (L and Fo value) by using thermal characteristics (D and z value), kinetic model and mathematic model. For the selection of target microorganisms, we are selected two microorganisms because of spoilage increasing by acid production and decreasing quality of food, and heat resistance microorganisms. The target microorganisms were Bacillus cereus (D$_{121.1}$=0.0065 min, z=7.8$^{\circ}C$) and Bacillus subtilis (D$_{121.1}$=0.5 min, z =12$^{\circ}C$). The program was developed for the target microorganisms, and that was very useful for various microorganisms that direct introducing known D and z value.

• Korean Journal of Community Nutrition
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• v.13 no.3
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• pp.405-417
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• 2008

The purpose of the study was to investigate the sanitation management status and implementation barriers of the HACCP system. A survey was conducted based on 760 schools through e-mail after having gone through phone interviews to dieticians in Seoul, Gyeonggi and Incheon areas from December 2006 to March 2007. The following statistics were drawn out from the 459 surveys out of the 760, thus giving a response rate of 60.4% (N = 459). The statistical data analysis was completed using the SPSS program. 92.6% of the respondents operated sanitary education once a month and 67.1 % used internet as their sanitary educational source. 50.5% of the pre-preparation rooms were not divided and 78.0% of kitchen floors were always kept wet. Only 15.7% of the respondents used heat and cold insulators and 73.2% of drinking water was natural or purified water. 60.3% of food trays were electronically sterilized and 70.2% of spoons and chopsticks were sterilized by boiling water. The main cause of food-borne diseases was the lack of facilities and equipment (33.1%). Also, the deficiency of facilities and equipment (4.07 points) acted as an implementation barrier of the HACCP system. Compared to Gyeonggi or Incheon area results, Seoul's facilities and equipment (p < 0.001) and implementing barriers of the HACCP system (p < 0.001) results came out relatively high. After the analysis of the implementation barriers of the HACCP system, 91.7% of school principals said it was difficult to apply the HACCP system due to lack of financial support. In consideration to the school foodservice support, solutions for the facilities of school foodservice and a systematic sanitary education of the HACCP system must be made for the employees and everyone else who are related.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.32 no.4
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• pp.320-326
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• 2019

Recently, the application of atmospheric plasma technology in air filtration is increasing. Sterilization by an atmospheric plasma device is very effective. However, ozone gas, which is generated during atmospheric plasma formation, poses a hazard to human health. To reduce the ozone gas during plasma discharge, we fabricated a one-plate hybrid plasma discharge device with a heating element, which can decompose ozone gas effectively by a simple heating action. In this study, we evaluated the plasma discharge characteristics and ozone concentrations with various Ar flow rates and temperatures. With increasing Ar gas flow rate, the ozone concentration and spectrum intensity increased till an Ar gas flow rate of 60 sccm, and decreased thereafter. When discharged in high temperature, the ozone concentration and spectrum intensity decreased. Further, to evaluate the state of the treated surface under various plasma discharge and heating conditions, we measured the variation in the contact angles on the surface. Regardless of the temperature, the contact angle increased with increasing discharge voltage. However, the contact angle increased when discharged at high temperature.

• Journal of Biomedical and Translational Research
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• v.19 no.4
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• pp.103-109
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• 2018

Aspergillus luchuensis 34-1 was inoculated into wheat pellets with different conditions of raw materials to produce nuruk. The degree of substrate reactivity improvement of steam treated raw materials compared with that of non-heat treated was analyzed. The water content of the pellet was adjusted to 25% and 35%, and steam treatment for 10 minutes improved the substrate reactivity at 2.1-fold and 3.1-fold, and sterilization was also possible. The characteristics of improvement pellet nuruk were investigated according to the degree of crushing and water content of raw materials according to the temperatures and humidities ($23^{\circ}C$, $30^{\circ}C$ and RH 60%, RH 80%). The pH of the pellet nuruk was higher depending on the temperature, humidity and moisture content of the koji were lower, and the pH of the flour-pellet nuruk was lower than that of 2 mm milling wheat-pellet nuruk according to milling degree. It can be seen that the milling degree affects the growth of mold. The acidity and amino acid were generally higher as fermentation time increased. Also, the higher the incubation temperature, humidity and moisture content, the higher the value. Glucoamylase activity was significantly the highest in moisture content 35% D2b nuruk, cultured at $30^{\circ}C$ and 80% RH for 38 hours. This is higher than the previous reports on glucoamylase of rice-koji or commercial nuruk using fungi isolated from traditional nuruk. From these study, it is expected that making of improvement pellet nuruk would save the fermentation time considerably compared with traditional nuruks.

• Food Engineering Progress
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• v.21 no.4
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• pp.403-408
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• 2017

Acetic acid bacteria strains were isolated from a variety of fermented foods and fallen fruits. Among them, the strain MAK88, whose acetic acid fermentation ability, acid-tolerance, and alcohol-tolerance were high, was selected and identified as Acetobacter orientalis. A seed culture of A. orientalis MAK88 was inoculated into onion juice, and the optimum conditions of acetic acid fermentation was investigated. The optimum initial concentration of ethanol in onion juice was 5% (v/v) and in that condition, acidity was 4.31% at 144 h of fermentation. The optimum initial concentration of acetic acid was 1% and the final acidity was 5.32%. The optimum fermentation temperature was determined to be $28^{\circ}C$. The most appropriate preparation method of onion juice was to heat the onion at $121^{\circ}C$ for 15 min and produce juice with pressure followed by filtering, and then sterilization at $121^{\circ}C$ for 15 min. Prepared onion juice was used for fermentation without dilution.

• Journal of agriculture & life science
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• v.43 no.6
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• pp.85-93
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• 2009

The boiled oyster vacuum-packed in cylindrical can(No. 301-3) were thermally processed at $115^{\circ}C$ to reach Fo values of 5~20 min. The yield was slightly decreased with the increasing of Fo-values (79.2~ 83.7%), and volatile basic nitrogen (VBN) contents increased markedly with the increasing of Fo-value. In fatty acid composition of canned oyster, the composition ratio of saturates and monoenes such as 14:0, 16:0 and 18:1n9 increased, while polyunsaturated fatty acids such as 20:5n-3 and 22:6n-3 decreased with the increasing of Fo-value. In taste compounds, content of total free amino acid in raw oyster was 1,533.5 mg%, and this total content was slightly increased (1,140.8~1,266.2 mg%) with the increasing of Fo values. But contents of betaine and ionic minerals such as Na, K, Mg and P decreased markedly by thermal processing at $115^{\circ}C$. As compared with Fo 5 min. heat treatment; Fo 20 min. heat treatment at $115^{\circ}C$ became more hardened in texture of oyster meat. In sensory evaluations on organoleptic characteristics, no significant difference at 5% level was observed among the canned boiled oyster meats heated at Fo 5~15 min.