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United States Department of Agriculture

Agricultural Research Service

Title: Addressing the dilemmas of measuring amylose in rice)

Author
item Fitzgerald, Melissa
item Bergman, Christine
item Ressurreccion, Adoracion
item Moller, Jurgen
item Jimenez, Rosario
item Reinke, Russel
item Martin, Margrit
item Blanco, Pedro
item Molina, Federico
item Chen, Ming-hsuan
item Kuri, Victoria
item Romero, Marissa
item Habibi, Fatemeh
item Umemoto, Takayuki
item Jongdee, Supanee
item Graterol, Eduarda
item Reddy, K
item Bassinello, Priscila
item Sivakami, Rajeswari
item Rani, N
item Das, Sanjukta
item Wang, Ya-jane
item Indrassi, Siti
item Ramli, Asfaliza
item Rauf, Ahmad
item Dipti, Sharifa
item Xie, Lihong
item Lang, Nguyen
item Singh, Pratibha
item Toro, Damaso
item Tavasoli, Fatemeh

Submitted to: Cereal Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/30/2009
Publication Date: 9/1/2009
Citation: Fitzgerald, M.A., Bergman, C.J., Ressurreccion, A.P., Moller, J., Jimenez, R., Reinke, R.F., Martin, M., Blanco, P., Molina, F., Chen, M., Kuri, V., Romero, M.V., Habibi, F., Umemoto, T., Jongdee, S., Graterol, E., Reddy, K.R., Bassinello, P.Z., Sivakami, R., Rani, N.S., Das, S., Wang, Y., Indrassi, S.D., Ramli, A., Rauf, A., Dipti, S.S., Xie, L., Lang, N.T., Singh, P., Toro, D.C., Tavasoli, F. 2009. Addressing the dilemmas of measuring amylose in rice. Cereal Chemistry. 86(5):492-498.

Interpretive Summary: Amylose content is a parameter that correlates with cooked rice texture and other cooking properties. It is measured at the earliest possible stages of rice improvement programs to enable breeders to select for desired grain quality during cultivar development. However, the different values for amylose content for the same variety reported in different publications, and the different methods used for measuring amylose found in different research papers suggest confusion about measuring amylose at the international level. The International Network for Quality Rice (INQR) carried out a survey involving 27 quality evaluation laboratories from every rice-growing region of the world to determine: ways that amylose is measured; reproducibility between laboratories; and sources of variation. Each laboratory measured the amylose content of a set of 17 varieties of rice. The data show that repeatability was high within laboratories but reproducibility between laboratories was low. The major sources of variability were the way the standard curve was constructed and the sources of the potato amylose standards for constructing the standard curves. New research avenues for quantifying the real amount of amylose in rice grains are presented.

Technical Abstract: Amylose content is a parameter that correlates with the cooking behaviour of rice. It is measured at the earliest possible stages of rice improvement programs to enable breeders to build the foundations of appropriate grain quality during cultivar development. Amylose is usually quantified by absorbance of the amylose-iodine complex. The International Network for Quality Rice (INQR) carried out a survey to determine: ways that amylose is measured; reproducibility between laboratories; and sources of variation. Each laboratory measured the amylose content of a set of 17 varieties of rice. The study shows that five different versions of the iodine binding method are in operation. The data show that repeatability was high within laboratories but reproducibility between laboratories was low. The major sources of variability were the way the standard curve was constructed and the iodine binding capacity of the potato amylose. When laboratories are separated by type of standard curve, reproducibility is much lower between laboratories that used a standard curve of potato amylose alone compared with those who used calibrated rice varieties. We, as heads of most of the world’s rice quality programs, present new research avenues for quantifying the real amount of amylose in rice grains.

Last Modified: 8/24/2016
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