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Title: DEVELOPMENT OF RICE QUALITY EVALUATION METHODS

Author
item EARP, C - RICETEC
item Bergman, Christine
item BAUTISTA, R - RICETEC

Submitted to: Rice Technical Working Group Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 12/1/2002
Publication Date: 6/1/2002
Citation: EARP,C.F., BERGMAN,C.J., BAUTISTA,R.C., DEVELOPMENT OF RICE QUALITY EVALUATION METHODS, RICE TECHNICAL WORKING GROUP MEETING PROCEEDINGS, 2003. p. 102.

Interpretive Summary:

Technical Abstract: The Rice Milling and Quality Technical committee of the AACC is currently working on standardized methods for evaluating rice quality. Methods under development include Preparation of Milled Rice for Laboratory Tests and an RVA Method for Determining Gelatinization Temperature of Rice Flour. In 2000 a preliminary set of 10 varieties was dehulled and milled at RiceTec and Univ. of AR. Samples were milled for 20, 30, 40, 50, and 60 seconds in a McGill No. 2 mill. Total whole rice quantities were weighed and Satake Milling Degree was measured. Amylose percent and Alkali Spreading Value were measured on the RiceTec milled samples. Univ.of AR and RiceTec milling data were similar. Percent bran removal with milling time was typically 1 to 2 percent more in the University of Arkansas sample. After looking at the milling data, committee discussion during the 2000 and 2001 meetings concluded that milling to 12 percent bran removal for long grains and 10 percent bran removal for medium and short grains usually produce a well-milled rice. Well-milled in this case means no bran streaks. The preliminary study looked mainly at long-grain rice. The committee decided that data was needed for medium and short grain rices. A collaborative study is planned for 2002 to mill rices by a protocol with whatever mills are owned by the lab. After data have been collected, the milled samples will be collected from the participants and milling degree will be measured by several means. The second method under development is the determination of the gelatinization temperature of rice flour using the RVA. Preliminary data were received from seven of 10 labs receiving samples. Gelatinization temperature determined by the RVA correlated reasonably well with the onset temperature of the flours as determined by DSC in one lab. It was discussed that the calibration of the RVA in each lab must be done prior to the collaborative study data collection. Calibration starch samples provided by Foss Northamerica were used for checking the machines participating in the preliminary study.