United States

Department of

Agriculture

Agricultural

Marketing 

Service

Fruit and Vegetable

Programs

Processed

Products 

Branch

Grading Manual for

Canned Whole Kernel

(Whole Grain) Corn

Effective June 2001
Canned Whole Kernel

Corn Grading Manual

June 2001

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

representation accredited to private authorship is used with the permissionof 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 manual does notexcuse failure to comply with the

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

regulations.

ExceptforofficialUSDAinspectionaidsor devices and color guides (or standards) produced

underlicense of theDepartment,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 Programs, AMS

U.S. Department of Agriculture

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

Washington, DC 20090-6456
Canned Whole Kernel

Corn Grading Manual

June 2001

TABLE OF CONTENTS

Page

SAMPLING PROCEDURES .................................................. 1

SUGGESTED ORDER OF GRADING ......................................... 3

A. Non-quality Factors .................................................... 3

B. Prerequisite Quality Factors ............................................. 5

C. Foreign Material ....................................................... 9

D. Smut ................................................................. 9

E. Grading of EVM and Specified Defects ................................... 9

F. Assigning the Grade for a Lot. .......................................... 12

PROCEDURES FOR GRADING MIXED QUALITY LOTS ....................... 13

PROCEDURES FOR SINGLE SAMPLE UNITS

(UNOFFICIAL SAMPLES) .................................................. 13

TABLES

Table I, Minimum Sampling Rates ........................................ 1

Table II, Sampling Rates for Small Containers .............................. 2

Table III, Drained Weights ............................................... 4

Table IV, Acceptance Numbers for EVM .................................. 10

Table V, Acceptance Numbers for Other Defects .......................... 12

Time Sampling Tables ................................................. 15

Attachment 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Canned Whole Kernel

Corn Grading Manual

June 2001

1

SAMPLING PROCEDURES

Followthe generalproceduresand instructions asoutlinedinFile Codes 109-A-1 and 120-A1. Follow the procedures in File Code 128-A-20 (Vacuum); File Code 128-A-10 (Net

Weight); File Code 130-A-67 (Small units of Alien Vegetables); and File Code 128-A-30

(Drained Weight). Follow the procedures in Condition of Container File Code series 125

when a formal condition of container is required. Follow File Code 172-A-1 (Foreign

Material) to evaluate grit and soil found in canned whole kernel corn and for certifying "offflavor" sample units.

Follow Table I and Table II Minimum Sampling Rates for Canned Whole Kernel Corn when

sampling this product. When additional containers are required in Group 1, draw and

separately identify (mark) all of the containers. For example,using Table II, if the sampling

rate specifies six (6) containers, and the total number of containers needed is 12, draw two

(2) adjacent containers per sample unit. Identify the containers as 1a, 1b; 2a, 2b; etc.

Table I

Minimum Sampling Rates for Canned Whole Kernel Corn

Group 1 (up through 303) _1/ Group 2 (No. 1 sq. through

No.3 cylinder)

Group 3 (Exceeds 3 cylinder)

24 per case 48 per case 12 per case 24 per case 6 per case 12 per case

No. of Sample

Units

Cases Cases Cases Cases Cases Cases

 3 125 or less 63 or less 125 or less 63 or less 125 or less 63 or less

 6 126 to 500 64 to 250 126 to 500 64 to 250 126 to 500 64 to 250

13 501 to 1625 251 to 813 501 to 1625 251 to 813 501 to 1625 251 to 813

21 1626 to 3500 814 to 1750 1626 to 3500 814 to 1750 1626 to 3500 814 to 1750

29 3501 to 6042 1751 to 3021 3501 to 6042 1751 to

3021

3501 to 6042 1751 to

3021

8z Tall 211 X 304 No. 2 307 X 409 No. 10 603 X 700

No. 1 picnic 211 X 400 No. 2 1/2 401 X 411

No. 300 300 X 407 No. 3 cylinder 404 X 700

No. 1 Tall 301 X 411

No. 303 303 X 406

_1/ SEE TABLE II OF THIS MANUAL TO ENSURE THAT SUFFICIENT PRODUCT IS SAMPLED FOR

GRADING PURPOSES.
Canned Whole Kernel

Corn Grading Manual

June 2001

2

SAMPLING PROCEDURES

NOTE: THE SAMPLING RATES IN THE FOLLOWING TABLE ARE DESIGNED TO ENSURE THAT

SUFFICIENT PRODUCT IS DRAWN FOR GRADING PURPOSES.

Table II

Sampling Rates for Small Containers

of Canned Whole Kernel Corn (8 oz - No.303)

Container Size Sampling

Rate

Minimum

Units of

Product

Needed

Total Number of

Containers

Needed

Action

Draw and

Separately Identify (Mark) 1/

8 oz 3 3000 6 1 adjacent containers per sample unit.

8 oz 6 6000 12 1 adjacent containers per sample unit.

8 oz 13 13000 26 1 adjacent containers per sample unit.

8 oz 21 21000 42 1 adjacent containers per sample unit.

8 oz 29 21000 42 13 extra containers throughout the lot.

No. 300 & 303 3 3000 4 1 extra container throughout the lot.

No. 300 & 303 6 6000 7 1 extra container throughout the lot.

No. 300 & 303 13 13000 15 2 extra containers throughout the lot.

No. 300 & 303 21 21000 25 4 extra containers throughout the lot.

No. 300 & 303 29 21000 29 N/A

_1/ Identify the containers as 1a, 1b, 1c, 1d; 2a, 2b, 2c, 2d; etc.

The minimum number of units of product used to evaluate seriously damaged kernels,

damaged kernels, and pulled kernels is 1000 units. For larger can sizes more product

should be examined. For example: If the lot size for No. 10 cans requires 13 sample units,

the minimum sample size is 13 x1000. You should examine more product by selecting more

whole kernelcornbased uponthe next higher sample size whichis 21 x1000 or 21,000 units.

Bydividing 13 into 21000, you will be required to randomly draw 1615 whole kernels ofcorn

from eachof the 13 containers. Apply the acceptance numbers for the 21000 sample size to

this lot.

NOTE: Limit sample size to no greater than 29 sample rate.
Canned Whole Kernel

Corn Grading Manual

June 2001

3

SUGGESTED ORDER OF GRADING

A. Non-quality Factors.

1. Record the following applicable information on the tally sheet.

a. Name and address of applicant.

b. Size and kind of container.

c. No. of cases in lot (page 1 only).

d. Contract (Cont. No.) or Purchase Order (P.O. No.).

e. Label -- or attach a copy -- (page 1 only).

2. Select the containers to be used for non-quality and prerequisite evaluation.

Note: For small containers (8 oz), select 1a, 2a, 3a, etc.

3. Arrange the containers on the grading table in chronological order by code.

4. Record the codes, on the tally sheet, including case codes if available. 

NOTE: THE FINAL/AVG COLUMN (COLUMN 9) ON PAGE 1 OF THE TALLY SHEET SHALL BE

USED FOR THE SUMMATION OF THE GRADING RESULTS OF THE LOT. COLUMN 9

MAY BE USED ON SUCCEEDING PAGES FOR RECORDING INDIVIDUAL CONTAINER

DATA. 

IF THERE IS INSUFFICIENT SPACE IN THE CODE SECTION OF THE TALLY

SHEET FOR SINGLE LINE INK JET CODES, RECORD THEM AS DOUBLE LINE

CODES. REFER TO THE BACK OF THE TALLY SHEET AND SHOW AN

EXAMPLE OF THE ACTUAL CODE THERE.

5. Determine and record the net weight of each container using Branch

procedures for determination of tares and reading of scales.

6. Determine and record the vacuum reading for each container.

NOTE: TO GET A PROPER VACUUM READING, SLIGHTLY ELEVATE ONE SIDE OF THE

CAN AND TAKE THE VACUUM READING FROM THE HIGH SIDE.

7. Open each container, and for cans, leave the lid remaining on top of the

product.
Canned Whole Kernel

Corn Grading Manual

June 2001

4

8. Using the lid to stem the flow ofproduct, carefully empty the contents container

by container into tared draining screens that have been placed on a 17 to 20

degree incline in individualgrading trays. Determination of the drained weight

of whole kernelcornisessentialto properly determine the grade for extraneous

vegetable material (EVM).

The minimum drained weight recommendations of Table I of this section are not

incorporated in the grades of the finishedproduct,sincedrainedweight,as such, is not

a factor of qualityfor the purpose of these grades. The drained weight of whole kernel

(or whole grain) corn is determined by emptying the contents of the container upon a

United States Standard No.8 circular sieve of proper diameter so as to distribute the

productevenly, inclining the sieve slightlyto facilitate drainage and allowing the product

to drain for two minutes. The drained weight is the weight of the sieve and the whole

kernel (or whole grain) corn less the weight of the dry sieve. A sieve 8 inches in

diameter is used for the No.2-1/2 size can(401" x411") and smaller sizes and a sieve

12 inches in diameter is used for containers larger than the No. 2-1/2 size can.

TABLE III

RECOMMENDED MINIMUM DRAINED WEIGHTS OF WHOLE KERNEL CORN

(EXCEPT VACUUM PACK)

Container size or

designation

Grade A, tenderness and

maturity 

 Ounces Grams 

Grade B, C, and

Substandard tenderness

and maturity

 Ounces Grams

 8 ounce Tall 5.25 149 5.50 156

 No. 1 (picnic) 6.75 191 7.00 198

 No. 300 9.25 262 9.50 269

 No. 303 10.50 298 10.75 305

 No.2 12.75 361 13.25 376

 No. 10 70.00 1984 72.00 2041

9. Drain (undisturbed) for 2 minutes, using a U.S. Standard No. 8 circular

sieve, weigh and record the drained weights on the tally sheet. A sieve, 8

inches (20.3 centimeters) in diameter, is used for 8 oz, No. 300, No. 303

containers, and No. 2-1/2 containers, and a sieve 12 inches (30.5

centimeters) in diameter, is used for larger containers such as No. 10's. The

temperature of the packing medium at time of drained weight determination

shall be 20 degrees Celsius (68N Fahrenheit). See Attachment 1

instructions on drain weight determination for mixed maturity corn in

a lot.
Canned Whole Kernel

Corn Grading Manual

June 2001

5

NOTE: WHILE THE PRODUCT IS DRAINING EXAMINE THE INTERIOR CONDITION OF THE

CONTAINER(S), MAKING NOTE OF ANY UNUSUAL CONDITIONS UNDER

"REMARKS" OR ON BACK OF THE TALLY SHEET.

WHEN MULTIPLE SMALL CONTAINERS (8 OZ) ARE DRAWN TO PROVIDE

SUFFICIENT PRODUCT TO GRADE, DETERMINE THE DRAINED WEIGHTS

FOR EACH CONTAINER USED FOR GRADING.

10. Empty the product from each draining screen into the individual grading

trays.

11. Record the Varietal Type (Conventional Sweet Corn, Sugar Enhanced,

Supersweet, etc) and Color Type (Golden, White, Combination, etc.)

based on the units in the container.

B. Prerequisite Quality Factors.

1. Evaluate and grade the prerequisite quality factors on a container-bycontainer basis. Record the letter grade, as applicable, in the appropriate

place on the tally sheet.

a. Varietal characteristics. If applicable, apply File Code 130-A-67,

Small Units of Alien Vegetables.

(1) Grade A should be assigned to those sample units containing

whole kernel corn of similar varietal characteristics. 

(2) Sstd should be assigned to those sample units containing

whole kernel corn of dissimilar varietal characteristics.

b. Appearance - use the following guidelines in assigning a grade for

appearance:

(1) Good "Grade A" means the whole kernel corn is bright in

color and is practically uniform.

(2) Reasonably good "Grade B" means the whole kernel corn

may lack brightness and is reasonably uniform in color.

(3) Fairly good "Grade C" means the sample unit may be dull

and has a fairly uniform color. Any lots with samples

possessing fairly good appearance shall not be graded 

above "Grade B."

(4) Poor "Substandard" (Sstd) means the sample unit fails the

requirements for Grade C appearance.
Canned Whole Kernel

Corn Grading Manual

June 2001

6

c. Cut. Evaluate "Cut" and assign the grade using the following :

(1) Grade A - Well cut means the product is not more than slightly

affected by the presence of ragged cut kernels, torn kernels,

chaff, or irregular kernels.

(2) Grade B - Reasonably well cut means the product is not

materially affected by the presence of ragged cut kernels, torn

kernels and irregular cut kernels.

(3) Grade C - Fairly well cut means the product is not seriously

affected by the presence of ragged cut kernels, torn kernels,

chaff, or irregular cut kernels.

(4) Sstd - The sample unit fails the requirements for Grade C.

d. Tenderness and Maturity - Evaluate the tenderness and maturity

on a container by container basis. Tenderness and maturity means

the degree of tenderness and stage of development typical for the

varietal type of corn.

Record the level of quality within the grade and the letter grade

on the tally sheet for "Tenderness and maturity."

Conventional Sweet Corn 

(1) Good tenderness and maturity -- is tender in texture with

characteristics typical of the early stage of development of the

kernels for the varietal type(s). Good tenderness and maturity

in conventional sweet corn is tender corn with a creamy

texture and pericarp that chews easily. The kernels are full and

tender, typical of the milk or early cream stage of maturity. 

There are three levels of quality within "good tenderness and

maturity:" very tender, tender, and moderately tender.

Conventional Sweet Corn - Tenderness and Maturity - Grade A

Top Very tender (early milk)

Middle Tender (milk, early cream)

Bottom Moderately tender (cream stage)
Canned Whole Kernel

Corn Grading Manual

June 2001

7

(2) Reasonably good tenderness and maturity --is reasonably

tender in texture with characteristics typical of the intermediate

stage of development of the kernels for the varietal type(s). 

Reasonably good tenderness and maturity

 in conventional sweet corn typifies the cream stage of

maturity but lacks the attributes for "good tenderness and

maturity." Some pericarp residue may be evident upon

chewing. There are two levels of quality within "reasonably

good tenderness and maturity:" cream stage and moderate

cream stage. 

Conventional Sweet Corn - Tenderness and Maturity - Grade B

Top Cream stage

Bottom Moderate cream stage

(3) Fairly tough -- is fairly tough, but not hard, texture with

characteristics typical of the late stage of development of the

kernels for the varietal type(s). Fairly tough in conventional

sweet corn is dry, chewy corn. Kernels are doughy, may be

dented, but are not woody. Pericarp may be tough to very

tough.

Conventional Sweet Corn - Tenderness and Maturity - Grade C

Range Dough stage (starchy, doughy, chewy)

Supersweet Corn 

(1) Good tenderness and maturity in supersweet corn is crisp,

corn that may have slightly tough pericarp, compact internal

flesh, that is associated with plump or full kernels. There are

three levels of quality within "good tenderness and maturity:"

very tender and crisp; tender and crisp, and; moderately

tender and crisp.

Supersweet Corn - Tenderness and Maturity - Grade A

Top Very tender and crisp 

Middle Tender and crisp 

Bottom Moderately tender and crisp 
Canned Whole Kernel

Corn Grading Manual

June 2001

8

(2) Reasonably good tenderness and maturity in supersweet corn

lacks tenderness and may be moderately dry. Kernels may

have a reasonably tough pericarp and occasionally are

dented. There are two levels of quality within "reasonably

good tenderness and maturity" not crisp, not moist; and not

crisp, moderately dry, and may include occassional dented

kernels.

Supersweet - Tenderness and Maturity - Grade B

Top not crisp, not moist

Bottom lacks tenderness, moderately dry, occasional dented kernels

(3) Tough in supersweet corn is dry, chewy corn, with fairly tough

pericarp.

Supersweet Corn - Tenderness and Maturity Grade C

Range Dry, chewy, pulpy, dented kernels with tough but not very tough

pericarp

Reminder: The number of sample units in a lot that have "reasonably good

tenderness and maturity", and "fairly tough" shall not exceed the

applicable acceptance number specified in the sample plan

contained in the "Regulations Governing Inspection and

Certification of Processed Fruits and Vegetables and Related

Products."

e. Evaluate flavor and odor. Flavor and odor refers to the palatability

of the product. The natural flavor of the sweet corn for the varietal type

and/or the effect of added natural sweeteners, salt, or other suitable

optional ingredients (Food and Drug Standard of Identity 155.130)

are considered in evaluating this factor.

(1) Good flavor and odor means the product has a good

characteristic flavor and odor for the varietal type of canned

sweet corn and is free from objectionable flavors and odors. 

Good flavor and odor in conventional sweet corn is

characteristic flavor and odor typical of tender or reasonably

tender sweet corn with no unusual aftertaste. Good flavor and

odor in supersweet corn is free from objectionable flavors

and odors, typically crisp, moist, and sweeter flavor than

conventional sweet corn. The number of sample units in a lot

that have "fairly good flavor" shall not exceed the applicable

acceptance number specified in the sample plan contained in

the "Regulations Governing Inspection and Certification of

Processed Fruits and Vegetables and Related Products."

(2) Fairly good flavor and odor, in conventional sweet corn,

means the product may be lacking in good flavor and odor,

Canned Whole Kernel

Corn Grading Manual

June 2001

10

nearest category to the composite sample size in the Time Sampling Table for

EVM in the back of this manual. For No. 10 containers, use 30 ounces from each

container. For example: 6 - No. 10 cans may have a combined drained weight of

428 oz. Taking 30 oz per sample unit for EVM would be 5100 g. Use the

acceptance numbers in the 5100 column for cob, husk, silk, stalk, and shank.

Table IV

AQL's, TOLERANCES, AND ACCEPTANCE NUMBERS FOR EVM

BASED ON 850 GRAMS (30.0 oz.)

Sample Units x Sample Unit Size

1x

850

3x

850

6x

850

13x

850

21x

850

29x

850

Units of Product in Grams 850 2550 5100 11050 17850 24650

Extraneous Vegetable Material

(EVM) 

TOL 1/ AQL Acceptance Numbers

 GRADE A

Cob each cc (0.061 cu in) 2/ 1.41 1.25 0.80 2.05 3.85 7.85 12.35 16.85

Husk each cm2 (0.155 sq. in)

2/

0.57 0.47 7 17 32 64 99 133

Silk, each 2.54 cm, recorded in

inches

3.5 3.2 36 96 184 384 611 835

 GRADE B

Cob each cc (0.061 cu in) 2/ 3.5 3.2 1.8 4.8 9.2 19.2 30.6 41.8

Husk each cm2 (0.155 sq. in)

2/

1.14 0.99 13 33 62 126 198 270

Silk, each 2.54 cm, recorded in

inches

7.0 6.6 68 189 367 774 1235 1693

 GRADE C

Cob each cc (0.061 cu in) 2/ 4.94 4.6 2.45 6.75 13.0 27.3 43.4 59.5

Husk each cm2 (0.155 sq. in)

2/

1.71 1.5 18 48 91 187 244 402

Silk, each 2.54 cm, recorded in

inches

24.5 23.8 222 642 1264 2703 4342 5976

1/ Based on 13 x 850 (11,050 g) 

1/ Tolerance for cob is based on each 0.05 cc; for husk--each cm2; and for silk--each 9 cm. at 11050 grams. (This is the basis for the

calculation of the tolerances only.)

2/ Corn stalk and shank: If hard and tough, count as cob. If less severe, count as husk.

The allowance for cob is determined by displacement of water. Use a 10 ml graduated cylinder reading to 0.1

ml. Fill graduated cylinder with water to 8.0 ml. Drop in cob. The increase in volume from the starting point

of 8.0 ml is the amount of cob. Enter the measured amount of cob (cc), husk (cm2), and silk (in) for each

sample unit. They will be tallied after all sample units have been evaluated.

SPECIFIED DEFECTS

The procedureto determine theweightequivalent for eachsample unitof 1000 kernels

is to weigh one ounce of kernels and count the units. Then divide the kernel count in

one ounce into 1000 to determine the numbers of ounces needed to represent 1000

kernels.

1. Determine the average count of 3 random one ounce (1 oz) sub-samples

selected from different grading trays.
Canned Whole Kernel

Corn Grading Manual

June 2001

11

Example:102,118,and 122 whole kernelcornunits total342whole kernelcorn

units. The average is 114 whole kernel corn units per oz.

Weigh one ounce (1 oz) of randomly selected kernels of corn. 

2. Use the following formula to determine the number of units available on a

weight basis.

The average number of whole kernel units of corn per one ounce divided into

1000 equals the number ounces of product that represent 1000 whole kernels

of corn. For example, the average number of whole kernels of corn from three

one-ounce sub-samples equals 120.

1000 ÷ (number of whole kernels of corn in one ounce) = number of

ounces. 

(1000 ÷ 120 = 8.33) means 1000 whole kernels are represented by

each 8.33 oz of drained product.

3000 whole kernels are represented by: 3000 ÷ 120 = 25.0 oz, 6000

whole kernels are represented by 6000 ÷ 120 = 50.0 oz, etc.

3. Refer to the applicable acceptance numbers table in the standards or this

manual, and select the Units of Product (sample size) that will use the

maximum amount of product available.

Note: For smaller than No. 300 container sizes, refer to the tables in this

manual. For other container sizes and sampling rates, refer to the tables

in the standards. 

4. Count or weigh out a uniform amount of product from each grading tray to

arrive at the sample size selected for the lot as a whole.

WHEN THERE IS INSUFFICIENT PRODUCT FOR EVALUATING SPECIFIED

DEFECTS FROM ONE CONTAINER, ADD THE PRODUCT FROM SAMPLE 1b,

THEN 2b, ETC. UNTIL SUFFICIENT PRODUCT IS OBTAINED.

FOR THESE EXTRA CONTAINERS, YOU NEED NOT EVALUATE THE NON-QUALITY OR

PREREQUISITE QUALITY FACTORS. HOWEVER, IF IT IS OBVIOUS THAT SOME OF

THESE ADDITIONAL CONTAINERS DEVIATE EXCESSIVELY FROM THE SAMPLE AS A

WHOLE, YOU SHOULD: RECONSIDER THE EXAMINATION (E.G., ONE OF THE

CONTAINERS NOT IN THE PREDETERMINED NUMBER TO CHECK FOR NON-QUALITY

FACTORS IS OBVIOUSLY "SLACK FILLED".) FOLLOW BRANCH GUIDELINES AND

OTHER INSTRUCTIONS THAT COVER THE DEVIATION IN QUESTION IF YOU

RECONSIDER THE EXAMINATION. .

Record both the total Units of Product that comprise the sample size as well as the

number of units used from each container on the tally sheet. Acceptance numbers in

the Tables are based on count. If using a weight/count conversion, indicate it on the

tally sheet. For example: 
Canned Whole Kernel

Corn Grading Manual

June 2001

12

6000 or 6000/50.0 oz; 1000 or 1000/8.33 oz.

5. Countthe numberofseriouslydamagedkernels,damaged kernels, and pulled

kernels found in the sample unit and record on the tally sheet.

Table V

AQL's, TOLERANCES, AND ACCEPTANCE NUMBERS FOR OTHER DEFECTS 1/

Sample Units x Sample Unit Size 1x

1000

3x

1000

6x

1000

13x

1000

21x

1000

29x

1000

Units of Product by Count 1000 3000 6000 13000 21000 29000

Defects Other than EVM

TOL.

1/

AQL

Acceptance Numbers

 GRADE A

Seriously damaged kernels 0.08 .047 1 3 5 10 15 20

Damaged kernels 0.25 .192 4 10 17 33 51 68

Pulled kernels 0.25 .192 4 10 17 33 51 68

 GRADE B

Seriously damaged kernels 0.25 .192 4 10 17 33 51 68

Damaged kernels 0.50 .409 7 18 33 65 101 136

Pulled kernels 0.42 0.34 6 15 28 55 85 115

 GRADE C

Seriously damaged kernels 0.42 0.34 6 15 28 55 85 115

Damaged kernels 1.00 .867 13 34 64 130 204 277

Pulled kernels 0.67 .562 9 23 43 87 136 184

1/ Based on 1000 x 13 (13,000) kernels.

F. Assigning the Grade for a Lot

1. Determine the total amount of defects found in each category of specified

defects and enter these figures in the "Final/Average" columnonpage 1 of the

tally sheet.

2. Compare the number of specified defects found with the acceptance numbers

from the applicable tables in the standards or this grading manual.

Note: See "Procedures for Mixed Quality Lots" -- this manual -- on lots that meetthe

acceptance numbers but yet have pockets of obviously lower quality.

3. Enter the "Lot Grade" on the tally sheet based on the lowest grade assigned

to any prerequisite or specified qualityfactor. A sample unit assigned GradeC

"Appearance" due to fairly uniform color shall limit the "Lot Grade" to Grade B,
Canned Whole Kernel

Corn Grading Manual

June 2001

13

if it is the lowest grade assigned of all quality factors. Compare the number

found withthe corresponding acceptance numberfor eachgrade,and enterthe

applicable letter grade on the tally sheet.

PROCEDURES FOR GRADING MIXED QUALITY LOTS

If an inspection lot is encountered with individual (suspect) sample units in the sample which

seem to be of lower quality that the sample as a whole, take the following action:

1. Assemble 1000 units of product from the "suspect" container(s) regardless of

code.

2. Compare the number or weightofdefectsfound,as applicable to the style,with

the acceptancenumbersfromthe applicable table inthis manualand determine

the grade of the suspect sample units.

3. Compare the grade of the suspect sample units to the grade of the sample as

a whole. If the grade of the suspect sample is more than one grade below

the grade of the sample as a whole, certify to the lowest grade. Otherwise

certify to the grade of the original inspection results.

PROCEDURES FOR SINGLE SAMPLE UNITS (UNOFFICIAL SAMPLES)

Branchregulations providefor grading of samples submitted byanapplicant. These samples

are "unofficial samples" and do not represent a lot. When requested to perform grading on

unofficial samples, use the following guidelines:

1. Each unofficial sample must stand on its own;

2. Each unofficial sample must contain 30 oz of drained product to determine

EVM (additional containers may be needed to meet this requirement);

1000 kernels of corn for other specified defects.

3. Grade the sample as outlined in this manual.

4. Apply the applicable acceptance numbers found in the U.S. grade standards.

SEGREGATION PROCEDURES

If at any time during production, a portion of production falls into the next lower grade, the

entire productionfails at that point unless the offending portion canbe segregated by codes.

Plantmanagement has two options--(1) to request segregationof the offending portionor, (2)

to continue production without segregation anticipating better quality product
Canned Whole Kernel

Corn Grading Manual

June 2001

14

will offset the offending portion. If plant management requests that a portion of failing

production be segregated, all defects found that are associated with the failing portion shall

be excluded from the tally of the remaining portion. The failing portion may be re-inspected

as a new lot only under appeal inspectionor after the product has been reworked in an effort

to eliminate or reduce the defects from the failing portion.

OTHER REQUIREMENTS

Inspectors cannot switch back and forth between on-line single sampling rates and time

sampling unless an occurrence of mixed qualitysample units are encountered within

a production period. When this happens inspectors can switch from time sampling

to on-linesingle samplingdueto the processing operation's inability to pack product

at a consistent quality level. Inspectors should notify their supervisors when this

occurs.

The inspector must indicate that "time sampling" is being used on each tally sheet.
Canned Whole Kernel

Corn Grading Manual

June 2001

15

Time Sampling Acceptance Numbers for Canned Corn -- 1000 Plan

For Other Defects

U

N

I

T

S

O

F

P

R

O

D

S

E

R

D

A

M

A

G

E

D

D

A

M

A

G

E

D

P

U

L

L

E

D

K

E

R

N

E

L

S

S

E

R

D

A

M

A

G

E

D

D

A

M

A

G

E

D

P

U

L

L

E

D

K

E

R

N

E

L

S

S

E

R

D

A

M

A

G

E

D

D

A

M

A

G

E

D

P

U

L

L

E

D

K

E

R

N

E

L

S

GRADE A GRADE B GRADE C

(AQL) 0.47 0.192 0.192 0.192 0.409 0.34 0.34 0.867 0.562

1000 1 4 4 4 7 6 6 13 9

2000 2 7 7 7 13 11 11 24 17

3000 3 10 10 10 18 15 15 34 23

4000 4 12 12 12 23 19 19 44 30

5000 5 15 15 15 28 24 24 54 37

6000 5 17 17 17 33 28 28 64 43

7000 6 19 19 19 37 32 32 73 49

8000 7 22 22 22 42 36 36 83 56

9000 7 24 24 24 47 40 40 92 62

10000 8 26 26 26 51 44 44 102 68

11000 9 29 29 29 56 47 47 111 75

12000 9 31 31 31 60 51 51 121 81

13000 10 33 33 33 65 55 55 130 87

14000 11 35 35 35 70 59 59 139 93

15000 11 38 38 38 74 63 63 149 99

16000 12 40 40 40 79 66 66 158 105

17000 12 42 42 42 83 70 70 167 111

18000 13 44 44 44 88 74 74 176 117

19000 14 46 46 46 92 78 78 186 124

20000 14 48 48 48 96 81 81 195 130

21000 15 51 51 51 101 85 85 204 136

22000 15 53 53 53 105 89 89 213 142

23000 16 55 55 55 110 93 93 222 148

24000 17 57 57 57 114 96 96 232 154

25000 17 59 59 59 119 100 100 241 160

26000 18 61 61 61 123 104 104 250 166

27000 18 63 63 63 128 107 107 259 172

28000 19 66 66 66 132 111 111 268 178

29000 20 68 68 68 136 115 115 277 184
Canned Whole Kernel

Corn Grading Manual

June 2001

16

Time Sampling Acceptance Numbers for Canned Corn -- 850 Plan For Extraneous Vegetable Material (EVM)

G

 R

A

 M

S

O

F

P

R

O

D

C

O

B

C

C

E

A

C

H

H

U

S

K

E

A

C

H

S

I

L

K

E

A

C

H

C

O

B

C

C

E

A

C

H

H

U

S

K

E

A

C

H

S

I

L

K

E

A

C

H

C

O

B

C

C

E

A

C

H

H

U

S

K

E

A

C

H

S

I

L

K

E

A

C

H

GRADE A GRADE B GRADE C 

(AQL) 1.25 0.47 3.2 3.2 0.99 6.6 4.6 1.5 23.8

850 (30 oz) 0.8 7 36 1.8 13 68 2.45 18 222

1700 (60 oz) 1.45 12 66 3.3 23 129 4.65 34 434

2550 (90 oz) 2.05 17 96 4.8 33 189 6.75 48 642

3400 (120 oz) 2.65 22 126 6.3 43 249 8.85 63 850

4250 (150 oz) 3.25 27 155 7.75 53 308 10.9 77 1057

5100 (180 oz) 3.85 32 184 9.2 62 367 13.0 91 1264

5950 (210 oz) 4.4 37 213 10.65 71 425 15.05 105 1470

6800 (240 oz) 5.0 41 242 12.1 81 484 17.1 118 1676

7650 (270 oz) 5.6 46 270 13.5 90 542 19.15 132 1882

8500 (300 oz) 6.15 50 299 14.95 99 600 21.2 146 2087

9350 (330 oz) 6.7 55 327 16.35 108 658 23.2 160 2293

10200 (360 oz) 7.3 59 356 17.8 117 716 25.25 173 2498

11050 (390 oz) 7.85 64 384 19.2 126 774 27.3 187 2703

11900 (420 oz) 8.45 68 413 20.65 135 832 29.3 200 2908

12750 (450 oz) 9.0 72 441 22.05 144 889 31.35 214 3113

13600 (480 oz) 9.55 77 470 23.5 154 947 33.35 227 3318

14450 (510 oz) 10.15 81 498 24.9 163 1005 35.35 241 3523

15300 (540 oz) 10.7 86 526 26.3 172 1062 37.4 254 3728

16150 (570 oz) 11.25 90 554 27.7 180 1120 39.4 268 3932

17000 (600 oz) 11.8 94 583 29.15 189 1177 41.4 281 4137

17850 (630 oz) 12.35 99 611 30.55 198 1235 43.4 294 4342

18700 (660 oz) 12.95 103 639 31.95 207 1292 45.45 308 4546

19550 (690 oz) 13.5 107 667 33.35 216 1349 47.45 322 4750

20400 (720 oz) 14.05 112 695 34.75 225 1407 49.45 335 4955

21250 (750 oz) 14.6 116 723 36.15 234 1464 51.45 348 5159

22100 (780 oz) 15.15 120 751 37.55 243 1521 53.45 362 5364

22950 (810 oz) 15.75 125 779 38.95 252 1579 55.45 375 5568

23800 (840 oz) 16.3 129 807 40.35 261 1636 57.45 388 5772

24650 (870 oz) 16.85 133 835 41.75 270 1693 59.45 402 5976
Canned Whole Kernel

Corn Grading Manual

June 2001

17

ATTACHMENT 1

Drain Weight: Mixed Maturity Corn

The recommended minimum drained weight for whole kernel corn is different for

grade A maturity than for other maturities. Grade A maturity corn may have slightly

lower drained weight. This situation presents a problem if corn of mixed maturities

(e.g., 3 cans grade A maturity and 3 cans grade B maturity) is being certified. Use

the following system.

1. Acroynms and definitions for equation to determine mixed maturities:

"Adw" means recommended minimum drained weight for grade A

maturity for a given can size.

"Bdw" means recommended minimum drained weight for grade B or

lower maturity for a given can size.

"Na" means number of grade A maturity sample units.

"Nb" means the number of grade B or lower maturity sample units.

"N" means the number of sample units in the sample.

"Rdw" means the recommended average minimum drained weight

that the sample should meet.

2. Equation:

(Na x Adw) + (Nb x Bdw)/ N = Rdw

Example:

No. 300 cans: 3 cans A maturity; 5 cans B maturity; 4 cans C maturity; 1 can SSTD maturity.

Adw = 9.25; Bdw = 9.50; Na = 3; Nb = 10; N = 13

(3 x 9.25) + (10 x 9.50)/ 13 = Rdw = 9.44 
Canned Whole Kernel

Corn Grading Manual

June 2001

18

ATTACHMENT 1

RECOMMENDED AVERAGE MINIMUM DRAIN WEIGHT FOR NO. 10 CANS 

N=21 N=13

No. Adw No. Bdw Rdw No. Adw No. Bdw Rdw

21 0 70.00 13 0 70.00

20 1 70.01 12 1 70.15

19 2 70.19 11 2 70.31

18 3 70.29 10 3 70.46

17 4 70.38 9 4 70.62

16 5 70.48 8 5 70.77

15 6 70.57 7 6 70.92

14 7 70.67 6 7 71.08

13 8 70.76 5 8 71.23

12 9 70.86 4 9 71.38

11 10 70.95 3 10 71.54

10 11 71.95 2 11 71.69

9 12 71.05 1 12 71.85

8 13 71.14 0 13 72.00

7 14 71.33

6 15 71.43 N =6

5 16 71.52 No. Adw No. Bdw Rdw

4 17 71.62 6 0 70.00

3 18 71.74 5 1 70.33

2 19 71.81 4 2 70.66

1 20 71.90 3 3 71.00

0 21 72.00 2 4 71.33

1 5 71.66

0 6 72.00
Canned Whole Kernel

Corn Grading Manual

June 2001

19

ATTACHMENT 1

 RECOMMENDED AVERAGE MINIMUM DRAIN WEIGHT FOR NO. 10 CANS 

N = 3

No. Adw No. Bdw Rdw

3 0 70.00

2 1 70.67

1 2 71.33

0 3 72.00

ATTACHMENT 1

 RECOMMENDED AVERAGE MINIMUM DRAIN WEIGHT FOR NO. 300 CANS 

N = 3

No. Adw No. Bdw Rdw

3 0 9.25

2 1 9.33

1 2 9.42

0 3 9.50
Canned Whole Kernel

Corn Grading Manual

June 2001

20

ATTACHMENT 1

RECOMMENDED AVERAGE MINIMUM DRAIN WEIGHT FOR NO. 300 CANS 

N=21 N=13

No. Adw No. Bdw Rdw No. Adw No. Bdw Rdw

21 0 9.25 13 0 9.25

20 1 9.26 12 1 9.27

19 2 9.27 11 2 9.29

18 3 9.29 10 3 9.31

17 4 9.30 9 4 9.33

16 5 9.31 8 5 9.35

15 6 9.32 7 6 9.37

14 7 9.33 6 7 9.38

13 8 9.35 5 8 9.42

12 9 9.36 4 9 9.44

11 10 9.37 3 10 9.46

10 11 9.38 2 11 9.48

9 12 9.39 1 12 9.48

8 13 9.40 0 13 9.50

7 14 9.42

6 15 9.43 N =6

5 16 9.44 No. Adw No. Bdw Rdw

4 17 9.45 6 0 9.25

3 18 9.46 5 1 9.29

2 19 9.48 4 2 9.33

1 20 9.49 3 3 9.38

0 21 9.50 2 4 9.42

1 5 9.46

0 6 9.50