• Asian-Australasian Journal of Animal Sciences
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• v.17 no.12
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• pp.1712-1716
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• 2004

Copper-bearing montmorillonite (Cu-MMT) was produced by $Cu^{2+}$ cation exchange reaction. X-ray diffraction analysis showed that that the (001) basal spacing of the MMT crystal lattice increased from 1.544 to 1.588 nm after $Cu^{2+}$ exchange. This indicated that $Cu^{2+}$ entered into interlayer position of MMT as a hydrated cation or composite cation. In vitro results indicated that Cu-MMT had antibacterial activity on Escherichia coli $K_{88}$. Cu-MMT had unbalanced positive charge after cation exchange. Its antibacterial activity resulted from two aspects, one was electrostatic attraction which made E. coli $K_{88}$ being adhered on the montmorillonite surface, the other was the $Cu^{2+}$ slowly released, which could kill bacteria. In an in vivo study, four replicates of eight weanling pigs were assigned to each of two dietary treatments to study the effects of Cu-MMT on diarrhea, E. coli in the lumen of the jejunum and morphology of jejunal mucosa. As compared to the control, supplementation of the diet with 0.2% Cu-MMT improved average daily gain by 12.50% (p<0.05) and decreased F/G by 9.42% (p<0.05). The mean diarrhrea incidence was decreased by 71.80% (p<0.05). The viable counts of Escherichia coli in jejunal contents were significantly reduced (p<0.05). Villus height and the villus height to crypt depth ratio at the jejunal mucosa were increased by 19.09% (p<0.05) and 37.10% (p<0.05), respectively.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.2
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• pp.289-295
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• 2009

To develop a safer yogurt for immuno-compromised or allergy patients and to extend shelf-life, a plain yogurt was irradiated with doses of 0, 1, 3, 5, and 10 kGy using a gamma ray and the chemical and microbiological quality and allergenicity change were investigated. There was no difference in the content of protein, total solid, and amino acids of the plain yogurt by irradiation treatment and different storage temperatures (4, 20, and $35^{\circ}C$). The lactic acid bacterial counts of irradiated plain yogurt had approximately 3-decimal reduction at 3 kGy, and no viable cell at 10 kGy regardless of storage time and temperature. The binding ability of rabbit antiserum to milk proteins in irradiated plain yogurt showed that 10 kGy of irradiation produced significantly higher binding ability than other treatments. Sensory evaluation indicated that only appearance of the plain yogurt irradiated at 3 kGy or higher had a lower value than the non-irradiated control when stored at $20^{\circ}C$. Results suggest that irradiation of plain yogurt does not significantly affect the chemical and sensory quality of plain yogurt, but can extend the shelf-life, possibly reduce allergenicity, and provide a safer product.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.5
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• pp.533-540
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• 2016

This study assessed the risk of an oyster-shucking site to establish the hazard analysis critical control point (HACCP) system model by measuring viable cell counts, coliform group Staphylococcus aureus foreign material on oysters, oyster-producing equipment, and washing water. The viable cell count and coliform group levels of the harvested raw oysters were 4.00 log CFU/g and 1.1×10² MPN/100 g, while those of washed oysters were 2.99 log CFU/g and (3.2−4.6) × 10 MPN/100 g, respectively. After washing the oysters, no Escherichia coli or pathogenic bacteria (E. coli O157:H7, Listeria monocytogenes, S. aureus, Salmonella spp., Vibrio parahaemolyticus, and Clostridium perfringens) were detected. Regardless of the location of foreign matter, up to 100% more metallic and non-metallic foreign matter was detected at 1.5 mmΦ than at 3.5 mmΦ, using a metal detector with increased sensitivity. According to the results, the critical control points (CCP) are the washing and metal-detection processes. These results can be used as basic data to improve sanitation at oyster-shucking sites in factories with an HACCP system.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.51 no.1
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• pp.8-14
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• 2018

We investigated the levels of microbial contaminants and microbial hazards during dried-laver processing. We analyzed 321 samples obtained from 18 dried-laver Pyropia spp. manufacturing facilities, including water, swab-, and processing samples as well as final products. The levels of microbial contaminants, including viable cell counts (VCC) and coliform bacteria, increased as processing progressed. The sanitary indicator bacterium, Escherichia coli, was not detected in the final products although VCC levels were high, generally exceeding 5 log CFU/g. We also investigated changes in microbial contaminants at each processing step. Both VCC and total coliform dramatically increased after 4 days of continuous processing, indicating that microbial contaminants originated, mainly, from cross contamination during processing.

• Korean Journal of Food Science and Technology
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• v.40 no.6
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• pp.643-648
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• 2008

The principal objective of this study was to evaluate the effects of the addition of sourdough to bread dough, specifically with regard to the physicochemical characteristics of bread dough, organoleptic evaluation, and bread storage. Marked increases in lactic acid bacterial counts $10^{9-10}CFU/g$ in dough samples with 30, 50, and 100% of added sourdough to the respective bread dough were observed after the first fermentation period of the dough, but decreases were observed in yeast cells. The highest overall acceptance scores were recorded for the 100% sourdough-added bread, and almost no differences in taste and texture were detected between the regular bread (control bread) and sourdough-added bread on the sensory evaluations, with slightly lower evaluation scores (for sour taste) in the sourdough-added bread. The sourdoughadded bread also showed retarded mold growth in the bread on our storage tests. Six days had elapsed prior to the appearance of mold growth in the sourdough-added bread, whereas three days elapsed in the regular bread. The more sourdough was added to the dough, the less was the total count in bread. Increases of 13.1, 20.9, and 36.2% in the retardation of starch retrogradation of the bread were observed as the result of additional increases in sourdough quantity to bread at 30, 50, and 100%, respectively.

• Korean Journal of Food Science and Technology
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• v.35 no.6
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• pp.1110-1116
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• 2003

The effects of packaging methods on the storage quality of minimally processed (prepeeled) onions were investigated to determine the optimal packing design. Various packaging treatments used for modifying headspace atmospheres included two passive MAP using LDPE and PP films, two active MAP using a gas mixture of 20% $O_2/10%\;CO_2/balance\;N_2$ and an ethylene scavenging sachet, and moderate vacuum packaging (MVP). The quality attributes of onion samples were evaluated periodically in terms of flesh weight loss, color of cut surface, decay ratio, microbial counts, and sensory properties during storage at $10^{\circ}C$ for 28 days. Packaging methods did not significantly influence surface color, weight loss, and microbiological populations of mesophiles, psychrotrophs, and lactic acid bacteria. They did, however, affect sensory characteristics as well as decay occurrence. Results indicated that seal-packaging with a gas-permeable plastic film under a mild vacuum condition could retain better onion quality in terms of microbial decay and visual sensory aspects as compared with the other packages.

• Korean journal of food and cookery science
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• v.14 no.4
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• pp.367-374
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• 1998

The purpose of this study was to evaluate the microbiological quality of, and to assure the hygienic safety of, the kimbap production in the university foodservice facilities in accordance with the HACCP (Hazard Analysis Critical Control Point) Program. The time-temperature relationship and the microbiological quality (specifically, total plate count and coliform bacteria count) were assessed to find the critical control point (CCP) during each of the production phases. The average of the daily longest duration time of the kimbap at the facilities was 23.4 hours in summer, while 29.6 hours in winter. In the purchasing phase of the raw materials, the microbiological quality of laver, fish paste, carrot and cucumber in summer was not at an acceptable level according to the standard set by the Natick research center, especially the number of TPC and the coliform level of laver was higher than the threshold level. In the refrigerator storage phase, the temperature of the carrot was 7.4$^{\circ}C$. This temperature is far exceeding the standard so that the microbiological counts was increased by the 2 log cycle during the average storage time of 17 hours or more. In the preparation phase, the temperature of the blanching is too low compared to the standard. In the holding phase before serving, its time-temperature relationship was out of the FDA food code standard both in winter and summer. In the sewing phase, the number of microbiological count was higher than the threshold level in summer while that in winter was up to standard. According to the Harrigan and McCance standard, the number of microbiological count of the utensils was higher than the threshold level in summer while that in winter was up to standard.

• The Korean Journal of Food And Nutrition
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• v.33 no.5
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• pp.524-531
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• 2020

The purpose of this study was to evaluate the quality properties of Meju prepared by inoculating two strains of Bacillus amyloliquefaciens HJ5-2, and Aspergillus oryzae PS03. The three soybean varieties that include Daewonkong, Daechan, and Saedanbaek were used in this experiment. The fermentation temperature during the Meju aging varied at 20℃, 30℃, and 40℃, respectively. The physicochemical analysis of the soybeans, showed that the cured protein and fat contents were 34.83~43.49% and 12.91~18.90%, respectively. The pH and total acidity were 6.47~6.93 and 0.11~1.22%, respectively. The change in appearance of the Meju was that the yellow-green mold was well formed on seven days at fermentation temperature of 20℃ and 30℃, but at 40℃, there was minimal mold formation and cracking of the surface. The amino nitrogen content was highest on the Daechan Meju at 621.83 mg% for seven days. The amylase increased as the fermentation period increased in all samples, and the protease increased rapidly until the first day of the fermentation, and then gradually increased thereafter. The total number of bacteria increased or decreased as the fermentation proceeded to 6.66~10.07 log CFU/g. The mold counts increased with increasing fermentation period in the range of 6.38~8.79 log CFU/g.

• Food Science of Animal Resources
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• v.33 no.3
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• pp.363-368
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• 2013

The main attributes of yogurt that affect consumer satisfaction are taste, consistency, and a firm texture. This study evaluates the influence of xanthan gum, barley beta-glucan, and guar gum in concentrations of 0.05%, 0.1%, 0.2%, and 0.3% on probiotic yogurt. The set-type yogurt samples were prepared by using raw cow's milk. The statistical analysis showed that none of these gum additions had any marked effect on pH, titratable acidity, total solids content, and probiotic bacteria counts of yogurt samples. Evaluations for syneresis and water-holding capacity (WHC) in the yogurt samples were affected by the type and concentration of the stabilizer. Yogurts treated with 0.1% xanthan gum and 0.3% beta-glucan recorded the highest WHC and the least syneresis. The largest amount of gel firmness was recorded in yogurt samples treated with 0.2% xanthan gum and 0.3% beta-glucan. Yogurt samples treated with 0.1% xanthan gum and 0.3% beta-glucan were considered acceptable by trained panelists and gained the highest scores in sensory evaluations. The correlation coefficient between the amount of syneresis, WHC and stiffness of texture was significant compared to scores for sensory evaluation (p<0.01). Results for effects of guar gum on the tested parameters were contrary to the results expected from a gum. According to this study, the use of xanthan gum and beta-glucan are highly recommended for low-fat yogurt production.

• Food Science of Animal Resources
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• v.38 no.3
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• pp.451-467
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• 2018

Hot pepper has anti-obesity effects by controlling appetite and reducing blood fat level. To reduce the pungency of capsaicin, red or green hot pepper juice was fermented with Bacillus licheniformis SK1230. Fermented hot pepper juice was then added into yogurt at different ratios. The pH of yogurt added with hot pepper juice was decreased from 4.61 to 4.48. Titratable acidity and counts of lactic acid bacteria were increased with increasing amount of pepper juice added. However, the viscosity was decreased significantly compared to the control. On chromaticity test, when more pepper juice was added, $L^*-value$ was decreased whereas $a^*$- and $b^*$- values were increased significantly (p<0.05). The spectrum of antimicrobial activity of yogurt was slightly changed compared to using pepper juice. Total polyphenol contents and antioxidant activity were increased with increasing amount of pepper juice added. Stirred yogurt added with fermented red pepper juice at 3% or green pepper juice at 1% showed high scores in flavor, appearance, texture, and overall acceptance in sensory test. Yogurt added with fermented pepper juice with reduced pungency showed also good palatability during storage at $4^{\circ}C$. Yogurt with added hot pepper juice can be play an important role in functional food relative to anti-obesity.