• Journal of Dairy Science and Biotechnology
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• v.18 no.1
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• pp.22-37
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• 2000

In spite of adverse circumstances, dairy food industry of Korea has been developed continuously with the every efforts of farmers, processors, researchers and government officers. Development and extension of new technology, such as safety assurance, improvement of nutritive ingredient, and keeping freshness are very important issues considering short shelf life of dairy products which are prevalent in Korea. In addition to, demands for advanced technology would be increased rapidly with the increase of consumption development of high quality products supply structure, decrease of production basis, and appearance of environmental problems. And demands for information about standard would be enlarged. Development of new products and technology for quality improvement should be evolved with the application of developed technology and cooperation of relative institutes in order to enlarge the consumption of milk and dairy products. In conclusion, efficient production on the basis of balance and development of dairy products which are safe and high quality are the most important subjects for the development of dairy industry in Korea.

• Journal of Animal Science and Technology
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• v.50 no.4
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• pp.551-560
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• 2008

This study was carried out to investigate the effect of Opuntia ficus indica(prickly pear) pigment and sodium lactate on nitrite-reduced sausages. The a* value, total bacterial counts, pH, water holding capacity, texture analysis, sensory evaluation of sausages, body weight gain and blood glucose of rat for 4 weeks were not significantly different between the control and treatments. However, 2-thiobarbituric acid(TBA) values and cholesterol(total, LDL, HDL) and neutral fat of blood were significantly different between the control and treatments(P<0.05). TBA value was lower in control and cholesterol and neutral fat were lower in treatments. Among the treatments T2(30ppm of nitrite+2% of sodium lactate+0.2% Opuntia ficus indica pigment) was the most effective. In conclusions, this study suggested that T2 can reduce adding level of nitrite from 100 ppm to 30 ppm without any changes in color, shelf life and flavor of sausages. In addition, it had the effect on the reduction of cholesterol and neutral fat in blood.

• Korean Journal of Food Science and Technology
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• v.47 no.3
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• pp.350-358
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• 2015

Freezing is one of the main processes to extend the shelf life of foods. Before freezing, a thermal treatment is normally required to control the food quality. In this study, shiitake mushrooms were heated with boiling water and with superheated steam. After the thermal treatments, the samples were continuously frozen by an individual quick freezing (IQF) process, and put them into air-containing or vacuum packaging. Samples were stored at -12, -18 and $-24^{\circ}C$ for 24 weeks, and their physicochemical properties were determined. The lightness of the samples treated with boiling water and superheated steam was decreased by 12 and 15%, respectively, than that of the control. The hardness of all the samples rapidly increased after heat treatment. The contents of organic acids in the superheated steam treated samples were higher than those in the boiling water treated samples. Therefore, superheated steam treatment of samples may be a candidate thermal treatment to preserve frozen shiitake mushrooms.

• Horticultural Science & Technology
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• v.17 no.2
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• pp.115-117
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• 1999

Tomato (Lycopersicon esculentum) fruits were grown by the hydroponic cultivation system using perlite and soil cultivation system. The growth, yield, and fruit quality were compared between two growing seasons of spring and summer and two cultivation systems, respectively. In tomato, little difference was observed in growth and yield between two cultivation systems, but plant growth and total yield of fruits were much more in summer than in spring. The contents of glucose and fructose were more in spring-grown fruit than in summer-grown one, and in hydroponically cultivated fruit than in soilcultivated, respectively. The weight loss during room temperature storage was lower in hydroponically cultivated fruit than in soil-cultivated one, and in summer-grown fruit than in spring-grown one, respectively. In terms of color change, the shelf-life of tomato fruit was shorter by one day in summer-grown one fruit than in spring-grown one, and in hydroponcically cultivated one fruit than in soil-cultivated, respectively.

• Journal of Food Hygiene and Safety
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• v.15 no.1
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• pp.18-24
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• 2000

In this study, ohmic heating was applied for pasteurization of red pepper pow-der, and investigated its pasteurization effect. After pasteurization, seasoned squid-jeotkal was manufactured by using red pepper powder, and its quality changes were investigated. On com-paring sensory evaluation in squid-jeotkal by pasteurized and conventional red pepper powder during storage at 5, 16 and $25^{\circ}C$, quality changes in squid-jeotkal by the pasteurized red pepper powder. But quality change difference between two products were decrease with increasing stor-age temperature. Viable cell counts in two products stored at 5$^{\circ}C$ were increased slowly until 60 days. Viable cell counts in squid-jeotkal by conventional red pepper powder were increased up to ca. 10$^{8}$ CFU/g at 15, 25 $^{\circ}C$ after 30, 15 days, respectively, but that by pasteurized were ca. 10$^{8}$ CFU/g at $25^{\circ}C$ after 30 days. Changes in pH, VBN and NH$_2$-N in two products were shown difference significantly, but were decreased by increasing storage temperature. In squid-jeotkal by conventional red pepper powder, the main free amino acids were glutamic acid, leucine, glycine, aspartic acid and alanine, and these amino acids held 47.95% of the total free amino acid. But in squid-jeotkal by pasteurized red pepper powder, glutamic acid, glycine, aspartic acid, leucine and Iysine, and these amino acids held 57.58% of the total free amino acids.

• Journal of Food Hygiene and Safety
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• v.15 no.1
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• pp.13-17
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• 2000

The low salt seasoned jeotkal, salted and fermented fisheries product, may has some problems, such as short shelf-life, its putrefaction by mixing some microorganism from additives. It was considered that most microorganism in seasoned jeotkal were introduced from red pepper powder. Therefore, it is important to pasteurize red pepper powder for improving its microbial quality. When red pepper powder was pasteurized by ohmic heating, the survival cell concentration in red pepper powder was reduced to 1-log-unit at 500 V/m, 700 V/m, above 8$0^{\circ}C$. But viable cell counts were reduced from 8.5$\times$10$^{6}$ CFU/g to 2.1 $\times$ 10$^2$CFU/g, i.e. 4.6-log-unit, during ohmic heating at 9$0^{\circ}C$ for 40 min. Color values of red pepper powder during ohmic heating with different holding time were not changed significantly. When squid-jeotkal was manufactured by using the pasteurized red pepper powder, viable cell counts of the product were decreased by about three log cycles, compare with control product. And also the counts of fungi were significantly decreased.

• The Korean Journal of Food And Nutrition
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• v.24 no.2
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• pp.191-203
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• 2011

We conducted a study to investigate milk and dairy products consumption among elementary school students to identify ways to increase their intake of milk and dairy products. We asked 518 students in Seoul to fill out questionnaire. Only 55.6% of the subjects consumed milk daily, and 43.7% of them drank at least 1 cup per day. The frequency and quantity of milk consumption were higher in male students than female students. The majority of the subjects consumed whole milk, and most students(59.5%) preferred flavored milk to whole milk. The reasons given for drinking milk included 'wanting to be tall'(66.1%) and 'for good health'(47.1%), while the main reason given for not drinking milk was stomach pain (68.4%). Records of having an unpleasant experience and upset stomach after drinking milk occurred at a higher rate for those who did not drink milk(84.2%) than for those who did(53.3%). Of the students questioned, 36.9% consumed dairy products other than milk 3~4 times per week, and liquid-type yoghurt(43.8%) and ice cream(35.4%) were the preferred dairy products among students. The reasons given for consuming dairy products were 'good taste'(56.6%), 'good to eat'(46.6%), 'wanting to be tall'(32.4%), and 'for good health' (25.4%). Among those students who did not consumed dairy products, the major reason given was 'family does not eat at home'(33.3%). After consuming the dairy products, 71.4% of participants thought that dairy products did not result in physical improvement. Most students had experienced purchasing milk and dairy products by themselves. When they bought milk or dairy products, the reasons given for making a particular selection were 'shelf-life'(61.6%) for milk, and 'favorite dairy products'(54.1%) for dairy products. According to participants, the factors that need to be considered for milk and dairy product consumption among elementary school students are 'higher nutrition' (60.8%), 'better sanitation'(57.3%), and 'better quality and taste'(55.2%).

• The Korean Journal of Food And Nutrition
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• v.31 no.1
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• pp.127-134
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• 2018

To prolong the shelf-life of chicken breast meat, samples were treated with gel packs containing slow-released chlorine dioxide ($ClO_2$) gas at 7~15 ppm for eight days at $4^{\circ}C$. The microbial, physicochemical properties and sensory evaluation of the treated samples were investigated. The total number of bacteria in the control increased during storage and showed 6.78 log CFU/g on the 8th day of storage, but $ClO_2$ gas treatments showed 6.24~6.58 log CFU/g at the same time. The initial pH of chicken breast meat was 6.00 and gradually increased during storage. And $ClO_2$ gas treatments did not show any significant difference from the control during storage period, but maintained a generally lower pH than that of the control. The lightness, redness, and yellowness during storage were not significantly different between the control and the 7~10 ppm $ClO_2$ gas treatments. However, as the storage period was increased, the redness of 15 ppm $ClO_2$ gas treatment was reduced. The cooking loss and shear force were not different between the control and $ClO_2$ gas treatments during the storage period. Volatile basic nitrogen (VBN) increased in the control from the 6th day of storage and 23.80 mg% in the 8th day of storage. However, VBN of $ClO_2$ treatments showed lower than that of the control. In the change of sensory evaluation during storage, 10 ppm $ClO_2$ treatment showed the highest preference in odor, appearance and overall acceptance during storage period.

• Korean Journal of Food Science and Technology
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• v.31 no.2
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• pp.368-374
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• 1999

This study was designed to investigate effects of pulsed electric field (PEF) treatment on physiological changes of microbial cells, using domestically fabricated pilot scale PEF device. The effect of non-thermal PEF treatment on physiological characteristics of microorganisms was determined by salt resistance, the amount of UV absorbents, cell staining, recovery rate of defected cells, and changes in structure of cell membrane. Salt resistance of Escherichia coli, Bacillus subtilis and Rhodotorula minuta was examined after PEF treatment at 40 kV/cm, 84 pulse, $10{\mu}s$ pulse duration. Approximately $1\;log_{10}$ cell number of viable microorganisms was decreased by addition of salt. PEF treatment significantly increased the amount of UV absorbents at 260 and 280 nm because of leakage from damaged cell membrane by PEF treatment. Although three kinds of microorganisms treated by PEF were difficult to be observed due to their cell membrane damage, untreated cells were clearly observed by a microscope. PEF-treated R. minuta was not stained by methylene blue due to cell membrane defect. When E. coli, B. subtilis and R. minuta were cultured after PEF treatment, they showed 5, 4, and 8 hr longer lag phase, respectively, compared to control, but growth rates were not affected.

• Korean Journal of Food Science and Technology
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• v.32 no.3
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• pp.481-490
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• 2000

Modified atmosphere packaging was applied to oriental melon(Cucumis melo L. var. makuwa Mak.) to extend its freshness during distribution. Gas composition and ethylene content in the film bags changed rapidly at the early stage of storage. Within 10 days, weight loss of the unpackaged increased upto 7.68% while those of the packaged remained less than 1.0% except LDPE film modified by addition of 5%(w/w) zeolite with $20\;{\mu}m$ thickness(20CK, 2.38%). Firmness was effectively maintained in the LDPE film modified by addition of 5%(w/w) zeolite with $40\;{\mu}m$ thickness(40CK) and the LDPE film with $40\;{\mu}m$ thickness containing ethylene absorber sachet(40LP). Peel color of the fruit changed rapidly in control and a little in 40CK. Oriental melon packages using 40CK provided better visual and sensory quality retention compared with others. Results suggested that packaging treatment such as 40CK could be used for extending freshness of oriental melon during transport period at ambient temperature.