Putrefactive anaerobes in canning — preferred growth in relation to food acidity Putrefactive anaerobes that cause gas and foul odor in canned foods grow best in which acidity class of canned products?

Introduction / Context:
Identifying which products are vulnerable to putrefactive anaerobes helps processors prioritize thermal process validation and pH control. Putrefaction is associated with strong proteolysis, gas production, and can swelling.

Given Data / Assumptions:

• Organisms: putrefactive anaerobes (for example, certain Clostridium spp.).
• Outcome: gas, foul odors, can distension.
• Variable: product acidity class (low-, medium-, high-acid).

Concept / Approach:
Clostridial putrefaction is favored in low-acid foods (pH > 4.6) where heat-resistant spores can survive and subsequently grow under anaerobic conditions. As acidity increases, growth and toxin/odor production are progressively inhibited.

Step-by-Step Solution:
Relate organism physiology to pH: clostridia thrive in low-acid, protein-rich matrices.Recognize that medium- and high-acid foods suppress clostridial growth post-process.Therefore, select low-acid canned foods as highest risk.

Verification / Alternative check:
Process schedules for low-acid foods demand retort sterilization with strict F₀ targets precisely to control clostridial hazards.

Why Other Options Are Wrong:
Medium- and high-acid environments inhibit these anaerobes; “any of these” is inaccurate; high-sugar content alone does not define risk if pH remains low.

Common Pitfalls:
Underestimating spore loads in soil-contaminated raw materials; misclassifying borderline pH foods.

Final Answer:
Low-acid canned foods.