• Title/Summary/Keyword: milled rice quality

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The Quality of Milled Rice with Reference to Whiteness and Packing Conditions during Storage (백도 및 포장조건별 쌀의 저장 중 품질 특성)

  • Yoon, Doo-Hyun;Kim, Oui-Woung;Kim, Hoon
    • Food Science and Preservation
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    • v.14 no.1
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    • pp.18-23
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    • 2007
  • This study investigated the effectsof whiteness and packing conditions on the quality characteristics of milled rice during storage at $25^{\circ}C$. Three kinds of packing materials (kraft paper sealed polyethylene and perforated polyethylene) were used to pack milled rice of different whiteness grades (36, 38, 40 and 42). The moisture content and weight of milled rice packed in kraft paper dropped very rapidly compared to values from milled rice packed in polyethylene because of high gas exchange through the paper. On the other hand, the increase in fat acidity of milled rice packed in kraft paper was less than that of milled rice packed in polyethylene because the moisture content of paper-packed rice fell rapidly. The overall quality of cooked rice rose with whiteness, and dropped with extended storage. The overall eating quality of milled rice paced in perforated polyethylene was bestwhen rice was prepared for the table after 8 weeks of storage.

Comparison of Some Characteristics Relevant to Rice Bread Processing between Brown and Milled Rice (백미와 현미 쌀빵의 특성 비교)

  • 강미영;최영희;최해춘
    • Korean journal of food and cookery science
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    • v.13 no.1
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    • pp.64-69
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    • 1997
  • The experiments of rice bread processing were carried out to compare the varietal difference in processing adaptability to rice bread between brown and milled rice flour, and to analyze the interrelations among chemical properties of rice grain and some characteristics relevant to rice bread processing and quality There was varietal difference in adaptability to rice bread processing in both brown and milled rice, but there was not significant adaptability difference between brown and milled rice flours to rice bread processing. However, there was remarkable adaptability difference between brown and milled rice flours to rice bread processing in some rice varieties. Three high-amylose rices AC 27, IR 44, Suweonjo showed high quality of milled rice bread among tested rice materials. Brown rice revealed better adaptability to rice bread processing compared with milled rice in all varieties except the above three varieties. Especially, the glutinous rice Hangangchalbyeo failed to normal formation of rice bread from milled rice flour, but it showed the successful formation of rice bread from brown rice flour. The interrelations among chemical components of rice grain and some characteristics relevant to rice bread processing and quality exhibited quite different tendency between brown and milled rices. In the case of rice bread processing by brown rice flour, the larger volume expansion of dough during fermentation made the more springy rice bread and the more moist rice bread showed the more soft and cohesive physical property. In the case of rice bread processing by milled rice flour, the lower protein of rice flour was closely associated with the more moistness of rice bread and the higher lipid led to the more uniformal air pore distribution, the smaller pore size and the lower springiness of rice bread. Also, the larger volume expansion of dough during fermentation made the better loaf formation and the larger pore size of rice bread. The better loaf formation of rice bread revealed the softer hardness and the lower chewiness, and the lower springiness was closely correlated with the more uniformal size distribution of air pore and the smaller pore size in rice bread.

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Determination of Whiteness Condition for Efficient Milling in Rice Processing Complex (RPC에서 효율적인 도정을 위한 백도조건 결정)

  • Kim O. W.;Kim H.;Kim D. C.;Kim S. S.
    • Journal of Biosystems Engineering
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    • v.30 no.4 s.111
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    • pp.242-248
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    • 2005
  • There was no useful milling standard to produce high quality milled rice efficiently and adequately in Rice Processing Complex. Therefore, the whiteness of milled rice produced Rice Processing Complexes were different according to Rice Processing Complexes and milling periods at the same Rice Processing Complex. This research was carried out to contribute the production and distribution of high quality milled rice through determination of whiteness condition of milled rice as a milling stndard based on degree of bran removal using New $May-Gr\ddot{u}wald$ reagent dyeing method and taste of cooked rice. The optimum whiteness value of milled rice for efficient milling in Rice Processing Complex was found to be from 40 to 41, while the degree of milling was from $8.9\%\;to\;9.2\%.$ At this whiteness condition, the first derivative of whiteness value according to degree of milling was higher than the average value from brown rice to well milled rice, and the broken kernel ratio was from $3.0\%\;to\;3.4\%.$ This whiteness condition ($40\~41$) could be considered as a milling condition in Rice Processing Complex.

Changes in Water Content Affect the Post-Milling Quality of Paddy Rice Stored at Low Temperature

  • Kim, Young-Keun;Hong, Seong-Gi;Lee, Sun-Ho;Park, Jong-Ryul;Choe, Jung-Seob
    • Journal of Biosystems Engineering
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    • v.39 no.4
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    • pp.336-344
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    • 2014
  • Purpose: In this study, the effect of milling on paddy rice stored at low temperature, the changes in grain temperature of bulk storage bags exposed at room temperature, the post-milling water content of paddy rice, the whiteness of rice, and the rate of pest incidence were investigated and data were analyzed. Methods: Changes in temperature inside the bulk storage bags kept at low temperature and grain temperature after exposure to room temperature were measured. Experiments were conducted for identifying the reasons of post-milling quality changes in paddy rice stored at low temperature. Results: It was determined that a short-term increase of water content in paddy rice was directly related to surface condensation, and that rice should be milled at least 72 h after removal from low-temperature storage, in order to completely eliminate surface condensation of paddy rice kept in bulk storage bags. It was observed that post-milling quality of rice changed, but water content was maintained at high levels for more than 18 d in rice that was milled when condensation occurred, regardless of paper or vinyl packaging. Rice whiteness rapidly decreased in rice that was milled when condensation occurred, regardless of packaging, while rice that was milled 72 h or more after removal from low temperature storage did not show any significant changes in whiteness. No pest incidence was observed up to 12 d after removal from low temperature storage, regardless of packaging. Starting at 18 d, after removal from low temperature storage, rice that was milled when condensation occurred, was affected by pests, while 24 d after removal from low temperature storage, all portions of rice were affected by pests. Conclusions: Our results suggest that changes in post-milling quality of rice could be significantly reduced by exposing paddy rice to room temperature for at least 72 h before milling, in order to allow the increase of grain temperature and prevent surface condensation.

Interrelation between Physicochemical Properties of Milled Rice and Retrogradation of Rice Bread during COld Storage (쌀의 이화학적 특성과 저장 쌀빵의 노화성과의 관계)

  • 강미영;최영희;최해춘
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.26 no.5
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    • pp.886-891
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    • 1997
  • The interrelation between physicochemical properties of milled rice and retrogradation of rice bread during cold storage was examined to compare the varietal difference in maintenance of rice bread quality. Twelve rice materials showed big varietal difference on physicochemical properties of rice starch such as amylose content(0.0~29.2%), gel consistency(20~98mm), and alkali digestion value(2.0~7.0). Rice bread made from milled rice of Jungwonbyeo, AC 27 and IRAT 177 exhibited soft texture and late retrogradation of rice bread during cold storage(4$^{\circ}C$). The amylose content of milled rice was closely associated with gel consistency negatively and with springiness of rice bread positively. The retrogradation of rice bread texture during cold storage was correlated with gel consistency of rice flour positively and with alkali digestion value of milled rice negatively.

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Effect of Non-Uniform Milling on Quality of Milled Rice during Storage (불균일도정이 저장 중 쌀의 품질에 미치는 영향)

  • Kim, Hoon;Lee, Hyun-Jung;Kim, Oui-Woung;Lee, Se-Eun;Yoon, Doo-Hyun
    • Food Science and Preservation
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    • v.13 no.6
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    • pp.675-680
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    • 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 $25^{\circ}C$.

Physicochemical Characteristics and Varietal Improvement Related to Palatability of Cooked Rice or Suitability to Food Processing in Rice (쌀 식미 및 가공적성에 관련된 이화학적 특성)

  • 최해춘
    • Proceedings of the Korean Journal of Food and Nutrition Conference
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    • 2001.12a
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    • pp.39-74
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    • 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.

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Physicochemical characteristics of rice variety for dry-milled flour

  • Yoon, Mi-Ra;Kwak, Jieun;Lee, Jeom-Sig;Won, Yong-Jae;Kim, Mi-Jung;Choi, Induck;Jeon, Yong-Hee;Kim, Sun Lim
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2017.06a
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    • pp.294-294
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    • 2017
  • Rice (Oryza sativa L.) is one of the main agricultural crops in Asian countries, including Korea, and is considered as the most important staple food in the world. Rice is also processed into flour, which is consumed through various foods such as cake, noodle, bread, and confectionary. Rice flour quality is highly dependent on variety and milling conditions. Producing rice flour with fine particles is more difficult than wheat flour because of its grain hardness. The Korean rice varieties representing different amylose contents were selected for this study. The relationship between the morphological and starch characteristics of rice kernels and the appropriate varieties for producing good-quality, dry-milled rice flour were examined. The hardness of the rice kernels was determined by measuring the pressure at the grain breakage point. The damaged starch content of the rice flour was determined using a Megazyme starch damage assay kit. The particle-size distribution of the rice flour was measured as the volume-base distribution using a laser-diffraction particle size analyzer. The mean particle-size distribution of the dry-milled flour obtained was between $65.3{\sim}105.1{\mu}m$ among the rice varieties. The opaque, non-glutinous, Seolgaeng rice demonstrated a narrow peak at the fine size, whereas the entire particle-distribution range for other varieties was wide. Seolgaeng exhibited significantly lower damaged starch content of dry-milled flour than the other varieties (p < 0.05). Seolgaeng showed lowest in energy consumption on rice flour production with 200 mesh particle size. Accordingly, it is possible to produce dry-milled rice flour which is similar to wheat flour that would considerably reduce milling costs.

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Mapping of grain alkali digestion trait using a Cheongcheong/Nagdong doubled haploid population in rice

  • Kim, Hak Yoon;Kim, Kyung-Min
    • Journal of Plant Biotechnology
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    • v.43 no.1
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    • pp.76-81
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    • 2016
  • We performed a molecular marker-based analysis of quantitative trait loci for traits that determine the quality of appearance of grains using 120 doubled haploid lines developed by anther culture from the F1 cross between 'Cheongcheong' (Oryza sativa L. ssp. Indica) and 'Nagdong' (Oryza sativa L. ssp. Japonica). We therefore calculated the alkali digestion value (ADV), used to indirectly measure gelatinization temperature, to evaluate the quality of cooked rice in 2013 and 2014. The ADV score of frequency distribution was higher milled rice than brown rice. In total, nine different quantitative trait loci (QTLs) were found on 5 chromosomes in 2013 and 2014. Also, chromosome 5, 8 were detected over two years. We conclude that selected molecular markers from this QTL analysis could be exploited in future rice quality. In conclusion, we investigated ADV of brown and milled rice in CNDH population. This study found nine QTLs related to the ADV of brown and milled rice. The detected one marker can be used to select lines with desirable eating-quality traits because ADV is closely associated with the eating quality of cooked rice. Therefore, it will be useful to collect resources and distinguishable in many varieties for rice breeding program.

Cooling and Storage Characteristics of Milled Rice by Different Cooling Storage Methods (냉각저장방식에 따른 백미의 냉각 및 저장특성)

  • Kim Oui-Woung;Kim Hoon;Lim Tae-Gyu
    • Food Science and Preservation
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    • v.11 no.4
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    • pp.448-454
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    • 2004
  • This study was conducted to analyze the cooling and the quality characteristics of milled rice stored in the forced air-blast type using thermo -electric semiconductor and in the still-air type chambers using refrigeration system with refrigerant(R-22). Cooling rates of milled rice in the forced air-blast type and in the still-air type chambers were $0.30\;^{\circ}C/hour$ and $0.21\;^{\circ}C/hour$, respectively. And the temperatures of cooling air and of milled rice at different positions in the forced air-blast type chamber showed severer change than those in the still-air type chamber. During storage of milled rice in the forced air-blast type and still-air type chambers for 14 weeks, there was no significant difference in the quality characteristics, such as b value and fat acidity of milled rice, and overall sensory quality of cooked rice. But the quality characteristics of milled rice stored in room temperature chamber($25^{\circ}C$) as control decreased very rapidly compare to those stored in the cooling chambers. In aspect of fat acidity of milled rice, 6 weeks was the limitation for the safe storage in room temperature.