• Journal of the Korean Society of Food Science and Nutrition
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• v.13 no.2
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• pp.181-187
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• 1984

Lysine is known as a limiting amino acid in rice. In addition, it is considered to be important in that it is easily non-activated by the browning reaction during processing or storage. The present study was designed to utilize a kinetic approach to analyse the effect of temperature and water activity on available lysine loss in rice. Simplified kinetic models were used to obtain the various kinetic parameters for available lysine loss in rice subjected to accelerated shelf-life tests (ASLT). These kinetic parameters were then used to predict protein quality loss under the non-steady state storage. The predicted losses were compared to the actual losses. As expected, available lysine loss was increased with increased temperature and water activity. The activation energies and $Q_{10}$ values for available lysine loss ranged from 4.03 to 5.10 Kcal/ mole and 1.22 to 1.27, respectively, The shelf-lives at $25^{\circ}C$, the time to reach 25% loss of the available lysine, which was derived from the accelerated shelf-life tests showed 67 to 107 days according to $a_w$'s. The amount of loss for the fluctuating condition was greater than that occurring at the mean temperature of $45^{\circ}C$. Actually, the differences in effective temperature for the fluctuating storage were between about 4 and $6^{\circ}C$. In predicting the extent of loss using constant state data, the predicted shelf-lives were 2 to 7 days shorter than the actual storage values.

• Applied Biological Chemistry
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• v.13 no.3
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• pp.219-222
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• 1970

Riboflavin in the various materials which used for Takju brewing was determined and its quantitative changes in the Takju mashes which were mashed with polished rice and wheat flour respectively using Nuruk only for enzyme source, and with wheat flour and corn powder respectively using Nuruk and Koji, were checked at 24 hours intervals during the whole brewing period. The results obtained were as follows. a) The riboflavin contents in 100 grams of each materials were: Polished rice $46.9{\gamma}$ Wheat flour $67.3{\gamma}$ Corn powder $73.9{\gamma}$ Nuruk $169.0{\gamma}$ Koji of wheat flour $87.1{\gamma}$ Koji of corn powder $84.4{\gamma}$ b) About 30 to 40 percent of riboflavin in the polished rice, wheat flour and corn powder were losed by steaming at 10 pounds for 50 minutes. c) Riboflavin content in the plots used Nuruk only was decreased during 3 days after mashing and then increased markedly after 5 days and, more or less, decreased after 6 days. Quantitative changes of riboflavin in the plots used Nuruk and Koji showed a rugged curve without decreasing in early stages, and its content was also increased markedly 5 days after mashing and then decreased a little after 6 days. d) Approximately $82{\gamma}$ of riboflavin was determined in 100ml. of the ripened mash of the rice plot and $72{\gamma}$ in the wheat flour plot in the case of using Nuruk only. $88.6{\gamma}$ of riboflavin were determined in 100ml. of the ripened mash of the wheat flour plot and $83.6{\gamma}$ in the corn powder plot in the case of using Nuruk and Koji. e) It was assumed that $28.8{\gamma}$ to $41{\gamma}$ of riboflavin were contained in 100 ml. of finished Takju of the two plots used Nuruk only and 33.6 to 44.5${\gamma}$ in the both two plots used Nuruk and Koji. f) About $47.3{\gamma}$ of riboflavin were determined in 100 grams of Takju cake of the rice plot and $66.2{\gamma}$ in the wheat flour plot used Nuruk only, and $62.9{\gamma}$ in the corn powder plot and $64.5{\gamma}$ in the wheat flour plot used Nuruk and Koji.

• Korean Journal of Agricultural Science
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• v.6 no.2
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• pp.205-212
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• 1979

Red pepper paste were prepared by using various raw materials such as rice, glutinous rice, polished barley, polished wheat and corn powder, and their chemical compositions including reducing sugar, amino-N and ethanol were analyzed during the period of aging in order to elucidate effects of these starchy materials on the compositions and qualities of the products. The results obtained are summarized as follows: 1) Koji of these materials were manufactured respectively by inoculating a strain of Asporyzae and their activities of protease and saccharifying amylase were determined. Wheat koji was found to have the highest level of protease activity among the koji, while glutinous rice koji had the strongest amylase activity. 2) Contents of moisture, crude protein, crude fat, and sodium chloride in the red pepper pastes were not changed significantly, however total sugar content was decreased during the period of aging. 3) After 60 days of aging, the highest amount (160mg%) amino nitrogen was detected in the red pepper paste of polished wheat, but higher levels of reducing sugar and ethanol contents were detected in that of glutinous rice. 4) Amino acids in the products were analyzed after 60 days of aging: a) Total 17 amino acids were detected. b) Free amino acid ratio to total amino acid content was approximately 35 percent in average. c) Free glutamic acid was higher than any other free amino acid In the amount and free ratio, but free methionine was lower. d) Lysine content was relatively high, while histidine and glycine were detected in trace. 5) Sensory tests including color, odor and taste on the products resulted in the highest mark for the red pepper paste of glutinous rice but in the lowest mark for that of corn powder.

• Applied Biological Chemistry
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• v.13 no.1
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• pp.105-109
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• 1970

Thiamin in the various materials which used for Takja braving was determined and its quantitative changes in the Takju mashes which were mashed with polished rice and wheat flour respectively using Nuruk only for the enzyme source, and with wheat flour and corn powder respectively using Nuruk and Koji, were checked at 24 hours intervals during the whole brewing period. The results obtained were as follows. a) The thiamin contents in 100 grams of each materials were: Polished rice 107.8${\gamma}$ Wheat Pour 185.0${\gamma}$ Corn powder 410.2${\gamma}$ Nuruk 347.4${\gamma}$ Koji of wheat flour 170.1${\gamma}$ Koji of corn powder 257.3${\gamma}$ b) About 40 to 50 percent of thiamin in the polished rice, wheat flour and, corn powder were losed by steaming at 10 wounds for 50 minutes. c) The quantitative changes of thiamin in the Takju meshes showed a similar tendency. Thiamin contents were decreased markedly during 2 days after mashing but thereafter, almost unchanged till the mashes were ripened. Its decreasing rates in tile two plots uses Nuruk and Koji wereless thaw those in the two plots used Nuruk only. d) Approximately 6${\gamma}$ of thiamin was determined in 100 ml. of the ripened mash of the rice plot and 7.5${\gamma}$ in tire whet flour plot in the case of using Nuruk only. 12.4${\gamma}$ of thiamin was determined in 100 ml. of the ripened mash of the wheat flour plot and 15.4${\gamma}$in the corn powder plot in the case of using Nuruk and Koji. e) It was assumed that 2.4 to 3.5${\gamma}$ of thiamin were contained in 100 ml. of finished Takju of the two plots used Nuruk only and 5 to 7${\gamma}$ in the two plots used Nuruk and Koji. f) About 43.7${\gamma}$ of thiamin were determined in 100 grams of Takju cake of the rice plot and 56.1${\gamma}$ in the wheat flour plat used Nuruk only, and 81.4${\gamma}$ in the corn powder plot and 57.7${\gamma}$ in the wheat flour plot used Nuruk and Koji.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.6
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• pp.1047-1052
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• 2001

The pigment content in meju fermented by a Monascus species with different materials was studied. The relations between growth of M. pilosus and pigment production were positive and the correlation coefficient associated with this relationship was determined to be : r = 0.9879. Pigments produced by M. purpureus and M. pilosus were composed of 9 and 8 bands, respectively. One kind of them was yellowish, whereas the others were reddish. Total pigment levels in rice meju fermented by M. purpureus and M. pilosus were 335.25 and 1428.90$\mu\textrm{g}$/g, respectively. Pigment levels in the mejus fermented at 3$0^{\circ}C$ showed higher than those at 20 and 4$0^{\circ}C$. The order of pigment content in meju was polished rice > germinated brown rice > wheat > brown rice > waxy brown rice > germinated waxy brown rice. Pigment production by M. pilosus was higher than that of M. purpureus. Pigment content in rice meju prepared by adding 10% seed culture was highest, and pigment content of granulated rice was higher than that of powdered rice. Pigment production was not desirable in soybean meju fermented by seed culture, whereas the pigment levels in meju by adding 10% powdered rice and 10% powdered rice seed meju increased by 23.0 ~75.0 $\mu\textrm{g}$/g.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.10
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• pp.1336-1341
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• 2009

This study was performed to investigate the effects of rice added with mulberry leaves and fruit on blood glucose, body fat and serum lipid levels in Sprague-Dawley male rats for 4 weeks. Mulberry rice diet was prepared with mixture of 50% of purified AIN-diet and 50% of formulated rice consisting of soybean, barley, polished rice, black rice, uncleaned rice bud, mulberry leaves and fruit. The experimental animals were fed the mulberry rice diet (group A) and the purified AIN-diet (group B, diabetic control) for 4 weeks in rats injected with streptozotocin. In terms of observing hypolipidemic effect of mulberry rice, rats were fed either high-fat diet (13% fat) with additional lard, corn oil, cholesterol to AIN-diet (group C, control) or mulberry rice diet mixed with high fat diet (group D) for 4 weeks. Blood glucose level at the 4th week of group A had increased 5 mg/dL compared with that of day 0, while group B increased 51 mg/dL. However, the glucose levels of the groups A and B at the final day were 156 mg/dL (12.4% decrease compared with B) and 178 mg/dL, respectively. As for hypolipidemic effect, weight gain and body fat were 8% lower in the group D and serum triglyceride level also 19% lower in the group D compared with those of group C (p<0.05).

• Journal of Applied Biological Chemistry
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• v.53 no.4
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• pp.219-224
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• 2010

This study was conducted to investigate the effect of medical herbs extracts on physicochemical characteristics of cooked rice. Three types (CLP 1, CLP 2, CLP 3) of extracts were prepared using 11 medicinal herbs, respectively. Polished rice was cooked with different concentration of medicinal herbs extracts by electric cooker. The moisture contents in cooked rice were decreased by increased concentration of herbs extracts, while total polyphenol contents were significantly increased. DPPH radical scavenging activities of cooked rice obviously were increased as herb extracts level increased. The consistency and setback value of the rice flour was reduced at all of the extracts, while breakdown and initial pasting temperature was increased. Color of cooked rice was shown different comparing to the control. However, the hardness, adhesiveness, springiness, cohesiveness and gumminess of cooked rice was increased depending on the concentration of extracts. These results showed that medicinal herbs extracts, which can benefit human health, is inducing the changes of physicochemical characteristics of cooked rice.

• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.1
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• pp.101-108
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• 1992

Changes were evaluated in chemical and textural properties of Jeung-pyun (fermented rice cake) altered by the particle size of rice flour, amount of added Tak-ju (Korean traditional unrefined liquor) and sucrose, fermentation time and temperature, and steaming time. Particle size of polished rice flour did not affect the volume expansion during fermentation of rice dough by Tak-ju. The maximum expanded volume was noted in the dough, containing 20% sucrose (rice flour vs sucrose = 5 : 1, w/w), fermented at $35^{\circ}C$ for 3 hours. Any volume expansion was not occurred in rice dough without sucrose. The highest value of reducing power and gelatinization degree were observed in the rice dough with Tak-ju (rice flour vs Tak-ju = 2 : 1, w/v), while the lowest blue value was revealed in that case. Steaming followed after fermentation made the smaller volume of bulk by $45{\sim}50%$ of the initial volume be showed just after fermentation. Jeung-pyun prepared under the conditions could give maximum expanded volume by fermentation showed the best overall quality by sensory and textual properties.

• Korean Journal of Environmental Agriculture
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• v.4 no.1
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• pp.1-5
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• 1985

Fate of tricyclazole in rice paddy system was studied. The effect on soil microorganism as well as the mutagenicity of the compound was also examined. The residues of tricyclazole in crops and soil with two times application before harvest were 0.37 in unpolished rice, 0.29 in polished rice, 0.14 in rice straw, and 0.15 ppm in paddy soil. With three times of application the residues were increased to 0.46, 0.39, and 0.19 ppm, respectively. Until $2{\sim}3$ weeks after treatment of pesticide the degradation of tricyclazole was progressed comparatively but very slowly afterward and the half life of that was about $140{\sim}180$ days. There was no effect for viable count of soil microorganisms and for mutagenic test by Salmonella and Saccharomyces systems.

• Korean Journal of Environmental Agriculture
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• v.37 no.4
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• pp.291-301
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• 2018

BACKGROUND: Rice is one of the main sources for inorganic arsenic among the consumed crops in the world population's diet. Arsenic is classified into Group 1 as it is carcinogenic for humans, according to the IARC. This study was carried out to assess dietary exposure risk of inorganic arsenic in husked rice and polished rice to the Korean population health. METHODS AND RESULTS: Total arsenic was determined using microwave device and ICP-MS. Inorganic arsenic was determined by ICP-MS coupled with HPLC system. The HPLC-ICP-MS analysis was optimized based on the limit of detection, limit of quantitation, and recovery ratio to be $0.73-1.24{\mu}g/kg$, $2.41-4.09{\mu}g/kg$, and 96.5-98.9%, respectively. The inorganic arsenic concentrations of daily exposure (included in body weight) were $4.97{\times}10^{-3}$ (${\geq}20$ years old) $-1.36{\times}10^{-2}$ (${\leq}2$ years old) ${\mu}g/kg\;b.w./day$ (PTWI 0.23-0.63%) by the husked rice, and $1.39{\times}10^{-1}$ (${\geq}20$ years old) $-3.21{\times}10^{-1}$ (${\leq}2$ years old) ${\mu}g/kg\;b.w./day$ (PTWI 6.47-15.00%) by the polished rice. CONCLUSION: The levels of overall exposure to total and inorganic arsenic by the husked and polished rice were far lower than the recommended levels of The Joint FAO/WHO Expert Committee on Food Additives (JECFA), indicating of little possibility of risk.