Off-odors from nearby sources — Growth of Streptomyces on straw or in the vicinity of egg storage is most likely to impart which sensory defect to eggs?
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Amusty or earthy flavors
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Bhay odour
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Cfishy flavor
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Dcabbage-water flavor
Answer
Correct Answer: musty or earthy flavors
Explanation
Introduction / Context:Eggs readily absorb environmental odors through their porous shells. Understanding which off-flavors correlate with specific environmental microbes aids in diagnosing storage and facility issues.
Given Data / Assumptions:
- Streptomyces spp. are filamentous actinomycetes common in soil and straw.
- They produce geosmin and related compounds responsible for earthy, musty odors.
- Eggs stored near contaminated straw or dusty areas can absorb these volatiles.
Concept / Approach:Geosmin (and 2-methylisoborneol) from Streptomyces cause characteristic musty/earthy flavors perceived at extremely low thresholds. While “hay” notes might be present in a barn, the microbial signature specifically points to musty/earthy rather than fishy or cabbage-like notes (often linked to amines or sulfur compounds).
Step-by-Step Solution:
Link Streptomyces to geosmin → musty/earthy aroma.Recognize eggshell porosity allows odor absorption during storage.Choose “musty or earthy flavors” as the closest sensory description.Verification / Alternative check:Food flavor literature and environmental taint investigations repeatedly associate earthy/musty taints with actinomycete growth on nearby substrates.
Why Other Options Are Wrong:
- Hay odour: could occur from environment, but the signature of Streptomyces is musty/earthy.
- Fishy: amine-related spoilage by certain bacteria, not actinomycetes.
- Cabbage-water: sulfur volatiles, not typical for Streptomyces.
Common Pitfalls:Confusing general barn odors with the specific microbial geosmin taint.
Final Answer:musty or earthy flavors