• Journal of Biosystems Engineering
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• v.26 no.5
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• pp.469-474
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• 2001

Milling the rice with low moisture requires more energy, produces more cracked rice, and results in reducing taste of cooked rice. Accordingly, it is necessary to add moisture to the rice with low moisture to obtain optimum moisture level for milling and taste of rice. This study was performed to evaluate the influence of initial moisture content and absorption rate on rice crack, milling energy and whiteness of milled rice and to obtain the information for design of rewetting system mounted on stirring device in grain bin. The tests were conducted for the four levels of initial moisture content in the range of 11.4 to 14.5%(w.b.) and six levels of absorption rate in the range of 0.04 to 1.0%, w.b./hr. In the case of lower moisture content below 12%(w.b.), crack ratios of brown rice were remarkably high regardless of initial moisture contents. Therefore, it was found that rough rice below 12%(w.b.) in initial moisture content could not rewetted by spraying water without crack generation of low level. Absorption rate must be below 0.3%, w.b./hr to maintain crack ratio increase of less than 1% regardless of initial moisture contents. In the case of allowable crack ratio increase of 2% and 5%, it was found that the maximum absorprion rate was respectively 0.6%, w.b./hr and 1.0%, w.b./hr in the initial moisture content of above 13.5%(w.b.). Rewetting the rough rice in moisture content of 11.4 to 14.5%(w.b.) to 14.3 to 16.9%(w.b.) decreased milling energy consumption by 15.9 to 22.3%. The effect of energy saving was higher in the samples of higher initial moisture content. Whiteness of milled rice was decreased by 0.5 to 1.5.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.9
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• pp.1265-1270
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• 2011

We evaluated changes in the chemical composition of rough rice (Oryza sativa L.) according to germination period. Rough rice was germinated at $37^{\circ}C$ for 8 days. Crude protein content increased from 71.67 mg/g in raw rough rice to 85.20 mg/g after 8 days of germination. Crude lipid content increased from 2.19% to 3.58% (p<0.05), whereas crude ash was not significantly changed. Phytic acid content decreased from 6.25 mg/g in raw rough rice to 1.54 mg/g after 8 days of germination. Free fatty acid content increased from 0.17% to 0.32% during 8 days of germination. Major fatty acids were palmitic, oleic, and linoleic acids, and total fatty acid content increased up to 95%. Vitamin E and ${\gamma}$-oryzanol contents in raw rough rice were 2.94 mg/100 g and 6.47 mg/g, respectively, increased to 5.55 mg/100 g and 8.16 mg/g after 4 days of germination, and then decreased afterward. These results indicate that the optimum germination period of rough rice for increasing functional components may be 3~4 days.

• Journal of Biosystems Engineering
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• v.3 no.2
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• pp.62-68
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• 1978

Equilibrium moisture content of rough rice is an important factor because it has a close relationship to storage and drying problems. Determination of the EMC for 10 different varieties of rough rice were made in atmospheres of various constant humidities at three different constant temperatures. In addition , some physical properties were also measured for two different levels of moisture content of the samples. The results may be summarized as follows ; 1. Several physical properties of ten different varieties of rough were measured. Significant difference of the properties was appeared between the varieties in which the difference was pronounced in the dimensions of the varieties. Also, all the dimensions were increased as the moisture content of the rough rice was increased from 14 % to 16%. 2. Significant difference of the equilibrium moisture content was also appeared between some of the varieties in which the equilibrium moisture content of Josaengtongil and Minehikari was 24.26% while that of the others was in the range between 18 to 19% at the conditions of relative humidity of 84% and temperature of 47℃ , respectively. Similar pattern was also observed in other conditions. 3. The values of the constant of Henderson's equation were calculated from the data obtained but they are believed to be useful until more precise and complete data are obtained. There was a good agreement between the calculated and experimental results.

• Journal of Biosystems Engineering
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• v.5 no.1
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• pp.33-42
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• 1980

This study was carried out to investigate the actual environmental paddy storage conditions in conventional Korean farm warehouses. The paddy storage conditions by the locations and sizes of warehouses were figured out. The effectiveness of the small insulated box for storing paddy was also examined. Observations were made at sixteen different warehouses located in Moonsan-Myeon, Jinyandg-gun, Gyungnam Province from July lst to September 28 th, the period which was considered to be the worst for storing grains. The results are as follows ; 1. the average temperatures of rough rice and air inside the warehouse were 0.9 and 0.7$^\circ$ higher than the outside air temperature. 2. The average relative humidity in warehouses was 1.5percent higher than that of the atomosphere. This fact resulted in the increased moisture content of grains. Therefore, the ventilation for equalizing the relative humidity of inside and outside of warehouses was required. 3. The dry matter of stored rough rice was decreased by 1.1 percent in average druing the observation period. In order to reduce the dry matter loss, application of new grain storing method ;hermetic storage or filling inert gas storage, was highly recommended. 4. Environmental conditions for storing rough rice in a warehouse located in a sloping site are, in general , better than those of a warehouse located in a flat site. But as far as the dry matter of rough rice was concerned, above situation is not always satisfactory. Because it is fairly frequent to observe the higher rate of moisture absorption by grains stored in a warehouse located in a sloping site. 5. Environmental conditions for storing rough rice in a large-scale warehouse were better than those in a small size warehouse. Therefore, it is advisible for farmers to store their grins in the large-scale warehouses commonly used by villagers. 6. It was undesirable to store rough in a insulated box.

• Preventive Nutrition and Food Science
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• v.16 no.3
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• pp.272-277
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• 2011

The hypoglycemic effects of germinated rough rice extract in streptozotocin (STZ)-induced diabetic rats were investigated. Weight gain was significantly lower in the diabetic groups than in the normal control (NC); however, they were higher in the 1% and 3% diabetic groups given germinated Goami2 rough rice extract (DM-3%GGRRE) than in the diabetic control (DC). While food intake in all diabetic groups was significantly higher than that of the NC, there was no significant difference among all diabetic groups. The weight percentages of liver and kidney in all diabetic groups were significantly higher than that of the NC. In terms of blood glucose, the diabetic group showed about a three times larger value than the normal group. Moreover, in the 3% germinated rough rice extract group, the blood glucose level became lowered. The levels of alanine transaminase, aspartate transaminase, blood urea nitrogen, creatinine phosphokinsae, and creatinine increased in general with the induction of diabetes using STZ; however, the 3% GGRRE-treated group displayed a significant decrease in these levels compared to the diabetic group. The results show that the 3% GGRRE, rather than the 1% GGRRE, was considerably more effective at reducing blood glucose and improving impaired glucose tolerance, suggesting the germinated rice extracts may play a role in preventing liver and kidney damage.

• Journal of Biosystems Engineering
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• v.5 no.1
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• pp.15-23
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• 1980

Natural-air drying systems have been extensively used for cereal grains, and many researches on the systems have been conducted in foreign countries. However, little research on drying rough rice with natural air has been done. Especially . little research on natural air drying of rough rice based on weather data has been done in Korean. The objective of this study was to present fundamental data for estimating optimum requirements and basic information available for natural air drying of rough rice based on the weather data . The weather data analyzed in this study were the 10-year (1969 to 1978) record of air temperatures, wet-bulb temperatures and relative humidities, which were three-hourly observations in Taegu area. The results of this study are summarized as follows ; 1 From the results of weather data analysis the average air temperature was about $14.8^\circ$and the average relative humidty 67.5% . Average equilibrium moisture content appeared to be 13.8 percent on wet basis, which showed great potential for natural air drying in Taegue area in October. 2. Possible fan operation time based on the equilibrium moisture content of 15% on wet basis was about 14 hours a day during October in Taegu area. Probabilities of possible drying days based on minimum time available for drying in a day were analyzed. 3. Minimum air flow requirements based on the worst year were determined for different fan operation methods and initial moisture contents.

• Journal of Biosystems Engineering
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• v.6 no.1
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• pp.83-92
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• 1981

A simulation model of natural air drying to predict the changes of the grain moisture content and dry matter loss of rough rice was developed by the application of mass diffusion theory. A series of simulated drying tests was conducted using the 10 year weather data (1970-1979) obtained from Cheongju, Chuncheon, Daegu, Daejeon, Jeonju, Jinju and Suweon in Korea. System performance factors treated in this study were initial moisture content, airflow rate, bin diameter and grain depth. The results obtained in this study are summarized as follows: 1) The simulation model used in this study was validated with actual experimental results and was applicable to the natural air drying of rough rice. 2) Minimum airflow rates for safe drying were determined for different initial moisture contents and regional weather conditions as shown in Table 6. 3) Equations for estimating drying time and dry matter loss in terms of airflow rate and initial moisture content were derived in the form of an exponential function. 4) These results show that the natural air drying system of rough rice is feasible in Korea even for the poorest drying condition.

• The Korean Journal of Community Living Science
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• v.24 no.3
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• pp.391-397
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• 2013

This study was conducted to define the characteristics of the fan according to the bed depth of rough rice for the silo used in South Korea. In this study, the characteristics like air flow resistance and air flow rate of the fan were investigated for an independent blowing system with 1 fan and the serial blowing system with 2 fans. In the experiment, the depth of rough rice was determined by 0, 1, 2, 3.2 and 4.5 m for an independent blowing system and the depth of rough rice was 4.5 m for the serial blowing system. The air flow resistances of the blowing fan and the suction fan in an independent blowing system were 55 mmAq and 88 mmAq respectively. In addition, the air flow resistance of the serial blowing system was 61% lower than the blowing fan and 28% lower than the suction fan of the independent blowing system. The air flow rates of the blowing fan and the suction fan in the serial blowing system were 516 $m^3/min$, 570 $m^3/min$, respectively. The former was 22% higher than the blowing fan while the latter was 29% higher than the suction fan in the independence blowing system. In other words, the serial blowing system was superior to the independent blowing system in blowing characteristics because the air flow rate was lower and air flow resistance was higher than the independent blowing system. However, the fan power consumption of the serial blowing system was more than 100% comparing with the independent blowing system.

• Journal of Biosystems Engineering
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• v.17 no.1
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• pp.79-90
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• 1992

Viscoelastic characteristics of agricultural products may be determined through three basic tests ; stress relaxation, creep, and dynamic test. Considering the changeability of living materials, dynamic test in which information is derived in a relatively short time appears to be highly desirable, in which either cyclic stress or cyclic strain is imposed and the remaining quantity (strain or stress) is measured. The periodically varying stress will also result in periodically varying strain which in a viscoelastic material should theoretically be out of phase with the stress, because part of the energy subjected to sample is stored in the material as potential energy and part is dissipated as heat. This behavior results in a complex frequency-dependent compliance denoted by J($i{\omega}$). The complex compliance and therefore the storage compliance, the loss compliance, the phase angle, and percent energy loss for the sample should be obtainable with a given static viscoelastic property of the material under static load. The complex compliance of the rough rice kernel were computed from the Burger's model describing creep behavior of the material which were obtained in the previous study. Also, the effects of cyclic load and moisture content of grain on the dynamic viscoelastic behavior of the samples were analyized. The results obtained from this study were summarized as follows ; 1. The storage compliance of the rough rice kernel slightly decreased with the frequency applied but at above the frequency of 0.1 Hz it was nearly constant with the frequency, and the loss compliance of the sample very rapidly decreased with increase in the frequency on those frequency ranges. 2. It was shown that the storage compliance and the loss compliance of the sample increased with increase in grain moisture content. Effect of grain moisture content on the storage compliance of the sample was highly significant than effect of the frequency applied, but effect of the frequency on the loss compliance of the sample was more significant than effect of grain moisture content. 3. In low moisture content, the percent energy loss of Japonica-type rough rice was much higher than that of Indica-type rough rice, but, in high moisture content, vice versa.

• Korean Journal of Food Science and Technology
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• v.27 no.1
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• pp.119-123
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• 1995

In the present study, an attempt was made to investigate the effect of water activity(Aw) of rough rice on the growth of Fusarium moniliforme NRRL 13569 as well as on the production of Fumonisin $B_1(FB_1)$. The maximum growth of F. moniliforme and the production of $FB_1$, occurred at Aw 0.97 when the Aw of rough rice was controlled from 0.85 to 0.97. The fungal growth and $FB_1$, production decreased with the decrease of Aw. Sparse growth of fungus was observed even at Aw 0.85. $FB_1$ production on rough rice decreased considerably under Aw 0.97 and the trace amounts of $FB_1$ were observed at Aw 0.93 and 0.90. Therefore Aw required for the prevention of $FB_1$ production was turn out to be below 0.90 while that of fungal growth below 0.85.