IRRI SERVICE LABORATORIES
provides quality and efficient integrated laboratory testing services and expertise
or email: gqnsl@irri.org
Rice grain sample preparation and submission guide
ISL serves breeder requests for evaluating the quality of rice progeny from breeding programs. Prior to evaluation, sample preparation of paddy rice seeds is necessary to make it suitable for a specific analysis (Refer to table below for the sample type and weight requirement per test parameter). Rice grains are produced by dehulling and milling paddy rice seeds. The aim of dehulling and milling, is to process the paddy seeds into rice grains for tests of physical, cooking, sensory, and nutritional quality.
Cleaning removes the unfilled or semi-filled grains from paddy rice seed samples. Dehulling, on the other hand, removes the hull/shell from the seed resulting in brown rice fraction.
The outer layer (bran) is removed from brown rice, resulting in a white or polished rice fraction, also known as milled rice.
Polishing of brown rice is by using Grainman Mill (brown rice greater than or equal to 70 g weight) or Kett mill.
After dehulling and milling, grain samples are ground prior to evaluation of apparent amylose content, gel consistency, and viscosity, protein, macro, and micronutrients. Consistency of grinding is important because particle size affects analysis like viscosity.
Submit the sample in a brown paper bag or coin envelope and place it in plastic boxes to protect sample integrity. Label samples with the following information:
Sample identification/description
Customer name
Requested test parameter/s
Grain Quality Evaluation Sample Weight Requirement.pdf