• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.69-69
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• 2017

Due to the lack in storage facility, considerable amount of rice is stocked in the open air, which causes increased stale flavor and deteriorates palatability and merchantable quality. Lipoxygenase-3(LOX-3) is involved in the production of volatile constituents in stored rice, and the development of stale flavor is delayed in LOX-3 null rice. LOX activity in the rice grain is localized in bran fraction and the tropical Japonica cultivar 'Dawdam' was reported that the absence of LOX-3 is inherited as a simple recessive trait. Also, it was reported that the peroxidation of unsaturated fatty acids occurs at lower levels in the 'Dawdam' bran fraction during storage than in rice varieties with LOX-3. This study was conducted to develop LOX-3 null rice lines using 'Dawdam' and investigate changes of physicochemical properties of the lines stored at different storage temperatures and periods. So we analyzed texture, toyo glossiness value, germination rate and lipoxygenase activity of 15 LOX-3 null rice lines on the condition of which rough rice had been stored at different temperatures (high temperature condition at $35^{\circ}C$ and low temperature condition at $15^{\circ}C$ for 4months. Hardness and stickiness of the lines tendered to be increased when it was stored at high temperature and adhesiveness, springiness, cohesiveness and chewiness was not considerably different according to storage temperatures and periods. The germination rate of HR29062-B-98-2-1-B among LOX-3 null rice lines was higher than another lines, 99.3, 94.0% after 4months stored at low temperature and high temperature, respectively. The lipoxygenase activity was 3,304, 1,601unit/mg protein after 4months stored at low temperature and high temperatures, respectively. So, it is thought that this line will be useful to breed rice varieties with high storability after tested on agricultural traits.

• Korean journal of applied entomology
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• v.42 no.4
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• pp.329-334
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• 2003

To study the interaction between rice weevil and storage molds, the preference of rice weevil to the four mold species (Aspergilus candidus, A. niger, A. flavus and Penicillium spp.) and the resulting reproduction of the rice weevil were observed. The rice weevil preferred rice grains contaminated with the molds to autoclaved ones regardless of the mold species tested. Among the four mold species, A. candidus and Penicillium sp. were highly preferred than the others. Reproduction of the rice weevil was higher on the grains contalminated with A. candidus and Penicillium sp., than on autoclaved ones, but was lower on the grains contaminated with A. flavus. The partial disagreement between preference and reproduction of the rice weevil might be a suggestion that both the weevil behavior adapting nutritional requirements and the process of the long intensive coadaptation of the rice weevil and storage molds requiring similar moisture niche are the major components of the population interaction between the weevil and molds.

• Journal of Food Hygiene and Safety
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• v.14 no.1
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• pp.9-16
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• 1999

Effect of storage temperature, washing, and cooking on postharvest-treated pesticide residues in polished rice was investigated. After being treated with each 500 mg/kg of captan, carbaryl, phenthoate, fenthion, fenitrothion, chlorpyriphos-methyl, pirimiphos-methyl, the polished rice was stored for 8 weeks at 4 and 3$0^{\circ}C$, respectively. The penetation rate of carbaryl was the highest as 27.5% and the others, 13 to 18%. The half lives of pesticide residues were estimated as 30 to 230 weeks at 4$^{\circ}C$, but 1 to 12 weeks at 3$0^{\circ}C$. The residues were reduced faster at 3$0^{\circ}C$ than at 4$^{\circ}C$. The half lives of pesticide residues by water washing were estimated as 0.7 to 4.6 trials and the removed with the washing trials. The residues of captan and carbaryl in cooked rice were removed 100 and 98%, respectively, comparing to initial residues concentration in treated rice but those of other 5 pesticides were removed 80%.

• Journal of Biosystems Engineering
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• v.12 no.2
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• pp.44-59
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• 1987

The objectives of this study were to analyze and develop the model systems of rice post-harvest systems from drying to processing, and to develop a bulk system among them which requires minimum system cost and less operating time. The significance of this study was the development of a computer program (PPSARR). The PPSARR makes it possible to evaluate quantitatively the performance and economics of the rice post-harvest systems. The results show that the rice post-harvest bulk system requires less time and cost such as 37-60% and 46-59% of those of the sack system, respectively. Also, the former requires less manpower than the latter. For not more than 1,800 ton of rough rice production, the bulk system which is "drying & storage by IBDS-transport-milling" is recommended, and for more than 1,800 ton, the one which is "drying & storage by IBDS - transport - storing at flat storage improved - transport - processing by RPC" is recommended.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.3
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• pp.266-270
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• 1991

Storage in the form of brown or milled rice saves space and cut cost rather than storage of rough rice, the common way of grain storage in Korea. But, brown or milled rice may be more susceptable to grain aging and sensory change than rough rice. Rice stored in government warehouse for 20 months after harvest was hulled into brown or milled rice and packaged with kraft paper bag (paper package), polyprophylen (PP package), and polyethylene (PE package). Then, after those rice packages were stored under room condition for one year, we investigated germinability, fat acidity, and sensory change to determine milling and packaging effects. Germinability of rough and brown rice was decreased significantly after long-term storge. In germination rate, Chucheong cultivar was lower than Milyang #23, brown rice was lower than rough rice, but there was no differences within packaging materials. TTC test which had a significant correlation with germinability can be used as a handy procedure for predicting grain germination. Fat acidity was increased as the order of rough < milled < brown rice in terms of milling, and PP < paper < PE package in terms of packaging materials. Especially, storage of brown rice increased fat acidity above 30 mg KOH, indicating one of characteristics of grain aging. To prevent from high fat acidity it was necessary to store in forms of rough grain with paper or PP packaging and milled rice with paper, or PP, or PE packaging. In sensory test of stored grain, eating quality in brown rice was the worst because of acidification of fatty acid. Also, eating quality of stored grain became worse as fat acidity increased.

• Korean journal of food and cookery science
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• v.29 no.6
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• pp.679-690
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• 2013

This study was conducted to investigate the properties of rice makgeolli stored with different quantities of Cheonnyuncho fermentative extract (1%, 3%, 5%). Plain rice makgeolli(control)and cheonnyuncho-containing rice makgeolli(cheonnyuncho makgeolli) were stored and ripened for 0, 5, 10, 15 and 20 days at $5^{\circ}C$. The mineral contents of cheonnyuncho Makgeolli was higher than that of rice makgeolli. At the end of storage periods, the pH value of 1% cheonnyuncho makgeolli was higher than that of rice makgeolli. Of the major organic acids found in cheonnyuncho makgeolli (succinic, lactic, acetic, phosphoric, and malic), succinic acid had the highest concentration. Similarly, of all the free sugars, glucose was the most prominent. Before storage, hunter color L and b values were the highest in control followed by 1%, 3% and 5% cheonnyuncho makgeolli. At the end of storage period, color a value decreased in 1% cheonnyuncho makgeolli, whereas it increased in 3% and 5% cheonnyuncho makgeolli. The antioxidative effect of makgeolli was seen in 3% cheonnyuncho makgeolli. Total viable counts were the lowest in 3% cheonnyuncho makgeolli at the end of storage periods. A sensory evaluation test showed that the taste of cheonnyuncho-containing makgeolli was significantly better than that of control. From these results, we conclude that addition of cheonnyuncho fermentative extract at a concentration of 1-3% is suitable for the manufacturing of makgeolli products.

• Food Science and Preservation
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• v.10 no.1
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• pp.70-74
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• 2003

The distribution of mesophilic and thermophilic bacteria in milled rice was not different according to growing land and variety of rice. However, The number of these bacteria were abundant in milled rice of lower milling degree or longer storage period. The growth of thermophilic bacteria in cooked rice of electric rice cooker was rapidly increased during storage of lower temperature below 75 $^{\circ}C$. Thermophilic bacteria were not appeared just after cooking. After cooked rice was stored far 18∼24 hon thermophilic bacterial growth was rapidly increased by changing spore to vegetative cell. The positive relation between cell number of thermophilic bacteria and occurrence of off-odor was slightly observed. The number of thermophilic bacteria in upper cooked rice of oven and was higher than those in inner and lower cooked rice. Major volatile compound of milled rice cooked and stored in electric rice cooker was hexanal oriented from rice. After long storage, it was confirmed that furan was major volatile compound as off-odor.

• Korean journal of food and cookery science
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• v.2 no.2
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• pp.43-54
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• 1986

Back-pyun is a kind of rice cake made by steaming rice flour added sugar, water and salt and garnished with shredded chestnuts, dates, mushrooms and pinenuts. The Back-pyun has been widely used in Korean celebrations. This study aimed to compare and determine the effects on sensory characteristics and texture of Back-pyun 1) when the proportion of glutinous rice, added i.1 making Back-pyun, is 0%, 5%, 10%, 15%, 20%, 25% and 30% 2) then it reheated after storage for 0,24, 48 and 72 hours. Evaluation was conducted through sensory evaluation and objective evaluation. The results are as follows : 1. In sensory evaluation, color of Back-pyun turned yellow as the addition level of glutinous rice increased and then by reheating after storage for 24, 48 and 73 hours. Coarseness was not significantly different as the addition level of glutinous rice increased before storage. But Back-pyun reheated after storage for 24,48 and 72 hours were significantly different by the addition level of glutinous rice. Softness, dryness and crumblyness tended to decrease as the addition level of glutinous rice increased and by reheating after storage for 24, 48 and 72 hours. The most favorite tendency on the appearance was at the addition level of glutinous rice of 5%. Texture and overall preference were better at the addition level from 10% to 20% than any other levels. 2. Rheometer measurement indicated that compression force, gumminess ana chewiness tended to increase as the addition level of glutinous rice increased and decrease by the storage conditions. But work ratio and recovered height did not have much effect the addition level of glutinous rice and the storage conditions. Compression force of Back-pyun (not reheated) tended to increase by the storage time and the addition level of glutious rice. Especially it showed remakably increasing tendency during 24 hours storage (at $4^{\circ}C$) 3. Moisture content tended to increase by the addition level of glutinous rice and decrease by the storage time. But moisture content of Back-pyun reheated after storage for 24 hours stowed the increasing tendency. 4. Softness of Back-pyun had significant relationship with compression force and work ratio. Dryness and crumblyness had significant relationship with work ratio. Therefore compression force and work ratio represented the texture of Back-pyun.

• Korean Journal of Food Science and Technology
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• v.1 no.1
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• pp.51-61
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• 1969

In order to eliminate the considerable loss of rice by insects, to protect the human body from toxin excreted by some microbes, and to promote the storage efficiency of rice by employing the irradiation, the following experiments were carried out. Two varieties of rice, Paldal and Nongkwang polished and unpolished by the conventional methods and were packaged in polyethylene bags. After irradiating to the doses of 6-400 Krad of gamma-radiation from a $Co-^{60}$ source the samples were stored at the room temperature $20^{\circ}C$ for 8 months. The effects of radiation in terms of the removal of insects and microbes and the changes of chemical components (such as moisture, amylose, free sugar, and rancidity) were determined monthly from march to October during the storage. 1) Infestation of insects was greatly influeneed by the packaging materials used. There was no infestation in rice being packaged in a polyethylene bag, while as the rice packaged in a straw sack was infested in two months of the storage. 2) Some yeast and molds survived 400 K rad of radiation. Sterilizing dose to inhibit reproduction and growth of microbes was presumed to be higher than 400 K rad. Yeast mainly were found on the surface of rice, but mold were embeded into rice kernels by mycelium. 3) Changes of moisture contents during storage was not affected by radiation but was by humidity of the storage room. 4) Amylose content in starch increased with increasing dose of radiation and with the length of storage time, indicating possible depolymerization of starch molecules. 5) Free reducing sugar content was not affected by radiation and decreased with storage time. 6) Rancidity also increased with does and storage time.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.spc1
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• pp.25-29
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• 2006

This study was carried out to investigate physiochemical properties and factors related with eating quality in the rice and paddy rice with different storage methods. As storage period was longer and temperature was higher, the b values of chromaticity and degree of fatty acid were increased, and the b value of room temp. was higher than that of low temp. In the varieties, the b value of Samcheonbyeo was the highest among varieties. also b value of Gancheokbyeo and Sae-gyehwabyeo were more increased than those of Dongjinbyeo and Hojinbyeo. Toyo meter values were significantly different according to storage temperature and period. Toyo meter values in storage of low temp. small decreased from 8 month after storages and that of loom temp. was severe decreased from 2 month after storages. In storage of low temp, Toyo meter values in storage of low temp. $(5{\sim}10^{\circ}C)$ was the lowest, and those of the early varieties were the most decreased. Degree of fatty acid of brown rice was increased from 2 month after storages and those of low temp. was severe increased. So, they made rice quality and eating quality to be deteriorated.