California Code of Regulations
Title 3 - Food and Agriculture
Division 3 - Economics
Chapter 1 - Fruit and Vegetable Standardization
Subchapter 4 - Fresh Fruits, Nuts and Vegetables
Article 22 - Citrus
Section 1430.6 - Citrus, Maturity, Determining the Soluble Solids to Acid Ratio or the California Standard Scale

Universal Citation: 3 CA Code of Regs 1430.6

Current through Register 2024 Notice Reg. No. 38, September 20, 2024

(a) Application. Citrus soluble solids to acid ratio and California Standard Scale tests for maturity shall be performed in accordance with this section.

(b) Apparatus and Solutions Required.

(1) A Brix hydrometer with graduations in tenths of a degree, standardized at 17.5 degrees C., and with a centigrade thermometer and correction attachment.

(2) A cylinder tube, without a lip, suitable for floating the hydrometer without touching the sides or bottom.

(3) A 25 cubic centimeter pycnometer.

(4) A 50 cubic centimeter burette with graduations in tenths of a cubic centimeter.

(5) A receptacle of sufficient size to retain all of the extracted juice. It shall be of a material, or be plated with a material, that will not affect, or be affected by, the citrus juice being tested.

(6) A 250-550 cubic centimeter Erlenmeyer titrating flask.

(7) A wire strainer for straining juice. (17-30 mesh per lineal inch.)

(8) A standard solution of sodium hydroxide (NaOH), 1 cubic centimeter of which is equivalent to 0.01 gram (10 mgs.) of anhydrous citric acid (0.1562 normal).

(9) A solution of phenolphthalein in alcohol for use as indicator.

(c) Soluble Solids Content.

(1) Fill the tube with the properly extracted juice.

(2) Float the hydrometer in the tube until the temperature reaches equilibrium (minimum of two minutes). Read the Brix scale, remove the hydrometer from the tube and immediately read the temperature correction, and record the corrected Brix reading to the nearest tenth (.1) degree.

(d) Acid Content.

(1) Add exactly 25 cubic centimeters of the extracted juice into the Erlenmeyer flask with a 25 cubic centimeter pycnometer. After filling the pycnometer, replace the cap. With finger over the opening, rinse the exterior of the pycnometer. Pour the juice into the flask.

(2) Using the pycnometer, add approximately 100 cubic centimeters of distilled water to the juice. Pour the first 25 cubic centimeters of water through the stem of the pycnometer to remove any juice that may be trapped.

Neutral tap water may be used in lieu of distilled water. Tap water may be checked to determine whether it is neutral by adding 20 drops of phenolphthalein solution to 100 cubic centimeters of the water. If this combination remains colorless and then turns pink by the addition of one drop of the standard solution of sodium hydroxide, the tap water is neutral and can be used instead of distilled water.

(3) Add approximately 20 drops of indicator solution.

(4) Titrate by the addition of the NaOH until the first definite indication of color (pink) is obtained.

(e) Soluble Solids to Acid Ratio. The soluble solids to acid ratio shall be determined by use of the Citrus Maturity Ratio Tables compiled by the Department of Food and Agriculture.

(f) California Standard Scale score. The California Standard Scale score shall be determined by use of the California Standard Scale: Citrus Maturity Score Tables (September 22, 2010, Version 1.0), which is hereby incorporated by reference.

1. Amendment filed 3-25-77; effective thirtieth day thereafter (Register 77, No. 13). For prior history, see Register 76, No. 19.
2. Repealer of former Section 1430.6 and renumbering and amendment of former Section 1430.120 to Section 1430.6 filed 9-27-85; effective thirtieth day thereafter (Register 85, No. 45). For prior history, see Register 75, No. 4.
3. Amendment of section heading and subsection (a), new subsection (f) and amendment of NOTE filed 3-20-2012; operative 4-1-2012 pursuant to Government Code section 11343.4 (Register 2012, No. 12).

Note: Authority cited: Sections 407 and 42684, Food and Agricultural Code. Reference: Sections 42684 and 42941, Food and Agricultural Code.

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