• Title/Summary/Keyword: quality rice

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Trend and Further Research of Rice Quality Evaluation (쌀의 품질평가 현황과 금후 연구방향)

  • Son, Jong-Rok;Kim, Jae-Hyun;Lee, Jung-Il;Youn, Young-Hwan;Kim, Jae-Kyu;Hwang, Hung-Goo;Moon, Hun-Pal
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.47
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    • pp.33-54
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    • 2002
  • Rice quality is much dependent on the pre-and post harvest management. There are many parameters which influence rice or cooked rice qualitys such as cultivars, climate, soil, harvest time, drying, milling, storage, safety, nutritive value, taste, marketing, eating, cooking conditions, and each nations' food culture. Thus, vice evaluation might not be carried out by only some parameters. Physicochemical evaluation of rice deals with amy-lose content, gelatinizing property, and its relation with taste. The amylose content of good vice in Korea is defined at 17 to 20%. Other parameters considered are as follows; ratio of protein body-1 per total protein amount in relation to taste, and oleic/linoleic acid ratio in relation to storage safety. The rice higher Mg/K ratio is considered as high quality. The optimum value is over 1.5 to 1.6. It was reported that the contents of oligosaccharide, glutamic acid or its derivatives and its proportionalities have high corelation with the taste of rice. Major aromatic compounds in rice have been known as hexanal, acetone, pentanal, butanal, octanal, and heptanal. Recently, it was found that muco-polysaccharides are solubilized during cooking. Cooked rice surface is coated by the muco-polysaccharide. The muco-polysaccharide aye contributing to the consistency and collecting free amino acids and vitamins. Thus, these parameters might be regarded as important items for quality and taste evaluation of rice. Ingredients of rice related with the taste are not confined to the total rice grain. In the internal kernel, starch is main component but nitrogen and mineral compounds are localized at the external kernel. The ingredients related with taste are contained in 91 to 86% part of the outside kernel. For safety that is considered an important evaluation item of rice quality, each residual tolerance limit for agricultural chemicals must be adopted in our country. During drying, rice quality can decline by the reasons of high drying temperature, overdrying, and rapid drying. These result in cracked grain or decolored kernel. Intrinsic enzymes react partially during the rice storage. Because of these enzymes, starch, lipid, or protein can be slowly degraded, resulting in the decline of appearance quality, occurrence of aging aroma, and increased hardness of cooked rice. Milling conditions concerned with quality are paddy quality, milling method, and milling machines. To produce high quality rice, head rice must contain over three fourths of the normal rice kernels, and broken, damaged, colored, and immature kernels must be eliminated. In addition to milling equipment, color sorter and length grader must be installed for the production of such rice. Head rice was examined using the 45 brand rices circulating in Korea, Japan, America, Australia, and China. It was found that the head rice rate of brand rice in our country was approximately 57.4% and 80-86% in foreign countries. In order to develop a rice quality evaluation system, evaluation of technics must be further developed : more detailed measure of qualities, search for taste-related components, creation and grade classification of quality evaluation factors at each management stage of treatment after harvest, evaluation of rice as food material as well as for rice cooking, and method development for simple evaluation and establishment of equation for palatability. On policy concerns, the following must be conducted : development of price discrimination in conformity to rice cultivar and grade under the basis of quality evaluation method, fixation of head rice branding, and introduction of low temperature circulation.

Effect of Thawing Methods and Storage Periods on the Quality of Frozen Cooked Rice

  • Oh, Myung-Suk
    • Preventive Nutrition and Food Science
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    • v.3 no.3
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    • pp.234-240
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    • 1998
  • This study attempted to determine the effect of various thawing methods and storage periods on the quality of froen cooked rice. Frozen cooked rice was thawed at four different methods, such as pressure cooking, conventional cooking, microwave heating and thawing at room temperature after 10 days, 30days and 90 days frozen storage. We conducted a physico-chemical analysis (moisture content, dehydration rates, degree of gelatinization, color value and texture) and sensory evalution on the frozen-thawed cooked rice. The study showed that there were no significant differences on the quality characteristics of frozen-thawed cooked rice during the storage period of 90 days. However, the thawing method of pressure cooking caused high moisture content, rapid dehydration rates, and a high degree of gelatinization on the cooked rice. Thus, the desirabililty for the rice diminished becaused of the excess moisture content and the change of appearance and testure in the rice due to the high temperature. There were similiar quality characteristics to the cooked rice after forzen-thawing whether by conventional cooking or by microwave heating and just after cooking. Thawing at room temperature also caused a significant decrease in quality characteristics.

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Overexpression of starch branching enzyme 1 gene improves eating quality in japonica rice

  • Sun, Ming-Mao;Lee, Hye-Jung;Abdula, Sailila E.;Jee, Moo-Geun;Cho, Yong-Gu
    • Journal of Plant Biotechnology
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    • v.40 no.2
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    • pp.88-101
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    • 2013
  • Eating quality of rice attracts more and more attention from rice-eating consumers in the recent years. Thus, improvement of eating quality of cooked rice has become one of the most important breeding goals in japonica rice. Here, the generation of transgenic japonica rice with improved eating quality and grain yield are reported. Overexpression of OsSbe1 gene encoding rice starch branching enzyme 1 was driven by 35S promoter. Eleven independent homozygous $T_3$ transgenic lines were characterized and had shown higher palatability (71.2 ~ 72.6) than wild type Gopum (70.4). Moreover, transgenic rice lines showed an increase in 1000-grain weight and number of spikelets per panicle compared with the wild type. The yield of milled rice was 562.8 ~ 596.7 kg/10a in eight $T_3$ lines, but 542.1 kg/10a in wild type. Gene expression analyses in mRNA transcription and enzyme activity levels suggest that improved eating quality is due to the up-regulation of OsSbe1 gene.

Effect of Black Rice Powder Levels on Quality Properties of Emulsion-type Sausage

  • Park, Sin-Young;Kim, Hack-Youn
    • Food Science of Animal Resources
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    • v.36 no.6
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    • pp.737-743
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    • 2016
  • The effects of black rice powder on the quality of sausage were investigated. Samples were prepared with 0% (control), 1%, 3%, and 5% black rice powder. With increasing black rice powder content, the moisture and ash content of sausage increased, while protein con-tent was significantly less than that observed for the control (p<0.05). The fat content in samples containing 5% black rice powder was significantly less than that observed for other samples (p<0.05). With increasing black rice powder content, the pH of uncooked and cooked samples increased. In addition, lightness, redness, and yellowness decreased. With increasing content of black rice powder, emulsion stability decreased. On the other hand, with increasing black rice powder content, cooking yield increased. As compared to the other samples, those containing high content of black rice powder exhibited higher viscosity. With increasing black rice powder content, the hardness of samples decreased, while the gumminess and chewiness of samples containing black rice powder were less than those observed for the control (p<0.05). Moreover, with increasing black rice powder content, the flavor, juiciness, and overall acceptability of samples increased. In addition, the tenderness of samples containing 3% and 5% black rice powder was significantly greater than that observed for the control and sample containing 1% black rice powder (p<0.05). In addition to the economic benefits, black rice powder can be used to improve quality characteristics.

Correlations of Irrigation Water Quality to Yield and Quality of Rice Grain (관개용수 수질과 벼 수확량, 미질과의 상관관계 규명)

  • Choi, Sun Hwa;Choi, Ho Jin;Jang, Jeon Ryeol;Lee, Seung Heon;Oh, Jong Min
    • Journal of Korean Society on Water Environment
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    • v.21 no.2
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    • pp.169-175
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    • 2005
  • This study was carried out to investigate the effects of irrigation water pollution on the yield and grain quality of rice. It acquires fundamental data to set up water quality standards for irrigation and produce agricultural safety products. The correlations of BOD, T-N, T-P, pH, ECw of the irrigation water with yield, grain appearance quality, and the protein content were evaluated. The field and pot experiments were conducted by using Japonica of Oryza sativa L. during 2 years. BOD concentration in irrigation water effects strongly on grain appearance quality and yield of rice. T-N in irrigation water has strong effect on the yield, appearance, and quality of rice. T-P concentration in irrigation water have not any correlation with yield and quality of rice. pH showed strongly negative correlation with maturity ratio(MTR), 1000 grain weight(TGW), and yield of rice(YLD) as r=-0.803~-0.828(p<0.001) and have no effect on the appearance quality of rice. $EC_w$ indicating salt content showed strongly negative correlation with MTR, TGW, number of grains per panicles(NGP), and number of panicles per unit area(NPM) as r=-0.759~-0.798, and with YLD as -0.753.

Trend and Prospect of Rice Quality Evaluation (쌀의 품질평가 현황과 전망)

  • Kim Jae-Hyun;Lee Jung-Il;Youn Young-Hwan;Kim Je-Kyu;Hwang Hung-Goo;Moon Hun-Pal;Son Jong-Rok
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2002.05a
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    • pp.53-57
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    • 2002
  • Quality evaluation must be more developed in order to offer the sufficient information for producer, distribution centers buyer, consumer. There are many parameters which influence the rice quality and cooked rice. It is difficult to evaluate the quality of rice and cooked rice by only some parameters. In the case of rice quality evaluation in Korea, physicochemical inspection is performed by examining the minimum and maximum limits of brown rice recovery, moisture content, damaged kernel, and colored kernel as inspection standard. Marketing standard of rice defines the limits of perfect, white core and belly, colored, damaged kernels, and broken rice, classifying into special, excellent, and normal grades. As a research direction for the development of rice quality evaluation, establishment as parts of technical field, must be further developed as follows : more detailed measure of characters, search of unknown taste-related components, creation and grade classification of quality evaluation factors at each management stages of treatment after harvesting, evaluation as food material as well as cooking rice, method development for simple evaluation and establishment of equation for palatability. In the side of policy, the following concerns must be conducted: price discrimination in conformity to rice cultivar and grade under the basis of qualify evaluation method developed, fixation of head rice branding, and introduction of low temperature circulation.

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Pedigree Analysis of 17 High Quality Korean Rice Cultivars Using Web Database Systems

  • Yi, Gi-Hwan;Park, Dong-Soo;Chung, Eun-Sook;Song, Song-Yi;Jeon, Nam-Soo;Nam, Min-Hee;Kim, Doh-Hoon;Han, Chang-Deok;Eun, Moo-Young;Ku, Yeon-Chung
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.51 no.6
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    • pp.554-564
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    • 2006
  • It is important to understand pedigree of rice cultivars commonly used for breeding. In this paper, pedigree tables for tracking the pedigree of 17 representative rice cultivars recommended by Rural development Adminstration (RDA) were completed and analyzed using two kinds of web database system; 'IRIS' and 'RRDB'. Seven cultivars, namely, 'Sangmibyeo', 'Ilpumbyeo', 'Saegewhabyeo', 'Surabyeo', 'Shindongjinbyeo', 'Ilmibyeo' and 'Jungwhabyeo' had 'Koshihikari' on the pedigree of their ancestor. Besides 'Koshihikari', the most feguently used ancestral germplasms among the high quality rice cultivars were 'Fujisaka 5', 'Kameno o' and 'Asahi', 'Fujisaka 5' was used as ancestral parent in 12 out of 17 cultivars. Interestingly, 'Kameno o' was used in pedigree of 16 out of 17 high quality varieties and 'Asahi' was used in the ancestral pedigree of all 17 varieties. 'Hwayeongbyeo' was used as one of parent in the breeding of 'Dongjin 1', 'Hwabongbyeo', 'Saegewhabyeo' and 'Junambyeo'. 'Ilpumbyeo' was used in the breeding pathway of 'Junambyeo' and 'Saegewhabyeo', 'Mangeumbyeo' itself was not enlisted as one of high quality rice cultivars, but was used as a breeding parent of three high quality varieties, namely, 'Saegewhabyeo', 'Hwabongbyeo' and 'Nampyeongbyeo'. Incorporated with evaluation data, pedigree will provide a valuable chance to genealogical tracking of agronomic traits such as disease resistance, grain quality and etc.

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.

Effects of Addition Ratio of Pigmented Rice on the Quality Characteristics of Seolgiddeok (유색미의 첨가 비율이 설기떡의 품질 특성에 미치는 영향)

  • 김기숙;이재경
    • Korean journal of food and cookery science
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    • v.15 no.5
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    • pp.507-511
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    • 1999
  • This study was carried out to investigate the effects of addition ratio of pigmented rice(Suwon 415) on the color difference, mechanical characteristics and gelatinization degree, sensory characteristics of Seolgiddeok. As the amount of pigmented rice was increased, the redness was increased, however, the lightness and yellowness were decreased. The hardness, adhesiveness, cohesiveness and chewiness of, Seolgiddeok were decreased with the increase of pigmented rice content, however, the springiness was increased. As the amount of pigmented rice was increased in Seolgiddeok, gelatinization was getting increased. In sensory evaluation, quality characteristics of Seolgiddeok with pigmented rice was better than those of Seolgiddeok without pigmented rice. Especially, Seolgiddeok with 20% pigmented rice added had the best score in color, sweetness, flavor and overall quality.

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Effects of Supplementing Organic Citrus in Making Rice Straw Silage (볏짚사일리지 제조를 위한 유기감귤 첨가효과)

  • Ahn, Jong-Ho
    • Korean Journal of Organic Agriculture
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    • v.15 no.3
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    • pp.309-318
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    • 2007
  • The effects of supplementation of organic citrus on the quality of rice straw silage was investigated in this study. The aim of the study was to improve the quality of rice straw silage using agricultural by-products and therefore to secure the good quality forage sources. Firstly, looking at chemical composition of citrus added rice straw silage, crude protein content appeared improved with the addition of citrus to rice straw silage compared to control while NDF and ADF contents decreased. pH of the silages were different between control(4.39) and treatments$(3.47\sim3.53)$. Lactic acid content was higher in citrus added silage(4.87mM) than in control (3.65mM). External quality of the silages was also better in citrus added silage when citrus added at the equal ratio with rice straw(1 : 1). This trend was the same as with pH and lactic acid content. Propionate was significantly higher in citrus addd silage but butyrate was significantly lower. DM and NDF disappearance rates in the rumen were highest when citrus added at the equal ratio with rice straw(1:1). In conclusion, supplementation of citrus to rice straw silage with equal ratio contributed the best to the improvement of the quality of silage and it may have been due mainly to abundant content of non-structural carbohydrate in citrus.

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