• Korean Journal of Food Science and Technology
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• v.29 no.5
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• pp.919-924
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• 1997

The changes in physicochemical properties of cooked rice stored in an electric rice cooker at different temperature (63, 66, 69 and $72^{\circ}C$) were investigated. The growth of thermophilic bacteria was gradually increased in all samples with storage time up to 6 hours and increased rapidly afterward. The bacterial growth rate was higher during storage at low temperature than at high temperature, and the bacterial number generally reached the maximum at 18 hours of the storage. The number of bacteria in sample stored at $63^{\circ}C$ was increased to $10^6$ CFU/g after storage for 6 hours. The heat treatment at 6 hours of storage decreased the bacterial number to $10^5 $ CFU/g at 8 hours of storage. Bacterial number was gradually increased with storage time after the first heat treatment. When the sample was reheated after 8 hours of storage, the bacterial number was reduced to the level at which off-odor was not detected after storage for 24 hours. During the storage, moisture content of heat-treated sample was lower than that of sample stored at $63^{\circ}C$ but higher than that of sample stored at $72^{\circ}C$. The L value of heat-treated sample was higher than that of the sample stored at $72^{\circ}C$, but lower than that of the sample stored at $63^{\circ}C$. The b value showed an opposite trend to the L value with regard to the storage temperature. Changes in texture were not remarkable during the storage for the sample heat-treated and stored at low temperature. The occurrence of off-odor and browning was depressed in the heat-treated sample, and the texture and overall eating quality were more acceptable than the samples stored at low temperature.

• Korean Journal of Food Science and Technology
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• v.26 no.4
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• pp.382-388
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• 1994

Because of its restrictive harvest from spring to summer, It is necessary to preserve raw ascidians, Halocynthia roretzi, for the purpose of processing regardless of season. We evaluated low Temperature tolerance of ascidian and conditions for cold storage to secure the quality of the stock. To retard the browning of meat rapidly occurred after sucking, ascidians were blanched for 10 seconds in 10% boiling salt solution or dipped for 60 seconds in 0.2% $NaHSO_3$ solution, respectively. The samples were stored in ice, at $-17^{\circ}C$ or $-35^{\circ}C$ for 85 days, respectively. Changes in VBN, glycogen, brown pigment formation, total carotenoid, nucleotides and their related compounds during the storage were determined, and sensory evaluation of quality was also practiced. VBN and brown pigment formation were rapidly increased. Glycogen was gradually decreased and then not detectable after 85 days in case of ice storage. Lipophilic brown pigment was higher than hydrophilic and rapidly increased during storage. The result of sensory evaluation showed that the ascidian treated in 0.2% $NaHSO_3$ was good for 85 days of storage at $-35^{\circ}C$ . Judging from the results of chemical experiment and sensory evaluation, the quality of ascidian treated in 0.2% $NaHSO_3$ and stored at $-35^{\circ}C$ was better than that of other samples.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.2
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• pp.166-172
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• 2002

The top shell, Omphalius pfeifferi capenteri meat vacuum-packed in can (diameter$\times$height, 74.1mm$\times$50.7mm) were heated at 115$^{\circ}C$ up to $F_0$ values of 5 min, 10 min, 15 min and 20 min, and the changes in food components were studied. After 14 days storage at 37$^{\circ}C$ and 55$^{\circ}C$, no growth of microorganism and panelling were recognized from the canned meats which were sterlized at 115$^{\circ}C$ with $F_0$ value of S min and over. In the case of proximate composition of the canned meats, the moisture content decreased with the increase of $F_0$ value, while crude protein increased. The increase of volatile basic nitrogen content, pH and degree of browning and the decrease of mineral, total amino acid, free amino acid, trimethylamine oxide, total creatinine contents and yields were observed during thermal processing, In sensory evaluation on color, texture and taste in the canned meats, no significant difference was observed among a boiled sample and the canned meats heated at re value of 10 min and below. But, in the canned meats heated at $F_0$ value of over 15 min, its sensory scores decreased with the increase of $F_0$ value. From these results, the reasonable $F_0$ value for preparation of the heat-treated top shell meats was in the range of 5$\~$10 min.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.8
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• pp.1141-1149
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• 2011

The objective of this study was to analyze quality changes during storage of fresh-cut produce (leafy vegetables and condiment vegetables) as a function of packaging and storage temperature. Fresh-cut produce was washed using a three step cleaning process and was packed in vacuum packaging (green onion, hot pepper, onion, baechu) and perforated film packaging (buchu and perilla leaf). The effects of packaging method and storage temperature on quality of fresh-cut produce were determined by analyzing total plate counts, E. coli, coliform groups, moisture content, pH, Aw, surface color, and exterior quality during storage at 4 and 10$^{\circ}C$. According to the results, surface color change and microbial growth were delayed during storage at 4$^{\circ}C$. Additionally, E. coli was not detected during storage. Generally, moisture content decreased in the perforated film packaging. Changes in surface quality such as skin browning, softening of tissue and chlorosis at 4$^{\circ}C$ were inhibited, whereas rapid vacuum annealing and changes in color and flavor were observed in the sample stored at 10$^{\circ}C$. The result indicated that overall quality of the fresh-cut produce at 4$^{\circ}C$ was well maintained. The perforation in packing materials did not significantly increase the number of microorganisms on buchu and perilla leaf. The proper packaging methods and temperature may beneficial effect on microbial safety, quality and thus result in longer shelf-life fresh-cut vegetables during distribution.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.3
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• pp.348-356
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• 2008

For the effective use of rainbow trout, the seasoned and dried rainbow trout slice (SR) was prepared and its characterization was compared with the commercial skipjack tuna (CSS) and pork products (CSP) by determining chemical components and sensory evaluation. The moisture content of SR, 20.5%, was lower, and the lipid content of SR, 7.5%, was higher than those of commercial products, CSS and CSP. The protein content of SR (41.4%) was higher than that of CSS (28.6%), but lower than that of CSP (50.1%). The water activity of SR was 0.654, which was lower than those of CSS and CSP, 0.724 and 0.771, respectively. According to the results, the color of SR was lower in lightness and redness and higher in browning index and ${\Delta}$E value than that of commercial products. The texture of SR was harder than that of CSS, but softer than that of CSP. According to the result of taste value, the taste of SR was stronger than that of CSP, while weaker than that of CSS. The mineral (Ca, P, and Fe), total amino acid contents, and the n-3/n-6 of SR showed significant levels in nutrition and health functional senses.

• Journal of Bio-Environment Control
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• v.27 no.4
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• pp.312-318
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• 2018

We investigated the effect of postharvest treatments of calcium chloride, lysophosphatidyl ethanolamine (LPE) or 1-methylcyclopropene (1-MCP) on fruit quality during simulated marketing in Asian pear (Pyrus pyrifolia Nakai). 'Whangkeumbae' pear fruits were immersed in 0.25, 0.5 or 1.0% $CaCl_2$ solution with or without ultrasound (40kHz) at $25^{\circ}C$ for 3min followed by storage at $1^{\circ}C$ for 30 days simulated as abroad exportation. After simulated marketing at $25^{\circ}C$ and 80% relative humidity (RH) up for 10 days, quality parameters were evaluated. Results indicated that the ultrasound and $CaCl_2$ treatment had a synergic effect on keeping the green skin color which showed lower $a^*$ value. The combination treatment of ultrasound and 0.5% and 1.0% $CaCl_2$ significantly reduced internal browning disorders, although severe skin blemish disorder (20-23%) occurred in 1.0% $CaCl_2$ treatment. 'Wonhwang' pears were immersed in 1,000ppm LPE for 3 minutes or were fumigated in 1,000 ppb 1-MCP for 12 hours, respectively. The results of the fruit quality survey during the 21 days of distribution period are as follows. The 1-MCP treatment was maintained at a constant flesh firmness of 33N or higher during the distribution period. The LPE treated fruits had a lower physiological disorder index than the untreated group, but showed a relatively higher value than the 1-MCP treated group. In the case of 1-MCP treatment, the fruit respiration rate was significantly lower than of untreated control ($6.0mL{\cdot}kg^{-1}{\cdot}hr^{-1}$) during the simulaed marketing period. Consequently, it was expected that the postharvest treatments of 0.5% calcium chloride in pararell with ultrasound and 1-MCP fumigation can help to maintain Asian pear quality during distribution period.

• Food Science and Preservation
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• v.24 no.6
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• pp.734-745
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• 2017

The effects of combination treatment with sulfur dioxide generating pad ($SO_2$ pad) and modified atmosphere packaging (MAP) on grape quality were examined under simulated exporting condition and actual export to Los Angeles, USA. The 'Campbell Early' grape harvested in Hwaseong, Gyeonggi was precooled at $0^{\circ}C$, selected and packaged at $10^{\circ}C$, and stored at $0^{\circ}C$ for 30 days. The treatment was as follows: general export packaging (control), only $SO_2$ pad, combination of $SO_2$ pad and MAP (perforated polyethylene film, $SO_2$ pad+MA). In case of control and only $SO_2$ pad under simulated exporting condition, the grape quality changes with storage time were decrease in hardness and brush length, increase in stem browning, and increased in shattering rate. The treatment of $SO_2$ pad+MA was the most effective in preserving the grape quality since $SO_2$ concentration inside the package remained around 2.9 ppm by MA film. Grape exports from harvest to local distribution of the USA took 30 days, and only $SO_2$ pad+MA package showed no fungus, maintained brush length and rachis color, and was lowest at 4.0% of shattering rate since the concentration of $SO_2$ in the package was about 4.0 ppm. As a result, it was considered that the combination of $SO_2$ pad and MA was the most effective way to maintain freshness of grape during long-term marine transportation and extend the shelf-life in exporting countries.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.6
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• pp.862-868
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• 2005

Korean mountain ginseng roots were freeze-dried at $-70^{\circ}C$ and extracted by different extracting solution conditions to investigate chemical compositions of extracts. The soluble solid content of the extract from $7.04\~13.45\%\;and\;50\%$ EtOH and MeOH extracts were higher than those of other extracts. $100\%\;water\;and\;90\%$ EtOH extracts gave the highest Brix with $19.98\%$\;and\;19.65\%$, respectively. pH of the extracts were ranged from $5.82\~6.60$. Browning color at 470 nm of the extract were high value in 50$\%$ EtOH extract. In case of Hunter's color value, L value of extract was higher in $100\%$ water extract (21.28) than EtOH extract $(17.18\~21.02)$, a and b values of extract were the highest in $100\%$ water (-0.12) and $90\%$ MeOH extract (1.34). The contents of free sugars in the EtOH extract were increased with the ethanol concentration. Sucrose contents of $90\%$ EtOH and MeOH extracts were 6,159 mg/100 g and 5,238 mg/100 g. Major organic acids of the extract were citric and malic acids. Major free amino acids of the extract were L-arginine, L-proline, $\gamma$ -amino-n-butyric acid, alanine and aspartic acid. The highest ginsenoside content was shown to be about $10.50\%\;in\;90\%$ MeOH extract. Major minerals of extract were P, K, Na, Mg and Ca.

• Korean Journal of Food Science and Technology
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• v.41 no.4
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• pp.386-391
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• 2009

To verify the possibility of manufacturing a germinated rough rice tea, germinated rough rice was roasted at 200, 220, and $250^{\circ}C$ for 10, 20, and 30 min. The treated rice powder was then put into tea bags and leached for 1, 3, and 5 min, after which their antioxidant, physicochemical, and sensory characteristics were compared. The total polyphenol content and 2,2'-Azino-bis-(3-ethyl benzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activities of the germinated rough rice tea increased as the roasting temperature increased as well as in response to increased roasting and leaching times. Furthermore, the greater the roasting temperature, roasting time, and leaching time, the greater the increase in total soluble solid contents. Moreover, the turbidity and browning index of the germinated rice tea rose as the roasting temperature, roasting time, and leaching time increased. Additionally, the pH tended to decrease as the roasting temperature, roasting time, and leaching time increased. Evaluation of the sensory characteristics of the germinated rice tea revealed that the formation of a Maillard reaction product in the course of heating the rice added a unique flavor, which led to increase preference for the color, flavor, and taste, and therefore, the overall preference.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.5
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• pp.594-600
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• 2009

Quality characteristics of white lotus leaf tea (LLT) fermented with or without mycelial Paecilomyces japonica were investigated. Extraction yield and browning index of hot water extract from non fermented and fermented LLTs were higher than those of ethanol extract (p<0.05). In all LLTs, nutritional components such as total free sugar, free amino acids and minerals of hot water extracts were higher than those of ethanol extracts except for total organic acids (p<0.05). Contents of total free sugar and organic acids were markedly increased through fermentation process of mycelial Paecilomyces japonica. in the same solvent extracts (p<0.05). Contents of most taste components of fermented LLT were increased by mycelial solid fermentation (p<0.05), but total free amino acids of two extracts were decreased in the range of $37.1{\sim}67.2%$ as compared to non-fermented LLT. Fifty-nine volatile compounds were identified by GC and GC-MS, including 11 aldehydes, 14 alcohols, 11 ketones, 11 hydrocarbones and 12 acids. Aldehyde and ketone compounds were more identified in fermented LLT than in non-fermented LLT being abundant alcohol compounds by simultaneous steam distillation and extraction. The most abundant compounds of LLT identified in this study were curcumene followed by 2,6-bis(1,1-dimethylethyl)-4-methyl-phenol and cyclohexen. Main compounds of fermented LLT were 2,6-bis(1,1-dimethylethyl)-4-methyl-phenol, butanoic acid, furfural, benzaldehyde, hexanoic acid and 2(3H)-furanone.