The purpose of this study was to select some superior soybean varieties adaptable to growth in the northern parts of the Korean peninsula, and to identify the suitable growing regions of soybean in North Korea. Soybean varieties from South Korea were evaluated with the Chinese locally cultivated varieties as check varieties at two locations, Donggang City of Lianing Province, and at Longjing City of Jilin Province, 2017-2019. A total of 100 soybean varieties from South Korea and three Chinese check varieties were evaluated based on ecological adaptability, and a total of 18 varieties including ‘Suwon 212’ from the Longjing test site as well as a total of 59 genotypes the Donggang test site, were selected for further evaluation in the first experiment year. A total of 12 promising soybean varieties at Longjing and 15 varieties at Donggang that were selected from the previous year, were evaluated at the same sites for ecological adaptability as well as productivity in the second experiment year. A total of nine promising soybean varieties were selected at the test sites, respectively. The nine varieties at each site that were selected from the previous year for the production capacity including flowering date, degree of lodging, yield potential, and disease resistance, were reviewed to evaluate at both sites in the last experiment year. Finally, a total of eight superior varieties, including four at the Longjing site (‘Seonnogkong’, ‘Dajinputkong’, ‘Danweonkong’ and ‘Sinpaldalkong 2’) and the other four at the Donggang site (‘Iksan 13’, ‘Seonnogkong’, ‘Gangil’ and ‘Yeonpung’) were selected. The yield potential of four outstanding soybean varieties selected at the Longjin site was 1.5-2.6t/ha, and that of the other four at the Donggang site was 2.1-2.7t/ha.

This study was carried out to investigate milling's effect on the pasting properties and storage stability of dry-milled rice flour. Rice flour's moisture content was increased from 9.48% to 9.80% after going through a rice polisher, and the crude fat content of rice flour was decreased from 0.91% to 0.62% after going through a rice polisher. In the color index of rice flour, the rice polisher was only affected by yellowness. The pasting properties were verified through RVA, and it was confirmed that the use of a rice polisher had no significant effect on the pasting properties. As a result of observing the changes in fatty acid value, it was ascertained that the storage period could be increased using the rice polisher. These results suggest that the rice polisher can increase the storage period without changing the pasting properties.

This study was conducted to compare the quality characteristics of firm tofu (coagulant calcium chloride, CaCl2 used) made from eight imported and four domestic soybeans selling in Korean markets. The 100-seed weight of soybeans imported from China and Seonpung cultivated in Korea was the highest at 33.23 g and 32.51 g, respectively. Soybeans imported from the USA (bulk type) showed the lowest at 16.12 g, followed by Ukraine at 16.94 g, and Brazil at 18.51 g. The range of protein and fat in the 12 soybeans was 37.08~41.36% and 18.35~22.17%, respectively. The isoflavone contents were the highest in Daepung2 cultivated in Korea at 3,764.10 μg/g and the lowest in soybeans imported from Brazil at 1,439.85 μg/g. Tofu yield among the samples was in the following order: Seonpung (235.2%), China (232.0%) Daepung2 (228.7%), Daechan (225.7%), and Brazil (208%). Tofu made with soybeans cultivated in Korea (including from China) showed a higher yield compared to that made from soybeans from seven other countries. In the analysis of the correlation of quality factors of tofu, the hardness of the tofu was correlated with 100-seed weight (r=0.676*) and protein content of the soybeans (r=0.837**). Tofu yield was correlated with 100-seed weight (r=0.748**) and protein content of the soybeans (r=0.583*).

The purpose of this study was to derive the conditions for manufacturing rice porridge with optimum properties after reheating. The characteristics of rice porridge according to the soaking time, water addition rate, heating temperature, heating time, and cooling conditions were compared using the ‘Samkwang’ cultivar. In Step Ⅰ, as the heating temperature increased, the weight change decreased and the viscosity increased, and the temperature known as the main factor of the gelatinization also appeared to affect the viscosity increase. In Step Ⅱ, the viscosity and the texture properties was not significantly different as the soaking time was reduced, and 10 minutes was suitable because of due to the shortening effect of the total process time. In Step Ⅲ, the residual heat was lowered by cooling after the rice porridge production, so the viscosity could be greatly reduced. Also, it was confirmed that the water addition rate of 900% and the heating temperature of 15 minutes were optimal manufacturing conditions. The next study will investigate the porridge processability of rice cultivars using these results.

When producing rice products, it is very important to select suitable raw materials. Therefore, in this study, the quality characteristics of 16 rice cultivars were quantified to determine the criteria for evaluating the machinability of raw rice. The L value, which can affect the color of porridge prepared from rice, was the greatest for Hwaseonchalbyeo (84.17). The water-binding capacity, related to water interaction, was high in Hyangcheola (113.2%), and water solubility was high in Shingil (22.3%). Dodamssal (42.3%, 70.7 RVU) and Hwaseonchalbyeo (4.7%, 27.8 RVU) showed lower final viscosity compared to the cultivars in which the amylose content was medium groups (16.4~21.2%, 173.6~277.2 RVU). Specifically, cultivars with high or low amylose content had a low viscosity. The characteristics of the distribution of raw rice quality data were confirmed through 11 histograms. Furthermore, amylose content vs. water solubility, water solubility vs. peak viscosity, and peak viscosity vs. final viscosity showed high correlations (r=0.542, －0.569, and 0.836 respectively, p<0.01), and clear cultivar discrimination by the standard error of the mean (0.765~10.811). In conclusion, amylose content, water solubility, and peak viscosity were considered the most suitable characteristics for the quality evaluation of raw rice.

In this study, the physicochemical traits of soybean (100-seed weight, seed coat rate, protein content, composition, and amino acid content) and the quality of tofu (texture and sensory characteristics) were evaluated in order to determine the features of six varieties (Saedanbaek, Daechan, Daepung2, Seonpung, Miso, Saegeum) in terms of textural and sensory characteristics of tofu. Regardless of cultivar, the order of amino acid composition rate was as follows: Glutamic acid > Aspartic acid > Arginine > Leucine > Lysine. Approximately 50-60% of tofu (dry weight) consisted of protein, and among the cultivars, Tofu made from Saedanbaek showed the highest amount of protein at 59%. It was followed by tofu made from Miso at 54%. The rest contained about 50% protein. According to the result of correlation, crude lipid (-0.933**), crude protein (0.961**), and total phosphorus (0.924**) were strongly correlated with tofu hardness, and such factors could be utilized as an indicator of tofu quality.

In this study, the product characteristics and physicochemical properties were investigated through collection of commercial porridge. The addition rate of grain raw materials was about 6.5~11.75%, glutinous rice was added at a rate of about 23~60% to improve the viscosity and various other food additives were used. The moisture content characteristics varied among the products. The rotational viscosity of CP (Commercial Porridge)4 was the highest at 39,054 cP, while the flow viscosity of CP3 was least at 4.80 cm/30 seconds. The starch content differed among the products in the range of total starch 6.96~8.08%, amylose 1.41~2.61%, total sugar 6.55~12.81% and reducing sugar 0.50~0.99%. Particularly, total sugar showed a very high correlation ( 0.920) while rotational viscosity and color value (b) showed significant correlation with most of the properties i.e. moisture, solids content etc. There was a rapid increase in the reactivity of starch degrading enzyme at the early stage of the reaction which gradually decreased with time. The physicochemical characteristics of commercial porridge presented in this study could be expected to increase the industrial use value of the related research because it considers the quality of the currently commercialized porridge for the future selection of suitable porridge raw materials.

1. 주요 쌀 생산국 브랜드 쌀 및 MMA 쌀 40점의 품질을 조사한 결과, 수분함량은 11.6(인도)~14.2%(중국), 단백질 함량은 5.82(미국)~7.86%(중국), 아밀로스 함량은 16.2(태국)~24.4%(인도), 윤기치는 45.2(인도)~75.7(미국)의 범위를 나타내었다. 2. 국가별 수집된 브랜드 쌀의 형태적 특성을 살펴본 결과, 중국과 베트남의 브랜드 쌀은 주로 통통한 단립종이었고, 미국 브랜드 쌀은 중간 두께의 중립종이었으며, 태국 브랜드 쌀은 얇은 장립종의 형태를 나타내었다. 호주와 인도는 단립, 중립, 장립의 다양한 형태의 쌀을 확인 할 수 있었다. 3. 국가별 브랜드 쌀의 백미 품위를 살펴본 결과 완전미율은 72.4(인도)~95.2(태국)%의 범위였으며, 베트남 브랜드 쌀은 동할미 비율이 높았으며, 인도 브랜드 쌀은 분상질미 비율이 높은 특징을 나타내었다. 4. RVA를 이용한 호화특성을 분석 한 결과, 인도의 브랜드 쌀이 최고온도가 낮고 치반점도가 높으며 강하점도가 낮아 취반미의 찰기가 낮을 것으로 예측되었으며, 호화개시온도 또한 유의하게 높은 것을 확인할 수 있었다. 5. 국가별 브랜드 쌀의 식미 관능평가를 실시한 결과, 수집된 브랜드 쌀의 평균 종합기호도는 미국(-0.59), 중국(-0.76), 호주(-1.23), 베트남(-1.43), 태국(-2.09), 인도(-2.49) 순으로 나타났다.

Variations among 15 major waxy cultivars in terms of milling appearance and cooking characteristics at different moisture contents were investigated. Hardness of milled rice kernels increased and 1000-grain weights decreased with the reduction of moisture content. The milled rice kernels showed about two-fold hardness gap between 12 and 16% moisture contents. The 1000-grain weights revealed 6% reduction from 21.4 g to 20.2 g at 16% and 12% moisture contents, respectively. The whiteness of waxy rice which indicated varietal variation also increased with decrease of moisture contents. In most cultivars, the whiteness of waxy rice peaked and stabilized at around 14% moisture content. In milling properties, brown/rough rice ratios were not affected by moisture content, however, milled/brown rice ratios increased with the decrease of moisture contents between 14 - 16%. This implied that the proper moisture content for milling rate of waxy rice is lower than that of non-waxy rice. The chalkiness expression of milled waxy rice varied directly with moisture contents. At 16% moisture content, the rates of translucent and semi-translucent kernels like non-waxy rice were 49.0 - 84.4% while at 14% moisture content, the rates of chalky rice were 88.7 - 99.9%. In terms of cooking properties of milled waxy rice with different moisture contents, lower moisture contents (12 - 13%) were related with higher water absorption rates. The higher volume expansion of cooked milled rice and more soluble solid after cooking in most cultivars showed the possibility of low palatability of cooked waxy rice with lower moisture contents (below 13%).

This study was conducted the comparative analysis on quality and rice bread process suitability properties by four particle size classification of dry-milled flours for four rice varieties. Dry-milled rice flours were prepared by dry milling and classified according to particle size using 100, 150, 200, and 250 mesh sieves. The mean particle size by four particle size classification of 60 ~ 100 mesh, 100 ~ 150 mesh, 150 ~ 200 mesh, 200 ~ 250 mesh exhibited 118.9 μm, 87.4 μm, 65.3 μm, 46.1 μm, respectively. The particle size of dry-milled rice flours was the finer, the damaged starch content was the higher (r = − 0.570*). The particle size also had significant negative correlation with the water absorption index (r = − 0.533*, r = − 0.593*), and water solubility index (r = − 0.857**, r = − 0.584*). Dry-milled rice flours with particle size of 60 ~ 70 μm, passed through 150 and 200 mesh sieves exhibited the highest specific volume of rice bread. Whereas, the dry-milled rice flour with finer particle size above 200 mesh showed the lowest specific volume of rice bread. These results will be applied as a quality standard to aid in the selection of the most suitable dry-milled rice flour for baking.