GB 20371-2016[Replaced by GB 5009.183-2025] National food safety standard - Plant Protein for Food Processing (English PDF)

2.1 Plant protein

The products taking plant as raw materials, removing or partially removing the non-

protein components (such as water, fat, carbohydrates, etc.) from the raw materials of

plant, and the protein content is no less than 40%. The main products include beans

(such as soybean, pea, broad bean) protein; grains (such as wheat, corn, rice, oat)

protein; nuts and seeds (such as peanut) protein; tuberous crops (such as potato)

protein; and other plant proteins.

2.2 Crude protein

The products made, by the primary extraction, through partially removing the non-

protein components (such as water, fat, carbohydrates, etc.) from the raw materials of

plant.

2.3 Concentrated protein

The products made, by extraction, concentration, separation and the like technologies,

through removing or partial removing the non-protein components (such as water, fat,

carbohydrates, etc.) from the raw materials of plant. It includes the potato coagulation

protein made through extraction, heating coagulation and other technologies.

3.1 Requirements for raw materials

The raw materials shall conform to the corresponding product standards and relevant

provisions.

3.2 Sensory requirements

The sensory requirements shall conform to the provisions of Table 1.

3.3 Physical and chemical indicators

The physical and chemical indicators shall conform to the provisions of Table 2.

Table 2 -- Physical and Chemical Indicators

3.4 Contaminant limits and mycotoxin limits

3.5 Microbial limits

3.6 Food additives

The use of food additives shall conform to the provisions of GB 2760.

4.1 The product name shall label specific plant source, such as soybean protein,

wheat protein, corn protein, pea protein, potato protein, etc.

4.2 The product name can label the specific classification; take soybean and peanut

as an example, such as soybean crude protein, soybean concentrated protein,

soybean separated protein, soybean tissue protein, peanut crude protein, peanut

concentrated protein, peanut separated protein, peanut tissue protein, etc.

4.5 The soybean protein shall be labeled the urease activity and safety text

description in the following ways.

Urease activity is negative;

Urease activity is non-negative (the products that can be eaten after the heating and

enzyme-destructing treatment).

Appendix A

Test Method of Urease

(Urea Enzymes) Activity in Soybean Protein

A.1 Apparatus

A.1.1 Grinder. when grinding, generate no strong heat.

A.1.6 Acidity meter. precision of 0.02; equipped with magnetic stirrer and titration

device.

A.1.7 Laboratory commonly used glass instrument.

A.2 Reagents and solutions

The reagents shall be analytically pure, while water shall conform to the provisions of

GB/T 6682.

A.2.1 Urea buffer solution (pH 7.0±0.1)

Weigh 8.95g of disodium hydrogen phosphate (Na2HPO4-12H2O), 3.40g of potassium

dihydrogen phosphate (KH2PO4); dissolve into water and dilute to 1000mL; then

dissolve 30g of urea into such buffer solution; the valid date is 1 month.

A.3 Specimen preparation

Grind the representative sample by the grinder (A.1.1), so that it can totally pass

through the sample sieve (A.1.2). The special sample (the sample that can't be ground

due to the high content of moisture and volatile) can be pre-dried under the laboratory

temperature; then grind it; when calculating the results, the dry weight loss shall be

calculated.

A.4 Test procedures

Take about 0.2g of prepared specimen (A.3) (accurate to 0.1mg) into the glass test

tube (if the activity is very high, then take 0.05g of specimen); add 10mL of urea buffer

solution (A.2.1); immediately cover the test tube, after shaking it vigorously; place the

test tube into 30°C±0.5°C constant-temperature water bath (A.1.4); maintain for

30min±10s. The time interval required to each sample to be added to the urea buffer

solution remains the same. When reaction stops, add 10mL of hydrochloric acid

solution (A.2.2) at the same time interval; after shaking, swiftly cooling off to 20°C.

Transfer all the matters in the test tube into the small beaker; use 20mL of water to

wash the test tube for several times; use the acidity meter (A.1.6) to titrate pH to be

4.70 with sodium hydroxide standard solution (A.2.3). If the indicator is selected,

transfer all the matters in the test tube into the 250mL conical flask; add 8-10 drops of

mixed indicator (A.2.4), titrate the solution with sodium hydroxide standard solution

(A.2.3) till the solution turns to blue-green.

A.5 Results calculation

A.5.1 Urea enzymes activity of X in the soybean protein can be calculated as per

Formula (A.1). If the specimen is pre-dried before grinding, it shall be calculated as per

Formula (A.2).

......