쌀의 품질평가 현황과 금후 연구방향

손종록,김재현,이정일,윤영환,김제규,황흥구,문헌팔 韓國作物學會 2002 한국작물학회지 Vol.47 No.S

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.

쌀 품질 고급화 및 고 부가가치화를 위한 육종현황과 전망

최해춘 韓國作物學會 2002 한국작물학회지 Vol.47 No.S

1980-'90년대에 쌀의 자급생산이 지속되고 생활수준 향상에 따른 양질미 수요가 점증되면서 자포니카 다수성 품종의 미질 개선에 힘을 크게 기울이게 되었고 식미향상을 위한 육종연구 와 효율적 평가 기술개발 연구에 박차를 가하게 되어 쌀의 이화학적 특성과 식미 및 밥 물리성간 상관과 식미의 객관적 평가방법 개발, 양식미 쌀 및 가공적성 특수미 개발 등 그 동안 많은 연구성과를 올리게 되었다. 1990년대에 밥맛이 매우 좋은 고품질 자포니카 품종과 대립, 심백미, 향미, 유색미 등 가공용 특수미 품종을 개발 보급하였고 식미와 용도에 대하여 식미검정계, 신속점도측정계 및 texture 분석계 등을 이용하여 검토하였다. 최근에는 아밀로스 함량이 9%로 찹쌀과 맵쌀의 중간 성질을 가진 중간찰 품종인 '백진주벼'와 배유가 보얀 멥쌀인 '설갱 벼'를 비롯하여 라이신 함량이 높은 '영안벼' 육성하여 쌀의 가공 이용성과 기능성을 한층 높혀 놓았다. 식미와 여러 가지 미질 특성간 관련성에 관한 연구 결과를 요약해 보면 다음과 같다. 쌀의 상온흡수율 및 최대흡수율은 K/Mg율 및 알칼리 붕괴도와 유의한 부의 상관성을 나타내었으며 가열흡수율이 높은 품종일수록 밥의 용적팽창률이 컸다. 수분함량이 낮은 경질인 쌀일수록 침지 20분 후의 상온흡수율과 최대흡수율이 더 높은 경향이었으며 이러한 흡수 특성은 쌀 단백질 함량이나 아밀로스 함량 및 식미와는 유의한 상관성이 없었다 취반 적정가수량은 품종에 따라 마른 쌀 무게의 1.45-l.61배의 변이를 나타내었고 평균은 1.52배였으며 알맞게 취사된 밥의 부피는 평균 쌀 부피의 2.63배가되었다. 쌀 형태, 알칼리붕괴도, 호응집성, 아밀로스 및 단백질 함량은 거의 비슷하지만 식미에 차이가 있는 자포니카 품종들을 사용하여 식미와 관련된 쌀의 이화학적 특성을 검토한 결과, 밥의 윤기와 식미 총평은 생산 연도에 따라 호화점도 특성 중 최고점도, 최저점도 및 응집점도와 밀접한 관계를 나타내었다. 밥맛이 가장 좋은 일품 벼는 쌀의 외층에 아밀로스 함량 분포가 낮고 쌀을 열탕에 담근 20분간 우러난 용출액의 요드 정색도가 낮고 증가정도도 완만하였다. 일품 벼는 밥맛이 떨어지는 동해 벼에 비해 밥알 횡단면의 주사형 전자현미경 사진에서 밥알 외층의 호화전분의 그 물망이 매우 치밀하고 속층의 전분립의 호화정도가 양호하였다. 식미총평은 식미관련 이화학적 특성과의 관계를 이용한 중회귀식에 의해 매우 높은 결정계수로 추정이 가능하였다. 밥노화의 품종간 차이는 α-amylase-iodine 법으로 비교할 수 있었는데 노화정도가 적었던 품종은 일품벼, 추청벼, 사사니시끼, 진부벼 및 고시히까리였다. 통일형 품종인 태백벼와 자포니카 품종 중 섬진벼가 비교적 밥노화가 빨랐다 일반적으로 밥맛이 좋은 품종이 밥의 노화정도가 느렸으며 찬밥의 탄력성이 큰 경향이었다. 또한 밥노화가 느렸던 품종은 최저점도가 높았고 최종점도가 낮았다 찬밥의 탄력성은 쌀의 마그네슘함량과 밥의 용적팽창률과 밀접한 관계를 나타내었다. 식은밥의 더운밥 대비 경도 변화율은 취반용출액의 고형물량과 취반용적 팽창률과 부의 상관을 나타내었다. 식미관련 주요 이화학적 특성은 밥의 노화와도 직접 간접으로 상관이 있는 것으로 평가되었다. 쌀의 여러 가지 식품 가공적성과 관련된 형태 및 이화학적 특성은 가공식품 종류에 따라 매우 다르다. 쌀 튀김성은 호응집성이 연질이거나 아밀로스 함량이 낮을수록 양호하며 지질함량이나 단백질 함량이 높으면 좋지 않은 경향이다. 심복백정도가 심할수록 튀김현미 정립률이 떨어지며 현미 강도가 높을수록 튀김률은 높은 경향이었다 쌀국수는 밀가루와 50% 혼합시에 쌀의 칼륨 및 마그네슘 함량이 높은 품종일수록 제면 총평이 낮은 경향이었고 제면이 양호한 것이 국수물의 용출고형 물량이 적은 경향이었다. 쌀빵 가공적성은 품종에 따라서 현미와 백미간에 현저한 차이를 나타내는 것이 있는데 현미에서 반죽의 부피 증가율이 큰 쌀일수록 푹신한 감이 있는 쌀방 제조가 가능하였으며 백미에서 단백질 함량이 높은 품종일수록 쌀빵이 더욱 촉촉한 느낌이 있는 경향이었다. 아밀로스 함량이 높고 호응집성이 경질인 쌀일수록 쌀빵의 탄력성이 더 높은 경향이었다. 쌀의 발효 및 양조적성은 심복백이 심한 쌀이나 새로운 돌연변이인 뽀얀 멥쌀이 홍국균이나 홍국균의 균사활착 밀도가 높고 당화 효소 역가도 높은 경향이었으며 쌀알이 대립이면서 단백질 함량이 낮은 쪽이 양조에 유리한 것으로 알려져 있다. 찰벼 품종도 여러 가지 이화학적 특성과 전분구조 특성의 차이에 따라 9개의 품종군으로 나누어 볼 수 있을 만큼 품종적 변이가 크며 이들 이화학적 및 구조적 특성간에 상호 밀접한 연관성을 나타내었으며 유과·인절미·식혜·미숫가루 등에 상당한 가공적성의 차이를 보였다. WTO 체제 출범이후 생산비와 가격 면에서 경쟁력이 약한 우리 쌀이 살아남기 위해서는 품질의 고급화와 쌀 가공식품의 다양화 및 고기능성 개발을 추구할 수밖에 없다. 따라서 이와 같은 노력은 벼 품종개발만으로 소기의 성과를 올리기 어렵고 쌀 식 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 quality 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 cultivars 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, Recently, new special rices such as extremely low-amylose dull or opaque non-glutinous endosperm mutants were developed. Also, a high-lysine rice variety was developed for higher nutritional utility. 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 texture of cooked rice. The glossiness or gross palatability score of cooked rice were closely associated with the peak, hot paste and consistency viscosities of viscosities with year difference. The high-quality rice variety "IIpumbyeo" 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 microscope. 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 α -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 IIpumbyeo, Chucheongyeo, Sasanishiki, Jinbubyeo and Koshihikari. A Tonsil-type rice, Taebaegbyeo, and a japonica cultivar, Seomjinbyeo, showed the relatively fast deterioration of cooked rice. Generally, the better rice cultivars in eating quality of cooked rice showed less retrogradation 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 breed. 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 grain rices showed better suitability far fermentation and brewing. The glutinous rice were classified into nine different varietal groups based on various physicochemical and structural characteristics of endosperm. There was some close associations among these grain properties and large varietal difference in suitability to various traditional food processing. Our breeding efforts on improvement of rice quality for high palatability and processing utility or value-adding products in the future should focus on not only continuous enhancement of marketing and eating qualities but also the diversification in morphological, physicochemical and nutritional characteristics of rice grain suitable for proc

쌀 品質 高級化 및 多樣化 改良育種의 現?과 展望

崔海椿(Choi Hae-Chune) 동아시아식생활학회 2000 동아시아식생활학회 학술발표대회논문집 Vol.- No.-

A large effort on the breeding research for improving the grain quality of Tongil-type rice was intensively exerted during 1970s~1980s and the marketing and eating quality of them was remarkably improved through the selection of good grain appearance, low gelatinization temperature and low amylose content. The endeavors enhancing the grain quality of high-yielding japonica rice were steadly 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 quality 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 cultivars 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. Our breeding effort in rice quality improvement for the future should focus on enhancement of palatability of cooked rice as well as the diversification of varietal variation in physical and chemical characteristics of rice grain.

경상북도 지역별 최고품질 벼 품종의 수량 및 품질 특성

신종희,김상국,김세종 한국작물학회 2017 한국작물학회지 Vol.62 No.4

Rice quality should be considered as a primary consumer requirement. Regarding marketing, characteristics such as appearance, physicochemical properties, and palatability of brand rice are of high economic importance. Therefore, this study was conducted to select the optimal rice cultivars representing the commercial rice brands of Gyeongsangbuk-do province in Korea. Various rice grain quality components, grain appearance, several physicochemical properties of rice grain, and texture or palatability of cooked rice grains of ten cultivars (namely ‘top quality rice’) cultivated at three different locations, such as inland mountainous and southern plain areas of Gyeongsangbuk-do province in 2013~2014, were evaluated, and the obtained data was analyzed. ‘Hiami’ showed slightly higher protein contents and lower palatability of cooked rice than the other rice cultivars. Rice production and head rice yield produced at Gumi were the highest. The protein content of milled rice produced at Andong, an inland mountainous region, was approximately 0.3% point lower than that from other locations, whereas the amylose content of milled rice was approximately 1% point higher than those from the other plain regions, Daegu and Gumi. We evaluated the texture, Glossiness value determined using a Toyo teste meter and palatability of cooked rice of ten cultivars. The hardness of cooked rice produced in Andong was slightly lower than that produced in Daegu and Gumi, and additionally, the palatability of cooked rice produced in Andong was the best, followed by that producted in Gumi and Daegu. Considering rice yield and grain quality in the major rice cultivation areas of Gyeongsangbuk-do province, the rice cultivars that may be suitable for each region could be recommended mid-late maturation: ‘Younghojinmi’ and ‘Mipum’ in Daegu, ‘Daebo’, ‘Samgwang’, Chilbo’ and ‘Younghojinmi’ in Gumi, ‘Samgwang’, ‘Jinsumi’ and ‘Sukwang’ in Andong. These results obtained in this study imply that the selected cultivars with high yield and quality could be recommended with high priority to rice farmers in the regions. 2013~2014년간 벼 등숙기 기상은 평균기온은 평년대비±0.2℃ 로 비슷하고, 등숙 후반기인 10월 상순의 기온이 평년에 비해 지역별로 1.0~1.6℃ 높아 안정적인 등숙이 가능한 조건이었다. 지역별 출수기의 경우 대구, 구미지역보다5일 일찍 이앙한 안동지역의 평균 출수기가 2일 정도 늦어지는 경향이었으며, 영호진미의 경우 안동지역에서 출수기가 타 지역 보다 4~5일 더 늦어지면서 등숙률이 77.4%로현저히 낮았다. 구미지역의 쌀 수량이 평균 671 kg/10a로 가장 많았다. 수광의 경우 수당립수, 현미천립중, 등숙률, 쌀수량 등 전반적인 생육 및 수량특성이 지역별 차이 없이비슷하였다. 도정한 쌀의 완전미 비율은 대구지역에서는 진수미, 영호진미, 미품이 각각 92.0, 92.8, 90.0%로 높고 구미지역에서는 대보, 칠보, 수광이 90% 이상의 완전미율을 보였으며, 안동지역은 진수미와 수광의 완전미율이 높게 나타났다. 호품은 시험지역 모두에서 가장 낮은 완전미율을 나타내었다. 백미에 함유된 단백질 분석결과, 품종별로는 하이아미가 가장 높게 나타났으며 지역별로는 안동지방에서 재배된경우 모든 품종에서 단백질 함량이 낮았다. 특히 영호진미의 경우 대구, 구미, 안동지역 모두에서 6%이하의 단백질 함량을 나타내었다. 아밀로스 함량은 안동지역에서 재배된경우 대구와 구미지역에 비해 높았다. 고품과 대보의 경우대구지역에서 찰기와 부착성이 낮게 나타났고, 진수미와영호진미의 경우 재배 지역에 따른 식감 특성 차이가 적었다. 지역별 최고품질벼 수량 및 품질 특성 분석을 통하여대구지역은 진수미, 영호진미, 미품, 수광을 선발하고, 구미지역은 대보, 삼광, 칠보, 수광, 영호진미, 미품을, 안동지역은 삼광, 대보, 진수미, 수광을 선발 하였다. 이미 개발된 많은 우수한 품종의 특성을 파악하고 각 지역의 환경에 적합한 품종 선택하여 재배함으로써 고품질 쌀을 생산하면 농업인의 소득도 보장이 되고 우리 쌀도 지킬 수 있을 것이다. 따라서 본 시험결과를 활용하여 경북 주요 농업지대별식미가 우수한 품종을 선별하여 농가에서 지역브랜드로 활용토록 함과 동시에 지역별로 다른 환경변이에 맞추어 식미가 우수한 쌀을 생산 할 수 있도록 하는 자료를 제공하고자 한다.

Relationship between rice grain quality traits and starch pasting properties using early maturing rice cultivars in Chungnam plain area

Yeo-Tae Yun,Chong-Tae Chung,Jae-Chul Lee,Young-Ju Lee,Han-Jung Na,Kwang-Won Lee,Young-Hwan Yoon 충남대학교 농업과학연구소 2015 농업과학연구 Vol.42 No.3

This study was conducted to know the variation and relationship of rice grain quality and starch pasting properties by transplanting times. Two early maturing rice cultivars which accounted for the most area of early maturing rice cultivar in Chungnam province were used. The experiment was laid out in a split-plot design with 3 replications. The main plot consisted of three transplanting times viz. early (April 25), ordinary (May 25) and late (June 25) with sub-plots containing two cultivars. According to the transplanting times, most of rice grain quality and starch pasting properties showed significant difference and Joami showed higher grain quality than Unkwang in all transplanting times. Especially, rice grain quality was improved when transplanted late, showing high head rice and glossiness of cooked rice due to the lower mean temperature during grain filling stage. Glossiness of cooked rice was positively correlated with head rice ratio, amylose content and setback value, and negatively correlated with chalky rice ratio and protein content. The highest positive and negative correlation were observed between breakdown value and peak viscosity (r = 0.98**), and breakdown and setback (r = -0.94**), respectively. These results provide some information for rice researchers and producers producing cultivars with an improved quality, suggesting that rice quality is highly influenced by temperature at grain filling stage, and transplanting times is crucial in improving rice quality. In addition, starch pasting properties are useful for determining rice quality because rice grain quality and starch pasting properties are dependent on each other.

Relationship between rice grain quality traits and starch pasting properties using early maturing rice cultivars in Chungnam plain area

Yun, Yeo-Tae,Chung, Chong-Tae,Lee, Jae-Chul,Lee, Young-Ju,Na, Han-Jung,Lee, Kwang-Won,Yoon, Young-Hwan Institute of Agricultural Science 2015 Korean Journal of Agricultural Science Vol.42 No.3

This study was conducted to know the variation and relationship of rice grain quality and starch pasting properties by transplanting times. Two early maturing rice cultivars which accounted for the most area of early maturing rice cultivar in Chungnam province were used. The experiment was laid out in a split-plot design with 3 replications. The main plot consisted of three transplanting times viz. early (April 25), ordinary (May 25) and late (June 25) with sub-plots containing two cultivars. According to the transplanting times, most of rice grain quality and starch pasting properties showed significant difference and Joami showed higher grain quality than Unkwang in all transplanting times. Especially, rice grain quality was improved when transplanted late, showing high head rice and glossiness of cooked rice due to the lower mean temperature during grain filling stage. Glossiness of cooked rice was positively correlated with head rice ratio, amylose content and setback value, and negatively correlated with chalky rice ratio and protein content. The highest positive and negative correlation were observed between breakdown value and peak viscosity ($r=0.98^{**}$), and breakdown and setback ($r=-0.94^{**}$), respectively. These results provide some information for rice researchers and producers producing cultivars with an improved quality, suggesting that rice quality is highly influenced by temperature at grain filling stage, and transplanting times is crucial in improving rice quality. In addition, starch pasting properties are useful for determining rice quality because rice grain quality and starch pasting properties are dependent on each other.

중·남부 평야지산 발 형태 및 이화학적 특성의 품종 및 산지간 변이

崔海椿,池定鉉,李鍾燮,金榮培,趙守衍 韓國作物學會 1994 한국작물학회지 Vol.39 No.1

주요 미질특성에 대한 품종 및 환경변이정도를 파악하고자 자포니카 5개 품종과 통일형 두 품종을 1989년에 중부평야지인 수원 및 이천과 중서해안간 척지인 남양, 호남평야지인 이리 및 남서해안간척지인 계화에서는 보통기 보비재배로, 영남평야지인 밀양에서는 맥후작 만식으로 재배하여 생산된 쌀의 외관 및 도정특성과 주요 이화학적 특성 및 식미를 비교분석한 결과를 요약하면 다음과 같다. 1. 쌀 외관 및 도정특성을 비롯하여 쌀의 이화학적 특성, 밥의 물리성 및 식미총평 등 모든 미질특성에서 현저한 품종간 차이를 나타내었고, 산지간변이가 두드러졌던 미질특성은 쌀 외관, 도정특성, 알칼리붕괴도, 단백질함량, K/Mg율, 호화개시온도, 강하점도(breakdown) 및 치반점도(setback)였는데 이들 특성의 산지변이는 전변이의 14~54%에 달하였으며 품종 산지간 교호작용변이가 특히 켰던 미질특성은 식미총평과 응집(consistency) 및 치반점도였다. 2. 벼 품종간 미질특성의 차이는 특히 자포니카와 통일형 품종군간에 현저하였는데 통일형 품종들이 자포니카품종들에 비해 쌀 외관품질 및 도정률이 떨어지고 1.0% 저농도 KOH 용액의 쌀 붕괴도와 아밀로스함량이 약간 낮은 반면 단백질함량과 K/Mg율은 약간 높은 편이었으며 최고점도, 강하점도 및 응집점도가 다소 높은 반면 치반점도는 유의하게 낮았고 식미가 크게 떨어졌다. 식미가 양호했던 자포니카품종들은 단백질함량이 약간 낮으면서 K/Mg을 및 밥의 점성/경도비율이 약간 높은 경향이었다. 3. 현미천립중은 이리산미가 타 지역산미에 비해 두드러지게 무거웠고 수원, 계화 및 밀양산미가 소립인 경향이었으며 정현비율이나 등숙면에서는 밀양산이 가장 떨어졌고 이리나 이천산이 양호하였다. 건전미율은 남양간척지산미가 가장 높았으며 계화간척지산미가 가장 낮았다. 4. 쌀의 아밀로스함량은 계화간척지산미가 타 지역산미에 비해 약 1%가량 낮았고 단백질 함량은 중부지역산미가 남부지역산미에 비해 유의하게 약 1%가량 낮았으며 K/Mg율은 계화 및 이리산미가 가장 낮았던 반면 밀양산미가 가장 높았다. 식미총평은 품종별로 생산지에 따라 상당히 달랐는데 평균적으로 남양산미가 가장 좋았고 다음으로 수원>이리>이천>계화>밀양 순이었다 5. 쌀의 알칼리 붕괴도는 밀양 맥후작산미가 가장 높았고 호남평야지산미가 가장 낮았는데 비해 아밀로그래프의 호화개시온도는 수원과 이리산미가 가장 낮았던 반면 밀양산미가 가장 높았다. 강하점도는 밀양산미가 가장 낮았고 다음이 이천산미가 낮았던데 비해 계화 및 이리산미가 가장 높았으며 치반점도는 이와 정반대의 경향을 나타내었다. 밥의 점성 /경도비율은 지역간 차이가 유의하지는 않았으나 남부평야산미가 중부평야산미에 비해 다소 떨어지는 경향이었다. 6. 식미와 관련이 있는 쌀 외관품질 및 이화학적 특성을 이용한 주성분 분석에서 전정보의 약 59% 설명이 가능한 제 1 및 제 2 주성분치상의 7개 품종별 6개 산지미의 분포로 보아 품종에 따라서 산지 반응이 달랐는데 대체로 자포니카와 통일형 품종군간 구분과 밀양, 중부평야 및 호남평야의 세 산지간 구분이 가능하였다. 산지내 품종간 미질변이는 남양간척지와 이리산미가 비교적 작았는데 수원산미는 이천과 남양산미의 미질변이를, 계화산미는 이리산미의 미질변이를 거의 포괄하였다. To understand the relative contribution of varietal and environmental variation on various grain quality components in rice, grain appearance, milling recovery, several physicochemical properties of rice grain and texture or palatability of cooked rice for milled rice materials of seven cultivars(five japonica & two Tongil-type), produced at six locations of the middle and southern plain area of Korea in 1989, were evaluated and analyzed the obtained data. Highly significant varietal variations were detected in all grain quality components of the rice materials and marked locational variations with about 14-54% portion of total variation were recognized in grain appearance, milling recovery, alkali digestibility, protein content, K /Mg ratio, gelatinization temperature, breakdown and setback viscosities. Variations of variety x location interaction were especially large in overall palatability score of cooked rice and consistency or set- back viscosities of amylograph. Tongil-type cultivars showed poor marketing quality, lower milling recovery, slightly lower alkali digestibility and amylose content, a little higher protein content and K /Mg ratio, relatively higher peak, breakdown and consistency viscosities, significantly lower setback viscosity, and more undesirable palatability of cooked rice compared with japonica rices. The japonica rice varieties possessing good palatability of cooked rice were slightly low in protein content and a little high in K /Mg ratio and stickiness /hardness ratio of cooked rice. Rice 1000-kernel weight was significantly heavier in rice materials produced in Iri lowland compared with other locations. Milling recovery from rough to brown rice and ripening quality were lowest in Milyang late-planted rice while highest in Iri lowland and Gyehwa reclaimed-land rice. Amylose content of milled rice was about 1% lower in Gyehwa rice compared with other locations. Protein content of polished rice was about 1% lower in rice materials of middle plain area than those of southern plain regions. K/Mg ratio of milled rice was lowest in Iri rice while highest in Milyang rice. Alkali digestibility was highest in Milyang rice while lowest in Honam plain rice, but the temperature of gelatinization initiation of rice flour in amylograph was lowest in Suwon and Iri rices while highest in Milyang rice. Breakdown viscosity was lowest in Milyang rice and next lower in Ichon lowland rice while highest in Gyehwa and Iri rices, and setback viscosity was the contrary tendency. The stickiness/hardness ratio of cooked rice was slightly lower in southern-plain rices than in middle-plain ones, and the palatability of cooked rice was best in Namyang reclaimed-land rice and next better with the order of Suwon~geq Iri~geq Ichon~geq Gyehwa~geq Milyang rices. The rice materials can be classified genotypically into two ecotypes of japonica and Tongil-type rice groups, and environmentally into three regions of Milyang, middle and Honam lowland by the distribution on the plane of 1st and 2nd principal components contracted from eleven grain quality properties closely associated with palatability of cooked rice by principal component analysis.

벼 수확 후 수분함량별 건조지연에 따른 쌀 품위 및 화학성

권석주,송은주,권영립,최동칠,최영근,권태오,Kwon, Suk-Ju,Song, Eun-Ju,Kwon, Young-Rip,Choi, Dong-Chil,Choi, Yeong-Geun,Kwon, Tae-Oh 한국작물학회 2006 Korean journal of crop science Vol.51 No.suppl1

쌀 품질의 고급화를 위한 벼 수확 후 관리기술체계를 확립하기 위하여 벼 수확을 대형포대 및 콤바인포대로 수확한 후 수분함량 별 야적기간 연장에 따른 쌀 품위 및 품질변화에 미치는 영향을 조사였다. 수확당일 수확시간에 따른 정조의 수분함량은 $23.7{\sim}28.8%$로 수확시간이 늦어질수록 낮았고, 수확 후 건조지연에 따른 정조의 외관변화는 저장포대가 대형인 경우 3일째 정조의 색깔이 변하고 악취가 심하게 발생하였으며 콤바인포대는 4일째부터 색깔이 변하고 악취가 발생하였다. 포대내부의 온도변화는 대형포대는 저장기간이 길어질수록 그리고 수분함량이 높을수록 증가되는 폭이 컸으나 콤바인포대는 수확당시 수분함량에 따라 일정한 비율로 증가되는 경향이었다. 대형포대에 저장된 정조의 수분함량은 저장 2일째부터 증가되었고 수분함량이 높을수록 증가폭이 컸으나 콤바인포대의 경우는 수확 시 수분함량이 적은 경우 약간 감소하는 경향이고 높은 경우는 약간 증가되는 경향이었다. 수확 후 건조가 지연될수록 단백질, 아밀로스함량은 차이가 없으나 지방산은 증가되었고 대형포대가 콤바인포대에 저장된 정조보다 지방산 증가폭이 컸으며 수확 후 건조지연일수나 벼 수확 시 수분함량이 높을수록 현미의 완전미율은 감소되고 청미와 피해립율이 증가되었으며 백미품위 역시 비슷한 경향이었다. 따라서 미질저하를 최소화 할 수 있는 포대종류별 건조지연 한계기는 대형포대가 벼 수확 후 $1{\sim}2$일 이내, 콤바인포대는 $2{\sim}3$일 이내로 추정되었다. This study was conducted to establish the post-harvest management system in rice. Harvested hulled rice was gathered into large-scale bag and combine bag, in which the rice quality and the influence on quality change were investigated on various storage periods and moisture contents. Moisture content of hulled rice ranged from 23.7% to 28.8% on different harvest times, which grew lower as harvesting time was delayed. When desiccation was retarded hulled rice in large scale bag was changed in color and emitted an of offensive odor in 3 days and that in combine bag showed similar symptom in 4 days. Inner temperature in large scale bag was changed a lot when the storage period was prolonged and also the moisture content was higher while that in combine bag increased regularly corresponding to the moisture content at the time of harvest. Moisture content of hulled rice stored in large-scale bag increased 2 days after harvest and the more moisture content showed the more increased tendency, while in the case of combine bag the moisture content was not changed much whether the hulled rice contained low or high moisture content in harvesting. As desiccation was delayed fatty acid increased much more in large-scale bag than in combine bag even though protein and amylose contentwere not changed. As desiccation was delayed more and hulled rice contained moisture more in harvesting head rice ratio of brown rice decreased and green-kerneled rice and damaged grain ratio increased and quality of milled rice also became deteriorated. As a result, desiccation day to minimize the deterioration of rice quality was estimated 1-2 days in large scale bag and 2-3 days in combine bag after harvesting.

벼 만식재배시 묘령이 수량 및 품질에 미치는 영향

원종건,안덕종,김세종,최충돈,이상철 한국작물학회 2008 Korean journal of crop science Vol.53 No.-

This study was conducted to compare the yield and grain quality as affected by rice seedling age in late transplanted rice. The rice yield was remarkably reduced in 10 day-old seedlings but those of older seedlings over than 30-day were not different. In the rice quality, as the rice seedling age younger the rate of greened and damaged rice increased, suggesting decreasing of the head rice rate. Among the physicochemical characteristics, protein content of rice grain was increased in 10 day-old seedling but amylose content was not different, consequently, the palatability was improved in older seedlings over than 30-day. From these results, it is more beneficial to machine transplant the older seedlings over than 30-day for delayed transplanting. This study was conducted to compare the yield and grain quality as affected by rice seedling age in late transplanted rice. The rice yield was remarkably reduced in 10 day-old seedlings but those of older seedlings over than 30-day were not different. In the rice quality, as the rice seedling age younger the rate of greened and damaged rice increased, suggesting decreasing of the head rice rate. Among the physicochemical characteristics, protein content of rice grain was increased in 10 day-old seedling but amylose content was not different, consequently, the palatability was improved in older seedlings over than 30-day. From these results, it is more beneficial to machine transplant the older seedlings over than 30-day for delayed transplanting.

중산간지와 고냉지산 쌀 형태 및 이화학적특성의 품종 및 산지간 변이

崔海椿,池定鉉,李鍾燮,金榮培,趙守衍 韓國作物學會 1994 한국작물학회지 Vol.39 No.1

중산간지 및 산간고냉지대에서 재배된 벼의 주요 미질특성에 대한 품종 및 환경변이정도를 파악하고자 오대벼등 자포니카 조생종 5개 품종을 1989년에 중북부 중간지인 철원과 산간고냉지인 진부, 중남부 중산간지인 상주, 화서 및 남부고냉지인 운봉의 4개소에 재배하여 생산된 쌀의 외관 및 도정특성과 주요 이화학적 특성 및 식미특성을 조사하였던 바 이들 미질특성의 품종 및 산지변이를 비교 분석한 결과를 요약하면 다음과 같다. 1. 현미천립중, 아밀로스함량, K/Mg률, 호화개시온도, 최고점도, 강하점도(breakdown) 및 치반점도(setback)에서 품종 및 산지간 변이가 모두 품종x산지간 교호작용변이에 비해 현저하였고 정현비율, 알칼리 붕괴도 및 단백질 함양에서는 산지간 변이가, 밥의 점성 /경도비율에서는 품종간 변이가 유의하게 켰다. 특히 품종x산지간 교호작용 변이가 켰던 미질특성은 외관 및 등숙관련특성과 식미 및 응집점도(consistency)등이었다. 2. 현미천립중은 진부올벼와 오대벼가 가장 무거웠고 불완전등숙립률은 진부올벼가 가장 낮았으며 백미건전미율는 오대벼가 심복백 때문에 다른 품종에 비해 약간 멀어졌다. 아밀로스 함량은 출수기가 빠른 진부올벼와 소백벼가 타품종에 비해 약 1% 가량 낮았고 K /Mg율은 식미가 가장 좋았던 오대벼가 가장 낮았으며, 호화개시온도와 치반점도가 유의하게 낮았던 반면 최고점도와 강하점도가 현저하게 높았던 오대벼, 소백벼 및 진부올벼등이 밥맛이 약간 양호한 편이었다. 3. 철원산미가 가장 입중이 무겁고 등숙이 양호하였던 반면 건전미율은 오히려 떨어졌으며 진부산미가 가장 정현비율이 높으면서 건전미율이 높았다. 4. 아밀로스함량은 진부산미가 다른 지역산미에 비해 약 2~3%가 높았던 반면 철원산미가 가장 낮았고 단백질함량은 중부지역산미가 남부지역산미에 비해 약1%가량 낮았으며 K/Mg율은 진부산미가 가장 높았고 K함량은 중부지역산미가 남부지역산미에 비해 다소 높은 경향이었다. 식미총평은 품종별로 산지에 따라 크게 달라서 산지간 평균적 비교가 큰 의미가 없지만 운봉과 철원산미가 진부와 화서산미보다 양호한 경향이었다. 5. 쌀의 알칼리 붕괴도와 호화개시온도는 진부산미가 다른 지역산미에 비해 현저히 높았고 그 다음으로 운봉>화서>철원산미 순으로 낮았으며 강하점도는 철원산미가 가장 켰고 그 다음으로 화서>운봉>진부산미 순으로 저온하에서 등숙된 쌀일수록 낮았으며 치반점도는 이와 정반대의 경향이었다. 밥의 점성 /경도비율은 철원산미가 여타 지역에 비해 약간 높은 값을 나타내었다. 6. 식미관련 미질특성을 이용한 주성분 분석에서 전정보의 약 60% 설명이 가능한 제1 및 제2 주성분치상의 5개 품종별 4개 산지미의 분포로 보아 대체로 진부산미와 여타 지역산미로 확연히 구분되었고 다시 진부산미는 2개군, 여타 지역산미는 3개군으로 세분화 할 수 있었으며 산지내 품종변이가 가장 작았던 것은 화서산미였고. 고냉지산미는 품종 간 변이가 켰다. 식미관련 종합적 미질특성면에서 가장 양호한 군에 속하는 것은 철원, 운봉 및 화서산 오대벼와 운봉산 소백벼였다. To catch the relative importance of varietal and environmental variation in various grain quality components associated with palatability of cooked rice, grain appearance, milling recovery, several physicochemical properties of milled rice and texture or eating quality of cooked rice for rice materials of five japonica cultivars, produced at four locations of the mid-mountainous and alpine area of Korea in 1989, were evaluated and analyzed the obtained data. Highly significant varietal and locational variations were detected in 1000-grain weight, amylose content, K/Mg ratio, gelatinization temperature, peak viscosity, breakdown and setback viscosities as compared with variety x location interaction variation. Also, marked locational variations were recongnized in milling recovery from rough to brwon rice, alkali digestibility and protein content, and significant varietal variation was caught in stickiness /hardness ratio of cooked rice. The variety x location interaction variation was especially large in quality components of grain appearance and ripening, palatability of cooked rice and consistency viscosity. One thousand kernel weight was heaviest in Jinbuolbyeo and Odaebyeo, and the unfilled grain ratio was lowest in Jinbuolbyeo. Odaebyeo showed slightly' lower ratio of intact and clear milled rice because of more chalky rice kernels compared with other cultivars. Amylose content of Jinbuolbyeo and Sobaegbyeo was about 1% lower than that of others and K/Mg ratio of Odaebyeo was the lowest one among rice materials. Odaebyeo, Sobaegbyeo and Jinbuolbyeo revealed significantly low gelatinization temperature and setback viscosity while high peak and breakdown viscosities. Cholwon rice showed the greatest kernel weight, good grain filling but lowest ratio of intact and clear milled rice while Jinbu rices exhibited the highest milling recovery from rough to brown rice and ratio of sound milled rice. Amylose content of milled rice in Jinbu rices was about 2-3% lower than those in other locations. Protein content of polished rice was about 1% lower in rice materials of middle zone than those of southern part of Korea. K/Mg ratio of milled rice was highest in Jinbu rice and potassium content was slightly higher in the rice materials of middle region than in those of southern region. Alkali digestion value and gelatinization temperature of polished rice was markedly high in Jinbu rices as compared with other locations. Breakdown viscosity was hightest in Chlown rices and next higher with the order of Hwaso>Unbong>Jinbu rices, and setback viscosity was the quite contrary tendency with breakdown. The stickiness /hardness ratio of cooked rice was relatively higher value in Cholwon rices than in the others and the palatability of cooked rice was a little better in Unbong and Cholwon rices than in Jinbu and Hwaso rices, although variety x location interaction variation was large. The rice materials can be classified largely into two groups of Jinbu and the others by the distribution on the plane of 1st and 2nd principal components (about 60% of total informations) contracted from twelve grain quality properties closely associated with eating quality of cooked rice. Also, Jinbu and the other rices were divided into two and three rice groups respectively. Varietal variation of overall rice quality was smallest in Hwaso. The most superior rice group in overall quality evaluation included Odaebyeo produced at Cholwon, Unbong and Hwaso, and Sobaegbyeo grown at Unbong