• Journal of Food Hygiene and Safety
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• v.22 no.4
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• pp.317-322
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• 2007

The purpose of this study was to investigate the antibacterial effect of films on shelf-life and microbiological safety of mackerel. Effects of antimicrobial films against total aerobic bacteria, Escherichia coli O157:H7, Listeria monocytogenes, Vibrio parahaemolyticus in mackerel were evaluated during storage of 5-14 days at $5^{\circ}C,\;10^{\circ}C\;and\;15^{\circ}C$. Antimicrobial films were developed with addition of a natural substance, wasabi extracts (Wasabia japonica). At $5^{\circ}C$ storage, growth of total aerobic bacteria, Escherichia coli O157:H7, Listeria monocytogenes were inhibited higher than at 10 and $15^{\circ}C$. Especially, the numbers of V. parahaemolyticus were decreased gradually at $5^{\circ}C$ even in the control sample, and about $1\;log_{10}cfu/g\;and\;1.8\;log_{10}cfu/g$ reductions were observed at 1 and 4 days, respectively. After 7 days, V. parahaemolyticus in all samples were not detected. There is a limit of a single treatment of antimicrobial film to prolong shelf-life of mackerel. The synergistic effect of antimicrobial film were shown by addition of $5^{\circ}C$ refrigeration.

• Korean Journal of Food Science and Technology
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• v.32 no.4
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• pp.806-813
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• 2000

Attempts were made to evaluate possibilities of adding water soluble chitosan to milk for improving functionality of milk, and physico-chemical and sensory properties of chitosan added milk were studied. pH and acidity of milk with ethyl alcohol washed chitosan were close to those of control. Color and consistency of chitosan added milk were better with chitosan of lower molecular weight than with high molecular weight. Chitosan of high molecular weight resulted in increased consistency and browning of milk. Milk with less than 1.0% chitosan could be sterilized at $73^{\circ}C$ for 15 sec. with minimum protein coagulation and increase of consistency. Low molecular weight chitosan$(MW\;0.2{\sim}3\;kDa)$ accelerated the growth of Bifidobacterium bifidum, showing 10 times more cell population after 32 hrs incubation. Sensory tests showed that adding chitosan to the regular city milk resulted in significant difference in color and chemical off-flavor(p<0.05). When chitosan was added to coffee milk, there was no significant difference in sensory quality from control. The storage test showed that pH, acidity, consistency and color of coffee milk with 0.5% chitosan did not change markedly during 30 days storage at 0 and $5^{\circ}C$, but changed rapidly after 16days storage at $10^{\circ}C$. Bacterial counts increased when storage temperature was high, and the growth of bacteria was delayed in coffee milk with chitosan.

• Korean Journal of Food Science and Technology
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• v.48 no.4
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• pp.301-305
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• 2016

This study was conducted to investigate changes in pH, volatile basic nitrogen (VBN), thiobarbituric acid (TBA), $a^*$ (redness), shearing force, and microbial content (total plate count; TPC) in beef during freezing storage at -1, -5, and $-20^{\circ}C$ for 21 days. TPC as an effective quality indicator was used to identify the decay point by regression analysis. The pH, TBA values, and TPC significantly increased with storage at all tested temperatures (p<0.05). VBN significantly increased and shearing force significantly decreased with storage at -1 and $-5^{\circ}C$ (p<0.05). TPC showed significant correlation with temperature at $-1^{\circ}C\;(R^2=0.891)$, $-5^{\circ}C\;(R^2=0.856)$, and $-20^{\circ}C\;(R^2=0.444)$. The decay points at -1, -5, and $-20^{\circ}C$, were 27, 52, and 84 days, respectively. The results suggest that a freezing temperature of $-5^{\circ}C$ is effective for short-term storage of beef.

• Korean Journal of Agricultural Science
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• v.14 no.2
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• pp.301-308
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• 1987

The results of experiment to find out the optimum pasteurization condition by heating from $50^{\circ}C$ to $70^{\circ}C$ at intervals of $5^{\circ}C$ and to review chemical composition, microbiological aspects and keeping quality were summarized as follows: 1. The milk sample pasteurized at $50-70^{\circ}C$ showed the decreased pH value from 6.55 to 6.42 while the contents of protein, fat, lactose and ash did not have significant changes. 2. Non-casein nitrogen and filterable nitrogen decreased while casein nitrogen and non protein nitrogen increased as the heat treatment increased. 3. The content of calcium and vitamin C decreased and artificial digestibility for the pasteruized milk increased from 14.07% to 20.00% by the heat treatment. 4. Milk pasteurized at $65^{\circ}C$ had viable bacteria counts $1.3{\times}10^4/m{\ell}$, coliforms negative, psychrotrophic bacteria $9.5{\times}10^2/m{\ell}$ and 99.0% pasteurization effect. 5. Milk pasteurized at $65^{\circ}C$ did not show significant changes in chemical composition and microbiological aspects at $4^{\circ}C$ in refrigerator.

• Korean Journal of Food Science and Technology
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• v.48 no.6
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• pp.536-541
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• 2016

The purpose of this study was to evaluate changes in the quality characteristics of mackerel fish fillet under freezing storage conditions. The changes in product quality were determined by measuring pH, volatile basic nitrogen (VBN); thiobarbituric acid (TBA), lightness ($L^*$), redness ($a^*$), yellowness ($b^*$) values, shearing force, and microbiological evaluation (Total Plate Count, TPC) during 21 days of storage at -20, -5, and $-1^{\circ}C$, and their shelf-lives were established. TPC as an effective quality indicator was used to estimate the shelf-life via linear regression analysis. The TPC increased steadily with increasing storage periods at every temperature (p<0.05) and showed a significant relationship with temperature at $-1^{\circ}C$ (r=0.949), $-5^{\circ}C$ (r=0.919), and $-20^{\circ}C$ (r=0.905). Therefore, based on TPC, the shelf life of the mackerel fillet was noted to be 32 days when stored at $-1^{\circ}C$, more than 51 days when stored at $-5^{\circ}C$, and about 2 months when stored at $-20^{\circ}C$.

• Korean journal of food and cookery science
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• v.21 no.4 s.88
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• pp.406-415
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• 2005

To evaluate the storage characteristics of Korean soups for the utilization of the Ready-Prepared Foodservice System, Yukkaejang(spicy beef and vegetable soup), Sagol-woogeojitang (bone soup with young cabbage), Kalbitang(beef short-ribs soup) and Seolleongtang(beef and bone soup) were prepared and their physico-chemical characteristics were investigated according to storage time and temperature$(4^{\circ}\;to\;20^{\circ}C)$ through analysis of pH, TBA values, Hunter color values, microbial counts, and sensory evaluation. No significant difference in pH was shown among the 4 kinds of soup while TBA values were significantly increased with storage time and temperature. Hunter color values(L, a and b values) of the Korean soups were significantly increased except Yukkaejang. In the sensory evaluation, appearance, color, flavor, taste, texture and overall acceptability of the soups decreased significantly with increasing storage time and temperature. Through correlation analysis between quality factors of treatments stored at $4^{\circ}$, the overall acceptability in Yukkaejang and Seolleongtang showed significant positive correlation with appearance, color, flavor and texture. The evaluated shelf-life of all four Korean soups was within 3 days at $10^{\circ}$, suggesting that Korean soups are applicable to ready-prepared foodservice system.

• The Korean Journal of Food And Nutrition
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• v.26 no.3
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• pp.339-344
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• 2013

This study is conducted to investigate the shelf life of pork rectum stored at refrigerated temperatures (1, 5 and $10^{\circ}C$). The pH of the boiled pork rectum ($7.1{\pm}0.1$) was slightly higher than that of the raw pork rectum ($6.7{\pm}0.1$). TBA value of the boiled pork rectum was higher than that of raw pork rectum. The TBA values of the raw and boiled pork rectum stored at $10^{\circ}C$ was rapidly increased at 4 days after beginning of preservation. The TBA values of raw and boiled pork rectum stored at $5^{\circ}C$ rapidly increased after 8 and 6 days after beginning of preservation, respectively. VBN values of both raw and boiled rectum preserved at $10^{\circ}C$ were maintained below 20 mg% for 8 days since the beginning of storage. Furthermore, it is preferred that the pork rectum was boiled for 20 minutes at $100^{\circ}C$ to restrain mesophiles, psychrophiles, and coliform bacteria effectively. Thus, the most desirable condition was when the pork rectum was consumed within 6 days and stored at $10^{\circ}C$.

• The Korean Journal of Food And Nutrition
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• v.14 no.1
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• pp.40-45
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• 2001

This study was conducted to investigate the effects of various emulsifiers on the quality of the waxy rice cake. Falling numbers of the waxy rice flour with monoglyceride, lecithin and control were not significantly different, but with sugar esther 0.5% and 1% showed higher value as 88.4 and 81 than control Initial pasting temperature of the waxy rice flour was 66.78$\^{C}$ and others were 66.45 ∼ 67.05$\^{C}$ by adding 0.5%, 1% of emulsifiers such as monoglyceride, lecithin, sugar esther. Waxy rice flour with 1% sugar ester showed the highest peak viscosity as like as falling number. Waxy rice cake wish various emulsifiers showed tendency to be slowly firming rate as compared with control. In all case, waxy rice flour with sugar ester 1% was considered to be more effective to the decrease of firming rate. Waxy rice flour with lecithin showed worse visual color than others and sugar ester provided best visual and sensory quality. After 5 days cold storage, waxy rice flour with sugar ester 1%\`s Aw was 0.875 and control\`s 0.911. These results suggested that water holding capacity of sugar ester was the best during storage.

• Journal of Conservation Science
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• v.28 no.1
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• pp.21-27
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• 2012

In the Chosun period, the noble class usually buried the dead bodies in the lime-covered tomb. Recently their costumes are excavated while maintaining the shape. However, the textiles discovered from the inside have been degradated by a body and moisture. To conserve these textiles one of the most important thing is how to clean these textiles right after the excavation. The purpose of this study is to examine the effects of wet cleaning to minimize the color change of textile remains. For this purpose, silk and cotton were dyed with natural dyes (7 red, 1 blue, 6 yellow, 4 green and 4 purple colors), then they were kept for 6 months with pork meat at $10^{\circ}C$, and were washed by four cleaning solutions (water, anionic surfactant (SDS), non-ionic surfactant (Triton X-100) and natural surfactant (saponin)) at $20^{\circ}C$ and $40^{\circ}C$. The color change was evaluated by color difference (${\Delta}E$) between non-treated and after washed samples. From the results, it was found that the color changes are significantly different depending on the washing temperature, textile material, the cleaning agents and the type of dyes.

• Journal of the East Asian Society of Dietary Life
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• v.27 no.5
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• pp.576-582
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• 2017

This study evaluated the microbial quality of dried and powdered foods during storage with increased humidity because of climate change. Five types of dried and powdered foods (dried shredded squid, wheat flour, Sunsik, red pepper powder, and roasted sesame seed) were stored at different relative humidities (RH 23%, 43%, 68%, 85%, and 100%) and changes in water activity and microbial populations were measured during storage at $35^{\circ}C$ for 15 days. The results revealed that water activity values of dried and powdered foods were significantly increased during storage when samples were stored at RH 85 and 100%. In addition, levels of total mesophilic bacteria, yeast, and mold were significantly increased after storage for 6 days or 9 days at RH 85% and 100%. However, levels of Escherichia coli and coliform did not increase significantly during storage. Based on these findings, dried and powdered foods should not be stored at high RH because the increased water activity enables microbial growth.