United States

Department of

Agriculture

Agricultural

Marketing

Service

Fruit and

Vegetable

Division

Processed

Products

Branch

United States Standards

for Grades of

Frozen Leafy Greens

Effective date January 29, 1987
This is the second issue, as amended, of the United States Standards for Grades of

Frozen Leafy Greens, published in the FEDERAL REGISTER of December 30, 1986 (51

FR 46992) to become effective January 29, 1987. This issue supersedes the second

issue, which has been in effect since October 12, 1983.

Voluntary U.S. grade standards are issued under the authority of the Agricultural

Marketing Act of 1946, which provides for the development of official U.S. grades to

designate different levels of quality. These grade standards are available for use by

producers, suppliers, buyers, and consumers. As in the case of other standards for grades

of processed fruits and vegetables, these standards are designed to facilitate orderly

marketing by providing a convenient basis for buying and selling, for establishing quality

control programs, and for determining loan values.

The standards also serve as a basis for the inspection and grading of commodities by the

Federal inspection service, the only activity authorized to approve the designation of U.S.

grades as referenced in the standards, as provided under the Agricultural Marketing Act

of 1946. This service, available as on-line (in-plant) or lot inspection and grading of all

processed fruit and vegetable products, is offered to interested parties, upon application,

on a fee-for-service basis. The verification of some specific recommendations,

requirements, or tolerances contained in the standards can be accomplished only by the

use of on-line inspection procedures. In all instances, a grade can be assigned based on

final product factors or characteristics.

In addition to the U.S. grade standards, grading manuals or instructions for inspection of

several processed fruits and vegetables are available upon request for a nominal

fee. These manuals or instructions contain detailed interpretations of the grade standards

and provide step-by-step procedures for grading the product.

Grade standards are issues by the Department after careful consideration of all data and

views submitted, and the Department welcomes suggestions which might aid in improving

the standards in future revisions. Comments may be submitted to, and copies of standards

and grading manuals obtained from:

Chief, Processed Products Branch

Fruit and Vegetable Division, AMS

U.S. Department of Agriculture

P.O. Box 96456, Rm. 0709, So. Bldg.

Washington, D.C. 20090-6456
United States Standards for Grades of Frozen Leafy Greens

Section Page No.

§52.1371 Product description. ....................................... 2

§52.1372 Types. ................................................... 2

§52.1373 Styles. ................................................... 2

§52.1374 Definitions of terms. ........................................ 3

§52.1375 Recommended sample unit sizes. ............................. 4

§52.1376 Grades. .................................................. 4

§52.1377 Factors of quality. .......................................... 6

§52.1378 Classification of defects. ..................................... 6

§52.1379 Tolerance for defects. ....................................... 7

§52.1380 Sample size. .............................................. 8

§52.1381 Quality requirements. ....................................... 8

Authority: Agricultural Marketing Act of 1946, Secs. 203, 205, 60 Stat. 1087, as

amended, 1090, as amended (7 U.S.C. 1622, 1624).

Note: Compliance with the provisions of these standards shall not excuse failure to

comply with the provisions of the Federal Food, Drug, and Cosmetic Act, or with

applicable State laws and regulations.
2

§52.1371 Product description. 

Frozen leafy greens means the frozen product prepared from the clean, sound, succulent

leaves and stems of any one of the plants listed under § 52.1372 by sorting, trimming,

washing, blanching, and properly draining. The product is processed by freezing and

maintained at temperatures necessary for its preservation. Any functional, optional

ingredient(s) permissible under the Federal Food, Drug, and Cosmetic Act may be used

to acidify and/or season the product.

§52.1372 Types.

(a) Beet greens.

(b) Collards.

(c) Dandelion greens.

(d) Endive.

(e) Kale.

(f) Mustard greens.

(g) Spinach.

(h) Swiss chard.

(i) Turnip greens.

(j) Any other "market accepted" leafy green.

§52.1373 Styles.

(a) Leaf consists substantially of the leaf, cut or uncut, with or without adjoining

portion of the stem.

(b) Chopped consists of the leaf with or without adjoining portion of the stem

that has been cut into small pieces less than approximately 20 mm (0.78 in)

in the longest dimension but not comminuted to a pulp or a puree.

(c) Pureed consists of the leaf with or without adjoining portion of the stem that

has been comminuted to a pulp or a puree.
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§52.1374 Definitions of terms.

In these U.S. standards, unless otherwise required by the context, the following terms shall

be construed, respectively, to mean:

(a) Acceptable Quality Level (AQL) means the maximum percent of defective

units or the maximum number of defects per hundred units of product that,

for the purpose of acceptance sampling, can be considered satisfactory as

a process average.

(b) Blemished means any unit affected by discoloration or other means to the

extent that the appearance or eating quality is adversely affected. For leafy

greens other than leaf style spinach, each 4 cm2 in leaf style or each 2 cm2

in chopped and pureed styles (aggregate area measurement) is counted as

one defect. In leaf style spinach only, each 6 cm2 is counted as one defect.

(c) Character (other than pureed style). 

(1) Good character means:

(i) The frozen spinach is tender upon cooking.

(ii) The frozen leafy greens, other than spinach, may be slightly

tough upon cooking.

(2) Reasonably good character means:

(i) The frozen spinach is reasonably tender upon cooking.

(ii) The frozen leafy greens, other than spinach, may be

moderately tough upon cooking.

(3) Poor character means the frozen leafy greens fail the requirements

for reasonably good character.

(d) Defect (or defective) means any nonconformance of a unit(s) of product from

a specified requirement of a single characteristic.

(e) Extraneous vegetable material (EVM).

(1) Group I - Green, fine, tender string-like blades and stems of grass

and weeds.
4

(2) Group II - Green, coarse grass and weeds.

(3) Group III - Grass and weeds other than green.

(f) Flavor and odor. Normal flavor and odor means the frozen product is free

from objectionable flavors and odors of any kind after cooking.

(g) Root crown means the solid area of the leafy green plant between the root

and attached leaves or clusters of leaves.

(h) Root stub means any portion of the root whether or not leaves are attached.

(i) Sample unit means the amount of product to be used for grading. It may be:

(1) the entire contents of a container;

(2) a portion of the contents of a container;

(3) a combination of the contents of two or more containers;

(4) a portion of unpacked product.

(j) Seed head means the seed bearing portion of the leafy green plant that is

longer than 2.5 cm (1 in) or that is objectionable in appearance.

(k) Stem material (in leaf and chopped styles of spinach only) means the

portion of the plant located between the stalk or root crown and the point of

attachment to the leaf.

(l) Unit means any whole or portion of a leaf or stem from the leafy green plant.

§52.1375 Recommended sample unit sizes.

(a) Leaf style - 300 g (10.6 oz).

(b) Chopped style - 75 g (2.65 oz).

(c) Pureed style - 75 g (2.65 oz).

§52.1376 Grades.

(a) U.S. Grade A is the quality of frozen leafy greens that:
5

(1) Meets the following prerequisites in which the leafy greens:

(i) Have similar varietal characteristics;

(ii) Have a good overall brightness as a mass;

(iii) Have a normal flavor and odor;

(iv) Have a good character (other than pureed style);

(v) May have stem material (leaf style spinach only) that does not

exceed an AQL of 20.0;

(vi) May have stem material (chopped style spinach only) that

slightly affects the appearance or eating quality;

(vii) May have blemished areas that do not exceed an AQL of 20.0.

(2) Is within the limits for defects as classified in Table I and specified in

Table II.

(b) U.S. Grade B is the quality of frozen leafy greens that:

(1) Meets the following prerequisites in which the leafy greens:

(i) Have similar varietal characteristics;

(ii) Have a fairly good overall brightness as a mass;

(iii) Have a normal flavor and odor;

(iv) Have a reasonably good character (other than pureed style);

(v) May have stem material (leaf style spinach only) that does not

exceed an AQL of 25.0;

(vi) May have stem material (chopped style spinach only) that

materially affects the appearance or eating quality;

(vii) May have blemished areas that do not exceed an AQL of 40.0.
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(2) Is within the limits for defects as classified in Table I and specified in

Table II.

(c) Substandard is the quality of frozen leafy greens that fails to meet the

requirements of U.S. Grade B.

§52.1377 Factors of quality.

The grade of frozen leafy greens is based on meeting the requirements for the following

quality factors:

(a) Prerequisite quality factors:

(1) Varietal characteristics;

(2) Brightness;

(3) Flavor and odor;

(4) Character (other than pureed style);

(5) Stem material (leaf and chopped styles of spinach only);

(6) Blemished.

(b) Classified quality factors:

(1) Root crowns (leaf style only);

(2) Root stubs (leaf style only);

(3) Seed heads (leaf style only);

(4) Extraneous vegetable material.

§52.1378 Classification of defects.

All defects are classified as minor, major, severe, or critical. Each X in Table I represents

one (1) defect.
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Table I

Classification of Defects

Quality Factor Defects

Classification

Minor Major Severe Critical

LEAF STYLE

Root crowns Each piece X

Root stubs Each piece X

Seed heads Each piece X

Extraneous

vegetable

material

Group I (each 2.5 cm X

increment)

Group II (each 2.5 cm X

increment)

Group III (each 2.5 cm X

increment)

CHOPPED; PUREED STYLES

Extraneous increment)

vegetable

material 1/

Group I (each 1.3 cm X

Group II (each 1.3 cm X

increment)

Group III (each 1.3 cm X

increment)

1/ Includes root crown, root stub and seed head material.

§52.1379 Tolerance for defects.

Table II

(ALL STYLES)

Total 1/ Major Severe Critical

Grade A: AQL 2/ 15.0 6.5 2.5 0.4

Grade B: AQL 2/ 25.0 12.5 6.5 1.5

1/ Total = Minor + Severe + Critical.

2/ AQL expressed as defects per hundred units.
8

§52.1380 Sample size.

The sample size to determine meeting the requirements of these standards shall be as

specified in the Regulations Governing Inspection and Certification of Processed

Fruits and Vegetables, Processed Products Thereof, and Certain Other Processed

Food Products (7 CFR 52.1-52.83) for lot grading and on-line grading, as applicable.

§52.1381 Quality requirements.

(a) Lot grading. A lot of frozen leafy greens is considered as meeting the

requirements for quality if:

(1) The prerequisite requirements specified in §52.1376 are met; and

(2) The Acceptable Quality Levels (AQL) in Table II are not exceeded.

(b) On-line grading. A portion of production is considered as meeting the

requirements for quality if:

(1) The prerequisite requirements specified in §52.1376 are met; and

(2) The Acceptable Quality Levels (AQL) in Table II are not exceeded.

(c) Single sample unit. Each single sample unit submitted for quality

evaluation will be treated individually and is considered as meeting the

requirements for quality if:

(1) The prerequisite requirements specified in §52.1376 are met; and

(2) The Acceptable Quality Levels (AQL) in Table II are not exceeded.

Dated: December 18, 1986.

/s/ 

William T. Manley

Deputy Administrator,

Marketing Program