• KOREAN JOURNAL OF CROP SCIENCE
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• v.39 no.1
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• pp.27-37
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• 1994

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

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.spc1
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• pp.152-160
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• 2005

This study was carried out to investigate selectable criteria in evaluating waxy corn $F_1$ hybrids for developing good eating quality waxy corn variety. The physicochemical property analysis of 6 waxy corn $F_1$ hybrids - Chalok1, Chalok2, Heugjeomchal, Yeonnongl, Chalok4, and Suwon45- showed a range of $11.2\~13.1\%$ for crude protein, $5.1\~6.0\%$ for crude fat, $91.8\~92.6\%$ for amylopectin, and $4.5\~6.6\%$ for free sugar content. The pericarp thickness which is one of the most important characteristics related to tenderness in waxy corn was ranged $34\~47{\mu}m$ in 4 waxy corn hybrids - Yeonnongl, Chalok4, Suwon45, and Heugjeomchal. On the other hand, it was ranged $64\~81{\mu}m$ in Chalok1 and Chalok2. The amylogram analysis by rapid visco analyzer showed that in fresh waxy corn hybrid (DAP25), all amylogram properties except setback were higher in Yeonnongl, Chalok4, and Suwon45 compared to those of Chalokl, Chnlok2, and Heugjeomchal. However, in matured waxy corn hybyids (DAP45), the result was the opposite - the amylogram properties were higher in Chalokl, Chalok2, and Heugjeomchal than those of Yeonnongl, Chalok4, and Suwon45. The texture analysis showed that gumminess, chewiness, and hardness increased dramatically with the time after the cooking in Chalokl and Beugjeomchal. On the other hand, these above pyoperties did not change as rapidly with the time in Yeonnongl, Chalok4, and Suwon45. Gumminess, chewiness, and hardness did not increase much within 6 hours after steamingr but increased significantly 32 hours after steaming. Therefore, we have reached a conclusion that texture analysis of cooked waxy corn should be carried out 6 hours after steaming. In the sensory evaluation, Yeonnongl, Chalok4, and Suwon45 revealed higher palatability -6.8, 7.1, and 6.9 respectively - than. that of Chnlokl, Chalok2, and Heugjeomchal. The palatability analysis of 6 waxy corn hybrids showed palatability positively correlating with free sugar content,100-kernel weight, kernel length, kernet width, and consistency, but negatively correlating with pericarp thickness, hardness, gumminess, and chewiness.