• Korean Journal of Food Science and Technology
• /
• v.28 no.1
• /
• pp.66-71
• /
• 1996

To extend shelf life of cooked rice, main putrefactive microorganism isolated from cooked rice were identified by using the API 50 CHB kit and fatty acid analysis of the cell and antimicrobial activity of water extract of green tea was tested against isolated strains and some type of strains. The growths of Bacillus subtilis ATCC 6633, Salmonella typhimurium ATCC 14028, Bacillus cereus YUFE 2004 and Staphylococcus aureus YUFE 2087 were inhibited in broth containing 500 and 1000 ppm of green tea extract. Main putrefactive microorganisms of cooked rice were identified as Bacillus subtilis RHJ-I and Bacillus subtilis RHJ-II. Green tea extract of 500 and 1000 ppm level inhibited the growth of Bacillus subtilis RHJ-I only.

• Korean Journal of Food Science and Technology
• /
• v.26 no.6
• /
• pp.733-739
• /
• 1994

To extend the self-life of Dooboo (tofu), fish paste and Makkoli (Korean traditional rice wine) for which severe heat treatment are not expectable, main putrefactive microorganisms were isolated from each product and tested their growth inhibition by ethanol and water extracts of several edible plants. The ethanol extract of Phellodandron amurense Ruprs had the strong effect of growth inhibiting to all three isolates from Dooboo and Makkoli, and Eugenia caryophyllus, Pinus rigia Mill, Bletilla striata (Thunb) Reichb. Fill and Paeonia albiflora Pall were also same effect to isolates from fish paste. The ethanol extract was more effective inhibiting than water extract in all test microorganisms. The evident inhibition level of each extract was 2000 ppm of Pa ethanol for fish paste and 1000 ppm for Makkoli.

• Food Science and Preservation
• /
• v.14 no.2
• /
• pp.183-187
• /
• 2007

The antimicrobial properties of methanolic extract (PML) from Prunus nune byproducts after liquor manufacturing weremeasured using various putrefactive and food spoilage microorganisms. PML showed remarkable antimicrobial effects against various putrefactive and food spoliage microorganisms when used at 500g/mL. The antimicrobial properties were stable for 30 min at 100C and at pH 3 11. PML seems to be a natural antimicrobial agent with high effectiveness, and shows both thernal and pH stability. In addition, the mode of antimicrobial action suggests that the active components may synergistically perturb microbial membrane functions.

• Food Science and Preservation
• /
• v.16 no.3
• /
• pp.392-399
• /
• 2009

Recent studies indicate that green tea may have anticancer, antioxidant, and antihypertensive effects, and aids body weight control and the promotion of various desirable physiological functions. However, few studies have investigated the antimicrobial effects of green tea. We sought to determine the antimicrobial activity of green tea extract against food spoilage microorganisms. The extract showed remarkable antimicrobial effects against a wide spectrum of putrefactive and food spoilage microorganisms when used at concentrations greater than $500{\mu}g/ml$. The extract showed thermal and pH stability in the range of $40{\sim}150^{\circ}C$ and pH 3.11, respectively. Green tea extract seems to be an ideal natural antimicrobial, considering both efficacy and thermal and pH stabilities. Antimicrobial substances in green tea extract were investigated using electron microscopy and a $\beta$-galactosidase assay. The data showed that the extract contains several efficacious materials, and that their activities are not synergistic but are instead independent. Our data indicate that hydrophilic antimicrobial substances in green tea extract might control food spoilage microorganisms owing to perturbation of the microbial cell membrane.

• Korean Journal of Food Science and Technology
• /
• v.18 no.1
• /
• pp.1-5
• /
• 1986

Putrefactive microorganisms from infected onion bulbs collected at several areas were isolated and identified. The infecting microorganisms were mostly the species of Botrytis, Fusarium, Penicillium, Ericinia and Pseudomonas, among which the last was not pathogenic to onion bulbs. Fumigation of onion bulbs with Tetrachloroisophthalonitrile cut down decay rate by half of the control and the onion bulbs stored at 80% RH showed slow decay rate than those stored at 90% RH. The decay of onion bulbs was mainly caused by molds and the portions of them were 78-85% of Botrytis, 11-17% of Fusarium and 3-5% of Penicillium.

• Journal of Microbiology and Biotechnology
• /
• v.4 no.2
• /
• pp.141-145
• /
• 1994

Conventional commercial thermal process for preparing Sikhae (Rice beverage) in a hermetically sealed container was evaluated to solve the nutritional deterioration and organoleptic inferiority problem caused by severe heat treatment. A milder thermal process with an aid of Nisin, a GRAS-grade, selectively germicidal compound, was introduced to destroy the putrefactive microorganisms. In this experiment, hot-filling method with Nisin, and thermal processing (at 110$^{\circ}C$ for 15 minutes with Nisin, at 121$^{\circ}C$ for 25 minutes without Nisin) were compared. The quality of Sikhae could be enhanced and over 90% of the thermal process could be conserved by this process in terms of sterilizing value without quality deterioration when processing the bottled Sikhae at 110$^{\circ}$ for 15 minutes $\{(F^{10}{_{121})_{process}=1.54\}$.

• Journal of Food Hygiene and Safety
• /
• v.10 no.1
• /
• pp.33-39
• /
• 1995

The antibacterial and antifungal effect of grapefruit seed extract(GFSE) was investigated for its purpose of application to a diverse spectrum of field as sanitizers, disinfectants and preservatives. GFSE showed coparatively high content of such flavoniods as naringin and hesperidin and ascorbic acid. GFSE containing a low level of organic acids is a heavy viscous and water-soluble liquid. As a result of the antimicrobial test of GFSE, Bacillus subtilis and Aspergillus oryzae did not survive at detectable levels when treated with more than 100 ppm of GFSE. The minimum inhibitory concentrations of GFSE for a wide variety of pathogenic and putrefactive bacteria, fungi and yeasts were 100 ppm and 250 ppm, respectively. In the comparable electron micrograph of microbial cells treated with GFSE or not, we could conclude that GFSE destroy microorganisms by disrupting the functions of the cell wall membrane and microbial spores.

• Korean Journal of Food Science and Technology
• /
• v.24 no.1
• /
• pp.29-30
• /
• 1992

Three microorganisms were isolated from staled market soybean curd and confirmed their reproducibility of putrefaction. The isolates were identified as Acinetobacter calcoaceticus var. anitrat(97.9%) and Klebsiella pneumoniae subgroup pneumoniae(99.0%). The third microorganism has same characteristics as A. calcoaceticus var. anitrat except mucoid production.

• Korean Journal of Food Science and Technology
• /
• v.10 no.2
• /
• pp.224-230
• /
• 1978

Heat resistant putrefactive microorganisms causing spoilage of canned and processed foods were surveyed in the compost on mushroom growing bed, casing soil, raw mushrooms and canned products before sterilization at canneries located at 8 places including Buyo in Chung-Cheung-Do and monitored the total count and spore formers from the sample taken. The 9 strains of most severe heat resistant among the selected 140 spore formers were selected and determined D and Z value by TDT method. The most strong heat resistant strain was No. F-10, facultative thermophile, which was isolated from raw mushroom in Buyo area and it's Z value was $21.1^{\circ}F$ (M/15 phosphate buffer solution) and $D^{250}$ was 6.6 min.

• Culinary science and hospitality research
• /
• v.22 no.3
• /
• pp.198-211
• /
• 2016

The objective of this study was to provide basic data that would help develop the natural preservatives that could replace them. This study examined antibacterial activity and preservative effects in soybean curd. When the concentration of Persicaria hydropiper L. was 1,000 ppm in the antibacterial activity by the paper disk law of three cultures(Bacillus subtilis KY-3, Bacillus sp. KY-7, Bacillus methylotrophicus KY-11) selected from 21 kinds of microorganism separated from tofu anaerobes, the clear zone (mm), which was similar to benzoic acid 0.1 M, the comparison group, was measured. The results were as follows. The result of impeding growth in liquid culture indicated considerable suppression of the growth of bacteria in the concentration of 800 ppm and 1,000 ppm respectively. In the measure of MIC, KY-3 and KY-7 were 0.06%, and KY-11 was 0.05%. For the changes in pH by concentration, three cultures and tofu anaerobes were not increased to $10^{5-6}/g$ in 1,000 ppm. In addition, in the search of total number was employed to find the preservative effects of tofu. Therefore, this study expect the Persicaria hydroper L. extract on preservative effects of tofu, which can be easily exposed to food poisoning bacteria in the food safety as well as improving the possibility of natural alternative preservatives.