Hydrogen swell (chemical can spoilage): Which conditions favor hydrogen swell development in canned foods?

Introduction / Context:
Hydrogen swell is a non-microbial (chemical) defect in metal cans. Acidic foods react with exposed iron on the can interior, generating hydrogen gas that causes bulging. Understanding the risk factors prevents costly rework and safety holds.

Given Data / Assumptions:

• Chemical corrosion pathway is implicated, not microbial growth.
• Potential contributors: food acidity, storage temperature, integrity of tinning/lacquer.
• Outcome: gas (H2) evolution and can swelling.

Concept / Approach:
Corrosion rate increases with both acidity and temperature. Imperfect tinning or damaged lacquer exposes base steel, accelerating electrolytic reactions that liberate hydrogen. Thus, all listed factors synergize to produce hydrogen swell, especially in acid foods stored warm or for long periods.

Step-by-Step Solution:
Relate acidity to metal dissolution.Relate temperature to reaction kinetics (Arrhenius behavior).Recognize coating imperfections as direct exposure points.Conclude that all listed conditions favor hydrogen swell.

Verification / Alternative check:
Container integrity testing and lacquer performance standards directly target these risks, with higher-acid products requiring robust linings.

Why Other Options Are Wrong:

• Low headspace vacuum only: A separate packaging parameter, not the core corrosion driver.

Common Pitfalls:
Misattributing hydrogen swell to microbial activity; unlike bacterial gas, chemical swelling lacks off-odors typical of putrefaction.

Final Answer:
All of these.