Meat spoilage identification — The defect known as “black spot” on meat is produced mainly by which mold?

Introduction / Context:
Color defects on meat are practical markers for specific spoilage organisms. Recognizing the characteristic “black spot” helps processors trace environmental sources and improve sanitation in chill rooms and cutting areas.

Given Data / Assumptions:

• Black spot refers to dark, sometimes sooty colonies on meat surfaces.
• Multiple molds may colonize chilled meats, but pigment type and colony morphology differ.
• We must identify the principal genus associated with black spotting.

Concept / Approach:
Cladosporium species produce dark (olivaceous to black) pigmented conidia and colonies, aligning with the visual description of black spots. Other meat molds like Thamnidium and Mucor tend to cause whiskery or fluffy growth without the intense black pigmentation.

Step-by-Step Solution:

Verification / Alternative check:
Inspection guides and plant records associate black or dark spots on chilled meat with Cladosporium contamination from air, walls, or cooling coils.

Why Other Options Are Wrong:

• Thamnidium, Mucor, Rhizopus: commonly produce grey/white whiskers or cottony colonies rather than black spots.

Common Pitfalls:
Judging solely by colony size or fluffiness instead of pigment color.

Final Answer:
Cladosporium