United States

Department of

Agriculture

Agricultural

Marketing Service

Fruit and

Vegetable

Division

Processed

Products Branch

Grading Manual 

for Frozen Apples

January 1977
This manual is designed for Processed Products Branch Personnel of the U.S. Department

of Agriculture. Its purpose is to give background information and guidelines to assist in the

uniform application and interpretation of U.S. grade standards, other similar specifications

and special procedures.

The citation of any data, criteria, techniques, illustrations, copyrighted material, or pictorial

representationaccredited to private authorship is used with the permission of the individuals

or sources cited. Unless a specific reference is cited, the information in this manual has been

compiled or developed from sources available to the public as well as from technical

knowledge of personnel in the Department.

Following the suggested guidelines in this manualdoes not excuse failure to comply with the

Federal Food, Drug, and Cosmetic Act or any other applicable Federal or State laws or

regulations.

Exceptfor officialUSDAinspectionaids ordevicesand color guides (or standards) produced

under license of the Department, the mentionof any supplier, patented device,product, brand

name or equipment does not imply endorsement by the Department over any other similar,

or equally effective material.

Address inquires to:

Chief, Processed Products Branch

Fruit and Vegetable Division, AMS

U.S. Department of Agriculture

P.O. Box 96456, Rm. 0709, South Building

Washington, DC 20090-6456
Frozen Apples

January 1977

1

PROCESSING TECHNIQUES

Apples oxidize rapidly whenever the cut surfaces are exposed to air. This oxidation may be

retarded by the use of an antioxidant or by deactivating the enzymes by a quick blanch, or

both. Weak salt brine may be used by some processors. Oxidation may be controlled by

using one or a combination of the following methods:

Steam or hot water blanch.

Hotwater blanching is effective but has a tendency to soften or disintegrate the slices and to

leachthe soluble solids from the apples. Careful adjustment and control of the blanching must

be maintained in order to avoid internal discoloration of the slices.

Addition of sulfur dioxide.

The bleaching actionofSO2 hasa tendencyto make all apple slices the same color. SO2 may

impart an objectionable flavor and/or odor to the product.

Vacuum processing.

This process is designed to pull a vacuum in the presence of a suitable additive (salt, sugar,

organic food grade acids, etc.) and suddenly release the vacuum. The vacuum process is

used rather widely because it retains the texture of the apple product.

QUALITY EVALUATION

Similar varietal characteristics.

Single varieties of apples are usually selected for freezing. Variation of color, texture, and

flavor within a single variety or similar varieties is normal and will be affected by the type of

process used to inhibit oxidation of the product. Only if the appearance and flavor are

seriously affected should the sample unit be graded Substandard.
Frozen Apples

January 1977

2

Flavor.

In evaluating flavor and odor, consider the type of process which is used to preserve the color

of the frozen apples and the maturity and varietal flavor characteristics of the fruit. When

additives (salt, organic food grade acids, SO2, etc.) are used, the flavor and odor evaluation

should consider the correct usage of these additives. The presence of additives might be

slightly noticeable upon tasting and yetbe considered normal. However, too much of any or

all of the additives might render the product objectionable. This is a subjective evaluation and

depends upon the experience and training of the analysts. A slight flavor and odor of sulfur,

in the uncooked product, should completely disappear upon cooking.

Color.

Color may range from an almost pure white to yellow, orange, or a greenish cast. The apple

slices in eachcontainer should indicate similar varietal characteristics. Different containers

in a lot may contain apples of different varietal characteristics.

Grade A Reasonably uniform, bright, and pleasing.

Grade C May be dull, slightly brown, or slightly gray. Slight internal discoloration is

permitted.

Uniformity of size.

Consider the average size of the units in the sample unit. Units that deviate from the average,

such as large units, small units, or both large and small units, may be removed from the

sample unit down to the required percentage, before determining uniformity of thickness.

Defects.

Exact weight sample units in 16-ounce multiples from large containers make for easier

calculation.
Frozen Apples

January 1977

3

1. Harmless extraneous material.

Grade A Allow only a very slight amount.

Grade C If the EVM is noticeable, but does not seriously affect the

appearance or eating quality.

Substandard Seriously affects the appearance or eating quality.

2. Damaged.

Defects which the consumer would not normally remove before using the

product. Slight flecks of corky tissue, very slight bruises and flecks of peel

which are inconspicuous are not considered.

3. Seriously damaged.

Defects which the consumer would normally remove before using the product.

Worm holes, unsightly calyx ends, large or dark bruises, dark internal

discoloration, and other serious discolorations would fall in this group.

Character.

Character of frozenapples maybe affected bymaturity, firmness, degree of blanch, addition

of firming agents, size of the units and the time and temperature of processing.

Grade A It is notexpected thatall the apple slices will be of uniform texture. However, to

be judged as having "good character" the texture should bereasonablyuniform

and should be firm but nothard. Soft or flabby slices tend to disintegrate when

reheated for pies or other baking products and are not Grade A.

Grade C The slices may be variable in texture.