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61 Rice Methods​

61-01.01 Amylograph Method for Milled Rice

This method measures the gelatinization and paste viscosity characteristics of milled rice flour. The amylograph measures and records viscosity changes that occur during heating, holding, and cooling of a starch-containing mixture. Curves obtained with a 10% rice flour slurry help predict rice starch behavior during cooking and processing of rice-based products. Curves of a 20% slurry provide an approximate indication of the gelatinization temperature of the starch, after which the paste viscosity exceeds the measuring ability of the instrument, and the test is terminated.

61-02.01 Determination of the Pasting Properties of Rice with the Rapid Visco Analyser

This method determines the gelatinization and paste viscosity characteristics of milled rice flour using a Rapid Visco Analyser (RVA). These measures, which are predictors of rice cooking and processing properties, are obtained by simultaneously heating and stirring an aqueous suspension of ground rice in a disposable canister placed in the instrument. A precisely controlled heat-hold-cool temperature cycle is used to cause viscosity changes in the paste.

61-03.01 Amylose Content of Milled Rice

A method to determine the apparent amylose content of milled rice, an indicator of cooking and processing qualities, by colorimetric determination at 620 nm of the greenish-blue starch-iodine complex developed at pH 4.5-4.8 in acetate buffer. This rapid screening method is applicable to all well-milled raw, parboiled, and precooked rices. Corrections for differences in moisture content are needed for precooked rices, rice noodles, etc. Brown rice must be milled or defatted.

61-04.01 Gelatinization Temperature of Milled Rice Flour

Gelatinization temperature (GT) is commonly measured to assess rice cooking and processing potential. Milled rice flour GT has historically been assessed using AACC Method 61-01.01 Amylograph Method for Milled Rice (20% solids). This method requires a large quantity of sample, which is often not available for those involved in activities such as rice breeding or research. The objective of the current method is to estimate the gelatinization temperature of milled rice flour using a small quantity of sample with the Rapid Visco Analyser (RVA).

61-10.01 Determining Crack Resistance and Translucency of Paddy Rice Kernels Using the PaddyCheck Instrument

The objective is to determine the crack resistance and translucency of paddy rice kernels. The PaddyCheck instrument measures crack resistance by applying a given force on a three-point bend rig and translucency by polarized light transmission. Singulation discs with different cavity sizes are chosen to match the kernel size dimensions of the sample. The method gives measurements on how many kernels in a sample can withstand a specific normal force without breaking and how translucent the kernels are. The method is applicable to indica and japonica paddy rice ideotypes.

61-99.01 Glossary—Rice