19.639

Gammelost cheese; identity.

19.650 Hard cheeses; identity; label statement of optional ingredients.

19.655 Semisoft cheeses; identity; label statement of optional ingredients. 19.660 Semisoft part-skim cheeses; identity; label statement of optional ingredients. 19.665 Soft ripened cheeses; identity; label statement of optional ingredients. 19.670 Spiced cheeses; identity; label statement of optional ingredients. 19.675 Part-skim spiced cheeses; identity; label statement of optional ingredients.

19.680 Hard grating cheeses; identity; label statement of optional ingredients. 19.685 Skim milk cheese for manufacturing; identity.

19.750 Pasteurized process cheese; identity; label statement of optional ingredients.

Grated cheeses; identity; label statement of optional ingredients.

AUTHORITY: The provisions of this Part 19 issued under secs. 401, 701, 52 Stat. 1046, as amended, 1055, as amended; 21 U.S.C. 341, 371.

CROSS REFERENCE: For other regulations in this chapter concerning cheese see §§ 3.19 and 5.4.

§ 19.499 Definitions.

For the purposes of this part, the phrase "safe and suitable" when used to describe ingredients of cheese or cheese

products means that such ingredients shall be functionally suitable substances that are not food additives as defined in section 201(s) of the Federal Food, Drug, and Cosmetic Act; or if they are food additives as so defined, they shall be used in conformity with regulations established pursuant to section 409 of the act.

[32 FR. 410, Jan. 14, 1967]

§ 19.500 Cheddar cheese, cheese; identity; label statement of optional ingredients.

(a) Cheddar cheese, cheese, is the food prepared from milk and other ingredients specified in this section, by the procedure set forth in paragraph (b) of this section, or by another procedure which produces a finished cheese having the same physical and chemical properties as the cheese produced when the procedure set forth in paragraph (b) of this section is used. It contains not more than 39 percent of moisture, and its solids contain not less than 50 percent of milk fat, as determined by the methods prescribed in paragraph (c) of this section. If the milk used is not pasteurized, the cheese so made is cured at a temperature of not less than 35° F. for not less than 60 days.

(b) Milk, which may be pasteurized or clarified or both, and which may be warmed, is subjected to the action of harmless lactic-acid-producing bacteria, present in such milk or added thereto. Harmless artificial coloring may be added. Sufficient rennet, or other safe and suitable milk-clotting enzyme that produces equivalent curd formation, or both, with or without purified calcium chloride in a quantity not more than 0.02 percent (calculated as anhydrous calcium chloride) of the weight of the milk, is added to set the milk to a semisolid mass. The mass is so cut, stirred, and heated with continued stirring, as to promote and regulate the separation of whey and curd. The whey is drained off, and the curd is matted into a cohesive mass. The mass is cut into slabs, which are so piled and handled as to promote the drainage of whey and the development of acidity. The slabs are then cut into pieces, which may be rinsed by sprinkling or pouring water over them, with free and continuous drainage; but the duration of such rinsing is so limited that only the whey on the surface of such pieces is removed. The curd is salted, stirred, further drained, and pressed into forms. A

harmless preparation of enzymes of animal or plant origin capable of aiding in the curing or development of flavor of cheddar cheese may be added during the procedure, in such quantity that the weight of the solids of such preparation is not more than 0.1 percent of the weight of the milk used.

(c) Determine moisture by the method prescribed on page 262 (15.124) [Ed. note. 10th edition, 1965, p. 247, sec. 15.157], under "Moisture-Official," and milk fat by the method prescribed on page 263 (15.131) [Ed. note, 10th edition, 1965, p. 248, sec. 15.164], under "FatOfficial," of "Official Methods of Analysis of the Association of Official Agricultural Chemists," Seventh Edition, 1950. Subtract the percent of moisture found from 100; divide the remainder into the percent milk fat found. The quotient, multiplied by 100, shall be considered to be the percent of milk fat contained in the solids.

(d) Cheddar cheese in the form of slices or cuts in consumer-sized packages may contain an optional mold-inhibiting ingredient consisting of sorbic acid, potassium sorbate, sodium sorbate, or any combination of two or more of these, in an amount not to exceed 0.3 percent by weight, calculated as sorbic acid.

(e) For the purposes of this section: (1) The word "milk” means cow's milk, which may be adjusted by separating part of the fat therefrom or by adding thereto one or more of the following: Cream, skim milk, concentrated skim milk, nonfat dry milk, water in a quantity sufficient to reconstitute any concentrated skim milk or nonfat dry milk used.

(2) Milk shall be deemed to have been pasteurized if it has been held at a temperature of not less than 143° F. for a period of not less than 30 minutes, or for a time and at a temperature equivalent thereto in phosphatase destruction. Cheddar cheese shall be deemed not to have been made from pasteurized milk if 0.25 gm. shows a phenol equivalent of more than 3 micrograms when tested by the method prescribed in paragraph (f) of this section.

(3) During the cheese-making process the milk may be treated with hydrogen peroxide solution followed by addition of a suitable catalase preparation to eliminate the hydrogen peroxide. The hydrogen peroxide solution shall comply with the specifications of the United

States Pharmacopeia, except that it may exceed the concentration specified therein and it does not contain added preservative. The amount of the hydrogen peroxide solution used shall be such that the weight of the hydrogen peroxide added thereby does not exceed 0.05 percent of the weight or the milk treated. The catalase preparation used shall be stable, and in potency, for eliminating added hydrogen peroxide from milk, it shall not be less than equivalent to livercatalase preparation testing 100 Keil units per gram. It shall be either a preparation that is not a food additive within the meaning of section 201(s) of the Federal Food, Drug, and Cosmetic Act, or a preparation that is a food additive but which is used in conformity with regulations promulgated pursuant to the authority of section 409 of the act. The amount of catalase preparation used shall be such that the weight of the catalase added thereby does not exceed 20 parts per million of the weight of the milk treated.

(f) The method referred to in paragraph (e)(2) of this section is as follows:

I. Reagents-1. Buffers—a. Barium boratehydroxide buffer. Dissolve 25.0 gm. of c. p. barium hydroxide (Ba(OH),:8H,Ö, fresh, not deteriorated) in distilled water and dilute to 500 ml. Dissolve, in another flask or cylinder, 11.0 gm. of c. p., boric acid (H,BO,) and dilute to 500 ml. Warm each to 50° C. (122* F.), mix the two together, stir, cool to approximately 20° C. (68° F.), filter, and stopper the filtrate tightly (pH approximately 10.6). The buffer prepared thus is designated as the 25-11 buffer, the figures indicating the grams per liter of each of the respective reagents.

b. Color-development buffer. Dissolve 6.0 gm. of sodium metaborate (NaBO,) and 20 gm. of sodium chloride in water and dilute to a liter with water (pH 9.8).

c. Color-dilution buffer. Dilute 100 ml. of color-development buffer 1-b to a liter with

water.

d. Standard borax buffer, 0.01-molar, for checking pH meter, pH 9.18 at 25° C.1 Dissolve 0.9544 gm. of pure borax (Bureau of Standards Sample 187) in distilled water (distilled recently or freshly boiled and cooled) and dilute to 250 ml. Keep stoppered tightly.

1All pH values reported herein were determined at 25° C. or corrected to that temperature.

2. Buffer substrates. Specify phenol-free crystalline disodium phenyl phosphate.

a. For evaluating pasteurization. Dissolve 0.10 gm. of the phenyl phosphate in 100 ml. of the appropriate (table 1) barium boratehydroxide buffer 1-a.

b. For quantitative results with raw-milk cheese. Dissolve 0.20 gm. of the phenyl phosphate in 100 ml. of the appropriate (table 1) barium borate-hydroxide buffer 1-a.

3. Protein precipitants—a. Zinc-copper precipitant for unripened cheese. Dissolve 6.0 gm. of zinc sulfate (ZnSO, 7H,O) and 0.1 gm. of copper sulfate (CuSO,·5H,O) in water and dilute to 100 ml. with water. The precipitant prepared thus is designated as the 6.0-0.1 precipitant.

b. Zinc precipitant for ripened cheese. Dissolve 6.0 gm. of zinc sulfate in water and dilute to 100 ml. with water. This precipitant is designated as the 6.0 precipitant. 4. BQC (2,6-dibromoquinone-chloroimine solution) (Gibbs' reagent): Dissolve 40 mg. of BQC powder in 10 ml. of absolute methyl alcohol and transfer to a dark-colored dropper bottle. This reagent remains stable for at least a month if kept in the ice tray of a refrigerator. Do not use it after it begins to turn brown.

5. Other reagents-a. Copper sulfate, 0.05 percent, for standards. Dissolve 0.05 gm. of copper sulfate in water and dilute to 100 ml. b. Butyl alcohol. Specify n-butyl alcohol, boiling point 116°-118° C. To adjust the pH, mix 50 ml. of the color-development buffer 1-b with a liter of the butyl alcohol.

6. Phenol standards-a. Stock solution. Weigh accurately 1.0 gm. of pure phenol, transfer to a liter volumetric flask, dilute to a liter with water, and mix. One ml. contains 1 mg. (0.001 gm.) of phenol. Use this stock solution to prepare standard solutions. It is stable for several months in the refrigerator.

b. Preparation of standards. Dilute 10.0 ml. of the stock solution 6-a to a liter with water, and mix. One ml. contains 10 micrograms (0.00001 gm., 10 gammas, or 10 units) of phenol. Use this standard solution to prepare more dilute standard solutions; e. g., dilute 5, 10, 80, and 50 ml. to 100 ml. with water to prepare standard solutions containing 0.5, 1.0, 3.0, and 5.0 gammas or units of phenol per milliliter, respectively. Keep standard solutions in the refrigerator.

In a similar manner, prepare from the stock solution such more concentrated standard solutions as may be needed, containing, for example, 20, 30, and 40 units per milliliter.

Measure appropriate quantities of the phenol standard solution into a series of tubes (preferably graduated at 5.0 and 10.0 ml.) to provide a suitable range of standards as needed, containing 0 (control blank), 0.5, 1.0, 3.0, 5.0, 10.0, etc., to 30 or 40 units. To increase the brightness of the blue color

improve the stability of the standards, 1.0 ml. of 0.05 percent copper sulfate tion 5-a to each.

d 5.0 ml. of color dilution buffer 1-c and water to bring the volume to 10.0 ml. 14 drops (0.08 ml.) of BQC 4, mix, and v to develop for 30 minutes at room perature. If the butyl alcohol extracmethod is to be used in the test, extract

the standards as described under III Conducting the Test.

Read the color intensities with a photometer, subtract the value of the blank from the value of each phenol standard, and prepare a standard curve (straight line). When the standards are to be used for visual comparisons they should be stored in a refrigerator.

II. Sampling-1. Hard cheese. Take a sample from the interior with 8 clean Roquefort trier, place in a small tube, stopper the tube, and keep it in a refrigerator.

2. Soft and semisoft ripened cheese. Harden the cheese by chilling it in the freezing chamber of a refrigerator. Taking special precaution to avoid contaminating the sample with phosphatase that may be present on the surface, use either of the following methods for sampling:

a. Cut a portion from the end of the loaf or from the side of the cheese, extending in at least 2 inches if possible or to a point somewhat beyond the center in the case of a small cheese. Cut a slit 1⁄4 to 1⁄2 inch deep at least halfway around the portion and midway between the top and bottom. Break the portion into two parts, pulling it apart careful not to contaminate the freshly exposed, broken surface. Remove the sample from the freshly exposed surface at or near the center of the cheese.

b. Remove the surface of the area to be sampled-e. g., the end and the adjacent sides with a clean knife or spatula, to a depth of 4 inch. Clean the instrument and hands with hot water and phenol-free soap so that it breaks on a line with the slit, being and wipe them dry. Remove the freshly exposed surface to a similar or greater depth and repeat the cleaning. Then take the sample from the center of the freshly exposed area, preferably at or near the center of the cheese in the case of a small cheese.

8. Process cheese, spreads, etc. Take the sample from beneath the surface with a clean knife or spatula.

Avoid the use of samples contaminated with mold.

sample (preferably two samples in duplicate) and place in a culture tube 16 or 18 x 150 mm. Similarly, weigh another sample and place in a tube as a control or blank. If the cheese is sticky, weigh the sample on a piece of wax paper about 1 x 1 inch and insert the paper with the sample into the tube. Macerate the blank and the test with a glass rod about 8 x 180 mm.

2. Add to the blank 1.0 ml. of the appropriate (Table 1) barium buffer 1-a (without substrate added), macerate with the rod, leave the rod in the tube, heat for about a minute to at least 85° C. (185° F.) in a beaker of boiling water with the beaker covered so that the entire tube becomes heated to approximately 85° C., cool to room temperature, and macerate again with the rod.

8. Add to the test 1.0 ml. of the appropriate (Table 1) barium buffer substrate 2-a or 2-b, and macerate.

From this point, treat the blank and the test in a similar manner.

Add 9.0 ml. of the appropriate barium buffer substrate 2-a or 2-b (total, 10.0 ml. added), and mix. The rod may be left in the tube during incubation; or, if removing it at this point, cut a piece of filter paper approximately 1 x 1 inch, wrap and hold it tightly around the rod, rotate the rod while withdrawing it from within the tube so as to wipe the rod clean, insert the paper with the adhering fat into the tube, and stopper the tube.

4. Incubate in a water bath at 87°-38° C. (99°-100° F.) for 1 hour, mixing or shaking the contents occasionally.

5. Place in a beaker of boiling water for nearly a minute, heating to 85° C. (185° F.), and cool to room temperature.

6. Pipet in 1.0 ml. of the zinc precipitant 3-b for ripened cheese or the zinc-copper precipitant 3-a for unripened cheese, and mix thoroughly (pH of mixture, 9.0-9.1).

7. Filter (5-cm. funnel, 9-cm. Whatman No. 42 or No. 2 paper recommended), and collect 5.0 ml. of filtrate in a tube, preferably graduated at 5.0 and 10.0 ml.