• Preventive Nutrition and Food Science
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• v.14 no.3
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• pp.226-232
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• 2009

The effects of UV-C irradiation on the quality characteristics of powdered foods, sunsik and misutkaru, were examined during storage, where samples were irradiated at doses of 27, 54, and 108 kJ/$m^2$, respectively. In addition, sunsik and misutkaru samples were inoculated with Enterobacter sakazakii as a pathogen and then irradiated at doses of 0.5, 1, and 5 kJ/$m^2$, respectively. After treatment, the sunsik and misutkaru samples were stored at $20^{\circ}C$. The microbiological data represented that populations of total aerobic bacteria, Bacillus cereus, and E. sakazakii were significantly (p<0.05) reduced with increasing UV-C doses. In addition, UV-C irradiation did not cause inferiority in the color quality of the samples during storage. Sensory evaluation results also indicated that there were no significant differences (p<0.05) among the irradiated samples. These results suggest that UV-C irradiation may be useful in maintaining the quality of sunsik and misutkaru during storage.

• Food Science of Animal Resources
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• v.39 no.5
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• pp.820-830
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• 2019

Most consumers consider yogurt to be a healthy food because it contains probiotic microorganisms. Although a plethora of commercially produced yogurts exists, nutritional and functional aspects of the commercial yogurts have not been well characterized. In this study, the microbiological and physicochemical properties of popular drinking yogurts in Korea were extensively characterized. The viability of lactic acid bacteria, including lactobacilli and bifidobacteria, varied between yogurt samples. These lactobacilli and bifidobacteria showed effective antimicrobial activities against foodborne pathogenic bacteria. Unlike the titratable acidity and pH, the soluble solids content varied between yogurt samples. All the yogurt samples contained high levels of potassium (average 143.53 mg/100 g) and calcium (average 133.92 mg/100 g), as well as phosphorus and sodium. Lactose, fructose, and glucose were the major sugar components in most yogurt samples, whereas the levels of sucrose and maltose were relatively low. Among several organic acids analyzed in the yogurt samples, lactic acid (average 767.67 mg/100 g) and citric acid (average 170.91 mg/100 g) were the most predominant. Taken together, this study provides preliminary information about the nutritional and functional characteristics of commercially available drinking yogurts.

• 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.

• Journal of Microbiology and Biotechnology
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• v.23 no.2
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• pp.246-250
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• 2013

In this study, a loop-mediated isothermal amplification (LAMP) method to rapidly detect Staphylococcus aureus strains was developed and evaluated by extensively applying a large number of S. aureus isolates from clinical and food samples. Six primers were specially designed for recognizing eight distinct sequences on the species-specific femA gene of S. aureus. The detection limits were 100 fg DNA/tube and $10^4$ CFU/ml. The LAMP assay was applied to 432 S. aureus strains isolated from 118 clinical and 314 food samples. Total detection rates for the LAMP and polymerase chain reaction assays were 98.4% (306/311) and 89.4% (278/311), respectively.

• Food Science and Biotechnology
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• v.17 no.4
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• pp.728-733
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• 2008

New gluten-free food product (tarhana) was produced using rice and com flours. Chemical and sensory properties of the tarhana samples were investigated and compared with those of traditional wheat tarhana. Generally, sensory analysis results indicated that utilization of com and rice flours in tarhana resulted in acceptable soup properties in terms of some of the sensory properties. The changes in electrophoretic properties of the proteins of the tarhana samples were also studied during the tarhana production. Sodium dodecyl sulfate-polyacryamide gel electrophoresis (SDS-PAGE) results showed that relative intensities of some of the protein bands in tarhana samples generally decreased during fermentation. The decrease was more obvious at the larger molecular weight region. Corn and rice tarhana seem to be promising food products for the celiac patients who have limited choice of cereal based foods.

• Journal of Food Hygiene and Safety
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• v.11 no.3
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• pp.171-176
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• 1996

Microbial distribution as well as content of salt and preservatives in side dishes was investigated by analyzing cell count of viable cells, coliform bacteria and food poisoning bacteria of sliced squid bokum and anchovy bokum, purchased at 17 different department stores and 2 different traditional market in Seoul, which are most preferred by many consumers to any other side dishes available in the market. 6.2$\times$103~1.2$\times$108 cells/g of viable cell was detected in 19 different samples of the sliced squid bokum, among which samples of the sliced squid bokum and 14 samples of the anchovy bokum contained 103~108 cells/g of coliform group. However food poisoning bacteria were not detected in all the samples tested. Salt content was 2.42~4.89 %w/w and 2.28~6.46 w/w for the sliced squid bokum and the anchovy bokum respectively. Analysis of preservatives by HPLC such as sorbic acid, benzoic acid, dehydroacetic acid and another 6 kinds of esters resulted that 1.0$\times$73.8 mg/100 g of sorbic acid was detected in the 19 samples of the sliced squid bokum, while only 6 samples of the 15 anchovy bokum samples contained sorbic acid.

• Food Science of Animal Resources
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• v.37 no.4
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• pp.606-616
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• 2017

The objective of this research was to investigate the effects microbial transglutaminase (mTGs) on the physicochemical, microbial and sensory properties of kefir produced by using mix cow and soymilk. Kefir batches were prepared using 0, 0.5, 1 and 1.5 Units m-TGs for per g of milk protein. Adding m-TGs to milk caused an increase in the pH and viscosity and caused a decrease in titratable acidity and syneresis in the kefir samples. Total bacteria, lactobacilli and streptococci counts decreased, while yeast counts increased in all the samples during storage. Alcohols and acids compounds have increased in all the samples except in the control samples, while carbonyl compounds have decreased in all the samples during storage (1-30 d). The differences in the percentage of alcohols, carbonyl compounds and acids in total volatiles on the 1st and the 30th d of storage were observed at 8.47-23.52%, 6.94-25.46% and 59.64-63.69%, respectively. The consumer evaluation of the kefir samples showed that greater levels of acceptability were found for samples which had been added 1.5 U m-TGs for per g of milk protein.

• The Korean Journal of Food And Nutrition
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• v.32 no.6
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• pp.598-610
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• 2019

The purpose of this study was to investigate the quality characteristics and antioxidant activity by collecting four times on six samples of Jeonbuk regional soybean pastes (Doenjang) traditionally prepared for this study. The water content of samples decreased according to progress of the aging period and the water content of the fourth sample collected was 42.40~59.64% (p<0.05). The salinity of the fourth Doenjang samples was 11.80~18.60%. The amino-type nitrogen content was 122.67~540.33 mg% immediately after the preparation of Doenjang in the Jeonbuk region and the content of the fourth collection samples increased from 251.49 to 982.36 mg% (p<0.05). The isoflavone glycosides decreased but daidzein, genistein and glycitein, which are aglycones, increased during aging periods. The total polyphenol content of the fourth collected samples was 11.99~19.27 mg GAE/g (p<0.05). The DPPH radical scavenging activity, ABTS radical scavenging activity and FARP of the fourth Doenjang samples were 51.88~81.21%, 84.14~90.32%, and 1.08~3.11 mg Trolox/g, respectively. As a result of quality analysis on Doenjang, the superiority of traditional Doenjang has been proven by the increase of amino nitrogen content and antioxidant activity according to the aging period. However, factor analysis on quality differences of regional Doenjang should be conducted to ensure standardization and quality improvement.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.6
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• pp.1045-1051
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• 2021

Eighty-nine different types of commercially salt-fermented fishery products comprising various raw materials were analyzed for total aerobic bacteria, number of coliform bacteria, fecal coliform, and Escherichia coli. The food-poisoning bacterial content of the samples was investigated using next-generation sequencing. The mean mass of total aerobic bacteria in Jeotgal was 6-1.8×10⁹ CFU/g, and that in Aekjeot and Sikhae was 4-2.2×10⁵ CFU/mL and 1.9×10⁵-8.4×10⁸ CFU/g, respectively. Coliform bacteria were detected in 9 (28.1%) of 32 Jeotgal samples; 15 (46.8%) of 32 seasonal Jeotgal samples; and in 5 (55.5%) of 9 Sikhae samples. Fecal coliform and E. coli were not detected in 86 of the 89 samples. Yersinia enterocolitica was detected only in Galchi jeot (salt-fermented hairtail) (1 type) and not in other Jeotgal samples. These results contribute to our knowledge regarding the bacterial stability of salt-fermented fishery products.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.7
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• pp.1024-1029
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• 2010

Opuntia ficus-indica and Aloe vera slices were dried using 20, 30, and 40% polyethylene glycol (PEG) 4,000 as a dehydration agent, and the dried samples were compared with the hot-air dried and freeze dried in terms of rehydration ratio, color, and sensory evaluation. The moisture content of the PEG-treated samples decreased with increasing concentrations of polyethylene glycol. The rehydration ratio of the PEG-treated samples was better than those of the hot air-dried or freeze-dried samples. The color of the PEG-treated samples was similar to that of the freeze-dried samples and better than that of the hot air-dried samples. The sensory evaluation of PEG-treated samples was better than those of the hot air-dried or freeze-dried samples. These results suggest that dehydration of Opuntia ficus-indica and Aloe vera slices using PEG is very effective in terms of rehydration ratio and minimal damage of cell structure.