• KOREAN JOURNAL OF CROP SCIENCE
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• v.67 no.3
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• pp.155-163
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• 2022

The tillering potential of panicle number type (PNT) rice greatly varies with planting density. Moreover, grain filling and ripening differ depending on the panicle position, which may further affect rice grain quality. The present study evaluated the grain quality of PNT rice sparsely planted to reduce production costs. The physicochemical characteristics of starch from the grains of PNT type rice 'Ilpum' planted at different densities (37, 50, 60, and 80 plants/3.3 m²) and at different positions of panicles (upper or lower on the culm) were determined. Overall, as the planting density decreased, the number of panicles increased but the starch content decreased, which further reduced the 1,000-grain weight. In particular, at the lowest density (37 plants/3.3 m²), protein content increased but particle size, enthalpy, and relative crystallinity decreased. The effects were more pronounced at lower than at upper panicle positions. These findings indicate that tillering potential differs with planting density, ultimately affecting the palatability of rice grains. Based on these findings, we propose restricting rice transplantation to a planting density of ≤37 plants/3.3 m² to achieve the best quality of grains at lower costs and with less labor.

• Journal of the Korean Society of Food Culture
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• v.22 no.4
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• pp.434-440
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• 2007

Yackwa is used as one of foods prepared for traditional rituals and holidays and enjoyed as snacks. Since Yackwas are fried, they contain oil, which can cause rancidity and undermines the freshness of Yackwas during distribution to retailers, not to mention a high level of calories. The study aims to develop baked Yackwas and analyze the quality in terms of calorie levels and characteristics by baking Yackwas in oven. Calorie level was 4.65 kcal/g in fried Yackwa, 3.96 kcal/g in baked Yackwa, and 2.95 kcal/g in baked peanut Yackwa prior to dip coating of grain syrup. baked Yackwa showed hardness of 13476.33 $g/cm^2$ before dipping in grain syrup, which was harder than 1912.56 $g/cm^2$ of fried Yackwa. After grain syrup coating, hardness of baked Yackwa reduced more significantly, compared with that of fried Yackwa, as grain syrup permeated through texture of Yackwa. And less hardness makes baked Yackwa tastier. Sensory evaluation was measured in a 5-point scale. Scores for texture and taste of baked Yackwa outpaced those of fried Yackwa. Score for the overall quality was 3.65 in baked Yackwa and 3.25 in baked peanut Yackwa, compared to 2.85 of fried Yackwa, indicating a higher potential of commercializing(p<0.05).

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.spc
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• pp.44-46
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• 2008

This study was carried out to observe the quality of commercial brand rices collected from Gyeongbuk Province, Korea in 2006-2007. Rice quality was analyzed as a mixed ratio with other varieties by DNA analysis, physicochemical and appearance characteristics among 26 commercial brand rices. In protein contents of rice grain, 12 brand rices were lower than 6.5%, 6 brand rices were ranged 6.6-7.0%, and others were higher than 7%. In head rice rates, 2 brand rices were higher than 95%, 4 brand rices were ranged 90-94%, and other brand rices were lower than 90%. In distribution of the mixed ratio with other varieties, 12 commercial brand rices were ranged 1- 10%, 9 commercial brand rices were ranged 11-20%, and 5 brand rices were lower than 20% of mixed ratio.

• 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.

• Proceedings of the Korean Society of Crop Science Conference
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• 1999.11a
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• pp.80-101
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• 1999

Self-sufficiency ratio of food crops in Korea is estimated under $20{\%}$ in 2010 because total food consumption including feed will be increased. but food grain production will be decreased. It is necessary to maintain the optimum level of food self-sufficiency rate to secure national food demand/supply balance and non-trade and multiple function of agriculture in Korea. It will be possible to produce more food grains having the acceptable quality if the appropriate policy and cropping techniques are developed and practised in future. Breeding for high yielding varieties should be the first target to raise the production potential of food crops . Number of varieties developed during last 30 years is counted as 353 in food crops. New varieties developed in 1990s showed the higher yield potential and the improved agronomic characteristics compared with 1970s and 1980s varieties. But number of varieties planted on the farmer's field over $5{\%}$ of national planting area is less than one third of total varieties developed Breeding efforts to maintain planting area of main food crops should be focussed on consumer's demand and farmer's need. They are the best quality variety in each field of crop utilization, the newly designed variety adapting to changes of natural, rural and cropping environment, and the higher yielding variety. It is also needed to develop new quality crop varieties for inducing more consumption of crop grain produced in Korea for direct food or processing. Development of barley varieties for animal feed. high income soybean varieties, high quality wheat variety. and super yielding rice and barley varieties are also needed to keep or maximize national food production potential. In order to establish the appropriate cropping technique for domestic food security, the strong and continuous interest and financial support on crop breeding are required, and the inter-disciplinary and inter-institutionary researches should be strengthened for successful crop breeding.

• Microbiology and Biotechnology Letters
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• v.52 no.2
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• pp.152-162
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• 2024

The microbial starter used to produce kefir beverages, kefir grain, contains a microbial exopolysaccharide called kefiran. Kefir grain consisting of water-insoluble polysaccharides, proteins, and fats, which can be applied as a multi-functional biopolymer. The mass of kefir grain can increase in the fermentation process of Kefir, but it is considered very slow. The purpose of this research is to study the impact of ammonium sulfate supplementation and yeast extract on reconstituted skim milk to increase the mass kefir grain and physical properties of kefiran. Results showed that the ammonium sulfate-supplemented substrate increased the mass of kefir grain by 547% in 14 days, with the condition that the substrate must be renewed every 2 days. Refreshing the substrate is considered one of the important factors. Supplementation on substrate did not appear to affect the viability of bacterial and yeast cells. Kefir grain produced from supplemented substrate also yields better thermal stability properties and has more functional groups than without supplementation. Two Lacticaseibacillus rhamnosus (RAL27 and RAL43) and one Limosilactobacillus fermentum (RAL29) were found to produce EPS. The three isolates also showed good skim milk fermentation ability after purification from kefir grain. The kefir grain produced in this study has the potential for wider application. This study also showed that kefir grain can be adjusted in quantity and quality through fermentation substrate engineering.

• Journal of Crop Science and Biotechnology
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• v.11 no.2
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• pp.135-140
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• 2008

Improving eating quality is one of the most important objectives in japonica rice breeding programs in Yunnan Province of China. Eating quality and its relevant traits of nine Korean and 11 Yunnan rice cultivars were comparatively analyzed in this study. The grain shape of most Yunnan japonica rice cultivars have a relatively slender shape and are slightly larger than Korean rice cultivars. Palatability value of cooked rice of Yunnan rice cultivars was significantly lower, while the protein content of Yunnan rice cultivars was significantly higher than that of Korean cultivars. Peak viscosity and breakdown viscosity of the Yunnan rice cultivars were significantly lower, while setback viscosity of the Yunnan rice cultivars was significantly higher than in Korean rice cultivars. Palatability value of cooked rice was negatively correlated with protein content and setback viscosity but positively correlated with peak viscosity, breakdown viscosity, and cool paste viscosity. Through multiple linear regression analysis, an equation for estimating palatability value(PV) of cooked rice based on quality traits was generated as dependent only upon protein content(PC), PV=139.024-(10.865$\times$PC) with an $R^2$ value of 0.822. The results suggest that reducing protein contents should be the major target in improving eating quality of Yunnan japonica rice cultivars through integrated approaches of both cultivar development and appropriate cultural practices. Genetic similarities among cultivars based on DNA markers which had been identified as associated with grain quality seemed not to be directly related to PV.

• Korean Journal of Food Science and Technology
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• v.21 no.6
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• pp.876-883
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• 1989

In order to investigate the index component and basis for the shelf-life of the grain share improved Meju, the effect of the storage time and package on the quality of Meju and soy sauce were studied during 90 days storage at $30^{\circ}C$. Also, sensory evaluation for the soy sauces from Meju with various storage time were carried out. During the storage period, moisture content, amylase and protease activity were decreased, on the other hand, the contents of amino-nitrogen and ammonia-nitrogen were increased. Among these components, protease activity was found the major index component for quality control because it was the most important component for soy sauce fermentation and the most changeable component of Meju during the storage period. According to the sensory test, the quality of soy sauce was agreed well with the protease activity of Meju, and the soy sauce from longer storage Meju was inferior organoleptic quality to that from shorter Meju. By the storage quality test, protease activity showed the highest value in 15 days storage Meju and decreased gradually with storage time passed. The basis of protease activity for quality control was 200 (O.D. at 660 nm/g). which was 50% of the initial activity And it was known that the shelf-life of the grain shape improved Meju was about 90 days . It was also shown that the storage in package did not affect noticeably to prolong the shelf-life of Meju on this study.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.35 no.1
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• pp.34-43
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• 1990

Six commerical rice varieties were cultivated and harvested at different locations in 1987 and 1988 to clarify the degree of locational variations. of several characteristics related to rice grain quality using the rice samples harvested from 8 to 20 locations for a variety each year. Locational variations of percent brown rice, percent milled rice, 1000-grain weight and amylose content were small, but whole grain rate, alkali digestibility, gel consistency, percent white-center and white-belly grain, degree of chalkiness and degree of translucency showed larger variations between locations. The degree of locational variation of sensory evaluation score for eating quality of cooked rice were varied from small to large along with rice variety used and year cultivated. Texture palatability index and stickiness of cooked rice among rheogram characteristics showed larger locational variations, but cohesiveness and springiness showed smaller variations between locations. Set back, break down and maximum viscosity showed larger locational variations among amylogram characteristics of rice flour. Special attention was given to a cultivated location, Anseong, because rice samples harvested at Anseong showed lower percent white-center and white-belly grain, and low set back and high break down in Chucheongbyeo, lower percent white-center and white-belly grain, higher texture palatability index and viscousness/hardness ratio, and low set back and high break down in Dongjinbyeo, higher texture palatability index, and low set back and high break down in Yongmunbyeo, lower percent white-center and white-belly grain in Sangpungbyeo, and low set back and high break down in Samkangbyeo. No other locations in this study produced rice samples showing wide acceptable quality-related characteristics except Anseong.

• Journal of the Korea Institute of Military Science and Technology
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• v.6 no.4
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• pp.159-166
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• 2003

Microstructures and mechanical properties of VIM/VAR/VAR-processed Ni-based Alloy718 ingot were investigated. Vacuum arc remelting(VAR) results in chill grain zone, columnar grain zone, and equi-axed grain zone in the ingot due to the difference in local solidification processes. Different grain structures of the remelting ingot result in the different hot workability for the given cogging conditions. Experimental results on microstructural inhomogeniety and material flow behavior under billet cogging conditions were presented, and their potential effects on the billet cogging process are discussed.