• Korean Journal of Food Science and Technology
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• v.32 no.2
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• pp.380-386
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• 2000

Electron beam (EB) was applied to study the sterilizing techniques for powdered red pepper and ginger by determining their quality over gamma radiation (GR) from the microbiological and organoleptic points of view. The samples showed high microbial loads, such as $10^5{\sim}10^6\;CFU/g$ in total aerobic bacteria, negligible levels in yeasts & molds and $10^2\;CFU/g$ in coliforms. EB irradiation at 5 kGy resulted in the reduction of microbial loads by 2 to 3 log cycles, thereby decreasing the levels of total bacteria to $10^2{\sim}10^3\;CFU/g$ and resulting in negative in coliforms. Decimal reduction doses $(D_{10})$ value on the initial bacterial loads in red pepper were $1.50{\sim}1.54\;kGy$ in EB and $1.68{\sim}1.80\;kGy$ in GR, while powdered ginger showed $1.30{\sim}2.27\;kGy$ in EB and $1.45{\sim}2.77\;kGy$ in GR, respectively. EB and GR showed a similar effect on microbial decontamination for both samples. Microbial populations in stored samples for 4 months at room temperature were not remarkably different from the initial loads in all samples. Irradiation caused little changes in Hunter's color parameters, but that were changable during storage. Sensory evaluations on color and odor of powdered samples indicated that no significant differences were observed among the all samples compared. These results revealed that EB irradiation at optimal dose levels for microbial control was not detrimental to the sensory quality of powdered red pepper and ginger.

• 한국생물공학회:학술대회논문집
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• 2000.04a
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• pp.418-421
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• 2000

A model was developed to describe the microbial decontamination of diesel contaminated soil in a soil column. The biodegradation rate of diesel in nature depends on temperature and the pH of soil, availability of nutrients, oxygen and water. The soil moisture content is one of the essential factors because it characterizes the availability not only of water to microorganisms but also of oxygen and nutrient dissolved in soil. In this work, the rate of biodegradation was modeled by coupling Michaelis-Menten kinetics for the aqueous-phase solute with adsoption-desoption equation for diesel sorption and desorption from soil.

• Food Engineering Progress
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• v.22 no.4
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• pp.386-391
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• 2018

Effects of a commercial scale intervention system combining ultraviolet (UV)-C and plasma treatments on the microbial decontamination of black pepper powder were investigated. The process parameters include treatment time, time for plasma accumulation before treatment, and water activity of black pepper powder. A significant reduction in the number of indigenous aerobic mesophilic bacteria in black pepper powder was observed after treatments lasted for ${\geq}20min$ (p<0.05) and the reduction was differed by powder manufacturer. The microbial reduction rates obtained by individual UV-C treatment, individual plasma treatment, and UV-C/plasma-combined treatment were 0.2, 0.5, and 1.0 log CFU/g, respectively, suggesting that the efficacy of the microbial inactivation was enhanced by treatment combination. Nonetheless, neither plasma accumulation time nor powder water activity affected the microbial inactivation efficacy of the combined treatment. The UV-C/plasma-combined treatment, however, decreased lightness of black pepper powder, and the decrease generally increased as operation time increased. The plasma accumulation time of 20 min resulted in significant reduction in both lightness and brown color. The results indicate that the commercial-scale intervention system combining treatments of UV-C and plasma has the potential to be applied in the food industry for decontaminating black pepper powder.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.3
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• pp.465-467
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• 1997

The comparative effects of ozone treatment and gamma irradiation on the sterilization, physicochemical properties and sensory quality of red pepper powder were investigated. As for the sterilization of microorganisms, 7.5~10 KGy of gamma irradiation completely eliminated the coliforms, yeast and molds, and total aerobic bacteria. On the other hand, ozone treatment failed to eliminate the highly contaminated microbial load, especially total aerobic bacteria. The physicochemical properties including capsaicin, capsanthin, browning, fatty acid compositions and sensory quality were not significantly changed by gamma irradiation up to 10 kGy, whereas ozone treatment caused significant changes in fatty acid compositions and destruction of natural pigments (p<0.05). The above results led us to conclude that gamma irradiation was more effective than ozone treatment for the sterilization and maintenance of physicochemical and sensory qualities of red pepper powders.

• Food Science and Preservation
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• v.3 no.2
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• pp.145-148
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• 1996

This paper was carried out to investigate change in the initial microorganism of Pepper which were treated with ozonated water for microbial decontamination. When ozonated water was 30, 60, 90minutes treatment, there was decrease in the overall total microbial of the black & white pepper. Total lactic acid bacteria died completely after contacted with ozonated water for 60minutes but the inhibition rate on the total aerobic bacteria of black & white pepper were 62% and 96%, respectively. Total aerobic bacteria of four packing material was increased after 1 months of storage at 37$^{\circ}C$ when it had treated with 90minutes ozone reaction Then, there was no significant changes in the piperin contents.

• Korean Journal of Food Science and Technology
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• v.45 no.6
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• pp.735-741
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• 2013

Effects of cold plasma treatment (CPT) against Salmonella Typhimurium inoculated on cabbage and lettuce, naturally occurring bacteria in black pepper powder and red pepper powder, and Bacillus cereus inoculated onto red pepper powder were investigated. The numbers of S. Typhimurium on cabbage and lettuce were reduced by $1.5{\pm}0.2CFU/cm^2$ (900W, 5 min) and $1.1{\pm}0.1$ log $CFU/cm^2$ (900W, 10 min), respectively. The numbers of naturally occurring aerobic bacteria in both black pepper powder and red pepper powder were reduced by $2.3{\pm}0.3$ and $0.6{\pm}0.2$ log CFU/g, respectively. The numbers of B. cereus vegetative cells on red pepper powder were reduced by $1.5{\pm}0.1$ log CFU/g, but the numbers of spores remained unchanged. The inhibition of S. Typhimurium on cabbage was adequately described by Fermi's model and the Weibull model. The predicted optimum treatment power and time for S. Typhimurium inoculated onto cabbage were 746 W and 6.8 min, respectively. Our results indicate that CPT represents a useful method for microbial decontamination of vegetables and spices.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.4
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• pp.655-662
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• 2000

Electron beam (EB) irradiation was applied to study microbial decontamination effects for kochujang powder by determining their microbiological and physicochemical qualities over gamma ray (GR) irradiation. The samples showed a high microbial population, such as 105~106 CFU/g of total aerobic bacteria, negative of yeasts & molds and coliforms. Total bacterial counts were decreased by 1~2 log cycles with EB irradiation at 5~7.5 kGy, and 10 kGy irradiation was enough to improve the microbiological quality by reducing populations to below 104CFU/g, which was similar to gamma energy. Such doses were effective for controlling the microbial growth in stored samples during storage for 4 months at room temperature. Decimal reduction doses (D10 value) on initial bacterial populations were 2.88~3.02 kGy in EB and 3.57~3.59 kGy in GR, which were influenced by initial populations and energy types applied. Based upon the above results, 7.5~10 kGy irradiation caused negligible changes in Hunter's color, capsaicin, fatty acid composition and organoleptic qualities. Considering the quality changes resulting from subsequent storage, such as a decrease in capsanthin content and an increase in TBA value in the samples, it is recommendable to irradiate kochujang powder at 7.5~10 kGy when used for food processing.

• Food Science of Animal Resources
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• v.42 no.1
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• pp.142-152
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• 2022

The present study was aimed at examining the antibacterial effects of nonthermal decontamination processes, which are equivalent to thermal treatment, to ensure microbiological safety of raw ground chicken. Escherichia coli or Salmonella were inoculated into 25 g of raw ground chicken samples. The raw ground chicken samples were non-treated or treated with high hydrostatic pressure (HHP) at 500 MPa (1-7 min), light-emitting diode (LED) irradiation at 405 nm wavelength (30-120 min), and heat at 70℃, 90℃ (1-60 min), and 121℃ (1-15 min). E. coli and Salmonella cell counts were enumerated after treatments. Moreover, the color parameters of treated raw ground chicken were analyzed. HHP treatment reduced E. coli and Salmonella cell counts by more than 5 Log CFU/g and more than 6 Log CFU/g after 7 min and 1 min, respectively; these effects were equivalent to those of thermal treatment. However, LED irradiation reduced Salmonella cell counts by only 0.9 Log CFU/g after 90 min of treatment, and it did not reduce E. coli cell counts for 90 min. Compared with those of the non-treated samples, the ΔE (total color difference) values of the samples treated with HHP were high, whereas the ΔE values of the samples treated with LED irradiation were low (1.93-2.98). These results indicate that despite color change by HHP treatment, HHP treatment at 500 MPa could be used as a non-thermal decontamination process equivalent to thermal treatment.

• Food Science of Animal Resources
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• v.37 no.2
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• pp.297-304
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• 2017

Animal-origin food products pose serious threat to public food safety due to high microbial loads. The microbial and radioactive contaminations in commercial cold duck meat products were evaluated. Ten different lots of commercial samples ($C_1-C_{10}$) were classified based on type and smoking process. All samples were highly contaminated (< 4-7 Log CFU/g) with total aerobic bacteria (TAB), yeasts and molds (Y&M), and 7 samples ($C_1-C_7$) were positive for coliforms. Furthermore, three samples were contaminated with Listeria monocytogenes ($C_4-C_6$) and one with Salmonella typhimurium ($C_6$). No radionuclides ($^{131}I$, $^{137}Cs$, and $^{134}Cs$) were detected in any sample. The results of DEFT (direct epifluorescent filter technique)/APC (aerobic plate count), employed to screen pre-pasteurization treatments of products, indicated that smoked samples were positive showing DEFT/APC ratios higher than 4. Notably, the samples showed a serious threat to microbial safety, thus were irradiated with electron-beam (e-beam). The $D_{10}$ values for S. typhimurium and L. monocytogenes were 0.65 and 0.42 kGy, respectively. E-beam application at 3 and 7 kGy resulted in reduction of initial TAB, Y&M, and coliform populations by 3 and 6 log cycles, respectively. Thus, e-beam was proven to be a good decontamination approach to improve the hygiene of cold duck meat.

• Korean Journal of Food Science and Technology
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• v.49 no.1
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• pp.20-27
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• 2017

Eighteen commercial laver (Porphyra sp.) products were purchased from Korean market and were monitored for their microbial contamination, pre-decontamination, and luminescence properties. The laver samples showed considerable variation in their microbial contamination, from $10-10^7CFU/g$ of total aerobic counts, <$10-10^2CFU/g$ of coliforms in 4 dried laver samples, and <$10-10^6CFU/g$ of yeasts and molds except in 3 samples. In addition, $10^2CFU/g$ of Bacillus cereus was found in one sample. DEFT/APC analysis was suitable for demonstrating whether the samples were pre-decontaminated or not, with DEFT/APC values lower than 2.0 log for non-heated samples and 1.0-8.5 log for heatprocessed samples. In photostimulated luminescence (PSL) calibration, 15 samples irradiated at 1 kGy showed positive (irradiated) values more than 5000 PCs. Furthermore, thermoluminescence (TL) analysis by separating the marker minerals from samples revealed the potential to be employed in identifying irradiation status by determining $1^{st}$ TL glow at $125-175^{\circ}C$ and TL ratio ($TL_1/TL_2$) of all the samples.