KOREAN JOURNAL OF CROP SCIENCE (한국작물학회지)

The Korean Society of Crop Science (한국작물학회)
권호 표지

Identification of Chalkiness Development of Milled Waxy Rice Grains with Harvest Times and the Moisture Contents

찰벼 수확시기 및 건조정도에 따른 찹쌀 외관 품질특성 구명

  • 정응기 (농촌진흥청 작물과학원) ;
  • 이춘기 (농촌진흥청 작물과학원) ;
  • 최윤희 (농촌진흥청 작물과학원) ;
  • 김정태 (농촌진흥청 작물과학원) ;
  • 김석 (농촌진흥청 작물과학원) ;
  • 손종록 (충청남도농업기술원)
  • Published : 2008.03.31
Download PDF
⟨ Previous Next ⟩

Abstract

Variation of chalkiness expression in milled waxy rice with the moisture contents of grains was investigated using instrument and naked eye evaluation methods. To find out any effects of varieties and harvesting times on the chalkiness development, rice grains of seven waxy varieties harvested at early, optimal and late times were tested after being sun-dried to have three different moisture contents of about $13.0{\sim}14.5%$, $14.5{\sim}16.0%$ and above 16.0%. The moisture contents of rice grains were distributed in the ranges of about 13.0% to 17.5% with the drying intensity right after harvesting. Although there were some genetical variations in whiteness and degree of transparency of milled rice grains among varieties at the same condition, chalkiness was most significantly affected by the changes of moisture content in all waxy varieties and harvesting times. At the moisture content less than 13.5%, all varieties exhibited waxy unique chalkiness, and at the moisture ranges between 13.5% and 14.0% the chalkiness was more or less affected by harvesting time and varieties. At the moisture content ranges between 14.0% and 16.0%, chalkiness gradually disappeared as with the increase of moisture content. However the degrees of chalkiness loses were strongly depended on individual kernels by showing as if the number of non-waxy rice kernels would be increasing in waxy rice grains with the moisture content increase. At the moisture content above about 16.0%, all waxy kernels lost their unique chalkiness, and showed non-waxy rice appearance.

1. 수확시기에 따른 도정수율은 메벼의 적기수확시기보다 5일정도 늦게 수확하는 것이 높았으며 품종에 따라서는 보석찰벼와 해평찰벼가 도정수율이 높았다. 2. 찹쌀의 특징인 불투명한 유백색은 수분함량 14.0%이상부터 점차 소실되기 시작하여 15.0%대에 마치 멥쌀이 섞인 것처럼 보이다가 16.0%이상에 도달될 경우는 거의 대부분이 멥쌀과 같은 외관을 나타냈다. 3. 수분 증가에 따른 찹쌀의 유백색 소실은 조기에 수확된 벼에서 더 민감하게 나타나기 때문에 가능한 수확시기를 적기 이후로 정하는 것이 건조효율이나 찹쌀 수율 측면에서 더 유리하다고 판단된다. 4. 찹쌀 고유의 유백색 발현을 최대로 하기 위해서는 찰벼 건조수분의 critical point은 13.5%이하였다.

Keywords

References

  1. Antonio, A. A. and B. O. Juliano. 1973. Amylose content and puffed volume of parboiled rice. J. Food Sci. 38 : 915-916 https://doi.org/10.1111/j.1365-2621.1973.tb02112.x
  2. Del Rosario, A. R., V. P. Briones, A. J. Vidal, and B. O. Juliano. 1968. Composition and endosperm structure of developing and mature rice kernel. Cereal Chem. 42 : 225-235
  3. Evers, A. D. and B. O. Juliano. 1976. Varietal differences in surface ultrastructure of endosperm cells and starch granules of rice. Staerke 28 : 160-166 https://doi.org/10.1002/star.19760280504
  4. French, . D. 1984. Organization of starch granules. In: R. L. Whistler, J. N. BeMiller, and E. F. Paschall, Editors, Starch: Chemistry and Technology, Academic Press, Orlando, pp. 183-247
  5. Jane, J., A. Xu, M. Radosavljevic, and P. A. Seib. 1992. Location of amylose in normal starch granules. I. Susceptibility of amylose and amylopectin to cross-linking reagents. Cereal Chem. 69 : 405-409
  6. Juliano, B. O. 1964. Hygroscopic equilibria of rough rice. Cereal Chem. 41 : 191-197
  7. Juliano, B. O. 1982. Properties of rice starch in relation to varietal difference in process ing characteristics of rice grain. J. Japan. Soc. Starch Sci. 29 : 305-317 https://doi.org/10.5458/jag1972.29.305
  8. Kim, K. J., Y. K. Son, S. Jin, S. L. Kim, J. R. Son, and Y. K. Min. 2001. Physico-chemical and milling characteristics of paddy rice at different harvesting times. Korean J. Crop Sci. 47(S1) : pp. 146-147
  9. Reyes, A. C., E. L. Albano, V. P. Briones, and B. O. Juliano. 1965. Varietal differences in physicochemical properties of rice starch and its fractions. J. Agri. Food Chem. 13(5) : 438-442 https://doi.org/10.1021/jf60141a016
  10. Sugawara, T. 1968. Thremmatological investigations on the chemical constitution of starch in cereal grains. II. The effect of the wx factor on amylopectin reserves in the mature endosperm. Gakujutsu Hokoku Utsunomiya Daigaku Nogakubu 7(2) : 97-105
  11. Sung, Y. M., H. C. Choi, and M. Y. Kang. 2000. Physicochemical properties of starch granules from thirteen glutinous rice varieties. Korean J. Breed 32(3) : 226-232
  12. Takeda, K., R. Nakayama, and K. Saito. 1975. Unvalanced growth in floral gumes and caryopsis in rice. IV. Influence of waxy character in gain size, Japan. J. Breed. 25 : 87-92 (In Japanese) https://doi.org/10.1270/jsbbs1951.25.87
  13. Takeda, K. 1980. Grain filling process in waxy (glutinous) and nonwaxy isogenic lines of rice. Japan. J. Breed. 30 : 329-334 (In Japanese) https://doi.org/10.1270/jsbbs1951.30.329
  14. Takeda, K. 1981. Response of grain filling to ripening conditions in waxy (glutinous) and non-waxy isogenic lines and their F1 hybrid of rice. Japan. J. Breed. 31 : 1-8 (In Japanese) https://doi.org/10.1270/jsbbs1951.31.1
  15. Utsunomiya, H., M. Yamagata, and Y. Doi. 1975. Scanning electron microscopy of the endosperm of cereal crops. IV. Starch cell layer of imperfect grain of rice (non-glutinous) and glutinous rice. Yamaguti Daigaku Nogakubu Gakujutsu Hokoku 26 : 19-44
  16. Woo, J. W., G. S. Yoon, M. H. Heu, and H. S. Kim. 1985. Comparison of Some Properties on Six Kinds of Waxy Starches. J. Korean Appl. Biol. Chem. 28(3) : 137-141