Sausage greening – Which bacteria are reported to cause greening by producing oxidizing compounds in comminuted meats?

Introduction / Context: Greening in sausages is an aesthetic defect where the normal red “bloom” shifts to green or gray-green. Lactic acid bacteria are frequently implicated via oxidizing metabolite formation (for example, hydrogen peroxide).

Given Data / Assumptions:

• Product: sausage (comminuted meat).
• Defect: greening of the cured/cooked product.
• Candidate organisms: Lactobacillus and Leuconostoc genera.

Concept / Approach: Certain lactic acid bacteria can generate peroxides and other oxidants that alter myoglobin/oxymyoglobin to forms that exhibit greenish tints (e.g., choleglobin/verdigris-like complexes). Literature cites both Lactobacillus and Leuconostoc in this role.

Step-by-Step Solution: Identify mechanism → oxidizing compounds (often hydrogen peroxide) from LAB metabolism. Match implicated genera → Lactobacillus + Leuconostoc have been reported in greening incidents. Therefore, the most complete answer is “Both (a) and (b)”.

Verification / Alternative check: Quality investigations of greening batches commonly recover peroxide-positive LAB; reduction in residual oxygen and good starter culture control reduce the issue.

Why Other Options Are Wrong: Pseudomonas typically causes slime/taint rather than greening in cured sausage; Brochothrix causes sour/cheesy odors but is not the classic cause of greening.

Common Pitfalls: Confusing nitrite curing color shifts with microbial greening; storage oxygen and redox strongly interact with LAB metabolism.

Final Answer: Both (a) and (b).