Sausage defects — “Chill rings” in sausages have been attributed to which of the following causative factors?

Introduction / Context:
Chill rings are circular discolorations visible in sausage cross-sections. They represent localized chemical and microbial processes affecting pigments such as myoglobin during processing and storage. Troubleshooting requires considering multiple, overlapping causes.

Given Data / Assumptions:

• Sausage pigments are sensitive to oxidation–reduction changes.
• Bacterial metabolism can generate acids or reducing agents that shift pigment states.
• Formulation and process water impact water activity and oxygen diffusion.

Concept / Approach:
Chill rings typically reflect a combination of oxidative reactions (e.g., metmyoglobin formation), bacterial by-products altering redox conditions, and physical factors like moisture distribution. Hence, an inclusive answer fits best with observed plant-floor variability.

Step-by-Step Solution:

Verification / Alternative check:
Quality manuals recommend controlling oxidation (antioxidants, packaging), tightening water content, and limiting microbial load to mitigate chill rings.

Why Other Options Are Wrong:
Any single factor alone cannot explain the frequent variability and ring patterns observed across batches and processors.

Common Pitfalls:
Focusing only on oxidation while ignoring bacterial redox shifts and formulation water.

Final Answer:
all of the above