• Food Science and Preservation
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• v.24 no.1
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• pp.100-106
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• 2017

This study was conducted to evaluate the genotoxicity of balanced nutritional formular for patients containing various ingredients after gamma irradiation at 4 kGy. Since viable bacteria were not observed within the detection limit of 1 log CFU/g, a dose of 4 kGy was appropriate for the pasteurization of the formular. In a bacterial reverse mutation assay, both hot water and methanol extracts of the formular exhibited dose-independent responses, which was similar to those obtained from that of the negative control (distilled water or dimethyl sulfoxide). In a chromosomal aberration test using lung fibroblast cells of Chinese hamster, the numbers of normal chromosomes were comparable to those observed in the negative control, regardless of the treatment dose and metabolic activation system. Furthermore, no significant increases in the frequency of micronucleated polychromatic erythrocytes were observed relative to the control, when mice were fed with the formular at doses up to 2,000 mg/kg body weight. Therefore, the balanced nutritional formular for patients did not exhibit genotoxicity when pasteurization by gamma irradiation at 4 kGy.

• Food Science and Biotechnology
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• v.17 no.1
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• pp.166-171
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• 2008

Abstracts Soybean sprouts which are a popular vegetable in Korea, are produced using the techniques of sous vide. The purpose of this study was to determine the effect of nisin and storage temperature on the microbiological and physicochemical qualities of sous vide processed soybean sprouts during storage in order to improve shelf-life and industrial applications. During storage of the cook-chilled soybean sprouts at $3^{\circ}C$, no development of mesophilic microorganisms was observed. However, at $10^{\circ}C$ storage without nisin, the number of mesophilic microorganisms increased markedly, whereas sprouts stored at the same temperature with nisin showed no observed increase. Psychrotrophic microorganisms, anaerobic microorganisms, and Bacillus cereus all showed similar trends. The ascorbic acid content, following the sequential heat processing of soybean sprouts through blanching and pasteurization decreased markedly during early storage, and stabilized thereafter. During storage, no major changes in the color or ascorbic acid content of samples at either temperature were observed. With regard to microbial and physicochemical qualities, the presences of nisin and storage temperature are important factors for extending shelf-life of soybean sprout.

• Journal of the Korean Society of Food Culture
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• v.31 no.5
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• pp.400-410
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• 2016

The purpose of this study was to discuss how 'milk' was produced and supplied introduced and spread in the modern Joseon period. Condensed milk and powdered milk were mainly consumed in Joseon during the Japanese colonial period since they could be conveniently preserved for a long time, although raw milk was also produced and consumed. For areas adjacent to farms, milk delivery service was offered while areas with great consumption received an additional supply from different areas by rail. Since no manufacturing plants were operational in Korea, condensed milk and powdered milk consumed in Joseon had to be imported. In the case of condensed milk, when production in Japan increased, extra supply was aggressively sent into their colony, Joseon. The 'Gyeongseong Milk Association' founded in 1937 is considered significant in that it led to standardization of the production system and prices as well as pasteurization of milk. In the late Japanese colonial era, milk production and consumption were controlled. As milk was purchased as a war supply, the milk consumption market became distorted and limited.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.4
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• pp.569-576
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• 2016

This study researched the effects of cooking methods on phytochemical-enriched thin rice porridge (RP) of three colors (red, yellow, and green). Each of the RPs was prepared by three cooking methods and retorted through two-steps (step 1, at $80^{\circ}C$ for 15 min; step 2, at $82^{\circ}C$ for 25 min) for pasteurization. Cooking method (CM) 1 involved heating a mixture of all ingredients while CM 2 involved addition of apple/beet (AB, red), sweet-pumpkin/cabbage (PC, yellow) or vitamin/pear (green) while heating rice flour and glutinous rice flour. CM 3 involved mixing pre-cooked fruits and vegetables with cooked thin RP. The viscosity of RP prepared by CM 1 was lower than those of other RPs (P<0.05). The result of colorimetric a value show that red and green color of AB and VP prepared by CM 2 and CM 3 were most vivid. Contents of phytochemicals and antioxidants were higher when RP was prepared by CM 2 and CM 3 compared to CM 1. ${\Delta}E$ values of PC showed no significant difference before and after pasteurization, whereas AB and VP were significantly different (P<0.05). Antioxidant activity after retorting was not significantly different from those of un-retorted RPs. The results of color, phytochemical content, and antioxidant activity show that CM 2 or CM 3 were considerably better than CM 1, whereas cooking method had no effect after two-step retorting. Therefore, uncomplicated cooking method such as CM 1 or CM 2 are suited for commercial production of RPs.

• Food Science of Animal Resources
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• v.37 no.2
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• pp.297-304
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• 2017

Animal-origin food products pose serious threat to public food safety due to high microbial loads. The microbial and radioactive contaminations in commercial cold duck meat products were evaluated. Ten different lots of commercial samples ($C_1-C_{10}$) were classified based on type and smoking process. All samples were highly contaminated (< 4-7 Log CFU/g) with total aerobic bacteria (TAB), yeasts and molds (Y&M), and 7 samples ($C_1-C_7$) were positive for coliforms. Furthermore, three samples were contaminated with Listeria monocytogenes ($C_4-C_6$) and one with Salmonella typhimurium ($C_6$). No radionuclides ($^{131}I$, $^{137}Cs$, and $^{134}Cs$) were detected in any sample. The results of DEFT (direct epifluorescent filter technique)/APC (aerobic plate count), employed to screen pre-pasteurization treatments of products, indicated that smoked samples were positive showing DEFT/APC ratios higher than 4. Notably, the samples showed a serious threat to microbial safety, thus were irradiated with electron-beam (e-beam). The $D_{10}$ values for S. typhimurium and L. monocytogenes were 0.65 and 0.42 kGy, respectively. E-beam application at 3 and 7 kGy resulted in reduction of initial TAB, Y&M, and coliform populations by 3 and 6 log cycles, respectively. Thus, e-beam was proven to be a good decontamination approach to improve the hygiene of cold duck meat.

• Journal of Dairy Science and Biotechnology
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• v.24 no.1
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• pp.9-18
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• 2006

Total 150 packs of UHT milk and UHT-ESL milk, produced by different domestic milk companies, were compared at refrigerated and room temperature for 35 days in terms of microbiological qualities such as incidence date, number of incidence packs, and numbers of bacteria, and post-pasteurization contamination. Overall qualities of UHT-ESL milk were slightly better than that of UHT milk in relations to total bacteria in milk. No coliforms were detected in two groups of UHT milk samples after 35 days. Aerobic spores were more common in two brands of UHT milks stored in 20$^{\circ}$C than those in 7$^{\circ}$C, in which spores were broken out at 7 and 14 day. No incidences of thermoduric bacteria were founded until 14 days in two groups of UHT milks, but high level of counts (<300${\sim}$<3,000 CFU/ml) after 21 days at 20$^{\circ}$C and 40${\sim}$3,600 CFU/ml at 7$^{\circ}$C were detected, respectively. Psychrotrophic bacteria were higher in UHT milk than in UHT-ESL milk, in which began to detect at 28 days. No post-pasteurization contamination by salmonella spp. and staphylococcus aureus were found throughout the experimental periods. One may conclude that the shelf life of UHT milk under cold-chains system can be extended up to 21days, as long as UHT treated milk are filled in sterilized containers by aseptic packaging system.

• Food Quality and Culture
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• v.3 no.2
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• pp.64-68
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• 2009

This descriptive analysis study investigated the sensory characteristics and the drivers of liking for seven types of makgeolli differing in grain composition and pasteurization conditions. Six trained panelists participated in the descriptive analysis. In the consumer acceptance test involving 23 males and 34 females, two of the seven varieties were excluded due to their similar sensory characteristics. Analysis of variance, principal component analysis, and partial least square regression analysis were conducted. Sensory characteristics of makgeolli varied markedly depending on the ingredients and processing methods. Makgeolli samples with relatively high content of millet flour were characterized as being smooth and strong, with a roasted carbohydrate flavor, whereas samples with enriched rice content were rated high in attributes such as bitterness, carbonation, and residual flavor. Sourness decreased in pasteurized samples. Participant's age rather than gender influence the liking for makgeolli. Older consumers tend to prefer samples with stronger flavor than did younger consumers. Clustering consumer groups based on the preference for makgeolli samples provided profound insight concerning the beverage aspects that were appealing, which should be useful in consumer targeting of particular varieties of makgeolli.

• Korean Journal of Food Science and Technology
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• v.34 no.4
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• pp.631-636
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• 2002

Lethality of high intensity light pulse on the pre-determined microbial populations has been investigated. Prior to the treatment, Lactobacillus plantarum, Lactobacillus brevis, Leuconostoc mesenteroides and Pediococcus pentosaceus were cultivated separately onto the surface of Lactobacilli MRS agar. Pre-determined microbial populations were applied to the test media and these sample were exposed to high intense light source with an exposure time ranging from 1 to $2500\;{\mu}s$. Results showed that at least 200 light pulses of $1\;{\mu}s$ duration were required to reduce L. Plantarum cells by 90% at 25 kV, the greater the number of light pulses, the larger the reduction in viable cell numbers. Viable cells of L. plantarum and the others were reduced by more than 5 and 6 log cycles at the upper exposure level of $750\;{\mu}s$, respectively. These study shows that pulsed light emissions can significantly reduce populations of lactic acid bacteria on exposed surface with exposure times. Killing efficiency for L. plantarum significantly increased with decreasing the distance between the lamp and the surface of samples.

• Food Science of Animal Resources
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• v.41 no.5
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• pp.894-904
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• 2021

Microencapsulation is a protective process for materials that are sensitive to harsh conditions encounted during food manufacture and storage. The objectives of this research were to manufacture a milk protein-based delivery system (MPDS) containing Lactobacillus rhamnosus GG (LGG) using skim milk powder and to investigate the effects of manufacturing variables, such as reaction temerpature and holding time, on the physiccohemical properties of MPDS and viability of LGG under dairy food processing and storage conditions. MPDS was prepared using chymosin at varing reaction temperatures from 25℃ to 40℃ for 10 min and holding times from 5 to 30 min at 25℃. The morphological and physicochemical properties of MPDS were evaluated using a confocal laser scanning microscope and a particle size analyzer, respectively. The number of viable cells were determined using the standard plate method. Spherical-shaped MPDS particles were successfully manufactured. The particle size of MPDS was increased with a decrease in reaction temperature and an increase in holding time. As reaction temperature and holding time were increased, the encapsulation efficiency of LGG in MPDS was increased. During pasteurization, the use of MPDS resulted in an increase in the LGG viability. The encapsulation of LGG in MPDS led to an increase in the viability of LGG in simulated gastric fluid. In addition, the LGG viability was enhanced with an increase in reaction temperature and holding time. In conclusions, the encapsulation of LGG in MPDS could be an effective way of improving the viability of LGG during pasturization process in various foods.

• Korean Journal of Food Science and Technology
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• v.42 no.4
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• pp.494-501
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• 2010

The purpose of this study was to examine the presence of Bacillus cereus, aerobic bacteria and coliforms in the raw material of infant formulas and investigate the manufacturing process in terms of microbial safety. Among ten kinds of raw infant formula material samples (n=20), Bacillus cereus appeared in two (n=4). Aerobic bacteria were not detected in raw infant formula material or maximum 4.15 log CFU/g. Eleven species of aerobic bacteria were isolated and 76% of them were Sphingomonas paucimobilis, Pseudomonas fluorescens, Rhizobium radiobactor, or Stenotrophomonas maltophilia. A Pearson's correlation analysis revealed that the most influential factors for detecting Bacillus cereus were aerobic bacteria and coliforms. In other words, when the measured values of aerobic bacteria and coliforms were higher, the possibility that Bacillus cereus would appear increased. In a regression model to predict Bacillus cereus, the rate of appearance was correlated with aerobic bacteria and coliforms, and its contribution rate for effectiveness was 86%. Improving microbial quality control by pasteurization, spray dry, popping and extrusion resulted in a decrease in the numbers of Bacillus cereus, aerobic bacteria and coliforms in the raw materials. The results suggest that a hazard analysis and critical control point system might be effective for reducing microbiological contamination.