• Journal of Food Hygiene and Safety
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• v.34 no.3
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• pp.296-302
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• 2019

Ganjang-gejang (soy sauce-marinated crab) is a ready-to-eat (RTE) seafood and is also one of the most popular traditional dishes in Korea. It is generally prepared by washing raw blue crabs and then preserving them in soy sauce. Since this process does not involve cooking or any treatment with heat, it is difficult to control the microbiological quality of the final product. Thus, the objectives of this study were to compare the efficacies of various sanitizers in eliminating microorganisms on raw blue crab during the washing step and to evaluate the effectiveness of chitosan on the inhibition of microbial growth in the ganjang-gejang during storage. The raw blue crabs were submerged in chlorinated water (50 mg/L), peracetic acid (40 mg/L), acetic acid (5%) and lactic acid (5%) for 10 min at $25^{\circ}C$, respectively. The blue crabs treated with 5% acetic acid were marinated with soy sauce containing 0.5 and 1% of soluble chitosan, followed by storing them at 4 and $12^{\circ}C$ for up to 30 days. Results show that 5% acetic acid reduced the microbial populations on the blue crabs by 1.5 log CFU/g, which was significantly higher than those of other treatments. Based on these results, 5% acetic acid was selected for the washing step. The microbial populations of all ganjang-gejang samples significantly increased to about 8.0 CFU/g at $12^{\circ}C$ for 7 days. At $4^{\circ}C$, the microbial populations of the products containing 1% chitosan increased by about 2.9 CFU/g for 20 days, which were significantly lower than those (4.2-4.5 log CFU/g) of the products without and with 0.5% chitosan. Thus, these results suggest that 5% acetic acid washing of raw blue crabs and the addition of 1% chitosan in ganjang-gejang could improve the microbiological quality of the final products under refrigerated condition.

• Journal of Korean Society of Forest Science
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• v.39 no.1
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• pp.57-63
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• 1978

Enzymatic hydrolysis of the substrate from Alnus hirsuta (Spach) Rupr (8-14years) was investigated using cellulase preparations of Trichoderma viride Pers. ex. Fr. SANK 16374 and conduced on the optimum reaction conditions of the cellulase on saccharification. The crude cellulase was produced by the submerged culture process and produced in the culture fluid was salted out quantitatively by the use of ammonium sulfate. The method of delignification from wood(Saw dust) was treated by the peracetic acid (PA) method. Reducing sugar was determined by the dinitrosalicylic acid (DNS) method. The results were summerized as follows; 1. The optimum pH of cellulase was 5.0 and the range of stability with respect to pH was generally from 4.0 to 6.0 2. The optimum temperature of cellulase was generally $40^{\circ}C$, but reducing sugar formation did not show significent differences at 5% levels in the reaction temperature from $40^{\circ}C$ to $50^{\circ}C$. 3. The redusing sugar were increased with increase of cellulase concentration. 4. The reducing sugar were decreased with increase of substrate concentration. 5. Fructose was a very good inhibitor of the enzyme from Trichoderma viride, but glucose inhibition was generally weak.

• Journal of Food Hygiene and Safety
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• v.24 no.4
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• pp.312-317
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• 2009

Usually, bacterial spores are hundreds or thousands of times more resistant to chemical sanitizers than are vegetable bacteria. Consequently, it is hard to assess whether a commercial sterilant, containing hydrogen peroxide and peracetic acid as ingredients, has or does not have sporicidal activity under certain conditions using the National Standard Test Method for assessing bactericidal activity against Escherichia coli and Staphylococcus aureus. Hence we established alternative the standard test method and requirements to determine whether they are effective in showing at least reduction of $10^3$ in the number of Bacillus subtilis ATCC 6633 spores under the required test condition for evaluation of sporicidal activity including verification methodology. This standardized method has proved to be suitable for evaluating effectiveness of commercial sterilants and could be used as Standardization Test Method for assessing sporicidal activity.

• Journal of the Korean Wood Science and Technology
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• v.15 no.4
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• pp.18-25
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• 1987

The cellulolytic activities of Aspergillus fumigatus KC-1 was investigated, which showed the most active producer of cellulase among the 256 strains of cellulose-decomposing microorganisms screened in our laboratory. All the examined cellulolytic activities (filter paper-, Avicel-, cotton-, CMC-, salicin- and xylansaccharifying activity) in a culture of A. fumigatus KC-1 grown on 1% popular sawdust pretreated with peroxide alkaline reached a maximum within 4-5 days. The optimum pH and temperature for the enzymatic activity was found to be pH 4.5 and $60^{\circ}C$ respectively. The sawdust of poplar wood delignified with 1% NaOH and 20% peracetic acid succesively recorded the highest hydrolysis rate in the tests of enzymatic saccharification. The major end product of hydrolysis of poplar wood with the cellulolytic enzymes obtained from A. fumigatus KC-1 was glucose with small amount of cellobiose and xylose. It can be concluded from these results that A. fumigatus KC-1 is an advantagous source of a cellulase that is capable of hydrolyzing cellulose to glucose rapidly. The influence of degree of delignification, substrate size and its concentration on the rate of hydrolysis of poplar wood was also discussed.

• Journal of Food Hygiene and Safety
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• v.38 no.4
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• pp.228-235
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• 2023

Peanut is a well-known food allergen that causes adverse reactions ranging from mild urticaria to life-threatening anaphylaxis. Consumers suffering from peanut allergies should thus avoid consuming undeclared peanuts in processed foods. Therefore, effective cleaning methods are needed to remove food allergens from manufacturing facilities. To address this, wet cleaning methods with washing water at different temperatures, abstergents (peracetic acid, sodium bicarbonate, dilute sodium hypochlorite, detergent), and cleaning tools (brush, sponge, paper towel, and cotton) were investigated to remove peanuts from materials used in food manufacture, including plastics, wood, glass, and stainless steel. Peanut butter was coated on the surface of the glass, wood, stainless steel, and plastic for 30 min and cleaned using wet cleaning. The peanut residue on the cleaned surfaces was swabbed and determined using an optimized enzyme-linked immunosorbent assay (ELISA). Cleaning using a brush and hot water above 50℃ showed an effective reduction of peanut residue from the surface. However, removing peanuts from wooden surfaces was complicated. These results provide information for selecting appropriate materials in food manufacturing facilities and cleaning methods to remove food allergens. Additionally, the cleaning methods developed in this study can be applied to further research on removing other food allergens.

• Journal of Korean Society of Forest Science
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• v.49 no.1
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• pp.1-5
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• 1980

In this study, enzymatic saccharification of substrates from Alnus hirsuta Ruper (8-14 years). Quercus acutissima Carruthers, Betula platyphylla var. japonica Nera, Populus euramericana Guiner and Platanus orientalis L. were investigated using crude cellulase preparations of Trichoderma viride Pers. ex. Fr. SANK 16374, and conduced on the optimum treated conditions of the cellulase sacchrification and reactivation of residue of digested substrates. The Trichoderma viride cellulase was produced by the submerged culture process and produced in the culture fluid was salted out quantitatively by the use of ammonium sulfate. The method of dilignification from wood (5 species) was treated by the peracetic acid(PA) method. The reducing sugar was determined by the dinitrosalicylic acid (DNS) method. 1. The results of tests carried out for 96 hr. (Figure 1), show conclusively the initial substrates from 5 species ($S_3$) which has been rendered highly reactive form and the mean rate of reducing sugar was 28.3 %. 2. The results of tests carried out for 96 hr., the reactivation of residue of digested substrates (improvement in the quality of the substrate through preheating in air at $190^{\circ}C$. for 45 min. followed by milling was (60 mesh size) at the same substrate level, increased concentrations of cellulase at the same substrate level, and increased concentrations of cellulase increases the rate of hydrolysis considerably. 3. Figure 1. shows conclusively that the residue of digested substrates ($S_1$ dried at $60^{\circ}C$) which has been rendered extremly resistant to cellulase action can be reactivated into a highly reactive form ($S_2$), almost comparable to that of the initial substrates ($S_3$). And the reducing sugar formation did not show statistically significent differences at 5% levels by initial substrates and the residue of digested substrates (preheating in air at $190^{\circ}C$. for 45 min. fallowed by milling was (60 mesh size).

• Journal of Chest Surgery
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• v.41 no.5
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• pp.550-562
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• 2008

Background: We attempted to reproduce a previously reported method that is known to be effective for decellularization, and we sought to find the optimal condition for decellularization by introducing some modifications to this method. Material and Method: Porcine semilunar valves, arterial walls and pericardium were processed for decellularization with using a variety of combinations and concentrations of decellularizing agents under different conditions of temperature, osmolarity and incubation time. The degree of decellularization and the preservation of the extracellular matrix were evaluated by staining with hematoxylin and eosin and with alpha-Gal and DAPI in some of the decellularized tissues. Result: Decellularization was achieved in the specimens that were treated with sodium deoxycholate, sodium dodesyl sulfate, Triton X-100 and sodium dodesyl sulfate with Triton X-100 as single-step methods, and this was also achieved in the specimens that were treated with hypotonic solution ${\rightarrow}$ Triton X-100 ${\rightarrow}$ sodium dodesyl sulfate, sodium deoxycholate ${\rightarrow}$ hypotonic solution ${\rightarrow}$ sodium dodesyl sulfate, and hypotonic solution sodium dodesyl sulfate as multi-step methods. Conclusion: Considering the number and the amount of the chemicals that were used, the incubation time and the degree of damage to the extracellular matrix, a single-step method with sodium dodesyl sulfate and Triton X-100 and a multi-step method with hypotonic solution followed by sodium dodesyl sulfate were both relatively optimal methods for decellularization in this study.

• Journal of the Korean Wood Science and Technology
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• v.9 no.3
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• pp.7-15
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• 1981

A Japanese larch has been reforested very much in Korea, but it is not used as a wood resources for paper pulp by now. So this study is carried out to utilize the larchwood for paper pulp manufacture through the Asplund pulping process. The experiment on increasing in the brightness of the pulp is made through the addition of $MgSO_4$, $ZnSO_4$, $Al_2(SO_4)_3$, and KI as a cellulose stabilizer in chip treatment with caustic soda which is followed by high-temperature defibration and conventional peroxide bleaching (5% NaOH plus 2% additive salt per wood in cold pretreatment), or in high-consistency (30%) pulp bleaching of hydrogen peroxide and peracetic acid (100% acitve oxygen per lignin) for conventional one. The results obtained are as follows: 1. The solution of 0.5% additive salts had different pH by the sort of bases that was pH 5.7 in $MgSO_4$, liquor, pH 4.9 for $ZnSO_4$, and pH 2.9 for $Al_2(SO_4)_3$, and in the precepitation of bases which ranged to pH 6-13 for $MgSO_4$, pH 5-12 for $ZnSO_4$, and pH 3-10 for $Al_2(SO_4)_3$. 2. The cellulose stabilizer affective in high-consistency peroxide bleaching was KI, $MgSO_4$, and $ZnSO_4$, but has made a little improvement in de lignification and brightness of pulp in comparison with no addition. 3. The higher alkalinity in the chip treatment has made the higher strength and brightness of larchwood Aspiund pulp instead of downing the pulp yield. And the effective compound for cellulose stabilizer in caustic soda pretreatment of chip was $ZnSO_4$, $Al_2(SO_4)_3$ and KI in order for the conventional peroxide bleaching after Asplund pulping. 4. Therefore, the more effective additives for cellulose stabilization in high-temperature defibration of larchwood suppose to be $ZnSO_4$, $Al_2(SO_4)_3$, and KI, while KI and $MgSO_4$ for peroxide bleaching.