• 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.

• Journal of Radiation Industry
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• v.8 no.1
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• pp.1-5
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• 2014

This study investigated the reduction of microbial population and sensory properties in red pepper powders irradiated by gamma ray, electron beam, and X-ray. Populations of total aerobic bacteria and yeast & molds in red pepper powders were decreased by irradiation treatment in a dose-dependent manner. Gamma ray, electron beam, and X-ray at doses above 8 kGy caused 100% inhibition on growth of aerobic bacteria in red pepper powders. Inhibitory activity of X-ray on sterilization of red pepper powders was significantly equal to or higher compared to gamma ray and electron beam. Color and off flavor in red pepper powders were no significant difference among the control and samples irradiated with gamma ray, electron beam, and X-ray. As a result, the gamma ray, electron beam, and X-ray irradiation can be used to sterilize the microbial growth in red pepper powders without quality loss.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.7
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• pp.1103-1112
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• 2020

Objective: To measure whether a microbial additive could effectively improve the fermentation quality of delayed-sealing (DS) silage, we studied the effects of inoculants of lactic acid bacteria (LAB) and cellulase enzyme on microbial populations, ensiling characteristics, and spoilage loss of DS silage of Napier grass in Africa. Methods: Quick-sealing (QS) and DS silages were prepared with and without LAB (Lactobacillus plantarum) inoculant, cellulase enzymes, and their combination. The QS material was directly chopped and packed into a bunker silo. The DS material was packed into the silo with a delay of 24 h from harvest. Results: In the QS silage, LAB was dominant in the microbial population and produced large amounts of lactic acid. When the silage was treated with LAB and cellulase, the fermentation quality was improved. In the DS silage, aerobic bacteria and yeasts were the dominant microbes and all the silages were of poor quality. The yeast and mold counts in the DS silage were high, and they increased rapidly during aerobic exposure. As a result, the DS silages spoiled faster than the QS silages upon aerobic exposure. Conclusion: DS results in poor silage fermentation and aerobic deterioration. The microbial additive improved QS silage fermentation but was not effective for DS silage.

• Microbiology and Biotechnology Letters
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• v.7 no.4
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• pp.191-195
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• 1979

This study was conducted to investigate the effect of saccharified extract of ginseng meal on alcohol fermentation and reproduction of yeast. Different concentrations of saccharified extract of ginseng meal in liquid medium were tested, and the experimental results obtained were summarized as follows : 1. In the process of alcohol fermentation of yeast, $CO_2$ output was much accelerated by the higher concentration of saccharied extracts from 1％ to 6％, but $CO_2$ output was disurbed at the concentrations of 10％ and 15％. .2. In the process of alcohol fermentation of yeast, the production of alcohol was increased by the higher concentration of saccharified extracts from 1％ to 6％, but decreased at the concentrations of 10％ and 15％. 3. Number of reproduced yeast cell after aerobic culture of Sacc. cervisiae was increased by the higher concentration of saccharified extracts from 1％ to 10％, but decreased at the concentration of 15％. The number of yeast cell at the concentratin of 10％ extract was 1.6 times more than that of control.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.11
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• pp.1632-1638
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• 2012

The effects of combined treatment of aqueous $ClO_2$ and UV-C or electron beam irradiation on microbial growth and quality in chicon during storage at $4^{\circ}C$ were investigated. Samples were treated separately with 50 ppm of $ClO_2$, 5 kJ/$m^2$ of UV-C, 2, 5, 7, and 10 kGy of electron beam irradiation, as well as a combination of $ClO_2$ and UV-C or 2 kGy of electron beam irradiation. The populations of total aerobic bacteria as well as yeast and molds in the chicon samples were determined following each treatment. The populations of total aerobic bacteria in the chicon samples decreased by 1.49~2.92 log CFU/g following combined treatment of $ClO_2$ and UV-C irradiation compared to the control, whereas the populations of yeast and molds decreased by 1.63~1.78 log CFU/g. On the contrary, following combined treatment of $ClO_2$ and electron beam irradiation, the populations of total aerobic bacteria as well as yeast and molds in the chicon samples were undetectable during storage. Color measurements indicated that Hunter $L^*$, $a^*$, and $b^*$ values were not significantly different among the treatments during storage. These results suggest that combined treatment of $ClO_2$ and electron beam irradiation can be useful for improving microbiological safety in chicon during storage.

• Journal of Food Hygiene and Safety
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• v.19 no.4
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• pp.209-216
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• 2004

Dry rehydratable film methods were compared to conventional methods for the enumeration of microorganisms in Korean traditional foods. Kimchi, doenjang, kochujang, kanjang, takju, sujeongkwa and sikhe were used as Korean traditional foods. $Petrifilm^{TM}$ aerobic count plate, $Petrifilm^{TM}$ coliform count plate, $Petrifilm^{TM}$ E. coli/coliform count plate, $Petrifilm^{TM}$ yeast and mold count plate and $Petrifilm^{TM}$ staph express count plate were compared to plate count agar, most probable number (MPN) for coliform, MPN for E. coli, potato dextrose agar and coagulase test, respectively. Regression analysis indicated that correlation coefficient values were 0.974-0.998, 0.913-0.995, 0.955-0.978, 0.968-0.986 and 0.998-0.999 for total aerobic bacteria, yeast and mold, coliform, E. coli and S. aureus, respectively. There were no significant differences between two methods, suggesting that $Petrifilm^{TM}$ plates can be used as an alternative to conventional method for the determination of microorganisms in Korean traditional foods.

• Korean Journal of Food Science and Technology
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• v.37 no.2
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• pp.294-300
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• 2005

Contents of total aerobic bacteria, coliform, Escherichia coli, yeast, mold, and Staphylococcus aureus in meat, dairy, and fishery products were analyzed by dry rehydratable film method using 3M $Petrifilm^{TM}$ and compared against those obtained through conventional method. Two methods showed high correlations of 0.990-0.999, 0.975-0.999, 0.979-0.987, 0.978-0.984, and 0.999 for total aerobic bacteria, yeast and mold, coliform, E. coli, and S. aureus, respectively; therefore, dry rehydratable film method using 3M $Petrifilm^{TM}$ offers acceptable alternative to conventional method for enumeration of microorganisms in meat, dairy, and fishery products.

• KSBB Journal
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• v.17 no.3
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• pp.307-310
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• 2002

In order to obtain high density seed cells for biofiltration, we studied batch and fed-batch culture of P. putida. Studies were carried out to find optimum fermentation conditions such as pH, concentration of glucose and agitation speed. Specific growth rate of P. putida was dependent on agitation speed and a high rpm of 300 was necessary to carry out the efficient aerobic growth of P. putida. Specific growth rate was highest at pH 7. Feeding glucose and yeast extract continuously at the initial growth phase was the most effective way to get high cell density of P. putida.

• KSBB Journal
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• v.26 no.5
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• pp.365-373
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• 2011

Effective Microorganisms (EM), a fermented medium developed by Professor Higa at the University of the Ryukyus, is a mixed culture containing dozens of microorganisms which are beneficial to nature including people, animals, plants and many microbial species in environment. EM is known to contain more than 80 kinds of anaerobic or aerobic microbes including photosynthetic bacteria, lactic acid bacteria, yeast, actinomycetes, fungi and so on, with yeast, lactic acid bacteria and photosynthetic bacteria as the main species of EM. Antioxidant effect generated by the concert of complex coexistence and coprosperity among these microbes is considered to be the main source of EM benefits. Currently, EM is earning an increasing attention with applications in agriculture, forestry, animal husbandry, fisheries, environment and medicine among others. At the same time, however, a quantitative interpretation of EM system based on a mixed culture model needs efforts from biochemical engineers for efficient production and further promotion of EM. In this paper, we describe the functions of major microbes in EM and current researches and applications of EM in agriculture, forestry, animal husbandry, fisheries, environment and medicine.

• Microbiology and Biotechnology Letters
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• v.16 no.6
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• pp.505-509
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• 1988

Ethanol productivity of a xylose fermenting yeast (Candida sp. X-6-4l) isolated from soil was investigated in laboratory scale using Erlenmeyer flask and mini-jar tormentor. The optimal conditions of xylose fermentation in flask experiment were pH 4, asparagine as nitrogen source, xylose 20g/$\ell$, and in these condition, ethanol yield was about 80% to theoretical yield. Using mini-jar fermentor containing 5% total sugar with 2.5% xylose and 2.5% glucose, we obtained 2.3%(v/ v) ethanol and the corresponding efficiency was 72.3% of total sugar. In this case, the consumming speed of sugar under aerobic condition was faster than that of anaerobic condition, and glucose was used previously to xylose. The optimum concentration of xylose for ethanol fermentation in mini-jar fer-mentor scale was 5%, and the efficiency was 69% of total sugar(Alc.2.2% v/v).