USDA 

 

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Module 19. Container Handling 

Section 431.2(a)(1-3) - Containers and 

Closures 

Section 431.6(i) - Post-Process 

Handling of Containers 

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Purpose and Objectives 

 Purpose of Module 19 

• Provide knowledge of good and bad 

practices for container handling. 

 Performance Objective 

• Can assess container handling and identify 

poor practices. 

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Introduction 

 Causes and prevention of loss of container 

integrity 

• Container integrity is easily taken for 

granted 

 Leaker spoilage diagnosis 

• Causes of leaker spoilage 

• Investigation of leaker spoilage 

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1978 Botulism Outbreak Caused by One 

Can with a Gouged Double Seam 

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1982 Botulism Outbreak 

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Can body torn at 

can Mfr.'s end 

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Food Containers 

 Must maintain hermetic seal under 

commercial operating conditions 

 Applies to all commercial containers 

• Metal can/tray 

• Glass jar/bottle 

• Semi-rigid & rigid plastic 

• Flexible pouch 

• Paperboard containers 

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Requirements for Safe Preservation of 

Canned Foods 

 Hermetically sealed container to prevent 

microorganism re-entry 

 Heat process to ensure product commercial 

sterility 

 Post process handling that protects container 

integrity 

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Requirements for Safe Preservation of 

Canned Foods (2) 

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Can 

damage 

can 

cause 

good 

seams to 

leak. 

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Pre-production Container Handling 

 Examine empty containers 

• Determine methods for cleaning 

 Minimize rough handling 

• Look for handling procedures that may 

damage containers prior to filling 

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Blanching 

 Raw vegetables are cooked in hot water or 

exposed to steam 

 May affect container integrity, the thermal 

process and product quality 

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Blanching (2) 

 Shrinks product to assist in the proper filling of 

container 

 Expels cellular gases to reduce strain on 

container during thermal processing 

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Filling 

 Provide adequate headspace 

 Prevent product from being trapped in seam 

or seal 

 Provide for correct fill weight and product 

characteristics 

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Measuring Headspace 

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Container Closure to Prevent Leakage 

 Maintain seaming/sealing equipment 

 Prevent over-filling 

 Avoid damaged containers 

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Container Vacuum 

Important Points: 

 Reduction of the oxygen level in the container 

 Protects containers from distortion 

 May affect heat transfer during thermal 

processing 

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Checking Vacuum 

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Benefits of Container Vacuum 

 Presence of vacuum normally indicates that 

seal is intact 

 Low oxygen content minimizes undesirable 

chemical reactions 

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Cb000f 

~---- i 

000000 

0 OOGO 

 

Thermal Processing Operations 

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 Examine retort racks for 

damage 

 Design loading/unloading 

systems to minimize 

damage 

 Operate retort properly 

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Container Buckling 

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 Prevented by adequate container vacuum 

and/or pressure cooling 

 May cause strained seams/seals to leak 

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Container Buckling (2) 

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Excessive buckled or swollen cans may be caused by malfunction during 

thermal processing, by microbiological growth, or by hydrogen swelling. 

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Container Paneling 

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 Inadequate pressure 

control during cooling 

(pressure too high 

and/or exposure time 

too long) 

 Not considered 

serious 

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Influence of the Cooling Operation 

 Containers usually water cooled 

 Seams or seals under stress 

 Minute amount of cooling water may enter 

container 

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Cooling Cans in Cooling Water Canal 

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Post Process Handling (2) 

 Careful handling necessary through: 

• Labelling 

• Palletizing 

• Casing 

• Warehousing 

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Leaker Spoilage in Canned Foods 

 Vacuum may draw bacteria through a less 

than secure seal 

 Spoilage due to bacterial contamination after 

processing 

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Cause of Leakage 

 Container defect occurring during manufacture 

or closing 

 Momentary failure of seal 

 Damage in warehouse or store 

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Post-cooling Container Handling 

Bacterial Contamination 

 May develop on wet and soiled container 

handling equipment 

 Transferred to seam/seal areas 

 May cause recontamination spoilage 

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High Speed Container Handling 

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 Small dents may occur 

that cause momentary 

leakage 

 If bacteria are present, 

some may be drawn 

through seam 

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Can Abuse Versus Microbial Count 

 Can abuse influences spoilage rate more than 

the number of microorganisms on seams 

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Can Runways 

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Cans roll on sides 

not on seams 

Constructed in a manner that prevents double seams from contacting 

contaminated surfaces 

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Can Runways (2) 

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Rolling cans on the body 
 

 

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Container Handling Lines 

 Tracks, belts and bars that contact container 

should be cleaned, sanitized and kept dry 

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Good quality air must be used to dry containers. 

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Key Points 

 Leaker spoilage occurs from re-entry of 

microorganisms after the thermal process. 

 Blanching and filling controls play a role in 

forming a good vacuum. 

 The seal surfaces need to be free of product 

debris during sealing. 

 Rough handling of containers may lead to 

leaker spoilage. 

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Key Points (2) 

 Container cooling water should be chlorinated 

or otherwise effectively sanitized. 

 Post-process equipment should be cleaned 

and sanitized. 

 Examine containers at several points in the 

line and look for defects. When defects 

appear, investigate back to the last point on 

the line where examination revealed no 

defects. Find the cause of the defects and 

repair. 

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Questions 

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Questions?