• Korean Journal of Food Science and Technology
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• v.15 no.2
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• pp.160-163
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• 1983

Alpha-barleys prepared by boiling had the highest water absorption and those prepared by autoclaving showed the lowest water absorption among all the treatments, but all of ${\alpha}-barleys$ were higher than untreated barleys. The values of hardness on cooked ${\alpha}-barleys$ decreased as the degree of polishing increased, and untreated burleys showed the higher values than ${\alpha}-barleys$. There were no significant difference in total scores of sensory evaluation between ${\alpha}-barley-rice$ mixtures and untreated barley-rice mixtures after cooking.

• Korean Journal of Food Science and Technology
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• v.22 no.6
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• pp.696-699
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• 1990

Some mixed culture systems consisting of koji molds and yeast were tested for the ethanol production by simultaneous saccharification and fermentation using polished rice as the substrate. Aspergillus shirousamii showed the highest ethanol production in the mixed culture with Saccharomyces cerevisiae on steamed rice added with 150 ml water in 250 ml Erlenmeyer flask. The optimum initial pH, temperature and specific surface for the ethanol production in this system were 6.5, $30^{\circ}C$, and 0.1, respectively. Under this condition, 12.9% ethanol was produced with inoculation with $5{\times}10^2$ conidia/ml of A. shirousamii and $5{\times}10^6\;cells/ml$ of S. cerevisiae in 10 days.

• Journal of Food Hygiene and Safety
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• v.25 no.2
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• pp.143-147
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• 2010

Chronic exposure to Arsenic (As) causes significant human health effects including various cancers. Total As concentrations from 300 polished rice samples cultivated near the mining areas in Korea were analyzed to estimate a probabilistic assessment of human health risk from As-contaminated rice. The mean of total As concentrations in rice was 0.09 mg/kg and lognormal distribution model was set for total As concentrations. Human health risk for As in rice was estimated using gender-specific rice consumption data and average daily dose (ADD). While cancer risk (CR) and hazard quotient (HQ) were calculated using oral cancer slope factor (OCSF) and Reference dose (RfD) suggested by the U.S. EPA. Mean of CR posed by total As was 2.16 (for male) and 1.83 (for female) per 10,000. The HQ for general population from rice cultivated near the mining areas in Korea was below 1 as the $50^{th}$ percentile of general population. However, less than 10% of general population consuming rice cultivated near the mining areas would exceed 1.0. This result is similar with those from each gender-specific group.

• Korean Journal of Food Science and Technology
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• v.10 no.1
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• pp.52-56
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• 1978

The mechanism of cooking rice was investigated using a japonica type rice variety, Akibare, of 50%, 70% and 90% polishing degrees. The hardness of rice cooked at various cooking temperatures ($90^{\circ}-120^{\circ}C$) was measured with a Texturometer. The cooking rate followed the equation of a first-order reaction. The reaction rate constants were in the increasing order of 50%, 70% and 90% polished rice. The temperature coefficient of the reaction rate constant at cooking temperatures of ($90^{\circ}-100^{\circ}C$) was about 2 in all rice samples. The activation energies of cooking at temperatures below $100^{\circ}C$ and above $100^{\circ}C$ were about 17,000 and 9,000 cal/mole, respectively. The polishing degrees and water soaking time of rice did not affect the activation energy of cooking; however, the lower polishing degrees and shorter soaking increased the cooking time The experimental results suggested that the cooking process of rice comprises two mechanisms: At temperatures below $100^{\circ}C$ the cooking rate is controlled by the reaction rate of rice constituents with water, and at temperatures above $100^{\circ}C$, it is controlled by the rate of diffusion of water through the cooked portion (or layer) toward the interface of uncooked core in which the reaction is occurring.

• Korean Journal of Microbiology
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• v.42 no.2
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• pp.160-163
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• 2006

Brown rice contains rice bran and germ with higher nutritional value and dietary fiber content compared with the polished rice. However, brown rice has a limitation of poor digestion. fermented brown rice could be better nutritional source and improve digestibility. Therefore, we tried to select good fermentative microorganisms which have nutritional values with high amylase and protease activities, and probiotic effects. Nineteen micro-organisms, including eight Bacillus strains isolated from Chongkukjang and 11 lactic acid bacteria, were screened for the fermentation ability and enzyme production. The liquid broths containing 2.5%(w/v) of raw brown rice powder as a sole nutritional source were used for culture media. Among the strains tested, all of the Bacillus strains and two lactic acid bacteria (Leuconostoc gelidum and Pediococcus pentosaceus) showed increase in cell population and enzyme activities. The viable cell counts of all the Bacillus strains and two lactic acid bacteria exceeded $10^7 CFU/mL$. The maximal enzyme activities produced by Bacillus sp. Bl, Bacillus sp. B2, Bacillus sp. B11, L. gelidum and P. pentosaceus were 17.85, 17.50, 17.10, 17.10 and 3.24 U/mL for amylase and 22.48, 22.04, 23.76, 12.13, and 3.4 U/mL for pretense, respectively. Therefore, the results of this study demonstrated that the above strains could be potential starters for the fermentation of raw brown rice.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.1
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• pp.53-61
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• 2013

This study was conducted to determine the proper mixing ratio of multigrains-added cooked rice for adolescent and aged people and analyze the nutritional and functional properties. As a result of sensory evaluation according to mixing ratio of polish rice and grains, the palatable grain mixing ratio of mixed grain rice for adolescent and aged people was 40% and 30%, respectively. The ratio of general grains to specialized grains was 9:1 in mixed grain rice for adolescent (MGA) and 8:2 in multigrain rice for aged people (MGAP). The ratio of mung bean to BacTae was 2:1 in MGA, and the ratio of adlay to buckwheat was 1:1 in MGAP. MGA contained the highest amount of crude protein, crude fat and minerals among the samples. In contrast, MGAP showed higher amounts of polyphenols and antioxidant activity compared to polished rice and MGA.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.spc1
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• pp.119-124
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• 2006

This study was carried out at the Chuncheon Substation, National Institute of Crop Science to determine the effect of cold water irrigation on the milling and polished quality of rice, as well as its physicochemical and amylogram characteristics, and palatability Chilling by Irrigation of cold water $(17^{\circ}C)$ induced delay of days to heading, reduction of culm length, inferiority of panicle exsertion and high sterility of panicle. Head rice ratio was decreased, while the percentage of chalky and creak rice increased with increasing sterility over from 20%. Protein content was gained 0.9-2.0% more than, while whiteness and palatability of the milled grain were reduced under cold water irrigation treatment. Significant decrease in maximum viscosity and breakdown viscosity of rice flour was investigated under cold water treatment by amylogram analysis, while the initial gelatinization temperature and setback viscosity were increased. Sensory panel test showed that the palatability of cooked rice was unfavorable and its stickiness was lower compared with that under normal condition. Differences in the aroma of cold-treated and untreated cooked rice were not performed significantly.

• Korean Journal of Food Science and Technology
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• v.38 no.4
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• pp.562-566
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• 2006

This study was carried out to investigate the supplementary effects of giant embryonic rice, which has over two times of embryo size compared the normal rice, on lipid metabolism of insulin dependent diabetic rats. Streptozotocin induced diabetic rats were fed four kinds of experimental diets com starch diet as a control (C-D), a polished rice diet (R-D), a brown rice diet (BR-D) and a giant embryonic rice diet (GER-D) respectively, for 6 weeks. Diet intake body weight, organ weights and lipid levels of serum, liver and feces were measured. There was significant difference in diet intake and body weight among experimental groups. The concentrations of serum triglyceride and total serum cholesterol of BR-D and GER-D groups were lower than those of others. The total hepatic cholesterol level was the lowest in GER-D group. The contents of total lipid and total cholesterol excreted in feces of BR-D and GER-D groups were higher than those of C-D and R-D groups. These results suggested the giant embryonic rice diets can effectively reduce serum triglyceride level and total hepatic cholesterol level in insulin dependent diabetic rats, and hypolipidemic effects be due to increasing fecal lipid excretion.

• 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 Food Science and Technology
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• v.28 no.3
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• pp.490-496
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• 1996

This study was undertaken in order to elucidate the elimination of phenthoate residues by washing and cooking processes of rice which if the most important food crop in Korea. When contaminated rice was washed with distilled water three times, the removal rate of total phenthoate was 51%. The removal rate in the successive washings was 37.3% (wash filtrate 7.8%, wash sediment 29.5%) in the first, 14.3% (wash filtrate 6.2%, wash sediment 8.1%) in the second and 8.9% (wash filtrate 5.8%, wash sediment 3.1%) in the third washings. More than half of the residue was removed by the first washing and most residues were found in the sediment rather than in the filtrate of the rice washings. The residue rate of phenthoate after cooking by an electric rice cooker was 41%, indicating that the removal rate after cooking was 59%, because phenthoate is thermally stable at the cooking temperature. In conclusion, phenthoate residues contaminated in rice grains are grcatly removed in the washing process and it is desirable to wash the grains before cooking in order to decrease the hazards from pesticide residues such as phenthoate. Reduction factor of phenthoate in rice cooking is proposed to be 0.4.