• Journal of Biosystems Engineering
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• v.32 no.1 s.120
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• pp.13-19
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• 2007

Storage rough rice in low temperature using the winter cold air avoids rough rice temperature increase which happens from early May, and this is possible by installing a cooling system in the top of a bin, the room between top rice level and bin ceiling. The research objective is to establish low temperature rough rice storage technique, furnishing winter cold air to rough rice, by investigating the cooling system potential of maintaining low rough rice temperature and by analyzing rough rice storage characteristics over a storage period. The rough rice storage characteristics were evaluated from January to August 2003, using a storage and dry bin of 400-ton capacity. Results of this research are as follows: Cooling bin using the cooling system in the top of the bin maintained the rice temperature less than 15$^{\circ}C$ in entire portions in August. Moisture contents and germination rates of rough rice were decreased over the storage period, on the other hand, the rough rice stored in the ambient temperature bin had relatively lower moisture contents and germination rates to compare with the bin using winter cold air. Crack ratio and acid value of brown rice in the ambient temperature bin storage had increased more than the cooling bin storage. The result indicates that the storage bin using winter cold air and the cooling system maintains moisture content and germination of rice, minimizes cracked kernel and acid value, and preserves rice quality as well.

• Food Science and Preservation
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• v.24 no.4
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• pp.491-496
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• 2017

Paddy rice is typically stored during postharvest until rice grain is processed into brown rice and milled rice by hulling and milling procedure, respectively. Recently, instead of storing paddy rice, storage of brown rice has been in the spotlight because it is more convenient and economically feasible. Different brown rice cultivars with varying amylose contents including waxy rice, medium-waxy rice, and non-glutinous rice were stored in room temperature storage for four months, and the changes in grain qualities of brown rice were evaluated. Amylose content significantly affected pasting properties in which rice cultivar with higher amylose content showed longer pasting time and higher peak viscosity. Storage also affected pasting viscosities, showing an increase in peak viscosity, but a decrease in breakdown viscosity. The changes in pasting viscosity during storage could be an important starch property for aged brown rice utilization. Waxy brown rice showed the weakest aging property in terms of free fatty acids (FFA) accumulation, whereas non-glutinous rice was more substantial grain quality against aging. The FFA values of two months storage were not significantly different from the initial FFA contents, suggesting that brown rice stored in room temperature for two months could be feasible for direct consumption of brown rice.

• Journal of Biosystems Engineering
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• v.30 no.3 s.110
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• pp.155-160
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• 2005

The objective of this research was to establish a domestically available cooling storage technique by cold-air in winter, using winter cool air ventilation fur determining rough rice cooling method in the storage and dry bin. The rough rice storage characteristics of two test conditions, winter cool-air ventilation storage and ambient temperature storage, were evaluated from January to July 2001, using a storage and dry bin of 300-ton capacity. Results of this research are as follows: Grain temperature was from $-5.1\~-8.5^{\circ}C$ after winter cool-air ventilation, and grain initial temperature for ambient temperature bin storage was $0.3\~1.9^{\circ}C$. Moisture content of rough rice decreased from $0.28\;to\;0.93\%$ and from $1.53\;to\;1.92\%$ to compare with original moisture contents for winter cool-air ventilation, and for ambient temperature bin storage, respectively. Broken ratio of brown rice from winter cool-air ventilation bin increased from $0.16\;to\; 0.92\%$, and brown rice broken ratio was from $2.24\;to\;2.86\%$ for ambient temperature bin storage to compare with initial broken ratio. Hardness of stored rice increased along storage period increase in alt storage methods, and cooling bin storage increased rice hardness of 0.271kgf: this increasing was lower then the other methods from 0.059 to 2.239kgf. Germination rates were decreased approximately 9.03, 3.14 and $3.20\%$ for upper, middle, and bottom of ventilating winter air bin, respectively, and germination rates of 2.70, 3.47 and $4.14\%$ were approximately decreased for upper, middle, and bottom parts of ambient temperature bin storage, respectively.

• Journal of Biosystems Engineering
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• v.39 no.4
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• pp.336-344
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• 2014

Purpose: In this study, the effect of milling on paddy rice stored at low temperature, the changes in grain temperature of bulk storage bags exposed at room temperature, the post-milling water content of paddy rice, the whiteness of rice, and the rate of pest incidence were investigated and data were analyzed. Methods: Changes in temperature inside the bulk storage bags kept at low temperature and grain temperature after exposure to room temperature were measured. Experiments were conducted for identifying the reasons of post-milling quality changes in paddy rice stored at low temperature. Results: It was determined that a short-term increase of water content in paddy rice was directly related to surface condensation, and that rice should be milled at least 72 h after removal from low-temperature storage, in order to completely eliminate surface condensation of paddy rice kept in bulk storage bags. It was observed that post-milling quality of rice changed, but water content was maintained at high levels for more than 18 d in rice that was milled when condensation occurred, regardless of paper or vinyl packaging. Rice whiteness rapidly decreased in rice that was milled when condensation occurred, regardless of packaging, while rice that was milled 72 h or more after removal from low temperature storage did not show any significant changes in whiteness. No pest incidence was observed up to 12 d after removal from low temperature storage, regardless of packaging. Starting at 18 d, after removal from low temperature storage, rice that was milled when condensation occurred, was affected by pests, while 24 d after removal from low temperature storage, all portions of rice were affected by pests. Conclusions: Our results suggest that changes in post-milling quality of rice could be significantly reduced by exposing paddy rice to room temperature for at least 72 h before milling, in order to allow the increase of grain temperature and prevent surface condensation.

• Korean journal of food and cookery science
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• v.16 no.6
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• pp.609-621
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• 2000

The purpose of this study was to investigate the effect of addition of jujube on lnjeulmi in storage. Jujube powder was added to lnjeulmi made from the steamed glutinous rice, glutinous rice flour and brown glutinous rice flour. As a result of the sensory evaluation, the more jujube is added, the stronger sweetness and the more bitterness is shown. The sweetness and bitterness, made from brown glutinous rice, of Deachu-Injeulmi added jujube powder is the highest, and the more jujubes are tasted. Tenderness and moistness of Deachu-Injeulmi is decreased in the order of Deachu-Injeulmi made from glutinous rice, brown glutinous rice, glutinous rice flour, tenderness and moistness is increased with less amount of jujube. Chewiness of Deachu-Injeulmi made brown glutinous rice flour is the highest and Deachu-Injeulmi made from glutinous rice is the most rough. Moisture content is decreased in the order of Daechu-Injeulmi from glutinous rice, glutinous rice flour, brown glutinous rice flour. The reducing sugar content about storage period of Daechu-Injeulmi is decreased in the order of glutinous rice, glutinous rice flour, brown glutinous rice flour, and it is dramatically reduced until 48 hours of storage. However, it is increased a little bit after 72 hours. The changes in degree of gelatinization by storage period is that it is rapidly reduced until 24 hours, and it is decreased in the order of glutinous rice, glutinous rice flour, brown glutinous rice flour. That is to say, the more jujube powder is added, the less change there is. Springiness and cohesiveness is decreased during storage. Chewiness and gumminess is higher with more jujube, and it is increased until 24hour of storage period, then it is decreased after 48 hours. Hardness of Daechu-Injeulmi made from glutinous rice flour is the highest and the more jujube is added. Hardness of Daechu-Injeulmi added jujube powder is decreased in the order of Daechu-Injeulmi of 2.5%, 10% and 7.5%. The more jujube is added, the less change of the hardness by the storage period Daechu-Injeulmi is observed, thus the speed of the retrogradation is getting slower.

• Journal of Biosystems Engineering
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• v.33 no.3
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• pp.167-172
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• 2008

The objective of this study was to investigate the adequate storage method that was able to maintain the high quality of rough rice according to storage methods and period. The quality change of the rough rice during the storage period was evaluated by storage method such as cooling bin using winter cold air, ordinary temperature bin, freezing, refrigeration and indoor storage. Moisture content, brown rice whiteness, hardness, crack ratio and germination ratio were measured in this study. Moisture content of rough rice stored in cooling bin using winter cold air and ordinary temperature bin were decreased by 0.07% and 0.42%, respectively, which were lower than the other storage method. The hardness of brown rice increased in order of storage method such as winter cooling bin, normal bin, freezing storage, refrigeration storage and indoor storage. Crack ratio by indoor and ordinary temperature bin storage were increased by 2.68% and 3.63%, respectively, whereas cooling bin using winter cold air, refrigeration and freezing storage showed below 1.0%. The highest germination rate was found in cooling bin using winter cold air. As a result, cooling bin using winter cold air can be evaluated for the adequate storage method of rough rice.

• Korean journal of food and cookery science
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• v.17 no.1
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• pp.29-42
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• 2001

The purpose of this study was 10 investigate the effect of jujube on the physicochemical properties of lnjeulmi during storage. Various lnjeulmi samples were prepared with steamed glutinous rice, glutinous rice flour, or brown glutinous rice flour along with the addition of chopped jujube at 3, 6, 9, or 12% of rice. In sensory evaluation, the more jujube was added, the stronger sweetness and bitterness were obtained. The samples made with steamed glutinous rice gave the harshest texture. Tenderness and moistness of Deachu-Injeulmi were the highest in the samples made with glutinous rice followed by brown glutinous rice flour, and glutinous rice flour, and they were increased with less amount of jujube. The chewiness of the samples made with brown glutinous rice flour' was the highest and the samples made with glutinous rice were the coarsest. The more jujube was added, the redness and yellowness of Daechu-Injeulmi were increased. The moisture content was higher in the samples made with glutinous rice followed by glutinous rice flour and brown glutinous rice flour. The reducing sugar content of samples during storage was higher in the order of glutinous rice, glutinous rice flour, and brown glutinous rice flour, and it was dramatically reduced until 48hr of storag e; however, it was increased a little bit after 72 hr. The degree of gelatinization was reduced rapidly during the first 24hr of storage, and it was decreased in the order of brown glutinous rice flour, glutinous rice flour, and glutinous rice. The springiness and cohesiveness were decreased during storage. The chewiness and gumminess were increased with the increase of added jujube, and they were increased until 24hr of storage, then decreased after 48hr. The hardness was the highest in the samples made with glutinous rice and 12% of chopped jujube showed the least change in the hardness. The more jujube was added, the less change in the hardness of samples was observed during storage, consequently retarded the speed of retrogradation

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.5
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• pp.886-891
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• 1997

The interrelation between physicochemical properties of milled rice and retrogradation of rice bread during cold storage was examined to compare the varietal difference in maintenance of rice bread quality. Twelve rice materials showed big varietal difference on physicochemical properties of rice starch such as amylose content(0.0~29.2%), gel consistency(20~98mm), and alkali digestion value(2.0~7.0). Rice bread made from milled rice of Jungwonbyeo, AC 27 and IRAT 177 exhibited soft texture and late retrogradation of rice bread during cold storage(4$^{\circ}C$). The amylose content of milled rice was closely associated with gel consistency negatively and with springiness of rice bread positively. The retrogradation of rice bread texture during cold storage was correlated with gel consistency of rice flour positively and with alkali digestion value of milled rice negatively.

• Korean Journal of Food Science and Technology
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• v.24 no.5
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• pp.470-476
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• 1992

The curd yogurt was prepared from milk added with skim milk powder or three Tongil rices of different storage period. The effect of storage period of rice on acid production by lactic acid bacteria in milk containing rice of 2%(w/v) was investigated. The effect of storage period of rice on quality of curd yogurt(sensory property, viscosity and keeping quality) was also examined. Addition of rice stimulated acid production by lactic acid bacteria more than control(milk yogurt). Storage period of rice did not significantly affect acid production by lactic acid bacteria though stimulating effect of rice on acid production was slightly different among species. Sensory property of curd yogurt added with rice was not significantly affected by storage period of rice. Apparent viscosity of curd yogurt added with rice increased in proportion to storage period of rice. Curd yogurt showed characteristics of thixotropic flow. When curd yogurt added with rice was kept at $5^{\circ}C$ for 15 days, its keeping quality was relatively good and was not markedly affected by storage period of rice.

• Journal of the East Asian Society of Dietary Life
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• v.22 no.1
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• pp.75-87
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• 2012

We investigated the physicochemical properties, pasting characteristics on the rapid visco analyzer, dough characteristics on a mixograph, product characteristics, and attributes of color and hardness of products made from a wheat bagel premix and rice bagel premix according to storage period and temperature. The pH and moisture content of stored rice bagel premix and wheat bagel premix, significantly decreased, depending on the storage temperature and time. The average of water retention capacity, alkaline water retention capacity, sedimentation value, and pelshenke value all significantly decreased temperature increases and increasing storage time. he initial pasting temperature and breakdown depending on the storage temperature and time showed a significant difference, but peak viscosity and setback with increasing storage time and temperature were not significantly different. The initial pasting temperature did not significantly affect the rice bagel premix. The midline peak time and band at 8 min of mixing time of the wheat bagel premix and rice bagel premix did not differ significantly. In product attributes, the cost of wheat bagel premix rice bagel premix and the L, a, and b value in color of wheat bagel premix showed significant difference. The hardness of wheat bagel premix according to storage time and the hardness of rice bagel premix depending on storage temperature significant difference. Therefore, storage time and temperature of wheat bagel premix and rice bagel premix and does not show significant differences. merchant can get regular and consistent, it is expected to lead to the promotion of rice consumption. Futhermore, research on better method to improve it's characteristics instead of wheat bagel premix is expected to.