United States

Department of

Agriculture

Agricultural

Marketing Service

Fruit and

Vegetable

Division

Processed

Products Branch

Grading Manual for

Canned Apple Juice

March 1982
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 officialUSDAinspectionaidsordevicesand color guides (or standards) produced

underlicense 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
Canned Apple Juice

March 1982

TABLE OF CONTENTS

Page

Sampling Procedures .................................................. 1

Non-quality Procedures ................................................. 1

Headspace and Fill of Container ......................................... 1

Volume Measurement .................................................. 2

Styles ................................................................ 3

Preparation of Clear Juice .............................................. 3

Preparation of Cloudy Juice ............................................. 6

Pasteurization ......................................................... 6

Mixed Lot of Clear and Cloudy Juice ...................................... 6

Pasteurization ......................................................... 6

Methods of Analyses ................................................... 6

Flavor ................................................................ 7

Suggested Order of Grading a Sample Unit of Clear Style Juice .............. 9

Suggested Order of Grading a Sample Unit of Cloudy Style Juice ............. 11
Canned Apple Juice

March 1982

1

Sampling Procedures

1. Regulations (109-A-1)

2. Sampling Procedures (120-A-1)

3. Time Sampling (120-A-4)

Follow 9

4. Condition of Container (125-A-1

5. In-Plant Inspection (160-A-1, 162-A-1)

6 Foreign Material (172-A-1)

Non-Quality Procedures

1. Time Sampling (120-A-5)

2. Net Contents (128-A-10)

3. Vacuum (128-A-20)

Follow 9

4. Fill of Container (128-A-40)

5. Brix Measurement (128-A-50, 135-A-3)

6. Acid Conversion Chart (135-A-25)

7. General Inspection Instructions (130-A-1)

Headspace and Fill of Container

Generally, the headspace of containers of canned apple juice need not be checked as long

as the declared net contents for the particular container size are met. The quality control

department of some plants may prefer to have the headspace recorded for all containers

opened for grading. Under lot grading, the headspace should be recorded for all containers

with low net contents.
Canned Apple Juice

March 1982

2

There are no Federal Food and Drug standards of fill for canned apple juice. The FDA

"general requirements" for fill ofcontainer whichare applicable to all products for whichthere

are no specific standards of fill are applicable. Essentially, this means that the container

should be filled as full as practicable without impairment of quality and the size and

configurationof the container must not be deceptive. The 90% minimum fill applies. The net

contents may be determined either by direct measurement in volumetric cylinder graduated

in fluid ounces or by net weight and conversion to fluid ounces. Refer to File Code 130-A-1

for this latter procedure.

The net content statement for canned apple juice must be declared in liquid measure in the

largest whole units (quarts, quarts and pints, or pints, as appropriate) with any remainder in

terms of fluid ounces or common or decimal fractions of the pint or quart.

Volume Measurement

Measuring Flask Method

Glass flasks are available that are accurately calibrated for measuring volume of liquids.

There are two important things to remember when using this method. The flask is calibrated

for volume of a liquid at a standard temperature, usually 20°C. The legend is etched oneach

flask. The juice must be at this temperature for accuracy. Also, it is important not to

incorporate air into the liquid when filling the flask. Heavier products such as cloudy apple

juice must stand after filling the flask to permit any occluded air to escape.

Net Weight to Fluid Ounces Conversion Method

Take the netweight of the juice. Convert this weight to volume measurement by the following

formula:

Net contents = 
Canned Apple Juice

March 1982

3

Example:

Apple juice No. 3 cylinder

Net weight - 49.2 ounces

Refractive Index (20°C) - 1.3414 (See File Code 135-A-50 for Sp. Gr.)

Specific gravity - 1.02289

Net contents = 

Example:

(1) A declaration of 1 quart shall be expressed as "Net 32 fl oz (1 qt)".

(2) A declaration of 1-3/4 quarts liquid measure shall be expressed as "Net

contents 56 fluid ounces (1 quart 1-1/2 pints)" or as "Net 56 fluid oz (1 qt 1 pt

8 oz)", but not in terms of quart and ounce suchas "Net 56 fluid oz (1 quart 24

ounces)".

(3) A declaration of 2-1/2 gallons liquid measure shall be expressed as "Net

contents 2-1/2 gallons," "Net contents 2.5 gallons," or "Net contents 2 gallons

2 quarts" and not as "2 gallons 4 pints".

When the contents are less than one pint only the fluid ounces must be declared.

Styles

(a) Style I, Clear -- Juice thathas beenproperly clarifiedand filteredshould be bright clear,

and practically free from any turbidity or sedimentation.

(b) Style II, Cloudy -- Cloudy style juice is unclarified and generally not filtered. The

cloudiness comes from natural apple materials. The amount of sedimentation may

varysubstantially depending onthe process used and naturalvariations in the apples.

Preparation of Clear Juice

The juice isusuallystrainedbeforeclarificationto remove the larger apple particles. Straining

maybe accomplished by the use of cleanpress cloths, bypassing the juice througha rotating

screen, or with a vibrating type shaker screen. The screens should be stainless steel.

A. Clarification

After straining, the juice is further clarified by one of the following methods:

Enzymatic Method

The enzymatic method is probably the most commonand mostreliable method

used to clarify apple juice. This method is a batch operation, which requires

several large holding tanks for commercial production. Some processors may
Canned Apple Juice

March 1982

4

heat the juice to about 125°F and let it settle overnight. Others may hold the

juice at 60 to 70°F for settling overnight. Pectolytic enzymes are added to the

juice for clarifying action.

The juice can also be flash heated to about 185 to 190°F, cooled to 120 to

130°F, and then treated with enzymes for about 30 minutes.

The pectic enzymes break down the natural pectins in the juice, precipitating

part of it, and making the rest soluble.

Bentonite Method

In this method the juice is heated to approximately 190°F, held for a few

seconds and then cooled rapidly. The juice is then pumped from the cooling

unitto a tank where 7 to 8 ounces of mixtureofequalparts of bentonite and filter

aid are added to 100 gallons of the juice. The heat treatment coagulates the

colloidal material in the juice and the bentonite mixture causes the coagulation

material to flocculate, making it easier to filter the juice.

Gelatin-tannin Method

The gelatin-tanninmethod works onthe principle thatwhen gelatin is dissolved

in water and added to the apple juice, it combines with the tannins of the juice

forming a bulky precipitate. When this precipitate settles out it pulls any

suspended material down with it, clarifying the juice. Exact amounts of gelatin

should be used since an excess of gelatin will have a tendency to stabilize the

colloidalmaterial. The precipitate should be allowed to stand for approximately

24 hours before the juice is drawn off. The juice is generally drawn off from near

the bottom of the vat.

Since the gelatin combines with tannins which is precipitated and settled out,

tannins should be added back to the juice to restore the naturalflavor qualityfor

which they are responsible.

Juice clarified by this method is generally lighter in color thanwhenclarified by

the other methods mentioned.

Flash Heat Method

The flash heat method is generally used in conjunction with one of the other

three methods previously explained since it does not do a thorough job of

clarification. Filtration of the juice is also slowed down below a satisfactory

speed for production.

In this method the juice is heated to approximately 190°F, held for a few

seconds, then rapidly cooled. The suspended material is coagulated, setting

it up for further clarification by one of the other methods.

Electrokinetic Adsorption Method
Canned Apple Juice

March 1982

5

This method employs a cartridge filter that provides electrokinetic adsorption

as well as small-pore mechanical straining. The filter medium is composed of

cellulose and polymers which impart a positive charge to the fibers.

B. Filtration

After the juice has been clarified it is pumped into mixing tanks where it is

prepared for filtering. The juice is mixed with a filter aid, generally

diatomaceous earth or siliceous powder, in the mixing tank. It is thenpumped

to the filter units where it is filtered througha filter cloth or filter paper. The clear

juice is caught in the filter units and the filter aid along with the flocculated apple

materialfrom the clarificationprocess is caught onthe filter cloth or filter paper.

The filter units should be made of stainless steel to prevent the juice from

coming in contact with iron. Another type of filter unit is now being used to

some extent inwhicha cake of filter aids up to 2-3/4 inches thick is first built up

on the outside of a cylindrical screen. The screen is covered by a filter cloth.

Approximately one half of the screen is immersed into a tank containing the

apple juice. A vacuum of about 17 inches is drawn on the interior of the screen

as it revolves throughthe unfiltered juice. The vacuum forces the juice through

the immersed portion of the filter cylinder. 

At the same time the upper portionis dried so thatthe solids and filter cake can

be continuously scraped off, presenting a fresh surface of filter aid to the

unfiltered juice. This system provides a fast and continuous filtration for

approximately eight or more hours before cleaning and rebuilding a new filter

cake is required.

Preparation of Cloudy Juice

The juice is held in deep holding tanks to permit the suspended solids to settle out. This

reduces the amount of sediment which would form in the bottom of the containers after

canning. The juice is siphoned off the sediment and is either put through a centrifuge to

remove the excess solids or given a preliminary heat treatment and then cooled to aid in

removalof solids that may be coagulated by subsequent heat treatment to sterilize the juice.

Pasteurization

The juice, in the case of both the cloudy and clear juice, is pumped to a heat exchanger or

pasteurizer where it is brought up to a temperature of 190°F just prior to filling.

Mixed Lot of Clear & Cloudy Juice

Under normal packing practice clear style juice would not be mixed with cloudy style.

However, if a lotis inadvertently mixed style, the packer may wish to segregate the lotbefore

offering for grading. In the event the packer declines the segregation grade the lot according

to the style that it is offered for -- either clear style or cloudy style.

Methods of Analyses
Canned Apple Juice

March 1982

6

Brix Measurement

The officialmethod for determining degrees Brixas specifiedin the canned apple juice grade

standards is byuse of the refractometer. A Brix hydrometer may be used only as an alternate

when a refractometer is not available. WhenBrix measurements are taken at temperatures

other than 20°C (68°F), a temperature correction should be made. Separate tables for this

correction for the hydrometer and refractometer are contained in File Code 135-A-3.

Procedures for taking Brix measurements are outlined in File Code 135-A-3 (Technical

Inspection Procedures -- Brix Measurement).
Canned Apple Juice

March 1982

7

Acid Determination

Transfer 10 mL of well mixed juice to a 250 mL Erlenmeyer flask. Rinse inside of flask down

with approximately 100 mL distilled water. Add 3 or 4 drops of phenolphthalein indicator or

other suitable indicator. Titrate this solution with approximately 0.1N sodium hydroxide

(NaOH)to the first signs of a permanent end point according to the indicator used (pink in the

case of phenolphthalein).

The acid content is expressed in grams malic acid per 100 grams of juice according to the

following formula:

mL NaOH x N of NaOH x 0.67 = gms malic acid/100 mL juice.

Refer to InspectionAid No.87 -- Acid ConversionChart (File Code 135-A-25) for conversion

from wt/volto wt/wt. For acid content in the range of 0.50 to 2.00 grams per 100 mL juice use

the conversion table in File Code 135-A-25 (Inspection Aid No. 87). Outside this range use

the formula:

NOTE: Degrees Brix must be converted to specific gravity per Table Aof

File Code 135-A-3 or File Code 135-A-50 (Sucrose Conversion

Table).

Flavor

Apropercombinationof various apple characteristics is essentialto a highqualityapple juice

flavor. Specifically, these are:

(1) A good sugar-acid balance; and

(2) Apple essences which provides the "fruity flavor", bouquet and aroma.
Canned Apple Juice

March 1982

8

Minimum requirements are provided for sugar, expressed as "DegreesBrix",ingradesAand

B. Minimum and maximum requirements are provided in these grades. Although a sample

unit of apple juice may meet the requirements for a particular grade for both sugar and acid,

a subjective evaluationmust be made with respect to sugar-acid balance. For example, if the

acidity of the juice approaches the maximum for Grade A, the sugar content should be such

that the juice is not too tart to the taste. 

On the other hand, if the acidity ofthe juice approaches the minimum for Grade A, the sugar

content should not be such as to cause the flavor to be too sweet, although it must meet the

specified minimum for the grade.

Apple essences must be present such as to provide a pronounced fruity flavor characteristic

of fresh, aromatic apples in addition to meeting sugar and acid requirements in order for the

juice to qualify for Grade A. If the juice does not have a pronounced fruity flavor, the sample

unit must not be classified above Grade B even though sugar and acid requirements for

Grade A are met.
Canned Apple Juice

March 1982

9

Suggested Order of Grading a Sample Unit

Clear Style

1. Draw 500 mL ( 250 mL for containers 12 fl. oz. or less) of well mixed canned apple

juice. This could be a portion of the contents of a container, the entire contents of a

container, or a composite of more than 1 container from a particular code.

2. Evaluate the color by pouring the suggested amount(250 mL or 500 mL) into a clean

glass cylinder approximately two inchesin diameter and twelve inches tall and viewing

the juice through the cylinder under good lighting conditions.

Grade A - the color should be good,bright and sparkling. Canned apple juice that falls

into this classification may be assigned a score of 18 to 20 points.

Grade B - the color should be reasonably good and may be slightly translucent.

Canned apple juice thatfalls into this classification may be assigned a score of 16 or

17 points and should notbe graded above U.S.Grade B regardless of the total score

for the product.

3. Evaluate the juice for absence of defects.

Grade A - may contain slight amounts of amorphous sediment or residue, trace of

nonamorphous sediment or residue and dark specks, and contains no particles of

seeds, pulp or other defects. Canned apple juice that falls into this classification may

be assigned a score of 18 to 20 points.

Grade B - may contain moderate amounts of amorphous sediment or residue,

moderate amounts of nonamorphous sediment or residue and dark specks, and a

slight amount of particles of seed,pulp or other defects. Canned apple juice that falls

into this classification may be assigned a score of 16 or 17 points and should not be

graded above U.S. Grade B regardless of the total score for the product.

Noticeable sedimentation may be determined by allowing the juice to stand in the

glass cylinder usedto determine color for approximately tenminutes. Examine for any

sediment that may accumulate in the bottom of the cylinder. Sedimentation check for

the 250 mL sample should be done with 1-1/2 inch diameter cylinder; 2 inchdiameter

cylinder for the 500 mL sample. Nonamorphous sediment is heavy; amorphous

sediment is lighter and stays partially in suspension. 
Canned Apple Juice

March 1982

10

Suggested Order of Grading a Sample Unit

Clear Style (Continued)

Dark specks, seed particles, pulp or other defects are evaluated by pouring 250 mL

portions of the sample onto a flatwhite grading tray (approx. 17" x12" ) and observing

the defects present.

NOTE: DONOT DISCARDTHIS JUICE (PLUS SEDIMENT,IF ANY) SINCE

IT WILL BE USED LATER FOR THE FLAVOR TEST.

4. Evaluate flavor.

Grade A - the juice has good flavor typical of apple juice that has been properly

processed. Canned apple juice that falls into this classification may be assigned a

score of 54 to 60 points.

Grade B - the juice has reasonably good flavor typical of apple juice that has been

properly processed. Canned apple juice that falls into this classification may be

assigned a score of 48 to 53 points and should not be graded above U.S. Grade B

regardless of the total score for the product.

Refer to Table I inthe grade standards for tolerances onacid and Brix measurements

forthe respective grades. Follow the AOAC method (or other acceptable method such

as is contained in File Code 137-0-210) for malic acid determination. Brix

measurement procedures are outlined in File Code 135-A-3.

Refer back to page 7 for a full discussion on flavor.
Canned Apple Juice

March 1982

11

Suggested Order of Grading a Sample Unit

Cloudy Style

1. Shake container well before opening; draw 500 mL (250 mL for containers 12 fl. oz.

or less) of well mixed canned apple juice. This could be a portion of the contents of a

container, the entire contents of a container,oracomposite ofmorethanone container

from a particular code.

2. Evaluate the color by pouring the suggested amount (500 mL or 250 mL) into a clean

glass cylinder approximately two inches in diameter and twelve inchestalland viewthe

juice under good lighting conditions.

Grade A - the color should be good, may be slightly translucent to definitely cloudy.

Canned apple juice thatfalls into this classification may be assigned a score of 18 to

20 points.

Grade B - the color should be reasonably good, typical of the cloudy style but not

off-color. Canned apple juice that falls into this classification may be assigned a score

of 16 or 17 points and should not be graded above U.S. Grade B regardless of the

total score for the product.

3. Evaluate the juice for absence of defects.

Grade A - may contain normal amounts of amorphous and nonamorphous sediment

or residue,trace of dark specks, and contains no particles of seeds, coarse particles

of pulp or other defects. Canned apple juice that falls into this classification may be

assigned a score of 18 to 20 points.

Grade B - may contain normal amounts of amorphous and nonamorphous sediment

or residue, moderate amounts of dark specks, and a slight amount of particles of

seeds, coarse particles of pulp or other defects. Canned apple juice that falls into this

classification may be assigned a score of 16 or 17 points and should not be graded

above U.S. Grade B regardless of the total score for the product.

Noticeable sedimentation may be determined by allowing the juice to stand in the

glass cylinder used to determine color for approximately tenminutes. Examine for any

sediment that may accumulate in the bottom of the cylinder. 
Canned Apple Juice

March 1982

12

Suggested Order of Grading a Sample Unit

Cloudy Style (Continued)

Sedimentationcheck for the 250 mL sample should be done with 1-1/2 inchdiameter

cylinder; 2 inch diameter cylinder for the 500 mL sample. 

Nonamorphous sediment is heavy; amorphous sediment is lighter and stays partially in

suspension. More sedimentation is allowed in the cloudy style than in the clear style. Dark

specks, particles of seeds, coarse particles ofpulp or other defects are evaluated bypouring

250 mL portions ofthe sample onto a flatwhite grading trayapprox. 17" x12") and observing

the defects present.

NOTE: DO NOT DISCARD THIS JUICE (PLUS SEDIMENT,IF ANY) SINCE

IT WILL BE USED FOR THE FLAVOR TEST.

4. Evaluate flavor.

Grade A - the juice has good flavor typical of apple juice that has been properly

processed. Canned apple juice that falls into this classification may be assigned a

score of 54 to 60 points.

Grade B - the juice has reasonably good flavor typical of apple juice that has been

properly processed. Canned apple juice that falls into this classification may be

assigned a score of 48 to 53 points and should not graded above U.S. Grade B

regardless of the total score for the product.

Refer to Table IIin the grade standards for tolerances onacid and Brix measurements

forthe respective grades. Follow the AOAC method (or other acceptable method such

as is contained in File Code 137-0-210) for malic acid determination. Brix

measurement procedures are outlined in File Code 135-A-3.

Refer back to page 7 for a full discussion on flavor.