Determination of crude fiber content in soybeans--Rough fiber analyzer

Determination of crude fiber content in soybeans Reference and quotation standards

International Standard ISO 5498-1981 "General Methods for Determination of Crude Fiber Content in Agricultural Products";

GB5009.10 Determination of crude fibres in foods;

GB 8858 Determination of dry matter and moisture content in fruit and vegetable products.

Determination of crude fiber content in soybeans:

The principle of the acid-alkali digestion method is used: the crushed substance of soybeans is digested with acid and alkali, and the acid can be eliminated by melting the acid-soluble substance in the sample. The alkali is also alkaline and can be dissolved in alkali. The material is dissolved and eliminated, and then treated with ethanol and ether. After a high temperature, the final residue is crude fiber.

Determination of crude fiber content in soybeans Reagents and instruments:

Analytical Balance, Crude Fiber Tester, Tissue Breaker, Electric Heating Plate, Return Device, Pulverizer, Linen Cloth, Funnel (Brugner's Hopper and Short-Necked Funnel), Caster, Filter Bottle, Drying Box, Muffle Furnace , CXC-06 fiber tester, dryer; ether and ethanol, sulfuric acid solution, sodium hydroxide solution, defoamer, asbestos. (Please refer to GB 10469-89 Determination Method for Crude Fibers of Fruits and Vegetables for specific instrument specifications and reagent concentrations. http://)

Determination of crude fiber content in soybeans:

The soybeans were crushed with a tissue masher and then placed in a jar for retention. The crushed sample 20g was weighed and placed in a 500ml Erlenmeyer flask. After the sample was weighed, the sample was soaked and washed with ether several times. The solvent was then removed by decantation, no residue was lost, and the excess solvent was finally air-dried. Samples were acid-base decocted with acid treatment agent and alkali treatment agent, respectively, the specific steps are as follows: (1) acid treatment, adding sulfuric acid solution of 95 ~ 100 °C 200ml (measured at room temperature). If there is more foaming, add a few drops of defoamer in advance. Put on the condenser tube, immediately heated to a slight boiling (about 2min) on a hot plate, slightly boiling 30 persons 1min. During the micro-boiling process, several Erlenmeyer flasks shall be shaken to prevent the sample from sticking on the liquid surface. Connect the suction filter device and quickly separate it by suction filtration. And the residue was washed with hot water of 95~100°C until the filtrate was neutral (blue litmus paper does not change color). (2) Alkali treatment. Place the linen with residue on the inner wall of the short neck funnel. Do not block the drain. The residue was rinsed into the original conical flask with 200 ml of sodium hydroxide solution (measured at room temperature) of 95-100°C. Put on the condenser tube, immediately heated to the micro-boiling on the hot plate (about 2min), micro-boil 30 persons 1min; connected to the suction filter device (courtesan cockroaches covered with asbestos), quickly filtered by suction. The residue was washed with 20 ml of sulfuric acid solution (room temperature), washed thoroughly with hot water of 95 to 100°C, and then drained, followed by washing with ethanol and diethyl ether in that order. After the acid-base digestion is completed, the sample is dried first and then weighed to obtain A1. Then, the residue muffled in the muffle furnace was ashed for 2 hours until the temperature fell below 200°C. Weighed continuously and weighed twice. If the difference exceeds 0.5 mg, continue drying until the difference is 0.5 mg. Inside. Take it as A2.

Determination of crude fiber content in soybeans:

The formula for sampling according to clause 7.1.1:

(1)

In the formula: A1 - Gushi 坩埚 + coarse fiber + residue ash, g;

A2 - Old Ashes + residue ash, g;

W - mass of sample, g.

Two consecutive measurements, taking the average. When the measurement result is less than 10%, the absolute value of the difference between the two measurement results must not exceed 0.4. When the measurement result is greater than 10%, the relative value of the difference between the two results must not exceed 4%.