• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.2
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• pp.125-130
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• 2009

Intact black raspberry fruits, which were crushed by hand or ground using a blender, were immersed in 20%, 40%, 60%, and 80% ethanol (125 g fruits per 900 mL ethanol) and exuded for 30, 60, and 90 days at room temperature. Monomeric anthocyanin contents (MAC) and polyphenol contents (PHC) of the exudates were determined measuring absorbance using a spectrophotometer. DPPH and ABTS free radical scavenging activities (50%: $SC_{50}$) were determined for the antioxidant activities of the exudates. Twenty % ethanol exudates from black raspberry had significantly lower MAC and PHC regardless of the fruit types. $SC_{50}$ were higher in 20% ethanol exudates, suggesting 20% ethanol exudates from black raspberry had lower antioxidant activities. MAC and PHC of the black raspberry exudates decreased with time. This study suggests that MAC and PHC in the black raspberry could be exuded more efficiently using 40% or higher concentration of ethanol and that crushing and grinding little affect exuding MAC and PHC. The exudates with higher MAC and PHC showed higher antioxidant activities.

• Korean Journal of Food Science and Technology
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• v.31 no.1
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• pp.171-175
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• 1999

Changes in physicochemical characteristics of steamed rice during roasting were investigated. Steamed rice was roasted at various temperature $(150{\sim}220^{\circ}C)$ for various time $(10{\sim}30min)$. L and b Hunter color values of steamed rice were decreased, but E value was increased by roasting. The water absorption index and the water solubility index were gradually with increasing roasting temperature and time up to $200^{\circ}C$ for 30min, but decreased at $220^{\circ}C$ for 20min. The yield of water extracts from steamed and roasted rice were sharply increased with increasing roasting temperature and time, however, precipitates and turbidity were decreased. The content of reducing sugar was slowly increased up to $200^{\circ}C$ and remarkably increased above it. The contents of amino acids were decreased by roasting. Among them, cystine, lysine and serin were significantly reduced with increasing roasting temperature.

• Korean Journal of Food Science and Technology
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• v.36 no.3
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• pp.490-500
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• 2004

Brown rice grains were coated by spraying aqueous protein solution extracted from rice bran using 10% ethanol, and dried at room temperature. Coating procedure was repeated 1-5 times to determine effect of repeated coating, Quality changes in coated brown rice grains were observed during 8 weeks storage. Most coated rice grains gave lower peroxide and acid values, which indicate antioxidative effects of coating. Lipase and lipoxygenase activities generally decreased in grains coated more than three times. Microscopic images of whole kernel and longitudinal section revealed cracking on all brown rice grains including control, and hydration rate constants were not significantly different among treated grains. Compared to non-coated brown rice grains, those coated more than three times, after 8 week storage, showed better quality retention observed in (meaning not clear) higher water-binding capacity, lower gel consistency decrease, less browning, and better textural properties in cooked rice, resulting in better sensory quality.

• Journal of Applied Biological Chemistry
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• v.60 no.2
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• pp.179-184
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• 2017

Tolaasin, a 1.9 kDa peptide toxin, is produced by Pseudomonas tolaasii and causes the brown blotch disease of cultivated oyster mushroom. It forms pores on the membrane and thus destroys cellular membrane structure, seriously reducing the productivity of mushroom cultivation. The mechanism of tolaasin-induced cytotoxicity is not known in detail. However, it has been reported to form a pore structure in the cytoplasmic membrane through the molecular multimerization. Therefore, food additives which can interact with tolaasin molecules may inhibit the pore formation by hydrophobic interactions with tolaasin molecules. In this study, various food additive materials have been identified as inhibitors of the tolaasin activity and named tolaasin-inhibitory factors (TIF). Most of TIFs are emulsifying agents for food processing procedures. Among various TIFs, polyglycerol and sucrose esters of fatty acids blocked effectively the cytotoxicity of tolaasins at the concentrations $10^{-4}-10^{-5}M$. These TIFs also successfully suppressed the blotch disease development in the shelf cultivation of oyster mushroom.

• Journal of Food Hygiene and Safety
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• v.27 no.2
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• pp.117-126
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• 2012

This study was conducted to assess the levels of microbiological hazards of preprocessed Namuls, which were served at the school foodservice. 19 preprocessed ground or root vegetables were collected from 21 schools in May to June of 2011. Heavy contamination of aerobic plate counts (from 3.39 to 8.42 logCFU/g) and total coliform groups (from 3.16 to 7.84 logCFU/g), enterobacteriaceaes (from 2.53 to 7.55 logCFU/g) were detected in preprocessed Namuls. In addition, the detection rates of Escherichia coli, Staphylococcus aureus and Bacillus cereus (emetic form) were 4.3%, 11.7% and 2.1%, respectively. In addition, sanitary indicative bacterium at preprocessing steps of root vegetables (lotus root, burdock root, bellflower root) and blanched Namuls (bracken, sweet potato vine, chinamul) were analyzed. Aerobic plate counts, coliform groups, and enterobacteriaceaes were not effectively removed during preprocessing including washing and soaking steps. In the case of blanched Namuls (bracken, sweet potato vine, chinamul), contamination levels increased more after drying process and no significant reduction effect on the levels of microbial contamination was observed during preprocessing steps. Thus, effect of preprocessing steps on the microbiological hazards in Namuls must be reevaluated to improve the microbiological quality of preprocessed Namuls at the school foodservice and retail markets.

• Journal of Food Hygiene and Safety
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• v.32 no.1
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• pp.14-19
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• 2017

The purpose of the study was to simplify standard HACCP manual for improving the on-site applicability and increasing the implementation rate of HACCP program for small- and medium-sized dairy farms (SMDF). A survey was carried out in 32 SMDFs using a structured questionnaire. The results indicated that the number of workers had a positive correlation with HACCP certifications (p < 0.05). Most of HACCP non-certified farms (66.7%) were run by two workers with 40-60 cows and milking yields of 1,000-1,500 L per day. Major drawbacks for dairy farmers to implement current HACCP system were the difficulties in daily recording and facility management (40%). On the basis of the survey results, it was suggested that the development of on-site standard HACCP manual and user-friendly record chart with O/X checklist were the most urgent factors to increase HACCP implementation rate. In addition, the alternative third party service for microbial and chemical tests could also be accompanied for small-sized dairy farms.

• Korean Journal of Food Science and Technology
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• v.23 no.1
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• pp.88-92
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• 1991

To analyze the effects of the system parameters on the target parameters, which include the amount of water evaporation, water solubility index(WSI) and water absorption index(WAI), test trials of fractional factorial design of the three process variables at three levels were carried out for corn grit with a laboratory twin-screw extruder with three different screw configurations. The system parameters collected from the trials, such as extrusion temperature, specific mechanical energy input(SME) and mean residence time(RT), were showed the ranges of $129{\sim}182^{\circ}C$, $67{\sim}163\;kwh/ton$ and $12{\sim}34\;sec$, respectively. Within these ranges of the system parameters, the target parameters were able to be quantified by using multiple regression equations. The correlation of results with the system parameters blocked by the screw configuration as dependent variables, yield correlation coefficients above 0.90, and the correlation using the system parameters obtained from whole experiment system as the dependent variables yield correlation coefficients around 0.80. The functional relationship, which can be quantified by second order polynomial regression equation with only two system parameters within necessary degree of accuracy, can he graped in three dimensional surface response and contour diagrams.

• Korean Journal of Food Science and Technology
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• v.23 no.1
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• pp.81-87
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• 1991

To examine the effect of the individual operational variables on extrusion process, test trials of the fractional factorial design of the three process variables at three levels, including feed rate, screw speed and die openings, were carried out by using a laboratory scale twin-screw extruder with three different screw configuration for corn grit with the water addition fixed at 15% of the powder feed rate. As the increase of feed rate, while extrusion temperature(ET), specific mechanical energy input (SME), and residence time(RT) were showed the tendency to decrease, extrusion pressure(EP) was increased and as the increase of screw speed, ET, SME and EP were showed the tendency to increase, but RT was decreased. However, as increase the number of die hole, all system parameters were showed the tendency to decrease. The influence of the change in each process parameters was increased as the increase of the number of reverse element in screw configuration. In case of using the screw configuration with increasing number of reverse element at the condition of same process parameters, ET, SME and RT was increased, but EP was decreased. The functional relationships of the system parameters to the process parameters can be quantified by using multiple regression equations(mostly R-sq>0.90) and maped on suface response diagrams to expedite evaluation.

• Korean Journal of Food Science and Technology
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• v.48 no.4
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• pp.317-322
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• 2016

A pesticide mix solution containing difenoconazole, lambda-cyhalothrin, and lufenuron was applied 3 times on field grown chili pepper at a fivefold overdose dilution concentration of the spray solution at a pre-harvest interval of 7 day. Difenoconazole, lambda-cyhalothrin, and lufenuron were detected at 4.43, 0.334, and 1.56 mg/kg, respectively, in raw chili pepper. Washing with water reduced the residue levels to 91.4, 94.3, and 85.3%, respectively. In dried chili pepper, the residues of difenoconazole, lambda-cyhalothrin, and lufenuron were 22.2 mg/kg (processing factor, Pf =5.01), 1.65 mg/kg (Pf =4.94), and 6.54 mg/kg (Pf =4.19). In the seeds, difenoconazole and lambda-cyhalothrin were not detected, and lufenuron was detected at 0.0075 mg/kg (n=1) and <0.005 mg/kg (n=2). Thus the pesticide residues in the seeds was negligible. In the seed oil, difenoconazole and lufenuron residues were 0.0263 and 0.0295 mg/kg, respectively (concentration factors=5.26 and 4.72). These concentration factors supported the theoretical concentration factor of 6.8, assuming that all of compound present in the seed are transferred into the oil.

• Korean Journal of Food Science and Technology
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• v.49 no.1
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• pp.20-27
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• 2017

Eighteen commercial laver (Porphyra sp.) products were purchased from Korean market and were monitored for their microbial contamination, pre-decontamination, and luminescence properties. The laver samples showed considerable variation in their microbial contamination, from $10-10^7CFU/g$ of total aerobic counts, <$10-10^2CFU/g$ of coliforms in 4 dried laver samples, and <$10-10^6CFU/g$ of yeasts and molds except in 3 samples. In addition, $10^2CFU/g$ of Bacillus cereus was found in one sample. DEFT/APC analysis was suitable for demonstrating whether the samples were pre-decontaminated or not, with DEFT/APC values lower than 2.0 log for non-heated samples and 1.0-8.5 log for heatprocessed samples. In photostimulated luminescence (PSL) calibration, 15 samples irradiated at 1 kGy showed positive (irradiated) values more than 5000 PCs. Furthermore, thermoluminescence (TL) analysis by separating the marker minerals from samples revealed the potential to be employed in identifying irradiation status by determining $1^{st}$ TL glow at $125-175^{\circ}C$ and TL ratio ($TL_1/TL_2$) of all the samples.