Question

Dirty taint defect in cream is due to

• A. Proteus
• B. Sarcina
• C. Bacillus
• D. Escherichia

Hint:

Bacterial Flavor Defects in Dairy:
Dirty Putrid Taint = Proteus spp.
Malty Flavor = Lactococcus lactis ssp. lactis biovar maltigenes.
Potato Flavor = Pseudomonas taetrolens.
Fruity Flavor = Pseudomonas fragi.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Proteolytic and putrefactive off-flavor defects in dairy products: non-fermentative Gram-negative enterobacteria like Proteus vulgaris produce volatile sulfur compounds and indole, imparting offensive dirty/putrid taints.

Step 2: Detailed Explanation:
In dairy microbiology and flavor defects of cream and butter:
- Spoilage of raw or poorly pasteurized cream held at ambient temperature:
- Genus {Proteus (specifically {Proteus vulgaris and Proteus mirabilis): Highly proteolytic, Gram-negative facultative rod that rapidly decomposes casein and sulfur-containing amino acids (methionine, cysteine).
- Produces volatile amines, hydrogen sulfide ($\text{H}_2\text{S}$), indole, and skatole, imparting an offensive, unpalatable 'Dirty Taint' (Putrid Sewage-like Fecal-like taint) to the cream.
- (Pseudomonas fragi produces fruity/unclean flavors; Bacillus causes sweet curdling/bitterness).

Step 3: Final Answer:
Hence, dirty taint defect in cream is due to Proteus, matching option (A).