band is of a monochromaticity sufficient to cause a sample and a neutral standard of equal reflectance to appear of the same hue. The comparator is rigidly mounted on a vertical stand attached to a base in which arrangement is provided for securely and accurately positioning two cans of size 307 x 113 in the two fields of view. Mounted on the base are two shaded lamps, which direct the center of their beams of light at about a 45° angle to the plane of the sample and standard surfaces. The lamps are so positioned that light from one bears mainly upon the sample surface and light from the other mainly on the standard surface, and are so placed in relation to sample and standard that no shadows, as from the can rims, appear in the fields of view. The lamps are strong enough to furnish adequate and convenient illumination through eyepiece and filter. Means is provided to alter the light intensity of one lamp in relation to the other, as may conveniently be achieved by using a 100-watt tungsten filament bulb in one lamp and using, in the other, a similar 150-watt bulb connected with the power source through a suitable rheostat. The stand is equipped with nonglossy black curtains on the side of the observer, to exclude variation in extraneous light reflected from the person of the observer.

(2) To adjust the comparator, place a pair of matte surface standards of Munsell value 5.3, mounted as described in subparagraph (4) of this paragraph, in position in the comparator base, and adjust the intensity of the variable lamp until the two halves of the optical field, viewed through the eyepiece, are of equal brightness. Then remove one of the standards and replace it with the prepared sample. Without altering any other adjustment, observe through the eyepiece whether the sample appears lighter or darker than the standard. In case of examination of albacore designated "white," conduct the procedure using standards of Munsell value 6.3.

(3) The standards with which comparisons are made are essentially neutral matte-finish standards, equivalent in luminous reflectance of light of 555 mu wavelength to 33.7 percent of the luminous reflectance of magnesium oxide (for Munsell value 6.3) and 22.6 percent of the luminous reflectance of magnesium oxide (for Munsell value 5.3),

as given by the relationship between Munsell value and luminous reflectance derived by a subcommittee of the Optical Society of America and published in the "Journal of the Optical Society of America," Volume 33, page 406 (1943).

(4) These standards shall be cut in circles 34 inches in diameter and shall be mounted in 307 x 113 size containers, bearing a top seam and painted flat black inside and outside, so that the surfaces of the standards are 16 inch below the top of the containers in which they are mounted.

(5) In the case of blended tuna, the foregoing method shall be varied by first separating the tuna flakes of the two different colors before passing them through the 14-inch mesh sieve, then proceeding with each portion separately for the determination of its color value, employing, if necessary, a sample container with false bottom greater than 1/2 inch deep.

(h) (1) The specified names of the canned tuna for which definitions and standards of identity are prescribed by this section, except where water is the packing medium or where the tuna is smoked, are formed by combining the designation of form of pack with the color designation of the tuna; for example, "Solid pack white tuna," "Grated dark tuna," etc. In the case of blended tuna, there shall be used both applicable color designations of the blended flakes, in precedence determined in accordance with the predominating portion found in the container; for example, "Blended white and dark tuna flakes," "Blended dark and light tuna flakes."

(2) The specified name of canned tuna when water is used as the packing medium is formed as described in subparagraph (1) of this paragraph, followed by the words "in water"; for example, "Grated light tuna in water."

(3) When the packing medium is vegetable oil or olive oil, the label shall bear the name of the optional packing medium used, as specified in paragraph (e) of this section, preceded by the word “in” or the words "packed in." In case of the optional ingredient specified in paragraph (e) (1) of this section, the name or names of the oil used may be stated, or the general term "vegetable oil" may be used.

(4) In case solid pack tuna is packed in olive oil, the designation "Tonno" may also appear.

(5) In case any of the specified forms of canned tuna are smoked, the word "smoked" shall appear as a part of the name on the label; for example, "Smoked light tuna flakes."

(6) Where the canned tuna contains one or more of the ingredients listed in paragraph (f) of this section, the label shall bear the statement "Seasoned with .," the blank being filled

in with the name or names of the ingredient or ingredients used, except that if the ingredient designated in paragraph (f) (6) of this section is used the blank shall be filled in with the term "vegetable broth"; and if the ingredient designated in paragraph (f) (5) of this section is used alone, the label may alternatively bear either the statement "spiced" or the statement "with added spice"; and if salt is the only seasoning ingredient used the label may alternatively bear any of the statements "salted," "with added salt," "salt added."

(7) Where the canned tuna contains the optional ingredient sodium acid pyrophosphate as provided in paragraph (a) of this section, the label shall bear the statement "pyrophosphate added" or "with added pyrophosphate."

(8) Wherever the name of the food appears on the label so conspicuously as to be easily seen under customary conditions of purchase, the names of the optional ingredients used, as specified in subparagraphs (3), (6), and (7) of this paragraph, shall immediately and conspicuously precede or follow such name, without intervening, written, printed, or graphic matter, except that the common name of the species of tuna fish used may so intervene; but the species name "albacore" may be employed only for canned tuna of that species which meets the color designation "white" as prescribed by paragraph (d)(1) of this section.

[22 F.R. 892, Feb. 13, 1957; 22 F.R. 979, Feb. 16, 1957, as amended at 29 F.R. 5225, Apr. 16, 1964]

If the can size in question is not listed, calculate the value for column II as follows: From the list select as the comparable can size that one having nearest the water capacity of the can size in question, multiply the value listed in column II for the same form of tuna ingredient by the water capacity of the can size in question, and divide by the water capacity of the comparable can size. Water capacities are determined by the general method provided in § 10.6 (a) of this chapter. For the purposes of this section, cans of dimensions 211 x 109 shall be deemed to have a water capacity at 68° F. of 3.55 avoirdupois ounces of water; cans of dimensions 307 x 113, a water capacity of 7.05 avoirdupois ounces of water; cans of dimensions 401 x 206, a water capacity of 13.80 avoirdupois ounces of water; and cans of dimensions 603 x 408, a water capacity of 68.15 avoirdupois ounces of water.

(b) The methods referred to in paragraph (a) of this section for determining the weight of the pressed cake and referred to in § 37.1 (c) (1) for determining the percent of free flakes and the percent of pieces that pass through a 2-inch-mesh sieve are as follows:

(1) Have each of the 24 cans and contents at a temperature of 75° F. within ±5° F. Test each can in turn as follows:

(2) Cut out the top of the can (code end), using a can opener that does not remove nor distort the double seam.

(3) With the cut top held on the can contents, invert the can, and drain the free liquid by gentle finger pressure on the cut lid so that most of the free liquid drains from the can.

(4) With the cut lid still in place, cut out the bottom of the can with the can opener, then turn the can upright and remove the cut can top (code end). Scrape off any adhering tuna particles into the tuna mass in the can.

(5) Place the proper size of press cylinder as provided in paragraph (c) (1) of this section in a horizontal position on a table; then, using the cut bottom of the can as a pusher, gently force the can contents from the can into the cylinder so that the flat side of the can contents lies in contact with the bottom of the cylinder. Remove the bottom of the can that was used as the pusher and scrape any adhering particles from the can body and bottom of the can, and put them in the cylinder.

(6) Place the cylinder plunger on top of the can contents in the cylinder. Remove the eyebolt and put the cylinder and plunger in position on the press (paragraph (c) (3) of this section).

(7) Begin the operation of the press, and as soon as liquid is observed coming from the cylinder start timing the operation. Apply pressure to the plunger slowly and at a uniform rate, so that a full minute is used to reach a pressure of 384 pounds per square inch of plunger face in contact with the can contents. Hold this pressure for 1 additional minute and then release the pressure and disengage the plunger from the press shaft. Tip the press cylinder so that any free liquid is drained out.

(8) Remove press cylinder with plunger from the press, insert eyebolt in plunger and withdraw it from the cylinder. Loosen the pressed cake from the cylinder with a thin blade and remove the entire pressed cake as gently as possible, to keep the mass in a single cake during this operation. Place the pressed cake and any pieces that adhered to the plunger and cylinder in a tared receiving pan and determine the weight of the pressed material.

(9) For cans larger than 401 x 206, cut out the top of the can and drain off free liquid from the can contents as in operations described in subparagraphs (2) and (3) of this paragraph. Determine the gross weight of the can and remaining contents. Using a tared core

cutter as provided for in paragraph (c) (2) of this section, cut vertically a core of the drained material in the can. Determine the weight of the core. With a thin spatula transfer the core to the pressing cylinder for 401 x 206 cans. Determine the weight of the pressed cake as in the operations described in subparagraphs (5) through (8) of this paragraph. Remove the remaining drained contents of the can, reserving the contents for the determination of free flakes (subparagraph (11) of this paragraph), weigh the empty can, and calculate the weight of the total drained material. Calculate the weight of pressed cake on the entire can basis by multiplying the weight of the pressed cake of the core by the ratio of the weight of the drained contents of the can to the weight of the core before pressing.

(10) Repeat the

determination of weight of pressed cake on the remainder of the 24 cans and determine the average weight of pressed cake for the purpose of paragraph (a) of this section.

(11) Determination of free flakes: If the optional form of tuna ingredient is solid pack, determine the percent of free flakes. Any flakes resulting from the operations described in this subparagraph or in other parts of this paragraph are to be weighed as free flakes. Only fragments that were broken in the canning procedure are considered to be free flakes. If the can is of such size that its entire drained contents were pressed as described in subparagraphs (1) to (8), inclusive, of this paragraph, examine the pressed cake carefully for free flakes. Using a spatula, scrape free flakes gently from the outside of the cake. Weigh the aggregate free flakes that were broken from the loin segments in the canning procedure and calculate their percentage of the total weight of pressed cake. If the can is of such size that a core was cut for pressing as described in subparagraph (9) of this paragraph, make the examination for free flakes on a weighed portion of the drained material remaining after the core was removed. The weight of the portion examined should approximately equal the weight of the core before pressing. Calculate the weight of the free flakes that were broken from the loins in the canning procedure as a percentage of the weight of the portion examined.

(12) Determination of particle size: If the optional form of tuna ingredient

is chunks, flakes, or grated, the pressed cake resulting from the operations described in subparagraphs (1) to (9), inclusive, of this paragraph is gently separated by hand, care being taken to avoid breaking the pieces. The separated pieces are evenly distributed over the top sieve of the screen separation equipment described in paragraph (c) (4) of this section. Beginning with the top sieve, lift and drop each sieve by its open edge three times. Each time, the open edge of the sieve is lifted the full distance permitted by the device. Combine and weigh the material remaining on the three top sieves (12-inch, 1-inch, 2inch screens), and determine the combined percentage retention by weight in relation to the total weight of the pressed cake.

(c) (1) The press cylinder and plunger referred to in paragraph (b) of this section are made of stainless steel. The press cylinders are made with a lip to facilitate drainage of the liquid. Plungers have a threaded center hole, about half as deep as the thickness of the plunger, for receiving a ringbolt to assist in removing the plunger from the press cylinder. Dimensions for press cylinders and plungers are as follows: For can size 211 x 109

Press cylinder:

Inside depth, approximately 34 inches. Inside diameter, 2.593 inches.

Wall thickness, approximately % inch.
Plunger:

Thickness, approximately 1 inch.
Diameter, 2.568 inches.

For can size 307 x 113

Press cylinder:

Inside depth, approximately 4 inches. Inside diameter, 3.344 inches.

Wall thickness, approximately % inch. Plunger:

Thickness, approximately 14 inches.
Diameter, 3.319 inches.

For can size 401 x 206

Press cylinder:

Inside depth, approximately 4% inches.
Inside diameter, 3.969 inches.
Wall thickness, approximately 1⁄2 inch.
Plunger:

Thickness, approximately 1 inches.
Diameter, 3.944 inches.

For can sizes where the diameter is greater than 401, the core cutter described in subparagraph (2) of this paragraph shall be used and the resulting core pressed in the press cylinder for can size 401 x 206. For can sizes differing from those specified in this subpara

graph, special press cylinders and plungers may be used. Special press cylinders have inside diameters 10-inch less than the outside diameters, at the double seam, for the can sizes for which the cylinders are used; plunger diameters are 0.025-inch less than the inside diameters of the press cylinders.

(2) The core cutter referred to in paragraph (b) (9) and (11) of this section and subparagraph (1) of this paragraph is made from a previously sealed 300 x 407 can. The cover, including the top seam, is cut out. The edge is smoothed and sharpened. A small hole to permit passage of air is made in the bottom.

(3) The hydraulic press referred to in paragraph (b) (6) to (10), inclusive, of this section is made by so mounting a hydraulic jack, in a strong frame, that it will press horizontally against the center of the plunger in the press cylinder used. The frame is so braced that it does not change shape when pressure is applied. The gauge on the hydraulic jack is so calibrated that it will indicate, for the plunger being used, when the plunger is pressing against the contents of the press cylinder with a pressure of 384 pounds per square inch of plunger face.

(4) The sieving device referred to in paragraph (b) (12) of this section consists of three sieves, each approximately 1 foot square, loosely mounted, one above the other, in a metal frame. The mesh in the top sieve complies with the specifications for 11⁄2-inch woven-wire cloth as set forth in "Standard Specifications for Sieves," as published March 1, 1940, in L. C. 584 of the U. S. Department of Commerce, National Bureau of Standards. The meshes in the sieves below comply with similar specifications for 1-inch and 1⁄2-inch woven-wire cloth as set forth in the same publication. sides of each sieve are formed, in a raised rim, from 34-inch x 8-inch metal strap. The frame has tracks made of %-inch angle metal to support each sieve under each side. The tracks are so positioned as to permit each sieve a free vertical travel of 134 inches.

The

(d) If canned tuna falls below the applicable standard of fill of container prescribed in paragraph (a) of this section, the label shall bear the general statement of substandard fill provided in § 10.7 (b) of this chapter, in the manner and form therein specified.

[22 F.R. 893, Feb. 13, 1957]

§ 37.5 Fish flour; identity.

(a) Fish flour is the finely ground, dried product made from edible species of fish. From the time of catching until the finished article is packaged the fish are handled expeditiously and with the sanitary precautions which are recognized as proper for fish which are used in other forms for human food. Before processing, the fish are properly prepared to remove and discard the heads, fins, tails, viscera, and intestinal contents. The cleaned fish are ground and treated to reduce the fat content of the finished fish flour to less than 1 percent. The product may be deodorized. The finished fish flour shall meet all of the requirements set out in paragraph (b) of this section.

(b) (1) Protein content. Protein content (NX6.25), measured by methods of the Association of Official Agricultural Chemists, shall not be less than 70 percent by weight of the final product (Official Methods of Analysis, A.O.A.C., 9th Ed. secs. 22.011; ch. 22, p. 285). Biological values of the finished fish flour shall not be less than 105 percent as measured by the official A.O.A.C. method for the biological evaluation of protein quality (secs. 39.133-39.137, inclusive, ch. 39, p. 680).

(2) Moisture, ash and fat content. Moisture, ash and fat content shall not exceed 6 percent, 25 percent and 1 percent respectively, by weight of the final product, measured by A.O.A.C. methods (secs. 22.003, 22.010, ch. 22, p. 283, 284; sec. 18.011-18.012, inclusive, ch. 18, p. 235).

(3) Odor and taste. The final product shall have no more than a faint fish odor and taste.

(4) Storage stability. Fish flour, after 6 months' storage at temperatures prevailing in areas of intended use (but not exceeding 38° C.) and when packed in metal containers or in polyethylene bags, shall show no spoilage as judged by the development of off-flavors, mold growth, production of toxic amines (histamine, tyramine), or by deterioration in protein quality.

(5) Bacteria. The product shall be free of Escherichia coli, Salmonella, and pathogenic anaerobes, and the total bacterial plate count shall not exceed 2,000 per gram.

(6) Safety. The finished product shall contain no food additive unless specifically authorized by regulation issued

pursuant to section 409 of the Federal Food, Drug, and Cosmetic Act.

[27 FR. 740, Jan. 25, 1962]

NOTE: 37.5 was stayed in its entirety, 27 F.R. 4063, Apr. 28, 1962.

Sec. 42.1 42.10

PART 42-EGGS AND EGG PRODUCTS

Eggs.

Liquid eggs, mixed eggs, liquid whole eggs, mixed whole eggs; identity. 42.20 Frozen eggs, frozen whole eggs, frozen mixed eggs; identity.

42.30 Dried eggs, dried whole eggs; identity; label statement of optional ingredients.

42.40 Egg yolks, liquid egg yolks, yolks, liquid yolks; identity.

42.50 Frozen yolks, frozen egg yolks; identity.

42.60 Dried egg yolks, dried yolks; identity; label statement of optional ingredients.

AUTHORITY: The provisions of this Part 42 issued under secs. 401, 701, 52 Stat. 1046, as amended, 1055, as amended; 21 U.S.C. 341, 371.

SOURCE: The provisions of this Part 42 appear at 20 F.R. 9614, Dec. 20, 1955, unless otherwise noted.

§ 42.1 Eggs.

No regulation shall be promulgated fixing and establishing a reasonable definition and standard of identity for the food commonly known as eggs.

§ 42.10 Liquid eggs, mixed eggs, liquid whole eggs, mixed whole eggs; identity.

Liquid eggs, mixed eggs, liquid whole eggs, mixed whole eggs, are eggs of the domestic hen, broken from the shells, and with yolks and whites in their natural proportions as so broken. They may be mixed, or mixed and strained. § 42.20 Frozen eggs, frozen whole eggs, frozen mixed eggs; identity.

Frozen eggs, frozen whole eggs, frozen mixed eggs, are the food prepared by freezing liquid eggs.

§ 42.30 Dried eggs, dried whole eggs; identity; label statement of optional ingredients.

(a) Dried eggs, dried whole eggs are prepared by drying liquid eggs. They may be powdered. Before drying, the glucose content of the liquid eggs may be reduced by one of the optional procedures set out in paragraph (b) of this section.