United States 

Department of 

Agriculture

Agricultural 

Marketing 

Service

National Grain Center 

10383 N. Ambassador Drive. 

Kansas City, MO 64153

Executive Summary of the Commercial Rice Mill First Year Report

Prepared by: Cathleen Brenner, Chief

Inspection Instrumentation Branch

Federal Grain Inspection Service (FGIS)

Date: May 10, 2018

Conclusion: “The obtained results during the first year of the project have revealed that there 

is no consistent trend of milling yield results from laboratory and commercial 

mills.”

The University of California, Davis (UC Davis) conducted a study on behalf of the Federal Grain 

Inspection Service (FGIS) to compare the milling yield results obtained using the FGIS 

procedures and approved equipment with the results obtained by commercial mills. This study 

includes samples from the 2015 and 2016 crops. The participating commercial mills collected 

samples from September 2016 through October 2017.

Four commercial mills located in Arkansas, California, and Louisiana agreed to participate in the 

study and provided 186 samples. These samples included long grain rice (pure and hybrid 

varieties), medium grain rice (unmixed and mixed), and short grain rice (unmixed and mixed). 

UC Davis subcontracted with the California Agri Inspection Company (Cal Agri), an FGIS 

official service provider, to provide results using the FGIS procedures and approved equipment.

The listed below are the findings from the study:

1. Milling Environment

a. The commercial mills had significantly higher temperatures and relative humidities 

than the Cal Agri lab although M1’s (mill 1) temperature was less than Cal Agri.

b. The temperature and relative humidity at the commercial mills varied by season.

c. Cal Agri’s temperature and relative humidity was consistent throughout the study 

period.

2. Milled Rice Temperature

The FGIS method and approved equipment yielded milled rice with significantly higher 

temperatures than the milled rice coming out of the commercial mills.

3. Dockage

The dockage in the collected samples varied by the participating commercial mill.

4. Color and Degree of Milling

The samples from the commercial mills and from the FGIS process were a creamy color. 

There was no difference in the Degree of Milling.
Executive Summary Of the Commercial Rice Mill First Year Report

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5. Moisture

a. M3 (mill 3) had significantly lower moistures than the other three commercial 

mills.

b. The moisture for the samples when tested at Cal Agri was lower but not 

significantly different than the moistures measured at the commercial mills.

6. Milling Yield and Whiteness

The milling yield is determined by the percentage of total rice yield (TRY or TR) and the 

percentage of whole kernels (WK) or head rice yield (HRY) after paddy rice is milled. 

Whiteness is not an FGIS factor but may be used to indicate the amount of bran removed 

from the rice during the milling process.

a. The results were not consistent over all four quarters for the same varieties.

b. The following table breaks down the percentage of samples for TRY, HRY, and 

Whiteness by statistically significant differences where the FGIS procedure 

yielded results less than the commercial mill process (FGIS < Commercial), where 

the FGIS procedure yielded results higher than the commercial mill process (FGIS 

> Commercial), and no statistically significant differences.

Category TRY HRY Whiteness

FGIS < Commercial 29% 16% 73%

No significant difference 29% 35% 27%

FGIS > Commercial 42% 49% 0%

7. Grades

The samples from the commercial mills and from the FGIS process yielded grades that are 

aligned with the exception of three varieties: CL111 (long grain rice pure variety), Jupiter 

(medium grain rice pure variety), and X745 (long grain rice hybrid variety).