• Applied Biological Chemistry
• /
• 제33권3호
• /
• pp.261-263
• /
• 1990

The water uptake rates of thirty-four japonica and twenty-five j x indica brown rices at $100^{\circ}C$ were analyzed. The water uptake rates had no correlation with size or volume of brown rice kernel. The regression equations for water uptake rates between brown rice at $100^{\circ}C$(Y) and milled rice at $23^{\circ}C(X)$ for japonica and j x indica varieties were Y = 1.12X-0.34(r = 0.976, p<0.001) and Y = 1.16X-0.54(r = 0.990, p<0.001), respectively (Received August 13, 1990 and accepted September 20,1990).

• Journal of the Korean Society of Food Science and Nutrition
• /
• 제31권5호
• /
• pp.885-892
• /
• 2002

The purpose of this research was to prove the excellency of unpolished (brown) rice with respect to nutritional composition and to compare chemical composition among six varieties of rice. Some nutritional composition in the Polished (well -milled) rice and unpolished (brown) rice of the six typical Korean varieties (Chucheong, Hwasung, Odae, Ilmi, Dongjin, Ilpum) were determined. Most of nutrients in the brown rice were much greater than those in the milled rice and there was significant difference among rice varieties in some chemical compositions. The major minerals of milled rices were Ca, 6～15 mg%;P, 91～125mg%;Fe, 0.3～1.2mg%; Na, 10～14mg%;K, 106～205 mg%; Zn, 1.0～1.8mg%; and Mg, 32～58 mg%. The mineral contents of brown rices wre Ca, 4～11mg%;P, 92～286mg%;Fe, 1.3～1.9mg%;Na, 12～15mg%;K, 243～320mg%;Zn, 1.5～2.3mg%;Mg, 112～140mg%. Major fatty acids in six rice varieties were linoleic acid, oleic acid and palmitic acid, which comprised of about 93% of total fatty acid. Amino acid analysis showed that aspartic acid, glutamic acid, arginine and leucine were major amino acids, whereas histidine, threonine and tryptophan were minor ones of rice. Most ammo acid contents was higher in Ilmi than the other varieties. The contents of vitamin in brown rices were considerably higher than those in well-milled rice. There was not significant difference in total dietary fiber among rice varieties : 1.1～1.2% for milled rice,3.2～3.5% for brown rice.

• Food Science and Preservation
• /
• 제13권6호
• /
• pp.675-680
• /
• 2006

Uniform milling is regarded as a very essential technology to produce high quality milled rice in Rice Recessing Complex. But non-uniformly milled rice can be produced very easily because of unadequate operation methods of milling system and bad brown rice conditions. This study was conducted to find out the bad effect of non-uniform milling degrees and store temperatures on quality characteristics such as taste of cooked rice, fatty acidity, whiteness and so on of milled rice during storage. According to the increase of non-uniform milling degrees, the fatty acid acidity and b value were increased very rapidly, and taste of cooked rice and whiteness were decreased very rapidly during storage. And the general quality characteristics of milled rice were better at low temperature storage of $5^{\circ}C$ than at high temperature storage at $25^{\circ}C$.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• 제59권2호
• /
• pp.174-180
• /
• 2014

This study was conducted to know the effect of low radiation during grain filling stage of rice on its grain yield, components, physicochemical properties and palatability, compared to the effect of natural light. Ripened grain ratio, 1000 grain weight of brown rice, milled rice yield of Mipum, Hopum, and Sindongjin were reduced as the shading treatments become higher. After harvest, physicochemical properties of rice influencing eating quality were investigated. Protein content of milled rice was increased, but palatability was decreased by shading treatments. Change of milled rice proteins and palatability due to shading treatments were found to be less in Mipum than that in Hopum and Sindongjin. With regard to amylogram properties, shading treatments resulted in a significant decrease in peak trough final breakdown viscosities of rice flour, though it increased pasting temperature and setback viscosity. The degree of the 55% shading effect was more intensive than the 35% shading effect in changes of ripened grain ratio, 1000 grain weight of brown rice, milled rice yield and milled rice protein.

• Korean Journal of Food Science and Technology
• /
• 제36권6호
• /
• pp.930-936
• /
• 2004

Effects of rice cultivars and degree of milling (DM) on composition, pasting properties, total phenolic contents, and distribution of phenolic acids were investigated. Rice and bran fractions with 94.4, 92.0, and 90.4% milling yields from brown rice of four cultivars (Odae, Nampyung, Chucheong, and Ilmi) were used. Fat and ash contents of milled rices decreased with increasing DM, whereas protein contents were not affected. In rice bran, differences in fat and ash contents by cultivars were higher than those caused by DM. With increasing DM, gelatinization temperature of rice flour decreased, whereas peak viscosity and hold viscosity at $95^{\circ}C$ increased. While cold viscosity, final viscosity, and setback varied among cultivars, DM had little effect. Total polyphenolic contents in brown rice, milled rice, and rice bran were 93.9-88.8, 30.3-71.9, and 310.0-541.6 mg catechin eq/100g, respectively. Major phenolic compounds were identified as ferulic and p-coumaric acids. Total phenolic content of brown rice (65.9-27.9 mg%) decreased with increasing DM, whereas ratio of ferulic acid composition increased. Chucheong and Ilmi varieties showed biggest reduction of phenolic acid contents by milling. In rice bran, ferulic and p-coumaric acids were 157.8-240.2 and 31.8-90.4 mg%, respectively. Contents of sinapinic, benzoic, and m-hydroxybenzoic acids in rice bran were higher than those of brown and milled rices.

• Journal of the Korean Home Economics Association
• /
• 제39권1호
• /
• pp.103-111
• /
• 2001

This study was attempted to investigate the effect of partial replacement of rice flour with black or brown rice flour on texture properties and retrogradation of Julpyun(Korean rice cake). In sensory evaluation, the Julpyuns replaced black or brown rice flour 20% had high score in color, flavor and overall acceptability not including mouthfeel. As the result of the measurement with texture analyzer, hardness, gumminess and chewiness of Julpyuns tended to decrease in proportion to the amount of black and brown rice flour in the formula. These resets implied that the degree of retrogradation of black and brown rice Julpyuns might be low. Julpyuns replaced with black rice were a little lower than those of brown rice in the hardness. In the retrogradation speed by Avrami,s equation, the rate constants of Julpyun replaced black and brown rice flour was lower than that of milled rice, restating in delay in firming.

• Journal of Biosystems Engineering
• /
• 제20권1호
• /
• pp.47-57
• /
• 1995

Rice Processing Complex(RPC) have being constructed with a rice mill plant and a facility of drying and storage to overcome problems caused by UR and to produce good quality of rice. An optimal design of a rice mill plant was required to successfully construct and operate it. The development of a simulation model was essential to the design of a rice mill plant. So, all the objectives of this study were to develop a simulation model for the design of a rice mill plant and to develop and evaluate the rice mill system. In this study the simulation model was developed to design a rice mill plant using SLAMSYSTEM, one of simulation languages. The results of this study were as followings. 1. A simulation model was developed with SLAMSYSTEM to represent the processes of a rice mill plant. The simulation model was used to design a rice mill pilot plant with the capacity of 0.5 ton per hour. The rice mill pilot plant was analyzed by the model with alternatives. 2. In the simulation the rice mill system was much influenced by the separating efficiency of a brown rice separator. Especially, the bottleneck of grain flow occurred at the buffer tank for brown rica. separator under 50% separating efficiency of brown rice separator. Hence, as the alternative simulation was conducted under 60% , 70% separating efficiency of brown rice separator, the bottleneck of the system could be minimized at the 60% separating efficiency of brown rice separator. 3. In the alternative simulation the bottleneck of the system was minimized under the hulling capacity of 1 t/h and 60% separating efficiency of brown rice separator with the capacity of 1 t/h. Under such a condition the max. weight of waiting entities at buffer tanks was less 250kg. So, the capacities of the buffer tanks were determined in the basis of simulation results. 4. The milled rice recovery and head rice recovery of the milling system were 74% and 92% in the simulation, respectively. These results of simulation almost corresponded to those of actual rice mill plants. The developed simulation model could be well applied to design a rice mill plant.

• Journal of the Korean Society of Food Science and Nutrition
• /
• 제39권3호
• /
• pp.467-473
• /
• 2010

The objectives of this study were to determine various bio-active components from some brown rice and milled rice of some cultivars, as well as to assess their contribution to the radical scavenging linked-antioxidant activity. DPPH or ABTS radical scavenging activities, and reducing power have been used to investigate the relative antioxidant activities of 70% ethanol extracts. The contents of total polyphenol, total flavonoid, $\gamma$-oryzanol, and vitamin E in the extracts were also measured by spectrophotometric methods or HPLC. The antioxidant components and antioxidant activities of 70% ethanol extracts from brown rice were higher than those from milled rice. In addition, our results showed that the high level of antioxidant compounds was found in brown rice of Hongjinju, and the antioxidant activities of the 70% ethanol extracts from pigmented brown rices, such as Hongjinju and Heugkwang, were comparably higher than the others.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 한국작물학회 2018년도 추계학술대회
• /
• pp.256-256
• /
• 2018

• Proceedings of the Korean Journal of Food and Nutrition Conference
• /
• 한국식품영양학회 2001년도 동계 학술심포지움
• /
• pp.39-74
• /
• 2001

The endeavors enhancing the grain quality of high-yielding japonica rice were steadily continued during 1980s∼1990s along with the self-sufficiency of rice production and the increasing demands of high-quality rices. During this time, considerably great, progress and success was obtained in development of high-quality japonica cultivars and qualify evaluation techniques including the elucidation of interrelationship between the physicochemical properties of rice grain and the physical or palatability components of cooked rice. In 1990s, some high-quality japonica rice caltivars and special rices adaptable for food processing such as large kernel, chalky endosperm aromatic and colored rices were developed and its objective preference and utility was also examined by a palatability meter, rapid-visco analyzer and texture analyzer. The water uptake rate and the maximum water absorption ratio showed significantly negative correlations with the K/Mg ratio and alkali digestion value(ADV) of milled rice. The rice materials showing the higher amount of hot water absorption exhibited the larger volume expansion of cooked rice. The harder rices with lower moisture content revealed the higher rate of water uptake at twenty minutes after soaking and the higher ratio of maximum water uptake under the room temperature condition. These water uptake characteristics were not associated with the protein and amylose contents of milled rice and the palatability of cooked rice. The water/rice ratio (in w/w basis) for optimum cooking was averaged to 1.52 in dry milled rices (12% wet basis) with varietal range from 1.45 to 1.61 and the expansion ratio of milled rice after proper boiling was average to 2.63(in v/v basis). The major physicochemical components of rice grain associated with the palatability of cooked rice were examined using japonica rice materials showing narrow varietal variation in grain size and shape, alkali digestibility, gel consistency, amylose and protein contents, but considerable difference in appearance and torture of cooked rice. The glossiness or gross palatability score of cooked rice were closely associated with the peak. hot paste and consistency viscosities of viscogram with year difference. The high-quality rice variety “Ilpumbyeo” showed less portion of amylose on the outer layer of milled rice grain and less and slower change in iodine blue value of extracted paste during twenty minutes of boiling. This highly palatable rice also exhibited very fine net structure in outer layer and fine-spongy and well-swollen shape of gelatinized starch granules in inner layer and core of cooked rice kernel compared with the poor palatable rice through image of scanning electronic mcroscope. Gross sensory score of cooked rice could be estimated by multiple linear regression formula, deduced from relationship between rice quality components mentioned above and eating quality of cooked rice, with high Probability of determination. The ${\alpha}$ -amylose-iodine method was adopted for checking the varietal difference in retrogradation of cooked rice. The rice cultivars revealing the relatively slow retrogradation in aged cooked rice were Ilpumbyeo, Chucheongbyeo, Sasanishiki, Jinbubyeo and Koshihikari. A Tongil-type rice, Taebaegbyeo, and a japonica cultivar, Seomjinbyeo, shelved the relatively fast deterioration of cooked rice. Generally, the better rice cultivars in eating quality of cooked rice showed less retrogiadation and much sponginess in cooled cooked rice. Also, the rice varieties exhibiting less retrogradation in cooled cooked rice revealed higher hot viscosity and lower cool viscosity of rice flour in amylogram. The sponginess of cooled cooked rice was closely associated with magnesium content and volume expansion of cooked rice. The hardness-changed ratio of cooked rice by cooling was negatively correlated with solids amount extracted during boiling and volume expansion of cooked rice. The major physicochemical properties of rice grain closely related to the palatability of cooked rice may be directly or indirectly associated with the retrogradation characteristics of cooked rice. The softer gel consistency and lower amylose content in milled rice revealed the higher ratio of popped rice and larger bulk density of popping. The stronger hardness of rice grain showed relatively higher ratio of popping and the more chalky or less translucent rice exhibited the lower ratio of intact popped brown rice. The potassium and magnesium contents of milled rice were negatively associated with gross score of noodle making mixed with wheat flour in half and the better rice for noodle making revealed relatively less amount of solid extraction during boiling. The more volume expansion of batters for making brown rice bread resulted the better loaf formation and more springiness in rice bread. The higher protein rices produced relatively the more moist white rice bread. The springiness of rice bread was also significantly correlated with high amylose content and hard gel consistency. The completely chalky and large gram rices showed better suitability for fermentation and brewing. Our breeding efforts on rice quality improvement for the future should focus on enhancement of palatability of cooked rice and marketing qualify as well as the diversification in morphological and physicochemical characteristics of rice grain for various value-added rice food processings.