How to determine the crude fiber content in fine powdered soybean samples

How to determine the crude fiber content in fine powdered soybean samples

The determination of crude fiber in fine powder samples is a difficult point in routine testing. Crude fiber measuring instrument is the most common fiber measurement method currently used. It integrates acid treatment, alkali treatment and rinsing. The operation is simpler than the national standard method GB/T 5009.10-2003, and can simultaneously measure multiple samples. And the measurement results can meet the requirements of most testing organizations. The high-fat fine soybean sample contains not only crude fiber content, but also crude fat, so the crude fat analyzer is often used. The fat analyzer is specialized in the determination of fat content, and it is the same as the crude fiber analyzer. , Can measure multiple samples at the same time.

Here we focus on how to determine the content of crude fiber in a soybean sample using a fiber tester.

Preparation stage: Materials: Soybean samples (40 mesh, 18.18% fat); Instruments: Crude fiber analyzer, analytical balance, blast drying oven (40-250°C), box resistance furnace (200-1200°C Reagents: 0.128moL/L sulfuric acid solution; 0.313moL/L sodium hydroxide solution; 95% ethanol, ether, n-octanol: analytically pure.

Experimental stage: Sampling and degreasing: Accurately weigh 1g sample, defatted the ether three times (soak 10min; 5min; 3min), each 25mL, suction filtration. The sample was treated with acid: Add 200 mL of boiled 0.128 moL/L sulfuric acid solution and 2 drops of n-octanol, keep the micro-boiler for 30 min, and then filter the washing solution. Wash with boiling water until the washing solution is not acidic. The sample was treated with alkaline solution: add boiling boiled water of 0.313moL/L sodium hydroxide solution 200mL and 2 drops of n-octanol, keep the micro-boiling for 30min and then filter the washing solution. Wash with boiling water until the washing solution is not alkaline. Finally, the sample is dried, burned and weighed. Heat 95% ethanol 20mL a total of 3 times washing, suction filtration; ether 20mL a total of 3 times washing, filtration and evaporation of ether; move into a 105 °C blast drying oven to constant weight; then move to 550 °C Box type resistance furnace is ashed to constant weight.

The above is the determination of the crude fiber content in the fine-powdered soybean sample by a fiber tester. Studies have shown that the results of the fiber content determined by this method are very close to those determined by the national standard method. Therefore, in actual operation, we usually choose the fiber tester to measure the crude fiber content of the sample because the instrument is convenient, fast, and highly safe. Many processes are automatically performed by the instrument.