• Food Science and Preservation
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• v.21 no.5
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• pp.652-660
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• 2014

To maintain the microbiological safety of Prunus mume fruit before it is processed, it was treated with a combination of 0.5% citric acid and 0.1% Tween 20, and stored at $4{\pm}1^{\circ}C$ for seven days. The combined treatment reduced total aerobic bacteria, yeast, and mold populations in the fruit by 2.20 and 1.70 log CFU/g, respectively, compared to those in the control. Organic acid contents and the Hunter $L^*$, $a^*$, and $b^*$ values were not affected by the treatment during the storage. In addition, the dried Prunus mume fruit prepared with 40% red algae extract (RAE) or maltodextrin (MD) treatment and hot-air drying were compared with respect to the fruit's physicochemical properties such as color, total phenolic and flavonoid content, and microstructure. The hot-air dried samples had undesirable color changes and inferior textures. The RAE-treated samples had a higher total phenolic content (225.15 mg gallic acid equivalent (GAE)/100 g) and total flavonoid content (49.25 mg quercetin equivalent (QE)/100 g) than the other treatments. The treatment of Prunus mume fruit with RAE can provide better-dried products than can MD treatment or hot-air drying. These results suggest that the combined treatment with citric acid and Tween 20 can be effective in preserving the microbiological safety of Prunus mume fruit, and its dehydration using RAE is an efficient drying method.

• Journal of Powder Materials
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• v.13 no.3 s.56
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• pp.192-198
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• 2006

The nanostructured cerium oxide powders were synthesized by spray thermal decomposition process for the use as the raw materials of resistive oxygen sensor. The synthesis routes consisted of 1) spray drying of water based organic solution made from cerium nitrate hydrate ($Ce(NO_3){_3}6H_2O$) and 2) heat treatment of spray dried precursor powders at $400^{\circ}C$ in air atmosphere to remove the volatile components and identically to oxidize the cerium component. The produced powders have shown the loose structure agglomerated with extremely fine cerium oxide particles with about 15 nm and very high specific surface area ($110m^2/g$). The oxygen sensitivity, n ($Log{\propto}Log (P_{O2}/P^o)^{-n}$ and the response time, $t_{90}$ measured at $600^{\circ}C$ in the sample sintered at $1000^{\circ}C$, were about 0.25 and 3 seconds, respectively, which had much higher performances than those known in micron or $100{\sim}200nm$ sized sensors.

• Journal of Food Hygiene and Safety
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• v.30 no.3
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• pp.242-248
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• 2015

This study was performed to investigate the microbiological contamination on toothbrushes, toothbrush caps, and tooth cleaning cups in the child care centers and to evaluate the toxin genes, toxin production ability and antibiotic resistance of food-borne pathogens. The average number of total aerobic bacteria and fungi were 5.3 log CFU and 3.2 log CFU. Coliform bacteria were detected in 41 (54.7%) of 75 toothbrushes, 13 (44.8%) of 29 toothbrush caps, and 29 (44.6%) of 65 tooth cleaning cups. Salmonella spp. was not detected in all of samples but Bacillus cereus was isolated from 1 (1.3%) of 75 toothbrushes and 2 (3.1%) of 65 tooth cleaning cups. Staphylococcus aureus was detected in 1 (1.5%) of 65 tooth cleaning cups. The nheA, nheB, nheC, hblC, hblD, hblA and entFM toxin genes were possessed in B. cereus isolated from toothbrush which also produce NHE and HBL enterotoxins. S. aureus was resistant to ampicillin and penicillin, while B. cereus was resistant to ${\beta}-lactam$ antibiotics. These results indicated that the sanitary conditions of toothbrushes and tooth cleaning cups in the child care centers should be improved promptly. The UV sterilization after drying and then storage in dried condition is required to improve the sanitary condition of toothbrushes and tooth cleaning cups in the child care center.

• Journal of the Korean Wood Science and Technology
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• v.15 no.2
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• pp.67-78
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• 1987

This study was designed to investigate the effect of board thickness and ring angle on the characteristics including internal check. ring failure, surface check, end check, collapse, thickness shrinkage and width shrinkage of press-drying. The exprimental materials of 6mm-. 9mm- and 12mm-thick board were taken from heartwood and sapwood of oak (Quercus acutissima Carr.) respectively. And boards were numbered according to position in the log(No. 1 to No. 4 for heartwood :md No. 9 for sapwood). Press-drying was at $145^{\circ}C$ platen temperature and 3.5kg/$Cm^2$ platen pressure. The results of this study were summarized as follows. 1. Drying rates for sapwood materials were greater than those for heartwood materials. And drying rates for thinner materials were greater than those for thicker materials. 2. The thinner boards were. the severer surface checking developed in the heartwood materials, and surface checking for heartwood materials had no tendency in board position for the same thickness. Sapwood materials were completely free from surface checking. 3. End checking for heartwood materials had no tendency in board position. The greater deviation of ring angle from perfectly edge-grained was, the severer and checking developed in the sapwood materials. But end checking did not occur in 6mm-thick sapwood materials. 4. The greater deviation of ring angle from perfectly edge-grained was, the severer end checking developed for heartwood and sapwood materials. As board thickness increased, maternal checking developed more severely for heartwood and sapweed materials. 5. For heartwood materials, ring failure, reduced with increasing deviation of ring angle from perfectly edge-grained except 12mm-thick material and showed no significant difference attributable to board thickness. Sapwood materials were completely free from ring failure. 6. For heartwood and sapwood materials, collapse was slight and showed no significant differences attributable to both board thickness and board position. 7. As deviation of ring angle from perfectly edge-grained increased, shrinkage of board thickness decreased for heartwood and sapwood materials. 8. Shrinkage of board width showed no significant differences attributable to both board thickness and board position for heartwood and sapweed materials.

• Journal of the Korean Wood Science and Technology
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• v.43 no.1
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• pp.52-59
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• 2015

Cross-cut disks from small diameter oak logs were thermally modified and developed to make accessories such as a brooch. However it is known that domestic oaks are refractory and it is hard to dry their cross-cut disks without any drying defects. The cross-cut disks of Quercus variabilis (7 mm long in the longitudinal direction) were forced to dry in air at two different air velocities in summer and fall season, and their drying yields were investigated. Under the same condition, the average final moisture contents (MCs) of the specimens dried in the fall were lower than those dried in the summer. The average final MCs of the small diameter specimens dried at higher air velocity were slightly lower than those at lower air velocity while those of the large diameter specimen were not influenced by the air velocity. The number of the large diameter specimens with cross checkings was higher than that of the small diameter specimen. This discrepancy between two different diameters was twice in the fall, while it was more than four times in the summer. The large diameter specimens dried at low air velocity in Summer were cross-checked most, which was attributed to repeated water condensation and evaporation due to high humidity and low air velocity.

• Food Science of Animal Resources
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• v.29 no.4
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• pp.437-444
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• 2009

${\gamma}-Aminobutyric$ acid (GABA) producing lactic acid bacteria, Lactobacillus acidophilus RMK567 was cultivated in 50 L of sterilized MRS broth using a fermenter at $40^{\circ}C$ for 24 h. The cell number was increased to $10.04{\pm}0.13$ Log CFU/mL with a growth rate constant (k) of 0.454 generation/h and a generation time (g) of 2.303 h after a lapse of a lag phase (L) of 5.16 h. A total of 487 g of cell paste with 40.5% moisture was harvested with viable cell number of 12.48 Log CFU/g cell paste. The cell pastes after preparation with glycerol, glucose, and polydextrose as cryo-protectants were lyophilized under a vacuum of 84 m torr. A total of 408 g of freeze dried (FD) cell powders were mixed with a commercial strain of Streptococcus thermophilus to prepare of three types FD starter cultures with the viable cell numbers of 12.42 (FDA-GY), 12.60 (FDBGG) and 12.91 (FDC-GP) Log CFU/g. During preservation the FD cultures at -$18^{\circ}C$, the cell viability of the FD starter cultures were rapidly dropped to below 3.24% of the day of storage. No significant difference was found in the cell viabilities among three types of FD starters cultures, but significant difference (p<0.01) was found in storage periods. Yoghurts fermented through FD starter culture of L. acidophilus RMK567 were determined to contain $155.16{\pm}8.53$ ppm, $243.82{\pm}4.27$ ppm, and $198.64{\pm}23.46$ ppm of GABA, respectively. This study shows that GABA production activity of L. acidophilus RMK567 is not affected during the freeze drying process and would be available for commercial production of yoghurt containing high GABA content.

• Journal of Food Hygiene and Safety
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• v.26 no.4
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• pp.410-416
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• 2011

Cereals are the main raw material for sunsik manufacture. As the fundamental processing step, it is very important to confirm the level of the microorganism contamination in the cereals. This study was carried out a micrbiological screening of cereal samples for sunsik from 19 companies located in South Korea. Ten kinds of cereals which were glutinous rice, barley, brownrice, blackbean, blackrice, blacksesame, sorghum, millet, perilla seed, and adlay were investigated. As the results, the contaminations of general bacterial were 3.1~8.6 log(CFU/g). The results of Escherichia coli were 1.0~3.4 log(CFU/g). There was no contamination of Salmonella. spp in any cereal samples except black sesame and mold was detected in barley. The experiment for microbiological contamination during sunsik processing was also investigated in this study. The results of general bacteria were detected as 5.1~8.5, 4.4~7.5, 1.0~2.3, 2.4~4.2, 1.0~4.0, 3.4~4.2, 4.3~5.2, and 3.3~5.5 log(CFU/g) during environment of warehousing, washing, steaming, 1st cooling, drying, 2nd cooling, grinding, and packaging process, respectively. The results of coliform were 1.0~2.0 log(CFU/g) during warehousing respectively. Mold was found in warehousing. In case of the instruments, the contaminations of general bacterial were 4.2~7.5, 0.1~2.0, 0.1~3.2, 3.7~4.0, 2.5~3.0, and 3.8~5.2 log(CFU/g) in cereals tanks, washing machines, grinding machines, packaging machines, and workrooms. The results of coliform were 2.4~4.0, 0.0~4.1 log(CFU/g) in cereals tanks and grinding machines, respectively. Mold were only found in cereals tanks, grinding machines, and workings. Therefore, the risk of hazard microorganisms contmination might be decrased as the exhaustive management is applied to the whole sunsik process.

• Korean Journal of Food Science and Technology
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• v.10 no.4
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• pp.398-403
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• 1978

Squid was dried on the fluidized-bed in the drying chamber filled with solid particles which were also fluidized with hot-air, and effects of the fluidized particles, the squid's height from the grid and the drying temperature on the drying rate and quality of the squid were observed The mechanism of moisture transfer during the falling rate period was also derived. 1. Sodium chloride was found to be the most suitable fluidized particles and at an air velocity of 3.8 m/sec, optimal fluidization state of this particle was obtained. 2. Uniform profiles of temperature were obtained at a point 4 cm above the grid and the location of squid on the fluidized-bed observed to be suitable when it was 4 cm above the grid. 3. At an air velocity of 3.8 m/sec and when the location height of the squid on the fluidized-bed was 4 cm, the optimal temperature for the drying time which is required to reduce the moisture from 80.8% to 18-22% was 8.5 hours. 4. Drying data followed the empirical equation of unsteady state diffusion $log\;(\frac{W-We}{Wc-We})=-m{\theta}$ in the region of the moisture contents measured and the drying constant (m) was calculated as $0.32hr^{-1}$. These results suggested that the migration of moisture during the falling rate period is due to a diffusion type mechanism. 5. The short constant rate period was observed in the early stage and thereafter, drying was controlled by the falling rate period, and the time ratio of the fluidized bed drying to the through circulation drying for reducing the squid's moisture contents to the same level at the same drying temperature was 1 : 1.4 6. Comparisons of fluidized-bed dried squid and sun dried squid in sale showed that there was no significant change in qualities such as external appearance and hydrogen ion concentration of dry product.

• Food Science and Preservation
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• v.22 no.2
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• pp.167-173
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• 2015

This study was conducted to evaluate effect of adding cryoprotectant agents on the growth of lactic acid bacteria during storage of powdered Kimchi. Powdered Kimchi was prepared by adding 1.5% cryoprotectant (glucose, maltose, lactose, and sucrose) and freeze-dried. For the preparation of micro-sized particle of Kimchi powder, the freeze-dried Kimchi was powered at 14,000 rpm for 2 min. The survival ratio of lactic acid bacteria in the powdered Kimchi was monitored during storage period of 4 months at -20, 0, 4, and $25^{\circ}C$ after the capsulation of the powedered Kimchi. The number of lactic acid bacteria in the powdered Kimchi capsule was the greatest stored at $-20^{\circ}C$, and the addition of glucose in cryoprotectant showed higher survival rate of lactic acid bacteria than that of control. More than $10^7CFU/g$ of lactic acid bacteria were survived in the powdered Kimchi stored at 0 and $4^{\circ}C$. However, the lactic acid bacteria were not detected in the powdered Kimchi stored at $25^{\circ}C$. As a results, the addition of cryoprotectant agents in the manufacturing process improved the survival rate of lactic acid bacteria in powered Kimchi products with accompanying with a cold-chain system for the distributon of powdered Kimchi products.

• Journal of Pharmaceutical Investigation
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• v.12 no.4
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• pp.112-125
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• 1982

Sulfamethoxazole particles were microencapsulated using the gelatin-acacia complex coacervation method. Micromeritic properties and dissolution characteristics of the microcapsules were studied. The particle size distribution followed log-normal form. As the hardening time increased, the particle size and wall thickness increased ($45.3-52.0\;{\mu}m$, $2.02-5.12\;{\mu}m$, respectively). This is considered to be due to the cross-linked wall structure of formalized microcapsules which prevents shrinking of gelatin during the dehydration and drying processes. An increase of hardening time clearly delayed the release rate. The in vitro 50% dissolution time $(t_{50})$ for unencapsulated sulfamethoxazole powder was less than 3 min.; for microcapsules hardened for 30 min, the $t_{50}$ was 20.1 min.; for those hardened for 60 min. the $t_{50}$ was 25.0 min.; for those hardened for 120 min., the $t_{50}$ was 35.8 min. The surface of the unhardened microcapsules was smooth and had no cracking or pore penetration. However, the surface of the hardened microcapsules was folded and invaginated.