Determination of Impurities and Imperfect Grains in Cereals and Oilseeds by Sieving

Overview

  Cereals and oilseeds are core raw materials for agricultural production and food processing, and their quality is directly related to food safety, storage security and market value. The content of impurities and imperfect grains is a key index for evaluating the quality of cereals and oilseeds. Excessive impurities will reduce the utilization rate of raw materials and affect the processing technology, while imperfect grains are prone to mildew and deterioration during storage, and also lower the edible and processing quality. Therefore, accurate determination of impurities and imperfect grains in cereals and oilseeds is an essential operation in the links of grain purchase, storage and processing.

Experimental Purpose

  To accurately determine the quality grade of cereals and oilseeds by screening and detecting the content of impurities and imperfect grains in them, so as to provide a scientific quality basis for grain purchase, storage management and processing production. This test is carried out in accordance with the national standard GB5494-85 Inspection of Cereals and Oilseeds - Method for Inspection of Impurities and Imperfect Grains. The ST134 Computerized Sieve Shaker is a special screening and testing equipment developed in accordance with this standard, which can realize the standardized and automatic screening of cereals and oilseeds.

Experimental Samples and Instruments

Experimental Samples

Tested cereal/oilseed samples

Experimental Instruments

• ST134 Electric Sieve Shaker (including matched grain sieves)
• Auxiliary accessories such as sample trays and brushes

Operating Procedures

• Select the corresponding specifications of grain sieve layers in accordance with national standards according to the type of cereals and oilseeds to be tested, and assemble them in order.
• Take 500g of the tested sample and pour it into the assembled grain sieve, cover the sieve lid, place the sieve into the equipment tray and tighten the pull rods to ensure the sieve layers are stable and firm.
• Connect the power supply of the ST134 Computerized Sieve Shaker and press the start switch. The instrument will operate automatically according to the program, performing forward sieving for 60 seconds and reverse sieving for 60 seconds before stopping automatically, with planar rotary sieving realized throughout the process.
• For continuous testing of multiple groups of samples, pour out the sieved samples, put new samples in and fasten the sieve layers again, then press the start switch once more without turning off the power supply.
• After the test is completed, loosen the pull rods to take out the sieve layers, pour the over-sieve and under-sieve materials into sample trays respectively, and sort and measure the impurities and imperfect grains in accordance with national standard regulations.

Data Analysis and Result Evaluation

  Through the standardized sieving of the ST134 Computerized Sieve Shaker, impurities and imperfect grains in cereals and oilseeds can be effectively separated from intact grains. The content ratio of impurities and imperfect grains calculated by measurement after sorting fully meets the test accuracy requirements of the national standard GB5494-85. The instrument features stable operation, uniform sieving amplitude and precise control of forward and reverse rotation time, which effectively avoids the errors of manual sieving. The test results can be directly used as a valid basis for determining the quality grade of cereals and oilseeds, and it is suitable for batch testing needs in various scenarios such as agricultural breeding, grain purchase and grain and oil processing.