Can Defects and Leakage Causes

Can Defects and Leakage

• Defects in tin plate and can manufacturing defects can cause can leakage
• Corrosion of can due to chemical reactions between food components or with the can can also lead to leakage

Mishandling of Cans

• Mishandling during manufacturing process or in transit can cause can defects and leakage
• Transportation and distribution errors can also contribute to can defects and leakage

Processing Operations

• Under-sterilization can lead to spoilage due to high initial bacterial load or inadequate thermal process for a food
• Inadequate can cooling can result in growth of thermophilic bacteria that survived the thermal process
• Slow cooling of sterilized cans can lead to spoilage, while too fast cooling can reduce the F0 value
• Poor can cooling water quality can also contribute to spoilage

Chemical Breakdown and Abnormal Physical Characteristics

• Food components can react with each other or with the container, causing deformities in the can, such as corrosion
• H2 produced from reactivity of food components in a metallic can can destroy the can vacuum and cause the container to swell

Types of Spoilage of Canned Foods

• External indication of spoilage includes:
  • Swells
  • Flippers
  • Springer
  • Hard and soft swells
  • Pinholing
• No external indication of spoilage:
  • Flat sours
  • Stack burn
• Discoloration of the food product is also a type of spoilage

Spoilage of Canned Foods - Swells

• Swells are caused by gas production due to microbial activity or chemical reactions
• Microbiological swells are a result of:
  • Inadequate sterilization
  • Can leakage
  • Activity of thermophilic microbes (can cooling/cooling water quality)
• Swells in low acid foods are caused by:
  • Inadequate sterilization/underprocessing
  • One type of spore former predominates
  • Can leakage
• Swells in high acid foods are caused by:
  • Aciduric organisms contaminating the canned food pre or post sterilization
  • If mixed cultures, then swells can be due to can leakage

Additional Facts

• Swells in under-sterilized canned products occur within 2-14 days under warm storage temperatures or >3 months under cold storage temperature
• The main gas in cans with swells is CO2, with H2 occurring in small quantities, and H2S may also be present, responsible for foul smells

This quiz covers the various defects that can cause can leakage, including defects in tin plate, can manufacturing defects, corrosion, and mishandling.