GB/T 12143-2008General analytical methods for beverage (English PDF)

4.4 Preparation of test solution

4.4.1 Transparent liquid products Mix the sample thoroughly, then directly measure.

4.5 Analytical procedures

4.5.1 Calibrate the refractometer according to the instructions before measuring; take Abbe refractometer as an example; other refractometers shall be operated as per their instructions.

4.5.2 Separate the two-side prism of the refractometer, wipe with degreasing cotton dipped into the ether or ethanol.

4.6 Allowable difference The difference between two measured values against the same sample shall be no greater than 0.5%. Take the arithmetic average value of the two measurements as the result, which shall be accurate to one digit after the decimal point.

5 Determination Method for Amino Nitrogen Content in Fruit (Vegetable) Juice Products (Formol Number)

5.1 Applicable range of method This Method is applicable to the fruit and vegetable juice beverage.

5.3 Reagents 5.3.1 30% Hydrogen Peroxide.

5.3.2 Neutral formaldehyde solution. take 200mL of formaldehyde solution into 400mL beaker; place onto the electromagnetic stirrer, adjust the pH to be

8.1 with 0.05mol/L sodium hydroxide solution as stir.

5.3.3 Sodium hydroxide standard solution. 0.1mol/L; prepare and calibrate as per GB/T 601.

5.4 Instrument

5.4.1 Acidometer. measuring range of 0~14pH; accuracy of ±0.1pH.

5.4.2 Electromagnetic stirrer.

5.4.3 Glass electrode and calomel electrode.

5.6.1 Turn on the acidometer, after pre-heating for 30min; use pH

6.8 buffer solution to correct the acidometer.

5.7 Result calculation The amino nitrogen in the specimen shall be calculated as per Formula (1). Where.

5.8 Allowable difference Take the arithmetic average value of the two measurements against the same sample as the result; which shall be accurate to one digit after the decimal point. The difference between two measurements against the same sample.

6 Determination Method for L-Ascorbic Acid in Fruit and Vegetable Juice Beverages (Ethyl Ether Extraction Method)

6.1 Applicable range of method This Method is applicable to the determination of L-ascorbic acid in fruit and vegetable juice beverages; but not applicable to the determination of dehydroascorbic acid.

6.2 Principle of method This Method abides by the principle of redox reaction; 2,6-dichloroindophenol can be reduced to be colorless by the L-ascorbic acid; the slight excess of 2,6- dichloroindophenol can be extracted by ethyl ether; then the end-point shall be titrated by the rose red in the ether layer.

6.5 Preparation of test solution

6.5.1 Concentrated juice Add the same amount of water into the concentrated juice as the natural water lost during the concentrating process; so that it becomes the normal juice. Then take certain amounts of samples from the same kind of normal juice; dilute, and mix evenly for testing.

6.5.7 Preparation of blank test solution Take the same sample (accurate to 0.001g) as the sampling amount determined during the preparing period of the test solution; place into 250mL conical flask; add 20mL of 10% copper sulfate solution; add water so that the total volume to be 100mL; place onto the electric stove padded with asbestos gauze; carefully heating to boiling, and keep slightly boiling for 15min; then use the flowing water to cool off to the room temperature. Transfer the solution into the 200mL volumetric flask; use water to dilute to the scale; shake evenly for the blank testing.

6.6 Analytical procedures

6.7 Result calculation The L-ascorbic acid content in the sample shall be calculated as per Formula (4).

6.8 Allowable difference Report the result by the arithmetic average value of three measurement results with error in the allowable range; accurate to the one digit after the decimal point. The relative difference of three measurement results against the same sample includes.

7 Method for Determination of Carbon Dioxide in Carbonated Soft Drink (Distillation and Titration Method)

7.1 Applicable range of method This Method is applicable to determine the carbon dioxide in carbonated soft drink.

7.2 Principle of method After through the strong alkali and acid treatment, the sample shall be hated and distilled.

7.3 Reagents

7.3.1 Water containing no carbon dioxide (prepared on the current day). boil water till 1/5~1/4 water volume is lost, then cool off quickly.

7.3.2 Acidic phosphate solution. take 100g of sodium dihydrogen phosphate, dissolve into water; add 25mL of phosphoric acid, and transfer to 500mL volumetric flask; use water to dilute to the scale.

7.3.7 Sodium hydroxide standard titration solution. 0.25mol/L.

7.3.7.1 Preparation Absorb the supernatant liquid of 13.5mL of 50% sodium hydroxide solution (7.3.6) into 1000mL volumetric flask; use the water containing no carbon dioxide (7.3.1) to dilute to the scale; shake evenly.

7.3.8 Hydrochloric acid standard titration solution. 0.25mol/L.

7.3.8.1 Preparation Take 21.0mL of hydrochloric acid into the 1000mL volumetric flask; use water to dilute to the scale; shake evenly.

7.4 Instrument and equipment

7.5 Preparation of test solution Place the new soft drink into ice-salt bath at 0°C below (or in the freezing chamber of the refrigerator); dip for 1h~2h; when the soft drink in the bottle is nearly to be frozen (no shaking), open the bottle cap; quickly add supernatant liquid of 50% sodium hydroxide solution (add 2.0mL~2.5mL per 100mL of soft drink); immediately cover with rubber stopper plug. Put the bottom of the bottle upward; slowly shake for several minutes, store at room temperature, and to be measured.

8.3 Reagents

8.3.1 Silicone oil.

8.4 Instrument and equipment

8.4.1 Constant temperature water bath. 100°C±1°C.

8.5 Preparation of test solution

8.5.1 Weigh sample Weigh 10g~40g of evenly-mixed sample (ethanol content is 0.005g~0.12g) into small beaker; accurate to 0.001g; transfer the sample into 1000mL distillation flask (total volume shall not exceed 1/2 capacity of the flask).

8.6 Analytical procedures

8.7 Result calculation The ethanol content in the specimen shall be calculated as per Formula (10). Where.

9 Determination of Juice Content in Orange, Mandarine, Tangerine Juice and Their Drinks

9.1 Applicable range of method This Method is applicable to judge the concentrated juice and fruit juice in orange, mandarine, tangerine; as well as the orange, mandarine, tangerine drinks with juice content no less than 2.5%.

9.2 Terms and definitions The following terms and definitions are applicable to this Method.

9.3 Principle of method

9.3.1 The method specified in this Standard measures the 6 components in the sample.

9.5 Determination method

9.5.1 Soluble solids Measure as per the method stipulated in Clause 4.

9.5.2 Potassium Measure as per the provisions of Appendix C.