• Preventive Nutrition and Food Science
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• v.3 no.3
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• pp.234-240
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• 1998

This study attempted to determine the effect of various thawing methods and storage periods on the quality of froen cooked rice. Frozen cooked rice was thawed at four different methods, such as pressure cooking, conventional cooking, microwave heating and thawing at room temperature after 10 days, 30days and 90 days frozen storage. We conducted a physico-chemical analysis (moisture content, dehydration rates, degree of gelatinization, color value and texture) and sensory evalution on the frozen-thawed cooked rice. The study showed that there were no significant differences on the quality characteristics of frozen-thawed cooked rice during the storage period of 90 days. However, the thawing method of pressure cooking caused high moisture content, rapid dehydration rates, and a high degree of gelatinization on the cooked rice. Thus, the desirabililty for the rice diminished becaused of the excess moisture content and the change of appearance and testure in the rice due to the high temperature. There were similiar quality characteristics to the cooked rice after forzen-thawing whether by conventional cooking or by microwave heating and just after cooking. Thawing at room temperature also caused a significant decrease in quality characteristics.

• Food Science of Animal Resources
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• v.31 no.3
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• pp.339-348
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• 2011

Ground pork containing 0, 1, 2, or 3% rice bran fiber was prepared. pH increased as the amount of rice bran fiber added increased (p<0.05) but decreased during storage. The lightness and redness values of the raw ground pork decreased with the addition of rice bran fiber, and ground pork containing 3% rice bran fiber had the highest yellowness value during early storage (p<0.05). Moreover, adding rice bran fiber was not associated with color stability during storage. Samples containing 2 or 3% rice bran fiber had improved cooking loss, hardness, gumminess, and chewiness. Furthermore, rice bran fiber enhanced tenderness, juiciness, and overall acceptability on a sensory evaluation. These physico-chemical properties were maintained to the final storage period. The best results were obtained with ground pork containing 2 or 3% rice bran fiber. Rice bran fiber combined with useful antioxidants may be a more effective approach to increase the stability of ground pork during cold storage.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2002.08a
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• pp.54-63
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• 2002

Post-harvest technology for rice was focused on in-bin drying system, which consists of about 100, 000 facilities in 1980s. The modernized Rice Processing Complex (RPC) and Drying Storage Center (DSC) became popular for rice dry, storage, process and distribution from 1990s. However, the percentage of artificial drying for rice is 48% (2001) and the ability of bulk storage is about 15%. Therefore it is necessary to build enough drying and bulk storage facilities. The definition of high quality rice is to satisfy both good appearance and good taste. The index for good taste in rice is a below 7% of protein, 17-20% of amylose, 15.5-16.5% of moisture contents and high concentration of Mg and K. To obtain a high quality rice, it is absolutely needed to integrate high technologies including breeding program, cropping methods, harvesting time, drying, storing and processing methodologies. Generally, consumers prefer to rice retaining below b value of 5 in colorimetry, and the whiteness, the hardness and the moisture contents of rice are in order of consumer preference in rice quality. By selection of rice cultivars according to acceptable quality, the periods between harvesting time and drying reduced up to about 20 days. Therefore it is necessary to develop a low temperature grain drying system in order to (1) increase the rate of artificial rice drying up to 85%, (2) keep the drying temperature of below 45C, (3) maintain high quality in rice and (4) save energy consumption. Bulk storage facilities with low temperature storage system (7-15C) for rice using grain cooler should be built to reduce labor for handling and transportation and to keep a quality of rice. In the cooled rice, there is no loss of grain quality due to respiration, insect and microorganism, which results in high quality rice containing 16% of moisture contents all year round. In addition, introducing a low temperature milling system reduced the percentage of broken rice to 2% and increased the percentage of head rice to 3% because of proper hardness of grain. It has been noted that the broken rice and cracking reduced significantly by using low pressure milling and wet milling. Our mission for improving rice market competitiveness goes to (1) produce environment friendly, functional rice cultivars, (2) establish a grade standard of rice quality, (3) breed a new cultivar for consumer oriented and (4) extend the period of storage and shelf life of rice during postharvest.

• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.3
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• pp.504-512
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• 1996

Changes in quality of cooked rice after microwave reheating were evaluated. Ceramic coated microwave oven reduced a reheating time(1 min). Storage temperature, storage time and microwave reheating did not affect the color value of cooked rice after microwave reheating. Hardness of cooked rice after microwave reheating decreased in frozen storage treatment. Photomicrographs of cross-section of cooked rice after microwave reheating showed restoration of starch. Effect of storage temperature and time were not significant in appearance, aroma, taste and texture of cooked rice after microwave reheating for sensory evaluation test.

• Applied Biological Chemistry
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• v.32 no.3
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• pp.265-269
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• 1989

Effects of air-tighteness of packing material and aluminum phosphide fumigation on mortality of rice weevil were studied during rice storage. Air-tight storage of rice in sealed bag of 0.1mm PE film or sealed glass bottle reduced the deterioration of rice quality and killed all rice weevils after 60 days storage, while paper bag, PP bag and straw bag storage kept them alive. One tablet of aluminum phosphide in one cubic meter heap of rice packed in PP bag was sufficient to kill all rice weevil in it, when the heap was covered by 0.15 mm PE film during fumigation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.7
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• pp.915-920
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• 2007

Rice flour milled from spray-washed rice was stored at $5^{\circ}C$, $20^{\circ}C$, and $35^{\circ}C$ for 4 months and changes in flour properties during the storage were investigated. Moisture content of rice flour tended to decrease during the storage, and the reduction in the moisture content was higher at higher storage temperature. Compared to dry-milled rice flour, lightness of the rice flour milled from spray-washed rice was slightly higher and tended to increase slightly during the storage. Rapid Visco-Aanlyzer (RVA) peak viscosity of rice flour milled from spray-washed rice was higher throughout the storage period, compared to dry-milled rice flour. The RVA peak viscosity was lower in the order of rice flour stored at $5^{\circ}C$, $20^{\circ}C$, and $35^{\circ}C$. Little changes in setback viscosity were observed in rice flour stored at $5^{\circ}C$ and $20^{\circ}C$, while an increase in the setback viscosity was found in rice flour stored at $35^{\circ}C$. Total bacteria count was consistently lower in the rice flour milled from spray-washed rice, suggesting that spray-washing prior to milling could lower microbial growth of rice flour during storage.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.293-293
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• 2017

The objective of this study was to determine physicochemical changes in brown rice during ageing condition. Five varieties (Haiami, Ilpum, Daecheong, Jungwon, and Dasan1) of brown rice were stored at $35^{\circ}C$ for 8 weeks. Crude protein and lipid content, seed germination rate, fat acidity, tocol content, TOYO glossiness value, pasting properties, and composition of storage proteins were measured to evaluate its quality during storage. The isomers of tocols (tocopherol and tocotrienols) were quantified using HPLC system, and the pattern of variation in rice storage proteins was examined through electrophoresis of protein extracts. Seed germination rate decreased by 2.7 times, whereas the fatty acid value dramatically increased by 4.8 times after 8 weeks of storage. Toyo glossiness value of cooked milled rice considerably affected by storage period, and the pasting properties of milled rice were also influenced by storage. The final viscosity and breakdown value increased, but setback decreased during storage. In terms of storage protein, proportion of prolamin (14.3 kDa) and globulin (26.4 kDa) increased, whereas percentage of glutelin (34-39 kDa and 21-22 kD) decreased. Furthermore, the contents of total tocol and isomers decreased in stored brown rice.

• The Korean Journal of Food And Nutrition
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• v.36 no.6
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• pp.581-587
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• 2023

Brown rice has various health benefits; however, it is more difficult to cook and has a harder texture as compared to milled rice. In this study, the effect of the sous-vide cooking method on starch retrogradation and textural properties of brown rice was investigated by comparative analysis with conventionally cooked brown rice based on moisture content assay, evaluation of the textural property analysis, and differential scanning calorimetry (DSC). The results of the study are as follows: First, the moisture content of sous-vide cooked brown rice was higher than in the conventionally cooked brown rice. Second, the sous-vide cooked brown rice has lower hardness, higher adhesiveness, and lower retrogradation enthalpy during storage than conventionally cooked brown rice. Finally, the retrogradation properties of cooked brown rice during storage were analyzed by DSC. The enthalpy increased more rapidly in the case of conventional cooked brown rice, reaching 1.58 J/g after 3 days of storage. This indicated that sous-vide cooking is effective in preventing retrogradation of rice during storage.

• Food Engineering Progress
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• v.15 no.4
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• pp.311-317
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• 2011

Rice bread premix was prepared from rice flour and vital wheat gluten, and the changes in the premix properties were studied during storage at 5, 25 and $35^{\circ}C$ for 4 months. Optimum level of 14-17% vital gluten could be added to the rice bread premix. The pH, sedimentation value, and Pelshenke value of the rice bread premix decreased with increasing storage period, whereas water retention capacity (WRC) and alkaline water retention capacity (AWRC) increased with increasing storage temperature. Mixograph peak time increased with increasing storage temperature. Rapid Visco Analyser (RVA) peak viscosity and setback values increased with increasing storage temperature and period. Decreased loaf volume was observed at the rice bread prepared from the premix during storage, especially at higher temperatures. Crumb hardness of the rice bread prepared from the premix increased during 4-month storage period.

• Applied Biological Chemistry
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• v.36 no.3
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• pp.146-153
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• 1993

The changes in water uptake rate, cooking property, color of rice grain, gelatinization property of milled rice during storage were studied. The water uptake rate constant of milled rice during storage at $4{\sim}30^{\circ}C$ for 3 months decreased, which was more pronounced at elevated storage temperatures. The activation energy of water uptake was different below and above $25^{\circ}C$ of storage temperature. The activation energy after storage for 3 months below and above $25^{\circ}C$ was 608 and 1269 cal/mole, respectively. The rice grain became harder and the cooking time was prolonged by $3{\sim}8$ minutes upon storage. The cooking rate constant was linearly decreased as a function of storage time. The activation energy of cooking after 1 month of storage was 235 cal/mole, which was increased by 1.7 times after storage of 1.5 months and thereafter by 1.2 times with the increase of 0.5 month. There were no significant changes in color of milled rice grains during storage at $4^{\circ}C$, but the increase of b value was observed at higher temperatures. The Initial pasting temperature of rice flour remained essentially unchanged during storage, but the peak viscosity consistently increased with the increase of storage time and temperature. The gelatinization temperature of rice flour by differential scanning calorimetry was not changed but enthalpy of gelatinization was decreased during storage.