• Korean Journal of Medicinal Crop Science
• /
• v.19 no.1
• /
• pp.47-53
• /
• 2011

HACCP methodology was applied in the post-harvest processing and storage of domestic medicinal produces. Particularly in terms of mold and mycotoxin contamination, candidate critical control points (CCP) in the conventional practice in Korean farms were selected and monitored by comparing with on the standard guided processing and storage. When each processing of Angelicae Gigantis Radix were assessed for their safety, the drying steps such as the sun drying or the thermal drying depending on each farm made differences in mold contamination. Moreover, the storage conditions before or after the processing were another critical determinant in the fungal contamination. In other words, storage under $4{\circ}C$ rather than at room temperature was favorable for reducing mold growth in the harvested crops. Occurrence rate of Aflatoxin $B_1 \;(AFB_1)$ in Angelicae Gigantis Radix were 12.8%, but amount of $AFB_1$ in all the collected samples were below 10 ppb regulatory limit allowed in Korea. However, for a few samples of Angelicae Gigantis Radix, still relatively high levels of total amount of the major aflatoxins (aflatoxin $B_1\; +\; B_2\; +\; G_1\; +\; G_2$) were observed around 0.18~49.94 ppb, which is not regulated presently in Korea. It thus can be suggested that post-harvest processing and storage of Korean medicinal crops need further investigation and monitoring to establish the Good Agricultural Practice (GAP), particularly to minimize microbial risk including mold and mycotoxin contamination under the changing climate. Additionally, it is also warranted for new enacting of regulatory limits for total aflatoxins in the medicinal crops.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.34 no.4
• /
• pp.567-571
• /
• 2005

In this study, the effects of varying the amount of water, soaking time at $25^{\circ}C$ and drying time after soaking at $45^{\circ}C$ on the induction of resveratrol were evaluated to optimize the soaking treatment by response surface methodology (RSM). After response surface regression (RSREG), the second-order polynomial equation was fitted to the experimental data. The analysis of variance showed that the model appeared to be adequate $(R^2=0.9547)$ with no significant lack of fit (p>0.1). From statistical analysis, amount of water and soaking time were found to be significant factors. On the other hand, drying time was not significant. Ridge analysis showed that the optimized parameters were $67.15\%$ for amount of water, 19.58 hr for soaking time, 65.56 hr for drying time. It was confirmed that resveratrol content was increased from $0.1\;{\mu}g/g$ to $4.55\;{\mu}g/g$ under the optimized conditions. In addition, the experimental values at the optimized condition agreed with values predicted by ridge analysis. The analytical method validation parameters such as accuracy, precision, and specificity were calculated to ensure the method's validity.

• Polymer(Korea)
• /
• v.35 no.1
• /
• pp.66-71
• /
• 2011

With the synthesis of hyper crosslinked polymer particle (HCPP), having microporous structure with hydroxyl functional group, synthesized via polymerization reaction consists of three stepssuspension polymerization, hyper crosslinking by Friedel-Craft catalysis and hydrolysis reaction, the effects of the ratio of each monomer, hyper crosslinking conditions and $CO_2$ supercritical drying on the variations of surface morphology, pore size & distribution and BET surface area of HCPP have been investigated. It was observed that the formation of surface crack or fracture of HCPP was intimately related with the degree of hyper crosslinking reaction between microphase separated domains. And the value of BET surface area of HCPP increased with the increase of reaction temperature, time and the amounts of solvent used in hyper crosslinking step. Moreover, $CO_2$ supercritical drying was proven to be a very effective method for removing stabilizer, unreacted monomers and oligomers from HCPP but needed to add methanol as a co-solvent for efficient removing of residual catalyst.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.12 no.2
• /
• pp.70-80
• /
• 2000

Princeton Ocean Model (POM) is modified to construct a three-dimensional, semi-implicit hydro¬dynamic model with a wetting-and-drying scheme. The model employs semi-implicit treatment of the barotropic pressure gradient terms and the vertical mixing terms in the momentum equations, and the velocity divergence term in the vertically-integrated continuity equation. Such treatment removes the external mode and thus the mode splitting scheme in POM, allowing the semi-implicit model to use a larger time step. Applied to hypothetical systems, both the semi-implicit model and POM give nearly the same results. The semi-implicit model, however, runs approximately 4.4 times faster than POM showing its improved computational efficiency. Applied to a hypothetical system with intertidal flats, POM employing the mode splitting scheme produces noises at the intertidal flats, that propagate into the main channel resulting in unstable current velocities. Despite its larger time step, the semi-implicit model gives stable current velocities both at the intertidal flats and main channel. The semi-implicit model when applied to Kyeonggi Bay gives a good reproduction of the observed tides and tidal currents throughout the modeling domain, demonstrating its prototype applicability.

• Journal of the Korean Recycled Construction Resources Institute
• /
• v.6 no.4
• /
• pp.331-335
• /
• 2018

The purpose of this study is to investigate the feasibility of CFBC artificial fine aggregate as a substitute for natural aggregate used in dry mortar. The basic performance of the flow, compressive strength and dry shrinkage of the dry mortar was evaluated. Four types of test dry mortar specimens using natural aggregate without expansion admixture, a specimen with modified CaO expansion admixture and natural aggregate, a specimen with modified CaO expansion admixture and CFBC artificial fine aggregate, and a specimen using CFBC artificial fine aggregate without modified CaO expansion admixture were evaluated respectively. As a result of evaluation of drying shrinkage performance at 20th day of age, the dry shrinkage performance of the specimen using modified CaO expansion admixture was found to be the highest at $250{\times}10^{-6}$. On the other hand, the specimen containing the modified CaO expansion admixture with CFBC artificial aggregate exhibited a shrinkage of $410{\times}10^{-6}$, and the drying shrinkage of specimen using natural fine aggregate without expansion admixture was $450{\times}10^{-6}$. When the modified CaO expansion material was used, and exhibited performance equal to or higher than that of the shrinkage-drying property.

• Food Science of Animal Resources
• /
• v.38 no.6
• /
• pp.1131-1143
• /
• 2018

This study aimed to investigate the drying yield, meat quality, oxidation stability and sensory properties of Hanwoo beef loin subjected to different dry-aging conditions. A total of 54 Hanwoo beef loins (bone-in, $6^{th}-13^{th}$ ribs) with fat cover at 2 d postmortem were assigned to four groups and hung in a dry-aging room at a controlled temperature ($2^{\circ}C-4^{\circ}C$), humidity (65%-85%) and air velocity (3 m/s). Four treatment conditions were tested; the respective temperature, humidity and treatment duration are as follows: T1, $2^{\circ}C$, 85%, 60 d; T2, $2^{\circ}C$, 65%, $20d+2^{\circ}C$, 75%, $20d+4^{\circ}C$, 85%, 20 d; T3, $2^{\circ}C$, 75%, $20d+4^{\circ}C$, 85%, 40 d; T4, $4^{\circ}C$, 85%, 60 d. The drying yield, total aerobic counts and fat contents increased, whereas the moisture content, meat color (CIE $L^*$, $a^*$, and $b^*$), and Warner-Bratzler shear force values decreased significantly during the aging period for all treatments (p<0.05). The cooking loss (%) did not change significantly until 40 d, and it was significantly higher in T1 and T4 than in T2 and T3 at 60 d (p<0.05). The water-holding capacity, pH and lipid oxidation [thiobarbituric acid reactive substance (TBARS) values] increased during aging (p<0.05). The sensory scores for tenderness, juiciness, flavor, and overall acceptability of dry-aged loin muscles increased as the aging period increased. T2 and T3 had significantly higher sensory scores and T1 had significantly lower scores for tenderness, juiciness, flavor, and overall acceptability at 20, 40, and 60 d for loin muscles (p<0.05).

• Journal of the Korean Electrochemical Society
• /
• v.27 no.3
• /
• pp.97-104
• /
• 2024

The electrodes of commercialized lithium secondary batteries are manufactured through a wet coating process, and the drying process (DC) is a very important factor as to electrode production speed and process cost. In this study, silicon anodes were manufactured under high-temperature (180 ℃) and low-temperature (50 ℃) DC to investigate the quality and the electrochemical performance of Si-electrodes according to DC. High-temperature DC can quickly evaporate the solvent in the Si-electrode slurry, improving the electrode production rate. However, this also causes the electrode composite to peel off from the current collector. As a result, the Si-electrode's adhesion weakened, and the electrode coating's quality deteriorated. In addition, the Si-electrode manufactured under high-temperature was found to have a thicker composite material than the Si-electrode manufactured under low-temperature. Si-electrodes manufactured under high-temperature had higher sheet resistance and lower electrical conductivity than those manufactured under low-temperature. Consequently, the Si-electrode manufactured under low-temperature showed 152.5% superior cycle performance compared to the Si-electrode manufactured under high-temperature. (Discharge capacities of Si-electrodes manufactured under high-temperature and low-temperature DC were 844 and 1287 mAh g^-1, respectively, after 300 cycles). Establishing the DC of Si-electrodes can easily provide new perspectives to improve the quality and stability of Si-electrodes.

• Korean Journal of Food Science and Technology
• /
• v.12 no.2
• /
• pp.82-87
• /
• 1980

The red color bleaching phenomena of red pepper powder by the exposure to sun light were studied on the various factors such as drying methods of pepper and the storage conditions of pepper powder, relative humidities, particle sizes, and the amounts and qualities of light. The surface color of red pepper was rapidly bleached by the successive daily exposures until the color retention value (capsanthin remained/original capsanthin content) reached to 0.5, while that of dark storge showed a negligible change. The color changes were related with the cumulative solar energy at various water activities $(a_w)$. As decreasing $a_w$ below 0.5, the bleaching reaction was highly accelerated, and thereafter was slowly progressed. Sun lights transmitted by red-, yellow- and blue-gelatin filters, respectivly, bleached in different degrees and at the shorter wavelength light, the more color bleaching occurred. From this fact a red colored package film could be effectivly used for the color preservation purpose in the red pepper storage.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.30 no.1
• /
• pp.72-78
• /
• 1997

The levels of reducing sugars, organic acids and fatty acids, known as precursors of major flavors induced from dried sellfish, were analyzed to investigate their behaviors during drying process. Free reducing sugar contents were markedly decreased in all samples by boiling, Its content in Blue mussel and Short-necked calm samples significantly decreased after drying process. Among the eight different organic acids from blue mussel, Short-necked calm and Pacific oyster samples, succinic acid in blue mussel and short-necked calm samples was measured with $74.9\%\;and\;67.4\%$, respectively. In the sample of Pacific oyster, succinic acid content was found to be $38.4\%$, but pyroglutamic acid content was the highest level with $41.6\%$. Contents of organic acids with exception succinic acid were significantly reduced in all three samples of sun-dried or hot-air dried. The content of succinic acid in the samples of sun-dried and hot-air dried pacific oyster reduced to $53.0\%\;and\;44.2\%$, respectively, but relatively small decrease $(29.0\%\;and\;10.0\%)$ was observed in sun-dried and hot-air dried short-necked calm samples, respectively. Content of polar lipid with the major fatty acids profile of C16:0, C16:1, C20:5 and C22:6 was consisted of $59.1\%,\;66.7\%\;and\;42.4\%$, respectively, in blue mussel, short-necked calm and pacific oyster samples and the content of polyene fatty acids was appeared to be $40.5\%,\;48.6\%\;and\;48.9\%$, respectively. Relatively high peroxide value in all boiled-dried products samples was found to be $41.64\~86.80\;meq/kg$ sample. Carbonyl value in boiled-dried products samples was found to be $15.55\~27.99\;meq/kg$, but its value in broiled products samples was significantly high level of $127.6\~136.5\;meq/kg$.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.17 no.2
• /
• pp.101-108
• /
• 1984

In order to study the optimal conditions of processing and storage for boiled and dried anchovy (Engraulis japonica) with high protein digestibility, the contents of trypsin indigestible substrate (TI) and in vitro apparent protein digestibility were determined. Peroxide value (PoV), TBA number and nonenzymatic brown pigments, that accounted for important antinutritional factors, were also measured and confirmed the relationship between those factors and formation of TI or in vitro protein apparent digestibility. The results were as follows; Samples boiled for 5 minutes showed the lower content of TI than the other samples boiled for 0.5 min. or 1 min. Hot air dried products had a lower TI content in comparison with the other dried ones such as sun dried or freeze dried products. It was revealed that the lower temperature ($8{\pm}1^{\circ}C$) did not affect to a great degree of forming TI and falling in vitro digestibility comparing to high temperature ($26{\pm}1^{\circ}C$) during storage. The lowest TI content (0.173 mg/g solid) was noted in the samples for 5 minutes and then sun drying after 56 days storage at $9{\pm}1^{\circ}C$. A rapid decrease of in vitro protein digestibility occurred within 0.5 min. of boiling and showed the value $85.3\%$. Freeze dried samples possessed the highest in vitro protein digestibility ($85.9\%$), when compared to sun dried or hot air dried products. Fat oxidation and nonenzymatic browning were proceeded with the various boiling times, drying methods and storing temperatures. It was noted that boiling for 5 minutes and freeze drying accelerate the fat oxidation significantly. More nonenzymatic brown pigments was developed in samples boiled for shorter time (0.5 min.) and that stored at high temperature ($26{\pm}1^{\circ}C$) than the other products. Therefore, fat oxidation and nonenzymatic browning assumed to be a major inhibitory reaction in enzyme digestion and those might be an important role in forming TI in boiled and dried anchovy products during processing and storage.