Cured meat defect – Beef hams sometimes become “spongy” due to gas formation. Which group is chiefly implicated?

Introduction / Context:
“Spongy” texture in cured beef hams is associated with internal gas production, creating holes and soft pockets. Pinpointing the causal agents assists in thermal process validation and post-cook hygiene.

Given Data / Assumptions:

• Product: beef hams (cured, cooked).
• Defect: sponginess from gas formation.
• Environment: post-cook handling and storage may allow survivors to grow if conditions permit.

Concept / Approach:
Gas-forming sporeformers (notably Bacillus spp.) can survive inadequate heating or contaminate post-process. When they grow, CO2/H2 accumulation leads to a spongy matrix. Aerobic spoilage bacteria like Pseudomonas usually affect surfaces, not deep internal gas pockets.

Step-by-Step Solution:
Consider heat resistance → Bacillus spores survive better than vegetative Gram-negatives. Map defect location → internal gas suggests sporeformers that germinate inside the product. Select Bacillus spp. as the most likely cause.

Verification / Alternative check:
Process deviation reviews commonly implicate Bacillus (e.g., B. subtilis group) in gassy/spongy defects of cooked meats, particularly when chilling is delayed or recontamination occurs.

Why Other Options Are Wrong:
Pseudomonas generally causes surface slime; pigmented yeasts lead to discolorations rather than gas pockets; “red Bacillus” is not a standard category.

Common Pitfalls:
Blaming packaging gases for internal holes; true sponginess derives from microbial gas, not residual packaging headspace.

Final Answer:
Bacillus species (sporeforming rods).